WorldWideScience

Sample records for reservoir engineering study

  1. Reservoir engineering studies of the Cerro Prieto geothermal field

    Science.gov (United States)

    Goyal, K. P.; Lippmann, M. J.; Tsang, C. F.

    1982-09-01

    Reservoir engineering studies of the Cerro Prieto geothermal field began in 1978 under a five-year cooperative agreement between the US Department of Energy and the Comision Federal de Electricidad de Mexico, with the ultimate objective of simulating the reservoir to forecast its production capacity, energy longevity, and recharge capability under various production and injection scenarios. During the fiscal year 1981, attempts were made to collect information on the evolution history of the field since exploitation began; the information is to be used later to validate the reservoir model. To this end, wellhead production data were analyzed for heat and mass flow and also for changes in reservoir pressures, temperatures, and saturations for the period from March 1973 to November 1980.

  2. Geothermal reservoir engineering

    CERN Document Server

    Grant, Malcolm Alister

    2011-01-01

    As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate.  For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference.  This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The bo

  3. Reservoir Engineering Management Program

    Energy Technology Data Exchange (ETDEWEB)

    Howard, J.H.; Schwarz, W.J.

    1977-12-14

    The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

  4. PDVSA Petrolera Sinovensa reservoir engineering project and optimization study

    Energy Technology Data Exchange (ETDEWEB)

    Campos, O. [PDVSA Petroleos de Venezuela SA, Caracas (Venezuela, Bolivarian Republic of). Petrolera Sinovensa; Patino, J. [Kizer Energy Inc., Katy, TX (United States); Chalifoux, G.V. [Petrospec Engineering Ltd., Edmonton, AB (Canada)

    2009-07-01

    This paper presented a development plan for an extra-heavy oil field in Venezuela's Orinoco belt involving cold heavy oil production (CHOP) as well as a thermal follow-up process to increase the ultimate recovery factor. A reservoir simulation model was used to model various reservoir formations in order to assess their oil recovery potential. Several thermal recovery processes were considered, such as steam assisted gravity drainage (SAGD), horizontal alternate steam drive (HASD), cyclic steam stimulation (CSS), horizontal continuous steam drive, and combined drive drainage (CDD). A geological static model and dynamic reservoir model were coupled for the well optimization evaluation. Production data were used to identify trends related to specific geological conditions. The study also examined methods of improving slotted liner designs and evaluated the use of electric heating as a means of improving CHOP performance. Results of the study showed that CDD offered the highest recovery rates as a follow-up to CHOP. The CDD process allowed for the use of existing wells drilled in the field. New horizontal wells will be placed between the existing wells. It was concluded that a CDD pilot should be implemented in order to prepare for a commercial implementation plan. 8 refs., 2 tabs., 14 figs.

  5. Reservoir engineering and hydrogeology

    International Nuclear Information System (INIS)

    Anon.

    1983-01-01

    Summaries are included which show advances in the following areas: fractured porous media, flow in single fractures or networks of fractures, hydrothermal flow, hydromechanical effects, hydrochemical processes, unsaturated-saturated systems, and multiphase multicomponent flows. The main thrust of these efforts is to understand the movement of mass and energy through rocks. This has involved treating fracture rock masses in which the flow phenomena within both the fractures and the matrix must be investigated. Studies also address the complex coupling between aspects of thermal, hydraulic, and mechanical processes associated with a nuclear waste repository in a fractured rock medium. In all these projects, both numerical modeling and simulation, as well as field studies, were employed. In the theoretical area, a basic understanding of multiphase flow, nonisothermal unsaturated behavior, and new numerical methods have been developed. The field work has involved reservoir testing, data analysis, and case histories at a number of geothermal projects

  6. Tenth workshop on geothermal reservoir engineering: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-22

    The workshop contains presentations in the following areas: (1) reservoir engineering research; (2) field development; (3) vapor-dominated systems; (4) the Geysers thermal area; (5) well test analysis; (6) production engineering; (7) reservoir evaluation; (8) geochemistry and injection; (9) numerical simulation; and (10) reservoir physics. (ACR)

  7. Fifteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The Fifteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23--25, 1990. Major topics included: DOE's geothermal research and development program, well testing, field studies, geosciences, geysers, reinjection, tracers, geochemistry, and modeling.

  8. Third workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P. (eds.)

    1977-12-15

    Workshop under the Stanford Geothermal Program was supported by a grant from DOE through a subcontract with the Lawrence Berkeley Laboratory of the University of California. A second significant event was the first conference under the ERDA (DOE)-ENEL cooperative program where many of the results of well testing in both nations were discussed. The Proceedings of that conference should be an important contribution to the literature. These Proceedings of the Third Workshop should also make an important contribution to the literature on geothermal reservoir engineering. Much of the data presented at the Workshop were given for the first time, and full technical papers on these subjects will appear in the professional journals. The results of these studies will assist markedly in developing the research programs to be supported by the Federal agencies, and in reducing the costs of research for individual developers and utilities. It is expected that future workshops of the Stanford Geothermal Program will be as successful as this third one. Planning and execution of the Workshop... [see file; ljd, 10/3/2005] The Program Committee recommended two novel sessions for the Third Workshop, both of which were included in the program. The first was the three overviews given at the Workshop by George Pinder (Princeton) on the Academic aspect, James Bresee (DOE-DGE) on the Government aspect, and Charles Morris (Phillips Petroleum) on the Industry aspect. These constituted the invited slate of presentations from the several sectors of the geothermal community. The Program Committee acknowledges their contributions with gratitude. Recognition of the importance of reservoir assurance in opting for geothermal resources as an alternate energy source for electric energy generation resulted in a Panel Session on Various Definitions of Geothermal Reservoirs. Special acknowledgments are offered to Jack Howard and Werner Schwarz (LBL) and to Jack Howard as moderator; to the panelists: James Leigh

  9. Reservoir engineering studies of the Gladys McCall geopressured-geothermal resource. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Lea, C.M.; Lee, K.; Miller, M.A.

    1993-09-01

    Transient pressure analysis techniques have been used to evaluate the performance of the Gladys McCall geopressured-geothermal reservoir. A fault-controlled aquifer influx model has also been developed to account for pressure support observed during both reservoir depletion and recovery phases. The Gladys McCall No. 1 well was drilled and completed in the lower Miocene geopressured sandstones under the US Department of energy geopressured-geothermal research program. The well was shut in october 1987 after producing over 27 MMstb of brine and 676 MMscf gas since October 1983. Eight pressure transient tests were conducted in the well. Analysis of transient pressure data provided a quantitative evaluation of reservoir characteristics, including: (a) formation transmissibility and skin, (b) the size and possible shape of the main producing reservoir, (c) characteristics of the pressure support mechanism. The pressure behavior of 1983 Reservoir Limits Test (RLT) suggested that the Gladys McCall reservoir might have a long narrow shape with the well located off-center. An elongated numerical model developed accordingly was able to reproduce the pressure characteristics show in the test. During both the reservoir production and shut-in periods, pressure buildup tests indicated some degree of external pressure support. Aquifer recharging was believed to be the main source. Based on reservoir material-balance calculations, an aquifer influx model was derived from a conceptual model of water leakage through a partially sealing fault into the reservoir under steady-state conditions. Moreover, a match of the pressure history required that the conductivity of the fault be a function of the pressure difference between the supporting aquifer and the reservoir.

  10. Reservoir engineering studies of the Gladys McCall geopressured-geothermal resource; Final report

    Energy Technology Data Exchange (ETDEWEB)

    Chen-Min; Less, K.; Miller, M.A.

    1994-01-01

    Transient pressure analysis techniques have been used to evaluate the performance of the Gladys McCall geopressured-geothermal reservoir. A fault-controlled aquifer influx model has also been developed to account for pressure support observed during both reservoir depletion and recovery phases. The Gladys McCall No. 1 well was drilled and completed in the lower Miocene geopressured sandstones under the US Department of Energy geopressured-geothermal research program. The well was shut in October 1987 after producing over 27 MMstb of brine and 676 MMscf gas since October 1983. Eight pressure transient tests were conducted in the well. Analysis of transient pressure data provided a quantitative evaluation of reservoir characteristics, including: (a) formation transmissibility and skin, (b) the size and possible shape of the main producing reservoir, and (c) characteristics of the pressure support mechanism. The pressure behavior of 1983 Reservoir Limits Test (RLT) suggested that the Gladys McCall reservoir might have a long narrow shape with the well located off-center. An elongated numerical model developed accordingly was able to reproduce the pressure characteristics shown in the test. During both the reservoir production and shut-in periods, pressure buildup tests indicated some degree of external pressure support. Aquifer recharging was believed to be the main source. Based on reservoir material-balance calculations, an aquifer influx model was derived from a conceptual model of water leakage through a partially sealing fault into the reservoir under steady-state conditions. Moreover, a match of the pressure history required that the conductivity of the fault be a function of the pressure difference between the supporting aquifer and the reservoir.

  11. Nonlinearities in reservoir engineering: Enhancing quantum correlations

    Science.gov (United States)

    Hu, Xiangming; Hu, Qingping; Li, Lingchao; Huang, Chen; Rao, Shi

    2017-12-01

    There are two decisive factors for quantum correlations in reservoir engineering, but they are strongly reversely dependent on the atom-field nonlinearities. One is the squeezing parameter for the Bogoliubov modes-mediated collective interactions, while the other is the dissipative rates for the engineered collective dissipations. Exemplifying two-level atomic ensembles, we show that the moderate nonlinearities can compromise these two factors and thus enhance remarkably two-mode squeezing and entanglement of different spin atomic ensembles or different optical fields. This suggests that the moderate nonlinearities of the two-level systems are more advantageous for applications in quantum networks associated with reservoir engineering.

  12. Fourteenth workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

    1989-01-01

    The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

  13. Fourteenth workshop geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Miller, F.G.; Brigham, W.E.; Cook, J.W.

    1989-12-31

    The Fourteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 24--26, 1989. Major areas of discussion include: (1) well testing; (2) various field results; (3) geoscience; (4) geochemistry; (5) reinjection; (6) hot dry rock; and (7) numerical modelling. For these workshop proceedings, individual papers are processed separately for the Energy Data Base.

  14. Sixth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P. (eds.)

    1980-12-18

    INTRODUCTION TO THE PROCEEDINGS OF THE SIXTH GEOTHERMAL RESERVOIR ENGINEERING WORKSHOP, STANFORD GEOTHERMAL PROGRAM Henry J. Ramey, Jr., and Paul Kruger Co-Principal Investigators Ian G. Donaldson Program Manager Stanford Geothermal Program The Sixth Workshop on Geothermal Reservoir Engineering convened at Stanford University on December 16, 1980. As with previous Workshops the attendance was around 100 with a significant participation from countries other than the United States (18 attendees from 6 countries). In addition, there were a number of papers from foreign contributors not able to attend. Because of the success of all the earlier workshops there was only one format change, a new scheduling of Tuesday to Thursday rather than the earlier Wednesday through Friday. This change was in general considered for the better and will be retained for the Seventh Workshop. Papers were presented on two and a half of the three days, the panel session, this year on the numerical modeling intercomparison study sponsored by the Department of Energy, being held on the second afternoon. This panel discussion is described in a separate Stanford Geothermal Program Report (SGP-TR42). This year there was a shift in subject of the papers. There was a reduction in the number of papers offered on pressure transients and well testing and an introduction of several new subjects. After overviews by Bob Gray of the Department of Energy and Jack Howard of Lawrence Berkeley Laboratory, we had papers on field development, geopressured systems, production engineering, well testing, modeling, reservoir physics, reservoir chemistry, and risk analysis. A total of 51 papers were contributed and are printed in these Proceedings. It was, however, necessary to restrict the presentations and not all papers printed were presented. Although the content of the Workshop has changed over the years, the format to date has proved to be satisfactory. The objectives of the Workshop, the bringing together of

  15. Seventeenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1992-01-31

    PREFACE The Seventeenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 29-31, 1992. There were one hundred sixteen registered participants which equaled the attendance last year. Participants were from seven foreign countries: Italy, Japan, United Kingdom, France, Belgium, Mexico and New Zealand. Performance of many geothermal fields outside the United States was described in the papers. The Workshop Banquet Speaker was Dr. Raffaele Cataldi. Dr. Cataldi gave a talk on the highlights of his geothermal career. The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy was awarded to Dr. Cataldi. Dr. Frank Miller presented the award at the banquet. Thirty-eight papers were presented at the Workshop with two papers submitted for publication only. Dr. Roland Horne opened the meeting and the key note speaker was J.E. ''Ted'' Mock who discussed the DOE Geothermal R. & D. Program. The talk focused on aiding long-term, cost effective private resource development. Technical papers were organized in twelve sessions concerning: geochemistry, hot dry rock, injection, geysers, modeling, and reservoir mechanics. Session chairmen were major contributors to the program and we thank: Sabodh Garg., Jim Lovekin, Jim Combs, Ben Barker, Marcel Lippmann, Glenn Horton, Steve Enedy, and John Counsil. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Ted Sumida, and Terri A. Ramey who also produces the Proceedings Volumes for publication. We owe a great deal of thanks to our students who operate audiovisual equipment and to Francois Groff who coordinated the meeting arrangements for the Workshop. Henry J. Ramey, Jr. Roland N. Horne Frank G. Miller Paul Kruger William E. Brigham Jean W. Cook -vii

  16. Twentieth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    1995-01-26

    PREFACE The Twentieth Workshop on Geothermal Reservoir Engineering, dedicated to the memory of Professor Hank Ramey, was held at Stanford University on January 24-26, 1995. There were ninety-five registered participants. Participants came from six foreign countries: Japan, Mexico, England, Italy, New Zealand and Iceland. The performance of many geothermal reservoirs outside the United States was described in several of the papers. Professor Roland N. Horne opened the meeting and welcomed visitors to the campus. The key note speaker was Marshall Reed, who gave a brief overview of the Department of Energy's current plan. Thirty-two papers were presented in the technical sessions of the workshop. Technical papers were organized into eleven sessions concerning: field development, modeling, well tesubore, injection, geoscience, geochemistry and field operations. Session chairmen were major contributors to the workshop, and we thank: Ben Barker, Bob Fournier, Mark Walters, John Counsil, Marcelo Lippmann, Keshav Goyal, Joel Renner and Mike Shook. In addition to the technical sessions, a panel discussion was held on ''What have we learned in 20 years?'' Panel speakers included Patrick Muffler, George Frye, Alfred Truesdell and John Pritchett. The subject was further discussed by Subir Sanyal, who gave the post-dinner speech at the banquet. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank our students who operated the audiovisual equipment. Shaun D. Fitzgerald Program Manager

  17. Eighteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Horne, R.J.; Kruger, P.; Miller, F.G.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1993-01-28

    PREFACE The Eighteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 26-28, 1993. There were one hundred and seventeen registered participants which was greater than the attendance last year. Participants were from eight foreign countries: Italy, Japan, United Kingdom, Mexico, New Zealand, the Philippines, Guatemala, and Iceland. Performance of many geothermal fields outside the United States was described in several of the papers. Dean Gary Ernst opened the meeting and welcomed the visitors to the campus. The key note speaker was J.E. ''Ted'' Mock who gave a brief overview of the Department of Energy's current plan. The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy was awarded to Dr. Mock who also spoke at the banquet. Thirty-nine papers were presented at the Workshop with two papers submitted for publication only. Technical papers were organized in twelve sessions concerning: field operations, The Geysers, geoscience, hot-dry-rock, injection, modeling, slim hole wells, geochemistry, well test and wellbore. Session chairmen were major contributors to the program and we thank: John Counsil, Kathleen Enedy, Harry Olson, Eduardo Iglesias, Marcelo Lippmann, Paul Atkinson, Jim Lovekin, Marshall Reed, Antonio Correa, and David Faulder. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Ted Sumida, and Terri A. Ramey who also produces the Proceedings Volumes for publication. We owe a great deal of thanks to our students who operate audiovisual equipment and to John Hornbrook who coordinated the meeting arrangements for the Workshop. Henry J. Ramey, Jr. Roland N. Horne Frank G. Miller Paul Kruger William E. Brigham Jean W. Cook

  18. Sixteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1991-01-25

    The Sixteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 23-25, 1991. The Workshop Banquet Speaker was Dr. Mohinder Gulati of UNOCAL Geothermal. Dr. Gulati gave an inspiring talk on the impact of numerical simulation on development of geothermal energy both in The Geysers and the Philippines. Dr. Gulati was the first recipient of The Stanford Geothermal Program Reservoir Engineering Award for Excellence in Development of Geothermal Energy. Dr. Frank Miller presented the award. The registered attendance figure of one hundred fifteen participants was up slightly from last year. There were seven foreign countries represented: Iceland, Italy, Philippines, Kenya, the United Kingdom, Mexico, and Japan. As last year, papers on about a dozen geothermal fields outside the United States were presented. There were thirty-six papers presented at the Workshop, and two papers were submitted for publication only. Attendees were welcomed by Dr. Khalid Aziz, Chairman of the Petroleum Engineering Department at Stanford. Opening remarks were presented by Dr. Roland Horne, followed by a discussion of the California Energy Commission's Geothermal Activities by Barbara Crowley, Vice Chairman; and J.E. ''Ted'' Mock's presentation of the DOE Geothermal Program: New Emphasis on Industrial Participation. Technical papers were organized in twelve sessions concerning: hot dry rock, geochemistry, tracer injection, field performance, modeling, and chemistry/gas. As in previous workshops, session chairpersons made major contributions to the program. Special thanks are due to Joel Renner, Jeff Tester, Jim Combs, Kathy Enedy, Elwood Baldwin, Sabodh Garg, Marcel0 Lippman, John Counsil, and Eduardo Iglesias. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Angharad Jones, Rosalee Benelli, Jeanne Mankinen, Ted Sumida, and Terri A. Ramey who also

  19. Nineteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Horne, R.J.; Kruger, P.; Miller, F.G.; Brigham, W.E.; Cook, J.W. (Stanford Geothermal Program)

    1994-01-20

    PREFACE The Nineteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 18-20, 1994. This workshop opened on a sad note because of the death of Prof. Henry J. Ramey, Jr. on November 19, 1993. Hank had been fighting leukemia for a long time and finally lost the battle. Many of the workshop participants were present for the celebration of his life on January 21 at Stanford's Memorial Church. Hank was one of the founders of the Stanford Geothermal Program and the Geothermal Reservoir Engineering Workshop. His energy, kindness, quick wit, and knowledge will long be missed at future workshops. Following the Preface we have included a copy of the Memorial Resolution passed by the Stanford University Senate. There were one hundred and four registered participants. Participants were from ten foreign countries: Costa Rica, England, Iceland, Italy, Japan, Kenya, Mexico, New Zealand, Philippines and Turkey. Workshop papers described the performance of fourteen geothermal fields outside the United States. Roland N. Home opened the meeting and welcomed the visitors to the campus. The key note speaker was J.E. ''Ted'' Mock who gave a presentation about the future of geothermal development. The banquet speaker was Jesus Rivera and he spoke about Energy Sources of Central American Countries. Forty two papers were presented at the Workshop. Technical papers were organized in twelve sessions concerning: sciences, injection, production, modeling, and adsorption. Session chairmen are an important part of the workshop and our thanks go to: John Counsil, Mark Walters, Dave Duchane, David Faulder, Gudmundur Bodvarsson, Jim Lovekin, Joel Renner, and Iraj Ershaghi. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank Pat Ota, Ted Sumida, and Terri A. Ramey who also produces the Proceedings Volumes for publication. We owe a great deal of thanks to our students who

  20. A quantum Szilard engine without heat from a thermal reservoir

    Science.gov (United States)

    Hamed Mohammady, M.; Anders, Janet

    2017-11-01

    We study a quantum Szilard engine that is not powered by heat drawn from a thermal reservoir, but rather by projective measurements. The engine is constituted of a system { S }, a weight { W }, and a Maxwell demon { D }, and extracts work via measurement-assisted feedback control. By imposing natural constraints on the measurement and feedback processes, such as energy conservation and leaving the memory of the demon intact, we show that while the engine can function without heat from a thermal reservoir, it must give up at least one of the following features that are satisfied by a standard Szilard engine: (i) repeatability of measurements; (ii) invariant weight entropy; or (iii) positive work extraction for all measurement outcomes. This result is shown to be a consequence of the Wigner–Araki–Yanase theorem, which imposes restrictions on the observables that can be measured under additive conservation laws. This observation is a first-step towards developing ‘second-law-like’ relations for measurement-assisted feedback control beyond thermality.

  1. Time-lapse seismic within reservoir engineering

    NARCIS (Netherlands)

    Oldenziel, T.

    2003-01-01

    Time-lapse 3D seismic is a fairly new technology allowing dynamic reservoir characterisation in a true volumetric sense. By investigating the differences between multiple seismic surveys, valuable information about changes in the oil/gas reservoir state can be captured. Its interpretation involves

  2. Multiscale ensemble filtering for reservoir engineering applications

    NARCIS (Netherlands)

    Lawniczak, W.; Hanea, R.G.; Heemink, A.; McLaughlin, D.

    2009-01-01

    Reservoir management requires periodic updates of the simulation models using the production data available over time. Traditionally, validation of reservoir models with production data is done using a history matching process. Uncertainties in the data, as well as in the model, lead to a nonunique

  3. Eleventh workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Counsil, J.R. (Stanford Geothermal Program)

    1986-01-23

    The Eleventh Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 21-23, 1986. The attendance was up compared to previous years, with 144 registered participants. Ten foreign countries were represented: Canada, England, France, Iceland, Indonesia, Italy, Japan, Mexico, New Zealand and Turkey. There were 38 technical presentations at the Workshop which are published as papers in this Proceedings volume. Six technical papers not presented at the Workshop are also published and one presentation is not published. In addition to these 45 technical presentations or papers, the introductory address was given by J. E. Mock from the Department of Energy. The Workshop Banquet speaker was Jim Combs of Geothermal Resources International, Inc. We thank him for his presentation on GEO geothermal developments at The Geysers. The chairmen of the technical sessions made an important contribution to the Workshop. Other than Stanford faculty members they included: M. Gulati, E. Iglesias, A. Moench, S. Prestwich, and K. Pruess. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and students. We would like to thank J.W. Cook, J.R. Hartford, M.C. King, A.E. Osugi, P. Pettit, J. Arroyo, J. Thorne, and T.A. Ramey for their valued help with the meeting arrangements and preparing the Proceedings. We also owe great thanks to our students who arranged and operated the audio-visual equipment. The Eleventh Workshop was supported by the Geothermal Technology Division of the U.S. Department of Energy through Contract DE-AS03-80SF11459. We deeply appreciate this continued support. January 1986 H.J. Ramey, Jr. P. Kruger R.N. Horne W.E. Brigham F.G. Miller J.R. Counsil

  4. Chickamauga reservoir embayment study - 1990

    Energy Technology Data Exchange (ETDEWEB)

    Meinert, D.L.; Butkus, S.R.; McDonough, T.A.

    1992-12-01

    The objectives of this report are three-fold: (1) assess physical, chemical, and biological conditions in the major embayments of Chickamauga Reservoir; (2) compare water quality and biological conditions of embayments with main river locations; and (3) identify any water quality concerns in the study embayments that may warrant further investigation and/or management actions. Embayments are important areas of reservoirs to be considered when assessments are made to support water quality management plans. In general, embayments, because of their smaller size (water surface areas usually less than 1000 acres), shallower morphometry (average depth usually less than 10 feet), and longer detention times (frequently a month or more), exhibit more extreme responses to pollutant loadings and changes in land use than the main river region of the reservoir. Consequently, embayments are often at greater risk of water quality impairments (e.g. nutrient enrichment, filling and siltation, excessive growths of aquatic plants, algal blooms, low dissolved oxygen concentrations, bacteriological contamination, etc.). Much of the secondary beneficial use of reservoirs occurs in embayments (viz. marinas, recreation areas, parks and beaches, residential development, etc.). Typically embayments comprise less than 20 percent of the surface area of a reservoir, but they often receive 50 percent or more of the water-oriented recreational use of the reservoir. This intensive recreational use creates a potential for adverse use impacts if poor water quality and aquatic conditions exist in an embayment.

  5. Twelfth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Rivera, J. (Stanford Geothermal Program)

    1987-01-22

    Preface The Twelfth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 20-22, 1987. The year ending December 1986 was very difficult for the domestic geothermal industry. Low oil prices caused a sharp drop in geothermal steam prices. We expected to see some effect upon attendance at the Twelfth Workshop. To our surprise, the attendance was up by thirteen from previous years, with one hundred and fifty-seven registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, Japan, Mexico, New Zealand, and Turkey. Despite a worldwide surplus of oil, international geothermal interest and development is growing at a remarkable pace. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Seven technical papers not presented at the Workshop are also published; they concern geothermal developments and research in Iceland, Italy, and New Zealand. In addition to these forty-eight technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was John R. Berg from the Department of Energy. We thank him for sharing with the Workshop participants his thoughts on the expectations of this agency in the role of alternative energy resources, specifically geothermal, within the country???s energy framework. His talk is represented as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: M. Gulati, K. Goyal, G.S. Bodvarsson, A.S. Batchelor, H. Dykstra, M.J. Reed, A. Truesdell, J.S. Gudmundsson, and J.R. Counsil. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and students. We would like to thank Jean Cook, Marilyn King, Amy Osugi, Terri Ramey, and Rosalee Benelli for their valued help with the meeting

  6. Thirteenth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.; Cook, J.W. (Stanford Geothermal Program)

    1988-01-21

    PREFACE The Thirteenth Workshop on Geothermal Reservoir Engineering was held at Stanford University on January 19-21, 1988. Although 1987 continued to be difficult for the domestic geothermal industry, world-wide activities continued to expand. Two invited presentations on mature geothermal systems were a keynote of the meeting. Malcolm Grant presented a detailed review of Wairakei, New Zealand and highlighted plans for new development. G. Neri summarized experience on flow rate decline and well test analysis in Larderello, Italy. Attendance continued to be high with 128 registered participants. Eight foreign countries were represented: England, France, Iceland, Italy, New Zealand, Japan, Mexico and The Philippines. A discussion of future workshops produced a strong recommendation that the Stanford Workshop program continue for the future. There were forty-one technical presentations at the Workshop. All of these are published as papers in this Proceedings volume. Four technical papers not presented at the Workshop are also published. In addition to these forty five technical presentations or papers, the introductory address was given by Henry J. Ramey, Jr. from the Stanford Geothermal Program. The Workshop Banquet speaker was Gustavo Calderon from the Inter-American Development Bank. We thank him for sharing with the Workshop participants a description of the Bank???s operations in Costa Rica developing alternative energy resources, specifically Geothermal, to improve the country???s economic basis. His talk appears as a paper in the back of this volume. The chairmen of the technical sessions made an important contribution to the workshop. Other than Stanford faculty members they included: J. Combs, G. T. Cole, J. Counsil, A. Drenick, H. Dykstra, K. Goyal, P. Muffler, K. Pruess, and S. K. Sanyal. The Workshop was organized by the Stanford Geothermal Program faculty, staff and students. We would like to thank Marilyn King, Pat Oto, Terri Ramey, Bronwyn Jones

  7. Heat Extraction Project, geothermal reservoir engineering research at Stanford

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.

    1989-01-01

    The main objective of the SGP Heat Extraction Project is to provide a means for estimating the thermal behavior of geothermal fluids produced from fractured hydrothermal resources. The methods are based on estimated thermal properties of the reservoir components, reservoir management planning of production and reinjection, and the mixing of reservoir fluids: geothermal, resource fluid cooled by drawdown and infiltrating groundwater, and reinjected recharge heated by sweep flow through the reservoir formation. Several reports and publications, listed in Appendix A, describe the development of the analytical methods which were part of five Engineer and PhD dissertations, and the results from many applications of the methods to achieve the project objectives. The Heat Extraction Project is to evaluate the thermal properties of fractured geothermal resource and forecasted effects of reinjection recharge into operating reservoirs.

  8. Standardized surface engineering design of shale gas reservoirs

    Directory of Open Access Journals (Sweden)

    Guangchuan Liang

    2016-01-01

    Full Text Available Due to the special physical properties of shale gas reservoirs, it is necessary to adopt unconventional and standardized technologies for its surface engineering construction. In addition, the surface engineering design of shale gas reservoirs in China faces many difficulties, such as high uncertainty of the gathering and transportation scale, poor adaptability of pipe network and station layout, difficult matching of the process equipments, and boosting production at the late stage. In view of these problems, the surface engineering construction of shale gas reservoirs should follow the principles of “standardized design, modularized construction and skid mounted equipment”. In this paper, standardized surface engineering design technologies for shale gas reservoirs were developed with the “standardized well station layout, universal process, modular function zoning, skid mounted equipment selection, intensive site design, digitized production management” as the core, after literature analysis and technology exploration were carried out. Then its application background and surface technology route were discussed with a typical shale gas field in Sichuan–Chongqing area as an example. Its surface gathering system was designed in a standardized way, including standardized process, the modularized gathering and transportation station, serialized dehydration unit and intensive layout, and remarkable effects were achieved. A flexible, practical and reliable ground production system was built, and a series of standardized technology and modularized design were completed, including cluster well platform, set station, supporting projects. In this way, a system applicable to domestic shale gas surface engineering construction is developed.

  9. Ninth workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Miller, F.G.; Horne, R.N.; Brigham, W.E.; Gudmundsson, J.S. (Stanford Geothermal Program)

    1983-12-15

    (Reservoir Chemistry), Malcolm Mossman (Reservoir Chemistry), Greg Raasch (Production), Manny Nathenson (Injection), Susan Petty (Injection), Subir Sanyal (Simulation), Marty Molloy (Petrothermal), and Allen Moench (Reservoir Physics). The Workshop was organized by the Stanford Geothermal Program faculty, staff and students. We would like to thank Jean Cook, Joanne Hartford, Terri Ramey, Amy Osugi, and Marilyn King for their valued help with the Workshop arrangements and the Proceedings. We also owe thanks to the program students who arranged and operated the audio-visual equipment. The Ninth Workshop was supported by the Geothermal and Hydropower Technologies Division of the U . S . Department of Energy through contract DE-AT03-80SF11459. We deeply appreciate this continued support. H. J. Ramey, Jr., R. N. Horne, P. Kruger, W. E. Brigham, F. G. Miller, J. S . Gudmundsson -vii

  10. Geothermal reservoir insurance study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1981-10-09

    The principal goal of this study was to provide analysis of and recommendations on the need for and feasibility of a geothermal reservoir insurance program. Five major tasks are reported: perception of risk by major market sectors, status of private sector insurance programs, analysis of reservoir risks, alternative government roles, and recommendations.

  11. Modeling a distributed environment for a petroleum reservoir engineering application with software product line

    International Nuclear Information System (INIS)

    Scheidt, Rafael de Faria; Vilain, Patrícia; Dantas, M A R

    2014-01-01

    Petroleum reservoir engineering is a complex and interesting field that requires large amount of computational facilities to achieve successful results. Usually, software environments for this field are developed without taking care out of possible interactions and extensibilities required by reservoir engineers. In this paper, we present a research work which it is characterized by the design and implementation based on a software product line model for a real distributed reservoir engineering environment. Experimental results indicate successfully the utilization of this approach for the design of distributed software architecture. In addition, all components from the proposal provided greater visibility of the organization and processes for the reservoir engineers

  12. Amplitude various angles (AVA) phenomena in thin layer reservoir: Case study of various reservoirs

    International Nuclear Information System (INIS)

    thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" data-affiliation=" (Wave Inversion and Subsurface Fluid Imaging Research Laboratory (WISFIR), Basic Science Center A 4thfloor, Physics Dept., FMIPA, Institut Teknologi Bandung (Indonesia); Rock Fluid Imaging Lab., Bandung (Indonesia))" >Nurhandoko, Bagus Endar B.; Susilowati

    2015-01-01

    Amplitude various offset is widely used in petroleum exploration as well as in petroleum development field. Generally, phenomenon of amplitude in various angles assumes reservoir’s layer is quite thick. It also means that the wave is assumed as a very high frequency. But, in natural condition, the seismic wave is band limited and has quite low frequency. Therefore, topic about amplitude various angles in thin layer reservoir as well as low frequency assumption is important to be considered. Thin layer reservoir means the thickness of reservoir is about or less than quarter of wavelength. In this paper, I studied about the reflection phenomena in elastic wave which considering interference from thin layer reservoir and transmission wave. I applied Zoeppritz equation for modeling reflected wave of top reservoir, reflected wave of bottom reservoir, and also transmission elastic wave of reservoir. Results show that the phenomena of AVA in thin layer reservoir are frequency dependent. Thin layer reservoir causes interference between reflected wave of top reservoir and reflected wave of bottom reservoir. These phenomena are frequently neglected, however, in real practices. Even though, the impact of inattention in interference phenomena caused by thin layer in AVA may cause inaccurate reservoir characterization. The relation between classes of AVA reservoir and reservoir’s character are different when effect of ones in thin reservoir and ones in thick reservoir are compared. In this paper, I present some AVA phenomena including its cross plot in various thin reservoir types based on some rock physics data of Indonesia

  13. Twenty-first workshop on geothermal reservoir engineering: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    None

    1996-01-26

    PREFACE The Twenty-First Workshop on Geothermal Reservoir Engineering was held at the Holiday Inn, Palo Alto on January 22-24, 1996. There were one-hundred fifty-five registered participants. Participants came from twenty foreign countries: Argentina, Austria, Canada, Costa Rica, El Salvador, France, Iceland, Indonesia, Italy, Japan, Mexico, The Netherlands, New Zealand, Nicaragua, the Philippines, Romania, Russia, Switzerland, Turkey and the UK. The performance of many geothermal reservoirs outside the United States was described in several of the papers. Professor Roland N. Horne opened the meeting and welcomed visitors. The key note speaker was Marshall Reed, who gave a brief overview of the Department of Energy's current plan. Sixty-six papers were presented in the technical sessions of the workshop. Technical papers were organized into twenty sessions concerning: reservoir assessment, modeling, geology/geochemistry, fracture modeling hot dry rock, geoscience, low enthalpy, injection, well testing, drilling, adsorption and stimulation. Session chairmen were major contributors to the workshop, and we thank: Ben Barker, Bobbie Bishop-Gollan, Tom Box, Jim Combs, John Counsil, Sabodh Garg, Malcolm Grant, Marcel0 Lippmann, Jim Lovekin, John Pritchett, Marshall Reed, Joel Renner, Subir Sanyal, Mike Shook, Alfred Truesdell and Ken Williamson. Jim Lovekin gave the post-dinner speech at the banquet and highlighted the exciting developments in the geothermal field which are taking place worldwide. The Workshop was organized by the Stanford Geothermal Program faculty, staff, and graduate students. We wish to thank our students who operated the audiovisual equipment. Shaun D. Fitzgerald Program Manager.

  14. The reservoir engineering report in financial transactions: 'a useful tool - neither panacea nor placebo'

    International Nuclear Information System (INIS)

    Porter, T.W.

    1996-01-01

    The important role that independent reservoir engineering reports play in the oil and gas industry, was discussed. Among other things, such reports often form the basis upon which oil and gas properties are valued, bought and sold, and of course, they are necessary for the industry to gain access to sources of capital. However, interpretation plays a critical role in the process, and very different conclusions can be drawn by equally reputable and qualified engineers. Because of this, financial investors insist upon independent reservoir engineering reports (and then frequently ignore the limitations and qualifications which are stated in the report). Some of the important limitations stated in reservoir engineering reports were discussed, along with the risks inherent in reservoir engineering reports, and the strategies for minimizing those risks. The engineer's professional responsibilities and potential liabilities in the matter of reserves estimates, were re-stated

  15. Impact of Reservoir Operation to the Inflow Flood - a Case Study of Xinfengjiang Reservoir

    Science.gov (United States)

    Chen, L.

    2017-12-01

    Building of reservoir shall impact the runoff production and routing characteristics, and changes the flood formation. This impact, called as reservoir flood effect, could be divided into three parts, including routing effect, volume effect and peak flow effect, and must be evaluated in a whole by using hydrological model. After analyzing the reservoir flood formation, the Liuxihe Model for reservoir flood forecasting is proposed. The Xinfengjiang Reservoir is studied as a case. Results show that the routing effect makes peak flow appear 4 to 6 hours in advance, volume effect is bigger for large flood than small one, and when rainfall focus on the reservoir area, this effect also increases peak flow largely, peak flow effect makes peak flow increase 6.63% to 8.95%. Reservoir flood effect is obvious, which have significant impact to reservoir flood. If this effect is not considered in the flood forecasting model, the flood could not be forecasted accurately, particularly the peak flow. Liuxihe Model proposed for Xinfengjiang Reservoir flood forecasting has a good performance, and could be used for real-time flood forecasting of Xinfengjiang Reservoir.Key words: Reservoir flood effect, reservoir flood forecasting, physically based distributed hydrological model, Liuxihe Model, parameter optimization

  16. Nanosensors as Reservoir Engineering Tools to Map Insitu Temperature Distributions in Geothermal Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Morgan Ames

    2011-06-15

    The feasibility of using nanosensors to measure temperature distribution and predict thermal breakthrough in geothermal reservoirs is addressed in this report. Four candidate sensors were identified: melting tin-bismuth alloy nanoparticles, silica nanoparticles with covalently-attached dye, hollow silica nanoparticles with encapsulated dye and impermeable melting shells, and dye-polymer composite time-temperature indicators. Four main challenges associated with the successful implementation of temperature nanosensors were identified: nanoparticle mobility in porous and fractured media, the collection and detection of nanoparticles at the production well, engineering temperature sensing mechanisms that are both detectable and irreversible, and inferring the spatial geolocation of temperature measurements in order to map temperature distribution. Initial experiments were carried out to investigate each of these challenges. It was demonstrated in a slim-tube injection experiment that it is possible to transport silica nanoparticles over large distances through porous media. The feasibility of magnetic collection of nanoparticles from produced fluid was evaluated experimentally, and it was estimated that 3% of the injected nanoparticles were recovered in a prototype magnetic collection device. An analysis technique was tailored to nanosensors with a dye-release mechanism to estimate temperature measurement geolocation by analyzing the return curve of the released dye. This technique was used in a hypothetical example problem, and good estimates of geolocation were achieved. Tin-bismuth alloy nanoparticles were synthesized using a sonochemical method, and a bench heating experiment was performed using these nanoparticles. Particle growth due to melting was observed, indicating that tin-bismuth nanoparticles have potential as temperature nanosensors

  17. Non-parametric Bayesian networks for parameter estimation in reservoir engineering

    NARCIS (Netherlands)

    Zilko, A.A.; Hanea, A.M.; Hanea, R.G.

    2013-01-01

    The ultimate goal in reservoir engineering is to optimize hydrocarbon recovery from a reservoir. To achieve the goal, good knowledge of the subsurface properties is crucial. One of these properties is the permeability. Ensemble Kalman Filter (EnKF) is the most common tool used to deal with this

  18. Geothermal reservoir engineering research at Stanford University. Third annual report for the period October 1, 1982-September 30, 1983

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.; Kruger, P.; Horne, R.N.; Brigham, W.E.; Miller, F.G.

    1983-09-01

    Progress is reported in the following areas: heat extraction from hydrothermal reservoirs; radon reservoir engineering; well test analysis and bench scale experiments; field applications; workshop, seminars, and technical information; reinjection technology; and seismic monitoring of vapor/liquid interfaces. (MHR)

  19. Geothermal engineering integrating mitigation of induced seismicity in reservoirs - The European GEISER project

    NARCIS (Netherlands)

    Bruhn, D.; Huenges, E.; Áǵustsson, K.; Zang, A.; Kwiatek, G.; Rachez, X.; Wiemer, S.; Wees, J.D.A.M. van; Calcagno, P.; Kohl, T.; Dorbath, C.; Natale, G. de; Oye, V.

    2011-01-01

    The GEISER (Geothermal Engineering Integrating Mitigation of Induced SEismicity in Reservoirs) project is co-funded by the European Commission to address the mitigation and understanding of induced seismicity (IS) in geothermal engineering. The aim of the project is to contribute to the improvement

  20. Reservoir management

    International Nuclear Information System (INIS)

    Satter, A.; Varnon, J.E.; Hoang, M.T.

    1992-01-01

    A reservoir's life begins with exploration leading to discovery followed by delineation of the reservoir, development of the field, production by primary, secondary and tertiary means, and finally to abandonment. Sound reservoir management is the key to maximizing economic operation of the reservoir throughout its entire life. Technological advances and rapidly increasing computer power are providing tools to better manage reservoirs and are increasing the gap between good and neutral reservoir management. The modern reservoir management process involves goal setting, planning, implementing, monitoring, evaluating, and revising plans. Setting a reservoir management strategy requires knowledge of the reservoir, availability of technology, and knowledge of the business, political, and environmental climate. Formulating a comprehensive management plan involves depletion and development strategies, data acquisition and analyses, geological and numerical model studies, production and reserves forecasts, facilities requirements, economic optimization, and management approval. This paper provides management, engineers geologists, geophysicists, and field operations staff with a better understanding of the practical approach to reservoir management using a multidisciplinary, integrated team approach

  1. Estimation of evaporation from open water - A review of selected studies, summary of U.S. Army Corps of Engineers data collection and methods, and evaluation of two methods for estimation of evaporation from five reservoirs in Texas

    Science.gov (United States)

    Harwell, Glenn R.

    2012-01-01

    Organizations responsible for the management of water resources, such as the U.S. Army Corps of Engineers (USACE), are tasked with estimation of evaporation for water-budgeting and planning purposes. The USACE has historically used Class A pan evaporation data (pan data) to estimate evaporation from reservoirs but many USACE Districts have been experimenting with other techniques for an alternative to collecting pan data. The energy-budget method generally is considered the preferred method for accurate estimation of open-water evaporation from lakes and reservoirs. Complex equations to estimate evaporation, such as the Penman, DeBruin-Keijman, and Priestley-Taylor, perform well when compared with energy-budget method estimates when all of the important energy terms are included in the equations and ideal data are collected. However, sometimes nonideal data are collected and energy terms, such as the change in the amount of stored energy and advected energy, are not included in the equations. When this is done, the corresponding errors in evaporation estimates are not quantifiable. Much simpler methods, such as the Hamon method and a method developed by the U.S. Weather Bureau (USWB) (renamed the National Weather Service in 1970), have been shown to provide reasonable estimates of evaporation when compared to energy-budget method estimates. Data requirements for the Hamon and USWB methods are minimal and sometimes perform well with remotely collected data. The Hamon method requires average daily air temperature, and the USWB method requires daily averages of air temperature, relative humidity, wind speed, and solar radiation. Estimates of annual lake evaporation from pan data are frequently within 20 percent of energy-budget method estimates. Results of evaporation estimates from the Hamon method and the USWB method were compared against historical pan data at five selected reservoirs in Texas (Benbrook Lake, Canyon Lake, Granger Lake, Hords Creek Lake, and Sam

  2. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2002-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 2 of the project has been reservoir characterization, 3-D modeling and technology transfer. This effort has included six tasks: (1) the study of rockfluid interactions, (2) petrophysical and engineering characterization, (3) data integration, (4) 3-D geologic modeling, (5) 3-D reservoir simulation and (6) technology transfer. This work was scheduled for completion in Year 2. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions is near completion. Observations regarding the diagenetic processes influencing pore system development and

  3. Interdisciplinary study of reservoir compartments and heterogeneity. Final report, October 1, 1993--December 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Van Kirk, C.

    1998-01-01

    A case study approach using Terry Sandstone production from the Hambert-Aristocrat Field, Weld County, Colorado was used to document the process of integration. One specific project goal is to demonstrate how a multidisciplinary approach can be used to detect reservoir compartmentalization and improve reserve estimates. The final project goal is to derive a general strategy for integration for independent operators. Teamwork is the norm for the petroleum industry where teams of geologists, geophysicists, and petroleum engineers work together to improve profits through a better understanding of reservoir size, compartmentalization, and orientation as well as reservoir flow characteristics. In this manner, integration of data narrows the uncertainty in reserve estimates and enhances reservoir management decisions. The process of integration has proven to be iterative. Integration has helped identify reservoir compartmentalization and reduce the uncertainty in the reserve estimates. This research report documents specific examples of integration and the economic benefits of integration.

  4. A Study of the Optimal Planning Model for Reservoir Sustainable Management- A Case Study of Shihmen Reservoir

    Science.gov (United States)

    Chen, Y. Y.; Ho, C. C.; Chang, L. C.

    2017-12-01

    The reservoir management in Taiwan faces lots of challenge. Massive sediment caused by landslide were flushed into reservoir, which will decrease capacity, rise the turbidity, and increase supply risk. Sediment usually accompanies nutrition that will cause eutrophication problem. Moreover, the unevenly distribution of rainfall cause water supply instability. Hence, how to ensure sustainable use of reservoirs has become an important task in reservoir management. The purpose of the study is developing an optimal planning model for reservoir sustainable management to find out an optimal operation rules of reservoir flood control and sediment sluicing. The model applies Genetic Algorithms to combine with the artificial neural network of hydraulic analysis and reservoir sediment movement. The main objective of operation rules in this study is to prevent reservoir outflow caused downstream overflow, minimum the gap between initial and last water level of reservoir, and maximum sluicing sediment efficiency. A case of Shihmen reservoir was used to explore the different between optimal operating rule and the current operation of the reservoir. The results indicate optimal operating rules tended to open desilting tunnel early and extend open duration during flood discharge period. The results also show the sluicing sediment efficiency of optimal operating rule is 36%, 44%, 54% during Typhoon Jangmi, Typhoon Fung-Wong, and Typhoon Sinlaku respectively. The results demonstrate the optimal operation rules do play a role in extending the service life of Shihmen reservoir and protecting the safety of downstream. The study introduces a low cost strategy, alteration of operation reservoir rules, into reservoir sustainable management instead of pump dredger in order to improve the problem of elimination of reservoir sediment and high cost.

  5. Studying Engineering Practice

    DEFF Research Database (Denmark)

    Buch, Anders

    2015-01-01

    The study of engineering practices has been the focus of Engineering Studies over the last three decades. Theses studies have used ethnographic and grounded methods in order to investigate engineering practices as they unfold in natural settings - in workplaces and engineering education. However......, engineering studies have not given much attention to conceptually clarifying what should be understood by 'engineering practices' and more precisely account for the composition and organization of the entities and phenomena that make up the practices. This chapter investigates and discusses how a 'practice...... will draw out some methodological consequences and discuss the ramifications of a practice theoretical approach for Engineering Studies....

  6. In-situ uranium mining: reservoir engineering aspects of leaching and restoration

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, M.I.

    1982-01-01

    To establish the feasibility of in-situ mining of uranium, a push-pull test of an in-situ uranium leaching process, which consists of a single injection/production test well and two observation wells, was designed to evaluate the parameters which govern the uranium production and restorability of a solution mined zone. The test procedure itself consists of injection (push cycle) of a preflush followed by lixiviant, a brief soak period (soak cycle), and subsequent production (pull cycle) into the same well. Based on computer modeling, procedures are defined which permit, for a properly designed test, the determination of both restoration and leaching parameters. The test procedure and design recommendations are also outlined. Two numerical simulators which model field scale uranium production and restoration operations are presented. These simulators are able to accommodate various well patterns and irregular reservoir boundaries, physical dispersion, directional permeability variations (if present), and a variety of injection/production strategies. A streamline-concentration balance technique has been used to develop the models. The assumption of time invariant boundary conditions and no transverse dispersion between the streamlines reduces the two dimensional problem to a bundle of one dimensional ones. It has been further shown that the production well effluent histories can easily be obtained by superposing the solution of the concentration balance equations for a single streamline, and thus reducing computation time significantly. Finally, the simulators have been used to study various reservoir engineering aspects to optimize in-situ uranium production from field scale operations.

  7. In-situ uranium mining: reservoir engineering aspects of leaching and restoration

    International Nuclear Information System (INIS)

    Kabir, M.I.

    1982-01-01

    To establish the feasibility of in-situ mining of uranium, a push-pull test of an in-situ uranium leaching process, which consists of a single injection/production test well and two observation wells, was designed to evaluate the parameters which govern the uranium production and restorability of a solution mined zone. The test procedure itself consists of injection (push cycle) of a preflush followed by lixiviant, a brief soak period (soak cycle), and subsequent production (pull cycle) into the same well. Based on computer modeling, procedures are defined which permit, for a properly designed test, the determination of both restoration and leaching parameters. The test procedure and design recommendations are also outlined. Two numerical simulators which model field scale uranium production and restoration operations are presented. These simulators are able to accommodate various well patterns and irregular reservoir boundaries, physical dispersion, directional permeability variations (if present), and a variety of injection/production strategies. A streamline-concentration balance technique has been used to develop the models. The assumption of time invariant boundary conditions and no transverse dispersion between the streamlines reduces the two dimensional problem to a bundle of one dimensional ones. It has been further shown that the production well effluent histories can easily be obtained by superposing the solution of the concentration balance equations for a single streamline, and thus reducing computation time significantly. Finally, the simulators have been used to study various reservoir engineering aspects to optimize in-situ uranium production from field scale operations

  8. Heat engine by exorcism of Maxwell Demon using spin angular momentum reservoir

    Science.gov (United States)

    Bedkihal, Salil; Wright, Jackson; Vaccaro, Joan; Gould, Tim

    Landauer's erasure principle is a hallmark in thermodynamics and information theory. According to this principle, erasing one bit of information incurs a minimum energy cost. Recently, Vaccaro and Barnett (VB) have explored the role of multiple conserved quantities in memory erasure. They further illustrated that for the energy degenerate spin reservoirs, the cost of erasure can be solely in terms of spin angular momentum and no energy. Motivated by the VB erasure, in this work we propose a novel optical heat engine that operates under a single thermal reservoir and a spin angular momentum reservoir. The novel heat engine exploits ultrafast processes of phonon absorption to convert thermal phonon energy to coherent light. The entropy generated in this process then corresponds to a mixture of spin up and spin down populations of energy degenerate electronic ground states which acts as demon's memory. This information is then erased using a polarised spin reservoir that acts as an entropy sink. The proposed heat engines goes beyond the traditional Carnot engine.

  9. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2001-09-14

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 1 of the project has been reservoir description and characterization. This effort has included four tasks: (1) geoscientific reservoir characterization, (2) the study of rock-fluid interactions, (3) petrophysical and engineering characterization and (4) data integration. This work was scheduled for completion in Year 1. Overall, the project work is on schedule. Geoscientific reservoir characterization is essentially completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been initiated. Observations regarding the diagenetic processes influencing pore system development and heterogeneity in these reef and shoal reservoirs have been

  10. Determination of verticality of reservoir engineering structure from ...

    African Journals Online (AJOL)

    Terrestrial laser scanners (TLS) are used nowadays as Geomatics instruments for various applications. One of these applications is 3D survey and management of oil and gas facilities and other engineering structures. This recent attention is due to the fact that laser scanner has the ability to generate massive amounts of ...

  11. The glaciogenic reservoir analogue studies project (GRASP)

    DEFF Research Database (Denmark)

    Moscariello, A.; Moreau, Julien; Vegt, P. van der

    Tunnel galleys are common features in Palaeozoic glacigenic succession in North Afrcica and Middle East and they are amongst the most challenging target for hydrocarbon exploration and developing drilling in these regions. Similarly, these buried valleys form important groundwater reservoirs...

  12. A Comparative Study of Reservoir Computing for Temporal Signal Processing

    OpenAIRE

    Goudarzi, Alireza; Banda, Peter; Lakin, Matthew R.; Teuscher, Christof; Stefanovic, Darko

    2014-01-01

    Reservoir computing (RC) is a novel approach to time series prediction using recurrent neural networks. In RC, an input signal perturbs the intrinsic dynamics of a medium called a reservoir. A readout layer is then trained to reconstruct a target output from the reservoir's state. The multitude of RC architectures and evaluation metrics poses a challenge to both practitioners and theorists who study the task-solving performance and computational power of RC. In addition, in contrast to tradit...

  13. Petrofacies analysis - the petrophysical tool for geologic/engineering reservoir characterization

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W.L.; Guy, W.J.; Gerlach, P.M. [Kansas Geological Survey, Lawrence, KS (United States)] [and others

    1997-08-01

    Petrofacies analysis is defined as the characterization and classification of pore types and fluid saturations as revealed by petrophysical measures of a reservoir. The word {open_quotes}petrofacies{close_quotes} makes an explicit link between petroleum engineers concerns with pore characteristics as arbiters of production performance, and the facies paradigm of geologists as a methodology for genetic understanding and prediction. In petrofacies analysis, the porosity and resistivity axes of the classical Pickett plot are used to map water saturation, bulk volume water, and estimated permeability, as well as capillary pressure information, where it is available. When data points are connected in order of depth within a reservoir, the characteristic patterns reflect reservoir rock character and its interplay with the hydrocarbon column. A third variable can be presented at each point on the crossplot by assigning a color scale that is based on other well logs, often gamma ray or photoelectric effect, or other derived variables. Contrasts between reservoir pore types and fluid saturations will be reflected in changing patterns on the crossplot and can help discriminate and characterize reservoir heterogeneity. Many hundreds of analyses of well logs facilitated by spreadsheet and object-oriented programming have provided the means to distinguish patterns typical of certain complex pore types for sandstones and carbonate reservoirs, occurrences of irreducible water saturation, and presence of transition zones. The result has been an improved means to evaluate potential production such as bypassed pay behind pipe and in old exploration holes, or to assess zonation and continuity of the reservoir. Petrofacies analysis is applied in this example to distinguishing flow units including discrimination of pore type as assessment of reservoir conformance and continuity. The analysis is facilitated through the use of color cross sections and cluster analysis.

  14. Feasibility study on application of volume acid fracturing technology to tight gas carbonate reservoir development

    Directory of Open Access Journals (Sweden)

    Nianyin Li

    2015-09-01

    Full Text Available How to effectively develop tight-gas carbonate reservoir and achieve high recovery is always a problem for the oil and gas industry. To solve this problem, domestic petroleum engineers use the combination of the successful experiences of North American shale gas pools development by stimulated reservoir volume (SRV fracturing with the research achievements of Chinese tight gas development by acid fracturing to propose volume acid fracturing technology for fractured tight-gas carbonate reservoir, which has achieved a good stimulation effect in the pilot tests. To determine what reservoir conditions are suitable to carry out volume acid fracturing, this paper firstly introduces volume acid fracturing technology by giving the stimulation mechanism and technical ideas, and initially analyzes the feasibility by the comparison of reservoir characteristics of shale gas with tight-gas carbonate. Then, this paper analyzes the validity and limitation of the volume acid fracturing technology via the analyses of control conditions for volume acid fracturing in reservoir fracturing performance, natural fracture, horizontal principal stress difference, orientation of in-situ stress and natural fracture, and gives the solution for the limitation. The study results show that the volume acid fracturing process can be used to greatly improve the flow environment of tight-gas carbonate reservoir and increase production; the incremental or stimulation response is closely related with reservoir fracturing performance, the degree of development of natural fracture, the small intersection angle between hydraulic fracture and natural fracture, the large horizontal principal stress difference is easy to form a narrow fracture zone, and it is disadvantageous to create fracture network, but the degradable fiber diversion technology may largely weaken the disadvantage. The practices indicate that the application of volume acid fracturing process to the tight-gas carbonate

  15. The glaciogenic reservoir analogue studies project (GRASP)

    DEFF Research Database (Denmark)

    Moscariello, A.; Moreau, Julien; Vegt, P. van der

    increasing the risk associated with developing effectively these reservoirs. Therefore a analogue-based predictive stratigraphical and sedimentological model can help to steer drilling strategy and reduce uncertainties and associated risks. For this purpose the GRASP joint industry programme was established......Tunnel galleys are common features in Palaeozoic glacigenic succession in North Afrcica and Middle East and they are amongst the most challenging target for hydrocarbon exploration and developing drilling in these regions. Similarly, these buried valleys form important groundwater reservoirs...... in Quaternary glaciated areas and their nature and sediment composition is critical to drive a sustainable production strategy and assess their vulnerability. Seismic resolution however, often limits the understanding of channel valleys morphology, 3D geometry and internal reservoir distribution, thus...

  16. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2003-09-25

    The University of Alabama in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company are undertaking an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling that utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary objective of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. The principal research effort for Year 3 of the project has been reservoir characterization, 3-D modeling, testing of the geologic-engineering model, and technology transfer. This effort has included six tasks: (1) the study of seismic attributes, (2) petrophysical characterization, (3) data integration, (4) the building of the geologic-engineering model, (5) the testing of the geologic-engineering model and (6) technology transfer. This work was scheduled for completion in Year 3. Progress on the project is as follows: geoscientific reservoir characterization is completed. The architecture, porosity types and heterogeneity of the reef and shoal reservoirs at Appleton and Vocation Fields have been characterized using geological and geophysical data. The study of rock-fluid interactions has been completed. Observations regarding the diagenetic

  17. Quantum efficiency bound for continuous heat engines coupled to noncanonical reservoirs

    Science.gov (United States)

    Agarwalla, Bijay Kumar; Jiang, Jian-Hua; Segal, Dvira

    2017-09-01

    We derive an efficiency bound for continuous quantum heat engines absorbing heat from squeezed thermal reservoirs. Our approach relies on a full-counting statistics description of nonequilibrium transport and it is not limited to the framework of irreversible thermodynamics. Our result, a generalized Carnot efficiency bound, is valid beyond the small-squeezing and high-temperature limit. Our findings are embodied in a prototype three-terminal quantum photoelectric engine where a qubit converts heat absorbed from a squeezed thermal reservoir into electrical power. We demonstrate that in the quantum regime, the efficiency can be greatly amplified by squeezing. From the fluctuation relation, we further receive other operational measures in linear response, for example, the universal maximum power efficiency bound.

  18. Dynamic bayesian networks as a possible alternative to the ensemble kalman filter for parameter estimation in reservoir engineering

    NARCIS (Netherlands)

    Hanea, A.; Hanea, R.; Zilko, A.

    2012-01-01

    The objective of reservoir engineering is to optimize hydrocarbon recovery. One of the most common and efficient recovery processes is water injection. The water is pumped into the reservoir in injection wells in order to push the oil trapped in the porous media towards the production wells. The

  19. Role of reservoir engineering in the assessment of undiscovered oil and gas resources in the National Petroleum Reserve, Alaska

    Science.gov (United States)

    Verma, M.K.; Bird, K.J.

    2005-01-01

    The geology and reservoir-engineering data were integrated in the 2002 U.S. Geological Survey assessment of the National Petroleum Reserve in Alaska (NPRA). VVhereas geology defined the analog pools and fields and provided the basic information on sizes and numbers of hypothesized petroleum accumulations, reservoir engineering helped develop necessary equations and correlations, which allowed the determination of reservoir parameters for better quantification of in-place petroleum volumes and recoverable reserves. Seismic- and sequence-stratigraphic study of the NPRA resulted in identification of 24 plays. Depth ranges in these 24 plays, however, were typically greater than depth ranges of analog plays for which there were available data, necessitating the need for establishing correlations. The basic parameters required were pressure, temperature, oil and gas formation volume factors, liquid/gas ratios for the associated and nonassociated gas, and recovery factors. Finally, the re sults of U.S. Geological Survey deposit simulation were used in carrying out an economic evaluation, which has been separately published. Copyright ?? 2005. The American Association of Petroleum Geologists. All rights reserved.

  20. A reservoir engineering assessment of the San Jacinto-Tizate Geothermal Field, Nicaragua

    Energy Technology Data Exchange (ETDEWEB)

    Ostapenko, S.; Spektor, S.; Davila, H.; Porras, E.; Perez, M.

    1996-01-24

    More than twenty yews have passed since geothermal research and drilling took place at the geothermal fields in Nicaragua- Tbe well horn Momotombo Geothermal Field (70 We) has been generating electricity since 1983, and now a new geothermal field is under exploration. the San Jacinto-Tizate. Two reservoirs hydraulic connected were found. The shallow reservoir (270°C) at the depth of 550 - 1200 meters, and the deep one at > 1600 meters. Both of theme are water dominated reservoirs, although a two phase condition exist in the upper part of the shallow one. Different transient tests and a multi-well interference test have been carried out, very high transmissivity value were estimated around the well SJ-4 and average values for the others. A preliminar conceptual model of the geothermal system is given in this paper, as the result of the geology, geophysics, hydrology studies, drilling and reservoir evaluation.

  1. An iterative ensemble Kalman filter for reservoir engineering applications

    NARCIS (Netherlands)

    Krymskaya, M.V.; Hanea, R.G.; Verlaan, M.

    2009-01-01

    The study has been focused on examining the usage and the applicability of ensemble Kalman filtering techniques to the history matching procedures. The ensemble Kalman filter (EnKF) is often applied nowadays to solving such a problem. Meanwhile, traditional EnKF requires assumption of the

  2. A knowledge engineering approach for improving secondary recovery in offshore reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, Milton P.; Tovar, Felipe T.R.; Guerra, Fabio A. [Parana Institute of Technology (TECPAR), Curitiba, PR (Brazil). Artificial Intelligence Div.; Andrade, Cynthia; Baptista, Walmar [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas. Tecnologia de Materiais, Equipamentos e Corrosao

    2004-07-01

    Secondary recovery in offshore petroleum reservoirs by seawater injection is a technique traditionally applied in oil and gas industry. However, the injected water quality must be compatible with the reservoir characteristics in order to prevent corrosion, formation plugging and reservoir souring. So, the seawater must be treated before injection in the reservoirs and on-line monitoring equipment are employed to check the treatments efficacy. Nevertheless, the amount of data to analyze is quite big and involves many different experts, which make their evaluation and the establishment of correlations very difficult. For these cases, where it's crucial to detect the contaminants presence as soon as they occur to indicate corrective procedures, the application of knowledge engineering techniques and the development of expert systems are a good solution proposal. This paper presents the expert system InjeX (heuristic approach), developed for seawater injection treatment plants to maintain the water quality in offshore platforms. The description and the analysis of the problem, a proposed solution and some preliminary results are detailed and discussed along the paper. (author)

  3. Studies of Reservoir Hosts for Marburg virus

    DEFF Research Database (Denmark)

    Swanepoel, Robert; Smit, Sheilagh B; Rollin, Pierre E

    2007-01-01

    To determine reservoir hosts for Marburg virus (MARV), we examined the fauna of a mine in northeastern Democratic Republic of the Congo. The mine was associated with a protracted outbreak of Marburg hemorrhagic fever during 1998-2000. We found MARV nucleic acid in 12 bats, comprising 3.0%-3.6% of 2...... species of insectivorous bat and 1 species of fruit bat. We found antibody to the virus in the serum of 9.7% of 1 of the insectivorous species and in 20.5% of the fruit bat species, but attempts to isolate virus were unsuccessful. ...

  4. Characterization of pediatric microtia cartilage: a reservoir of chondrocytes for auricular reconstruction using tissue engineering strategies.

    Science.gov (United States)

    Melgarejo-Ramírez, Y; Sánchez-Sánchez, R; García-López, J; Brena-Molina, A M; Gutiérrez-Gómez, C; Ibarra, C; Velasquillo, C

    2016-09-01

    The external ear is composed of elastic cartilage. Microtia is a congenital malformation of the external ear that involves a small reduction in size or a complete absence. The aim of tissue engineering is to regenerate tissues and organs clinically implantable based on the utilization of cells and biomaterials. Remnants from microtia represent a source of cells for auricular reconstruction using tissue engineering. To examine the macromolecular architecture of microtia cartilage and behavior of chondrocytes, in order to enrich the knowledge of this type of cartilage as a cell reservoir. Auricular cartilage remnants were obtained from pediatric patients with microtia undergoing reconstructive procedures. Extracellular matrix composition was characterized using immunofluorescence and histological staining methods. Chondrocytes were isolated and expanded in vitro using a mechanical-enzymatic protocol. Chondrocyte phenotype was analyzed using qualitative PCR. Microtia cartilage preserves structural organization similar to healthy elastic cartilage. Extracellular matrix is composed of typical cartilage proteins such as type II collagen, elastin and proteoglycans. Chondrocytes displayed morphological features similar to chondrocytes derived from healthy cartilage, expressing SOX9, COL2 and ELN, thus preserving chondral phenotype. Cell viability was 94.6 % during in vitro expansion. Elastic cartilage from microtia has similar characteristics, both architectural and biochemical to healthy cartilage. We confirmed the suitability of microtia remnant as a reservoir of chondrocytes with potential to be expanded in vitro, maintaining phenotypical features and viability. Microtia remnants are an accessible source of autologous cells for auricular reconstruction using tissue engineering strategies.

  5. Statistical analysis and experiment planning in reservoir engineering; Analyse statistique et planification d'experience en ingenierie de reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Zabalza-Mezghani, I.

    2000-05-24

    The aim of this thesis first part is the prediction of simulated production responses, when controlled or uncontrolled parameters act on them. The specificity of our work was to study an uncontrolled parameter: the geostatistical seed, which leads to an hetero-scedastic response behavior. In this context, a joint modelling of both mean and variance of the response was essential to get an efficient prediction. We have proposed two prediction intervals of the response, which either resorted to bootstrap re-sampling or not, and which were very efficient to predict the response accounting for the hetero-scedastic framework. Another aim of this part was to use the available information on gradient response to improve prediction. We have suggested a Bayesian prediction, that involves both response and gradients, in order to highlight the significance of gradient information to reach safe predictions. In the second part, which deals. with history matching problem, the originality of our work was the resort to experimental designs. This problem, which consists in calibrating a reservoir model with respect to dynamic data, fits the description of an objective function minimization. As the objective function behavior is non-linear and therefore cannot fit a polynomial function, we suggest to combine the simplex method, which permits to select a domain where the objective function reveals simple behavior, and experimental design theory, which allows to build an analytical model of the objective function. A minimization of this analytical model makes it possible to reach the parameter values that ensure dynamic data respect. In this way, this methodology highlights the efficiency of experimental designs for history matching, particularly when optimization methods are inadequate because of non-differentiability, as for the calibration of geostatistical facies models. Several reservoir application cases illustrate the efficiency of the approaches we have proposed in this thesis

  6. Preservation of Gaussian state entanglement in a quantum beat laser by reservoir engineering

    Science.gov (United States)

    Qurban, Misbah; Islam, Rameez ul; Ge, Guo-Qin; Ikram, Manzoor

    2018-04-01

    Quantum beat lasers have been considered as sources of entangled radiation in continuous variables such as Gaussian states. In order to preserve entanglement and to minimize entanglement degradation due to the system’s interaction with the surrounding environment, we propose to engineer environment modes through insertion of another system in between the laser resonator and the environment. This makes the environment surrounding the two-mode laser a structured reservoir. It not only enhances the entanglement among two modes of the laser but also preserves the entanglement for sufficiently longer times, a stringent requirement for quantum information processing tasks.

  7. Challenges of reservoir properties and production history matching in a CHOPS reservoir study

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Mahbub [Department of Geoscience, University of Calgary (Canada)

    2011-07-01

    In order to meet increasing world energy demand, wells have to be drilled within very thin reservoir beds. This paper, we present one of the solutions for optimizing the reservoir characterization. Reservoir characterization is the process between the discovery of a property and the reservoir management phase. Principal data for reservoir modeling are: 4D Seismic interpretation, wireline log interpretation, core analysis, and petrophysical analysis. Reservoir conditions, perforation and completion technology are the key issues to the production rate of cold production. Reservoir modeling intends to minimize the risk factor, maximize production, and help determine the location for infill drillings. Cold heavy oil production with sand (CHOPS) is a method for enhancing primary production from heavy oil reservoirs. Gravitational forces, natural fluid pressure gradients and foamy oil flow phenomena are the major driving forces of the CHOPS mechanism. Finally, Reservoir characterization allows better understanding of permeability and porosity prediction.

  8. Heat Extraction Project, geothermal reservoir engineering research at Stanford. Fourth annual report, January 1, 1988--December 1, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.

    1989-01-01

    The main objective of the SGP Heat Extraction Project is to provide a means for estimating the thermal behavior of geothermal fluids produced from fractured hydrothermal resources. The methods are based on estimated thermal properties of the reservoir components, reservoir management planning of production and reinjection, and the mixing of reservoir fluids: geothermal, resource fluid cooled by drawdown and infiltrating groundwater, and reinjected recharge heated by sweep flow through the reservoir formation. Several reports and publications, listed in Appendix A, describe the development of the analytical methods which were part of five Engineer and PhD dissertations, and the results from many applications of the methods to achieve the project objectives. The Heat Extraction Project is to evaluate the thermal properties of fractured geothermal resource and forecasted effects of reinjection recharge into operating reservoirs.

  9. Estimation of Bank Erosion Due To Reservoir Operation in Cascade (Case Study: Citarum Cascade Reservoir

    Directory of Open Access Journals (Sweden)

    Sri Legowo

    2009-11-01

    Full Text Available Sedimentation is such a crucial issue to be noted once the accumulated sediment begins to fill the reservoir dead storage, this will then influence the long-term reservoir operation. The sediment accumulated requires a serious attention for it may influence the storage capacity and other reservoir management of activities. The continuous inflow of sediment to the reservoir will decrease the capacity of reservoir storage, the reservoir value in use, and the useful age of reservoir. Because of that, the rate of the sediment needs to be delayed as possible. In this research, the delay of the sediment rate is considered based on the rate of flow of landslide of the reservoir slope. The rate of flow of the sliding slope can be minimized by way of each reservoir autonomous efforts. This effort can be performed through; the regulation of fluctuating rate of reservoir surface current that does not cause suddenly drawdown and upraising as well. The research model is compiled using the searching technique of Non Linear Programming (NLP.The rate of bank erosion for the reservoir variates from 0.0009 to 0.0048 MCM/year, which is no sigrificant value to threaten the life time of reservoir.Mean while the rate of watershed sediment has a significant value, i.e: 3,02 MCM/year for Saguling that causes to fullfill the storage capacity in 40 next years (from years 2008.

  10. Recycling of Clay Sediments for Geopolymer Binder Production. A New Perspective for Reservoir Management in the Framework of Italian Legislation: The Occhito Reservoir Case Study.

    Science.gov (United States)

    Molino, Bruno; De Vincenzo, Annamaria; Ferone, Claudio; Messina, Francesco; Colangelo, Francesco; Cioffi, Raffaele

    2014-07-31

    Reservoir silting is an unavoidable issue. It is estimated that in Italy, the potential rate of silting-up in large reservoirs ranges from 0.1% to 1% in the presence of wooded river basins and intensive agricultural land use, respectively. In medium and small-sized reservoirs, these values vary between 0.3% and 2%. Considering both the types of reservoirs, the annual average loss of storage capacity would be of about 1.59%. In this paper, a management strategy aimed at sediment productive reuse is presented. Particularly, the main engineering outcomes of an extensive experimental program on geopolymer binder synthesis is reported. The case study deals with Occhito reservoir, located in Southern Italy. Clay sediments coming from this silted-up artificial lake were characterized, calcined and activated, by means of a wide set of alkaline activating solutions. The results showed the feasibility of this recovery process, optimizing a few chemical parameters. The possible reuse in building material production (binders, precast concrete, bricks, etc. ) represents a relevant sustainable alternative to landfill and other more consolidated practices.

  11. Recycling of Clay Sediments for Geopolymer Binder Production. A New Perspective for Reservoir Management in the Framework of Italian Legislation: The Occhito Reservoir Case Study

    Directory of Open Access Journals (Sweden)

    Bruno Molino

    2014-07-01

    Full Text Available Reservoir silting is an unavoidable issue. It is estimated that in Italy, the potential rate of silting-up in large reservoirs ranges from 0.1% to 1% in the presence of wooded river basins and intensive agricultural land use, respectively. In medium and small-sized reservoirs, these values vary between 0.3% and 2%. Considering both the types of reservoirs, the annual average loss of storage capacity would be of about 1.59%. In this paper, a management strategy aimed at sediment productive reuse is presented. Particularly, the main engineering outcomes of an extensive experimental program on geopolymer binder synthesis is reported. The case study deals with Occhito reservoir, located in Southern Italy. Clay sediments coming from this silted-up artificial lake were characterized, calcined and activated, by means of a wide set of alkaline activating solutions. The results showed the feasibility of this recovery process, optimizing a few chemical parameters. The possible reuse in building material production (binders, precast concrete, bricks, etc. represents a relevant sustainable alternative to landfill and other more consolidated practices.

  12. INTEGRATED GEOLOGIC-ENGINEERING MODEL FOR REEF AND CARBONATE SHOAL RESERVOIRS ASSOCIATED WITH PALEOHIGHS: UPPER JURASSIC SMACKOVER FORMATION, NORTHEASTERN GULF OF MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2004-02-25

    The University of Alabama, in cooperation with Texas A&M University, McGill University, Longleaf Energy Group, Strago Petroleum Corporation, and Paramount Petroleum Company, has undertaken an integrated, interdisciplinary geoscientific and engineering research project. The project is designed to characterize and model reservoir architecture, pore systems and rock-fluid interactions at the pore to field scale in Upper Jurassic Smackover reef and carbonate shoal reservoirs associated with varying degrees of relief on pre-Mesozoic basement paleohighs in the northeastern Gulf of Mexico. The project effort includes the prediction of fluid flow in carbonate reservoirs through reservoir simulation modeling which utilizes geologic reservoir characterization and modeling and the prediction of carbonate reservoir architecture, heterogeneity and quality through seismic imaging. The primary goal of the project is to increase the profitability, producibility and efficiency of recovery of oil from existing and undiscovered Upper Jurassic fields characterized by reef and carbonate shoals associated with pre-Mesozoic basement paleohighs. Geoscientific reservoir property, geophysical seismic attribute, petrophysical property, and engineering property characterization has shown that reef (thrombolite) and shoal reservoir lithofacies developed on the flanks of high-relief crystalline basement paleohighs (Vocation Field example) and on the crest and flanks of low-relief crystalline basement paleohighs (Appleton Field example). The reef thrombolite lithofacies have higher reservoir quality than the shoal lithofacies due to overall higher permeabilities and greater interconnectivity. Thrombolite dolostone flow units, which are dominated by dolomite intercrystalline and vuggy pores, are characterized by a pore system comprised of a higher percentage of large-sized pores and larger pore throats. Rock-fluid interactions (diagenesis) studies have shown that although the primary control on

  13. Modeling Study of High Pressure and High Temperature Reservoir Fluids

    DEFF Research Database (Denmark)

    Varzandeh, Farhad

    S-characterization combinations and 260 reservoir fluids. PC-SAFT with the new general characterization method is shown to give the lowest AAD% and maximum deviation in calculation of saturation pressure, density and STO density, among all the tested characterization methods for PC-SAFT. Application of the new characterization...... be highly rewarding if successfully produced. This PhD project is part of the NextOil (New Extreme Oil and Gas in the Danish North Sea) project which is intended to reduce the uncertainties in HPHT field development. The main focus of this PhD is on accurate description of the reservoir fluid behavior under...... HPHT conditions to minimize the production risks from these types of reservoirs. In particular, the study has thoroughly evaluated several non-cubic Equations of State (EoSs) which are considered promising for HPHT fluid modeling, showing their advantages and short comings based on an extensive...

  14. Experimental study of water adsorption on Geysers reservoir rocks

    Energy Technology Data Exchange (ETDEWEB)

    Shubo Shang; Horne, Roland N.; Ramey, Henry J., Jr.

    1993-01-28

    Experimental isotherms of water vapor adsorption/desorption on three geothermal reservoir rock samples have been measured at temperatures of 80, 100, 120 and 140°C. Initial surface status of the sample was found to influence the amount of water adsorbed. At low relative pressures, adsorption is the dominant process of water retention onto the rock samples. Adsorption/desorption hysteresis was observed to exist over the whole pressure range at all temperatures. Similar observations were made for all three samples. The results of this study suggest that adsorption is important in storing water in geothermal reservoir rocks not only in itself, but also in inducing capillary condensation.

  15. study of ichtyofauna of daberam reservoir, katsina state 172

    African Journals Online (AJOL)

    DR. AMINU

    ABSTRACT. Research was carried out to explore the fish species diversity and study some aspects of the. Biology of fish of Daberam reservoir, Katsina state, for a period of three month from March to May. 2009. 66 Samples of fish were collected from commercial fishermen and experimental fishing gears, preserved in ...

  16. A chemical EOR benchmark study of different reservoir simulators

    Science.gov (United States)

    Goudarzi, Ali; Delshad, Mojdeh; Sepehrnoori, Kamy

    2016-09-01

    Interest in chemical EOR processes has intensified in recent years due to the advancements in chemical formulations and injection techniques. Injecting Polymer (P), surfactant/polymer (SP), and alkaline/surfactant/polymer (ASP) are techniques for improving sweep and displacement efficiencies with the aim of improving oil production in both secondary and tertiary floods. There has been great interest in chemical flooding recently for different challenging situations. These include high temperature reservoirs, formations with extreme salinity and hardness, naturally fractured carbonates, and sandstone reservoirs with heavy and viscous crude oils. More oil reservoirs are reaching maturity where secondary polymer floods and tertiary surfactant methods have become increasingly important. This significance has added to the industry's interest in using reservoir simulators as tools for reservoir evaluation and management to minimize costs and increase the process efficiency. Reservoir simulators with special features are needed to represent coupled chemical and physical processes present in chemical EOR processes. The simulators need to be first validated against well controlled lab and pilot scale experiments to reliably predict the full field implementations. The available data from laboratory scale include 1) phase behavior and rheological data; and 2) results of secondary and tertiary coreflood experiments for P, SP, and ASP floods under reservoir conditions, i.e. chemical retentions, pressure drop, and oil recovery. Data collected from corefloods are used as benchmark tests comparing numerical reservoir simulators with chemical EOR modeling capabilities such as STARS of CMG, ECLIPSE-100 of Schlumberger, REVEAL of Petroleum Experts. The research UTCHEM simulator from The University of Texas at Austin is also included since it has been the benchmark for chemical flooding simulation for over 25 years. The results of this benchmark comparison will be utilized to improve

  17. Stimulation and reservoir engineering of geothermal resources. Second annual report, July 1, 1978-September 30, 1979

    Energy Technology Data Exchange (ETDEWEB)

    Kruger, P.; Ramey, H.J. Jr.

    1979-09-01

    Individual projects are grouped under four main areas of study: energy extraction, bench-scale flow experiments, radon tracer techniques, and well test analysis. The energy extraction experiments concern the efficiency with which the in-place heat and fluids can be produced in the most economical manner. The bench-scale flow experiments cover the results of three models used to examine the properties of flow through porous media at elevated temperature and pressures. Random tracer techniques describe accelerated efforts to field test several geothermal reservoirs by both transient and transect test procedures. The well test analysis section describes several new developments: analysis of earth-tide effects, pressure transient analysis of multilayered systems, interference testing with storage and skin effects, determination of steam-water relative permeability from wellhead data, well test analysis for wells produced at constant pressure, the parallelepiped model, slug test DST analysis, and pressure transient behavior in naturally fractured reservoirs. (MHR)

  18. Reservoir Simulation on the Cerro Prieto Geothermal Field: A Continuing Study

    Energy Technology Data Exchange (ETDEWEB)

    Castaneda, M.; Marquez, R.; Arellano, V.; Esquer, C.A.

    1983-12-15

    The Cerro Prieto geothermal field is a liquid-dominated geothermal reservoir of complex geological and hydrological structure. It is located at the southern end of the Salton-Mexicali trough which includes other geothermal anomalies as Heber and East Mesa. Although in 1973, the initial power plant installed capacity was 75 MW of electrical power, this amount increased to 180 MW in 1981 as field development continued. It is expected to have a generating capacity of 620 MW by the end of 1985, when two new plants will be completely in operation. Questions about field deliverability, reservoir life and ultimate recovery related to planned installations are being presently asked. Numerical modeling studies can give very valuable answers to these questions, even at the early stages in the development of a field. An effort to simulate the Cerro Prieto geothermal reservoir has been undergoing for almost two years. A joint project among Comision Federal de Electricidad (CFE), Instituto de Investigaciones Electricas (IIE) and Intercomp of Houstin, Texas, was created to perform reservoir engineering and simulation studies on this field. The final project objective is tosimulate the behavior of the old field region when production from additional wells located in the undeveloped field zones will be used for feeding the new power plants.

  19. Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes

    Energy Technology Data Exchange (ETDEWEB)

    Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton

    2009-03-31

    Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications

  20. A History of Geothermal Energy Research and Development in the United States. Reservoir Engineering 1976-2006

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, B. Mack [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pruess, Karsten [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lippmann, Marcelo J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Majer, Ernest L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rose, Peter E. [Univ. of Utah, Salt Lake City, UT (United States); Adams, Michael [Univ. of Utah, Salt Lake City, UT (United States); Roberston-Tait, Ann [GeothermEx Inc., San Pablo, CA (United States); Moller, Nancy [Univ. of California, San Diego, CA (United States); Weare, John [Univ. of California, San Diego, CA (United States); Clutter, Ted [ArtComPhoto (United States); Brown, Donald W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2010-09-01

    This report, the third in a four-part series, summarizes significant research projects performed by the U.S. Department of Energy (DOE) over 30 years to overcome challenges in reservoir engineering and to make generation of electricity from geothermal resources more cost-competitive.

  1. A PC/workstation cluster computing environment for reservoir engineering simulation applications

    International Nuclear Information System (INIS)

    Hermes, C.E.; Koo, J.

    1995-01-01

    Like the rest of the petroleum industry, Texaco has been transferring its applications and databases from mainframes to PC's and workstations. This transition has been very positive because it provides an environment for integrating applications, increases end-user productivity, and in general reduces overall computing costs. On the down side, the transition typically results in a dramatic increase in workstation purchases and raises concerns regarding the cost and effective management of computing resources in this new environment. The workstation transition also places the user in a Unix computing environment which, to say the least, can be quite frustrating to learn and to use. This paper describes the approach, philosophy, architecture, and current status of the new reservoir engineering/simulation computing environment developed at Texaco's E and P Technology Dept. (EPTD) in Houston. The environment is representative of those under development at several other large oil companies and is based on a cluster of IBM and Silicon Graphics Intl. (SGI) workstations connected by a fiber-optics communications network and engineering PC's connected to local area networks, or Ethernets. Because computing resources and software licenses are shared among a group of users, the new environment enables the company to get more out of its investments in workstation hardware and software

  2. Multidisciplinary benefits from biomonitoring studies of cooling reservoirs

    International Nuclear Information System (INIS)

    Bowers, J.A.; Gladden, J.B.

    1990-01-01

    Therefore, biomonitoring studies of once-through cooling reservoirs for nuclear reactors not only provide field and laboratory information for environmental compliance, but also offer results which benefit lake and reservoir management constructs and limnetic community ecology. Biomonitoring programs have been performed at the Department of Energy's Savannah River Site to provide information fro compliance with Section 316a of the Clean Water Act. On Par Pond and Pond B comprehensive field efforts monitored nutrient chemistry, plankton populations, fisheries, benthic assemblages, and littoral zone biota from 1983 through 1985. A similar effort, begun in 1985 and continuing through 1992, is in progress on L Lake. Results have indicated that nonplanned whole-basin manipulations and the comprehensive intensity of monitoring studies offer new insights into how limnetic communities function

  3. Integrating geologic and engineering data into 3-D reservoir models: an example from norman wells field, NWT, Canada

    International Nuclear Information System (INIS)

    Yose, L.A.

    2004-01-01

    A case study of the Norman Wells field will be presented to highlight the work-flow and data integration steps associated with characterization and modeling of a complex hydrocarbon reservoir. Norman Wells is a Devonian-age carbonate bank ('reef') located in the Northwest Territories of Canada, 60 kilometers south of the Arctic Circle. The reservoir reaches a maximum thickness of 130 meters in the reef interior and thins toward the basin due to depositional pinch outs. Norman Wells is an oil reservoir and is currently under a 5-spot water injection scheme for enhanced oil recovery (EOR). EOR strategies require a detailed understanding of how reservoir flow units, flow barriers and flow baffles are distributed to optimize hydrocarbon sweep and recovery and to minimize water handling. Reservoir models are routinely used by industry to characterize the 3-D distribution of reservoir architecture (stratigraphic layers, depositional facies, faults) and rock properties (porosity. permeability). Reservoir models are validated by matching historical performance data (e.g., reservoir pressures, well production or injection rates). Geologic models are adjusted until they produce a history match, and model adjustments are focused on inputs that have the greatest geologic uncertainty. Flow simulation models are then used to optimize field development strategies and to forecast field performance under different development scenarios. (author)

  4. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1990-01-01

    The main focus of the work by the Fusion Plasma Engineering Group at the University during the prior contract year involved a study of fusion ash (helium) effects on burn efficiency and on potential ways to control ash buildup. This work has wide application to a variety of fusion reactor concepts, but the immediate application for the present work is in the ARIES tokamak reactor design study now being undertaken by a national design team headed by the UCLA. The examples presented here largely deal with the ARIES-I design which is a D-T device operating in the first instability regime

  5. Reservoir Engineering Optimization Strategies for Subsurface CO{sub 2} Storage

    Energy Technology Data Exchange (ETDEWEB)

    Mclntire, Blayde; McPherson, Brian

    2013-09-30

    The purpose of this report is to outline a methodology for calculating the optimum number of injection wells for geologic CCS. The methodology is intended primarily for reservoir pressure management, and factors in cost as well. Efficiency may come in many forms depending on project goals; therefore, various results are presented simultaneously. The developed methodology is illustrated via application in a case study of the Rocky Mountain Carbon Capture and Storage (RMCCS) project, including a CCS candidate site near Craig, Colorado, USA. The forecasting method provided reasonable estimates of cost and injection volume when compared to simulated results.

  6. Reservoir engineering in the 70's and 80's

    Energy Technology Data Exchange (ETDEWEB)

    Ramey, H.J. Jr.

    1971-01-01

    Most of the significant contributions to reservoir engineering were made by a handful of prodigious giants in the 1930's and 1940's. The most significant contribution that can be made in the next 20 yr will be to fully understand--perhaps with the help of that latest prodigy, the computer--what those giants were driving at. Even if only the presently known oil-recovery processes are considered, exciting happenings in the area of oil recovery can be forecast for the next 20 yr. During the 1950's and 1960's, thermal recovery, miscible fluid injection, and non-Newtonian (mobility control) fluid injection were developed and widely pilot tested. All of these methods offer the potential for very high oil recoveries--on the order of 80 to 100% of oil in the displaced region. It is hoped that the development of methods will occur, which are capable of recovering 75% of oil in place at the start of fluid injection. Technologically, this is really not a bold forecast--both wet combustion and micellar solution slug injection already appear to have this capability in well-designed operations. The late 1960's was a period of unusually successful exploration. Large finds were made, worldwide, almost daily: Prudhoe Bay, the North Sea, Australia, and Indonesia. (11 refs.)

  7. Monitoring Reservoirs Using MERIS And LANDSAT Fused Images : A Case Study Of Polyfitos Reservoir - West Macedonia - Greece

    Science.gov (United States)

    Stefouli, M.; Charou, E.; Vasileiou, E.; Stathopoulos, N.; Perrakis, A.

    2012-04-01

    Research and monitoring is essential to assess baseline conditions in reservoirs and their watershed and provide necessary information to guide decision-makers. Erosion and degradation of mountainous areas can lead to gradual aggradation of reservoirs reducing their lifetime. Collected measurements and observations have to be communicated to the managers of the reservoirs so as to achieve a common / comprehensive management of a large watershed and reservoir system. At this point Remote Sensing could help as the remotely sensed data are repeatedly and readily available to the end users. Aliakmon is the longest river in Greece, it's length is about 297 km and the surface of the river basin is 9.210 km2.The flow of the river starts from Northwest of Greece and ends in Thermaikos Gulf. The riverbed is not natural throughout the entire route, because constructed dams restrict water and create artificial lakes, such as lake of Polyfitos, that prevent flooding. This lake is used as reservoir, for covering irrigational water needs and the water is used to produce energy from the hydroelectric plant of Public Power Corporation-PPC. The catchment basin of Polyfitos' reservoir covers an area of 847.76 km2. Soil erosion - degradation in the mountainous watershed of streams of Polyfitos reservoir is taking place. It has been estimated that an annual volume of sediments reaching the reservoir is of the order of 244 m3. Geomatic based techniques are used in processing multiple data of the study area. A data inventory was formulated after the acquisition of topographic maps, compilation of geological and hydro-geological maps, compilation of digital elevation model for the area of interest based on satellite data and available maps. It also includes the acquisition of various hydro-meteorological data when available. On the basis of available maps and satellite data, digital elevation models are used in order to delineate the basic sub-catchments of the Polyfytos basin as well as

  8. Application of multitracer technology to petroleum reservoir studies. Quarterly progress report, April 1--June 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Senum, G.I.

    1992-09-01

    The objectives of this research program are to: Improve the assessment of the character of petroleum reservoirs using tracer technology for the monitoring and improvement of EOR techniques, specifically, (a) to apply the presently available multitracer perfluorocarbon tracer (PFI) technology to the study of petroleum reservoirs in characterizing reservoir bulk subsurface flow transport and dispersion rates; and (b) to demonstrate that PFTs with differing physical properties will interact with differing rates of adsorption and dispersion within such reservoirs, from which may be inferred difference in the character and/or extent of petroleum in those reservoirs. Develop additional tracers, and tracer injection, sampling and analyses methodologies for use in petroleum reservoir characterization experiments. Develop a data base of petroleum transport and dispersion properties from tracer experiments for use by modellers for developing, validating and extending petroleum reservoirs models used for characterizing petroleum reservoirs. Technical progress is discussed according to the three ongoing field experiments at the Naval Petroleum Reserve in California (NPRC).

  9. Application of multitracer technology to petroleum reservoir studies. [Perfluorocarbon tracer technology

    Energy Technology Data Exchange (ETDEWEB)

    Senum, G.I.

    1992-09-01

    The objectives of this research program are to: Improve the assessment of the character of petroleum reservoirs using tracer technology for the monitoring and improvement of EOR techniques, specifically, (a) to apply the presently available multitracer perfluorocarbon tracer (PFI) technology to the study of petroleum reservoirs in characterizing reservoir bulk subsurface flow transport and dispersion rates; and (b) to demonstrate that PFTs with differing physical properties will interact with differing rates of adsorption and dispersion within such reservoirs, from which may be inferred difference in the character and/or extent of petroleum in those reservoirs. Develop additional tracers, and tracer injection, sampling and analyses methodologies for use in petroleum reservoir characterization experiments. Develop a data base of petroleum transport and dispersion properties from tracer experiments for use by modellers for developing, validating and extending petroleum reservoirs models used for characterizing petroleum reservoirs. Technical progress is discussed according to the three ongoing field experiments at the Naval Petroleum Reserve in California (NPRC).

  10. Feasibility study of autoignition process in heavy-oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Razaghi, S.; Kharrat, R. [Petroleum Univ. of Technology, Tehran (Iran, Islamic Republic of); Price, D. [Bolton Univ. (United States); Vossoughi, S. [Kansas Univ., KS (United States); Rashtchian, D. [Sharif Univ. of Technology, Tehran (Iran, Islamic Republic of)

    2005-11-01

    In situ combustion involves simultaneous heat and mass transfer in a multi-phase environment coupled with the chemical reactions of crude oil combustion. This study investigated the effect of oxygen content in order to determine optimal auto-ignition conditions for heavy oil reservoirs. Heavy oil samples mixed with silica sand or crushed carbonate rock and clay from southwest Iran were studied using a thermogravimetric analyzer (TGA) and differential scanning calorimeter (DSC) techniques. Non-isothermal experiments were carried out with various oxygen concentrations in the inlet gas. The oxygen concentration was stabilized at a level measured by an oxygen paramagnetic analyzer placed before the gas inlet. Oxygen concentrations in the exhaust gas of the TGA was measured. Another set of experiments showed the clay effect in the presence of silica sand on auto-ignition temperature, and a further set of experiments were conducted to show both carbonate and clay effect on auto-ignition temperatures. The initial reservoir temperature of the reservoir formation type and the percentage of oxygen content were the main parameters of the auto-ignition condition. It was noted that the presence of clay reduced the auto-ignition temperature for both carbonate and silica sand. It was suggested that this could have a major impact on front propagation in the matrix formation. It was concluded that auto-ignition was dependent on the percentage of oxygen in the oxygen-enriched air purge gas for both the silica sand and carbonate rock in the presence of clay. It was also noted that carbonate rock decomposed above 600 degrees C. It was determined that CO{sub 2} evolution observed above 600 degrees C in experiments in which carbonate rock was used as the substrate, was due to rock decomposition and not any residual oil or carbon residue reactions. 12 refs., 4 tabs., 18 figs.

  11. Model-Based Control and Optimization of Large Scale Physical Systems - Challenges in Reservoir Engineering

    NARCIS (Netherlands)

    Van den Hof, P.M.J.; Jansen, J.D.; Van Essen, G.M.; Bosgra, O.H.

    2009-01-01

    Due to urgent needs to increase efficiency in oil recovery from subsurface reservoirs new technology is developed that allows more detailed sensing and actuation of multiphase flow properties in oil reservoirs. One of the examples is the controlled injection of water through injection wells with the

  12. U.S. Army Corps of Engineers (USACE) Owned and Operated Reservoirs

    Data.gov (United States)

    Department of Homeland Security — This dataset shows maximum conservation pool or is a reasonable representation of the boundaries for reservoirs and lakes owned and operated by USACE. Data is from...

  13. Experiments with Interaction between the National Water Model and the Reservoir System Simulation Model: A Case Study of Russian River Basin

    Science.gov (United States)

    Kim, J.; Johnson, L.; Cifelli, R.; Chandra, C. V.; Gochis, D.; McCreight, J. L.; Yates, D. N.; Read, L.; Flowers, T.; Cosgrove, B.

    2017-12-01

    NOAA National Water Center (NWC) in partnership with the National Centers for Environmental Prediction (NCEP), the National Center for Atmospheric Research (NCAR) and other academic partners have produced operational hydrologic predictions for the nation using a new National Water Model (NWM) that is based on the community WRF-Hydro modeling system since the summer of 2016 (Gochis et al., 2015). The NWM produces a variety of hydrologic analysis and prediction products, including gridded fields of soil moisture, snowpack, shallow groundwater levels, inundated area depths, evapotranspiration as well as estimates of river flow and velocity for approximately 2.7 million river reaches. Also included in the NWM are representations for more than 1,200 reservoirs which are linked into the national channel network defined by the USGS NHDPlusv2.0 hydrography dataset. Despite the unprecedented spatial and temporal coverage of the NWM, many known deficiencies exist, including the representation of lakes and reservoirs. This study addresses the implementation of a reservoir assimilation scheme through coupling of a reservoir simulation model to represent the influence of managed flows. We examine the use of the reservoir operations to dynamically update lake/reservoir storage volume states, characterize flow characteristics of river reaches flowing into and out of lakes and reservoirs, and incorporate enhanced reservoir operating rules for the reservoir model options within the NWM. Model experiments focus on a pilot reservoir domain-Lake Mendocino, CA, and its contributing watershed, the East Fork Russian River. This reservoir is modeled using United States Army Corps of Engineers (USACE) HEC-ResSim developed for application to examine forecast informed reservoir operations (FIRO) in the Russian River basin.

  14. Crosswell electromagnetic imaging for geothermal reservoir characterization - a feasibility study

    Science.gov (United States)

    Samrock, Friedemann; Saar, Martin O.

    2016-04-01

    Most regions in the world do not have ready access to natural convective hydrothermal resources. To use deep geothermal heat as a viable energy resource in low-permeability formations, permeable fracture networks have to be created artificially to enable deep fluid circulation for advective heat transport to a production well. Such generation of enhanced geothermal systems (EGS) is studied in the "Deep Underground Geothermal (DUG)" laboratory at the Grimsel pass, Switzerland. Here, an underground experiment is conducted by hydraulically stimulating a pre-existing shear zone within crystalline rock. The objectives of this project are to better describe and understand the processes acting during reservoir generation. We perform a feasibility study to evaluate the capability of low-frequency crosswell electromagnetic (EM) tomography for mapping of stimulation-induced changes in electrical conductivity. First numerical results show that crosswell EM data are generally sensitive to the inter-well conductivity distribution, which is affected by properties such as interconnected porosity, permeability and the presence of fluids. It thereby provides important information for characterization of potential EGS reservoirs. We present a 3-D forward modeling and inversion study using synthetic data and under realistic conditions, these include the true borehole spacing and the observed electromagnetic noise level in the DUG laboratory. Based on these results we discuss the system requirements and the capability of crosswell EM to recover the inter-well structure and stimulation-induced changes. Besides the numerical study we report on the current status of instrumentation and realization of crosswell EM measurements at the DUG laboratory.

  15. Coupling of a reservoir model and of a poro-mechanical model. Application to the study of the compaction of petroleum reservoirs and of the associated subsidence; Couplage d'un modele de gisement et d'un modele mecanique. Application a l'etude de la compaction des reservoirs petroliers et de la subsidence associee

    Energy Technology Data Exchange (ETDEWEB)

    Bevillon, D.

    2000-11-30

    The aim of this study is to provide a better description of the rock contribution to fluid flows in petroleum reservoirs. The production of oil/gas in soft highly compacting reservoirs induces important reduction of the pore volume, which increases oil productivity. This compaction leads to undesirable effects such as surface subsidence or damage of well equipment. Analysis of compaction and subsidence can be performed using either engineering reservoir models or coupled poro-mechanical models. Poro-mechanical model offers a rigorous mechanical framework, but does not permit a complete description of the fluids. The reservoir model gives a good description of the fluid phases, but the description of the mechanic phenomenon is then simplified. To satisfy the set of equations (mechanical equilibrium and diffusivity equations), two simulators can be used together sequentially. Each of the two simulators solves its own system independently, and information passed both directions between simulators. This technique is usually referred to the partially coupled scheme. In this study, reservoir and hydro-mechanical simulations show that reservoir theory is not a rigorous framework to represent the evolution of the high porous rocks strains. Then, we introduce a partially coupled scheme that is shown to be consistent and unconditionally stable, which permits to describe correctly poro-mechanical theory in reservoir models. (author)

  16. Integration of advanced geoscience and engineering techniques to quantify interwell heterogeneity in reservoir models. Final report, September 29, 1993--September 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, W.W.; Buckley, J.S.; Ouenes, A.

    1997-05-01

    The goal of this three-year project was to provide a quantitative definition of reservoir heterogeneity. This objective was accomplished through the integration of geologic, geophysical, and engineering databases into a multi-disciplinary understanding of reservoir architecture and associated fluid-rock and fluid-fluid interactions. This interdisciplinary effort integrated geological and geophysical data with engineering and petrophysical results through reservoir simulation to quantify reservoir architecture and the dynamics of fluid-rock and fluid-fluid interactions. An improved reservoir description allows greater accuracy and confidence during simulation and modeling as steps toward gaining greater recovery efficiency from existing reservoirs. A field laboratory, the Sulimar Queen Unit, was available for the field research. Several members of the PRRC staff participated in the development of improved reservoir description by integration of the field and laboratory data as well as in the development of quantitative reservoir models to aid performance predictions. Subcontractors from Stanford University and the University of Texas at Austin (UT) collaborated in the research and participated in the design and interpretation of field tests. The three-year project was initiated in September 1993 and led to the development and application of various reservoir description methodologies. A new approach for visualizing production data graphically was developed and implemented on the Internet. Using production data and old gamma rays logs, a black oil reservoir model that honors both primary and secondary performance was developed. The old gamma ray logs were used after applying a resealing technique, which was crucial for the success of the project. In addition to the gamma ray logs, the development of the reservoir model benefitted from an inverse Drill Stem Test (DST) technique which provided initial estimates of the reservoir permeability at different wells.

  17. Operational resilience of reservoirs to climate change, agricultural demand, and tourism: A case study from Sardinia.

    Science.gov (United States)

    Mereu, Simone; Sušnik, Janez; Trabucco, Antonio; Daccache, Andre; Vamvakeridou-Lyroudia, Lydia; Renoldi, Stefano; Virdis, Andrea; Savić, Dragan; Assimacopoulos, Dionysis

    2016-02-01

    Many (semi-) arid locations globally, and particularly islands, rely heavily on reservoirs for water supply. Some reservoirs are particularly vulnerable to climate and development changes (e.g. population change, tourist growth, hydropower demands). Irregularities and uncertainties in the fluvial regime associated with climate change and the continuous increase in water demand by different sectors will add new challenges to the management and to the resilience of these reservoirs. The resilience of vulnerable reservoirs must be studied in detail to prepare for and mitigate potential impacts of these changes. In this paper, a reservoir balance model is developed and presented for the Pedra e' Othoni reservoir in Sardinia, Italy, to assess resilience to climate and development changes. The model was first calibrated and validated, then forced with extensive ensemble climate data for representative concentration pathways (RCPs) 4.5 and 8.5, agricultural data, and with four socio-economic development scenarios. Future projections show a reduction in annual reservoir inflow and an increase in demand, mainly in the agricultural sector. Under no scenario is reservoir resilience significantly affected, the reservoir always achieves refill. However, this occurs at the partial expenses of hydropower production with implications for the production of renewable energy. There is also the possibility of conflict between the agricultural sector and hydropower sector for diminishing water supply. Pedra e' Othoni reservoir shows good resilience to future change mostly because of the disproportionately large basin feeding it. However this is not the case of other Sardinian reservoirs and hence a detailed resilience assessment of all reservoirs is needed, where development plans should carefully account for the trade-offs and potential conflicts among sectors. For Sardinia, the option of physical connection between reservoirs is available, as are alternative water supply measures

  18. Statistical study of seismicity associated with geothermal reservoirs in California

    Energy Technology Data Exchange (ETDEWEB)

    Hadley, D.M.; Cavit, D.S.

    1982-01-01

    Statistical methods are outlined to separate spatially, temporally, and magnitude-dependent portions of both the random and non-random components of the seismicity. The methodology employed compares the seismicity distributions with a generalized Poisson distribution. Temporally related events are identified by the distribution of the interoccurrence times. The regions studied to date include the Imperial Valley, Coso, The Geysers, Lassen, and the San Jacinto fault. The spatial characteristics of the random and clustered components of the seismicity are diffuse and appear unsuitable for defining the areal extent of the reservoir. However, from the temporal characteristics of the seismicity associated with these regions a general discriminant was constructed that combines several physical parameters for identifying the presence of a geothermal system.

  19. Twenty years of water-quality studies in the Cheney Reservoir Watershed, Kansas, 1996-2016

    Science.gov (United States)

    Graham, Jennifer L.; Foster, Guy M.; Kramer, Ariele R.

    2017-03-31

    Since 1996, the U.S. Geological Survey (USGS), in cooperation with the City of Wichita, has done studies in the Cheney Reservoir watershed to understand environmental effects on water-quality conditions. Early studies (1996–2001) determined subwatershed sources of contaminants, nutrient and sediment loading to Cheney Reservoir, changes in reservoir sediment quality over time, and watershed sources of phosphorus. Later studies (2001–present) focused on nutrient and sediment concentrations and mass transport from the watershed; the presence of cyanobacteria, cyanotoxins, and taste-and-odor compounds in the reservoir; and development of regression models for real-time computations of water-quality constituents of interest that may affect drinking-water treatment. This fact sheet summarizes key results from studies done by the USGS during 1996–2016 in the Cheney Reservoir watershed and Cheney Reservoir.

  20. Movement of geothermal fluid in the Cerro Prieto field as determined from well log and reservoir engineering data

    Energy Technology Data Exchange (ETDEWEB)

    Halfman, S.E.; Lippmann, M.J.; Zelwer, R.

    1982-01-01

    A hydrogeologic model of the Cerro Prieto geothermal field in its undisturbed state, developed on the basis of well log and reservoir engineering data, is discussed. According to this model, geothermal fluid enters the field from the east through a deep (>10,000 ft) sandstone aquifer which is overlain by a thick shale unit which locally prevents the upward migration of the fluid. As it flows westward, the fluid gradually rises through faults and sandy gaps in the shale unit. Eventually, some of the fluid leaks to the surface in the western part of the field, while the rest mixes with surrounding colder waters.

  1. Study on Dissipation of Landslide Generated Waves in Different Shape of Reservoirs

    Science.gov (United States)

    An, Y.; Liu, Q.

    2017-12-01

    The landslide generated waves are major risks for many reservoirs located in mountainous areas. As the initial wave is often very huge (e.g. 30m of the height in Xiaowan event, 2009, China), the dissipation of the wave, which is closely connected with the shape of the reservoir (e.g. channel type vs. lake type), is a crucial factor in risk estimation and prevention. While even for channel type reservoir, the wave damping also varies a lot due to details of the shape such as branches and turnings. Focusing on the influence of this shape details on the wave damping in channel type reservoir, we numerically studied two landslide generated wave events with both a triangle shape of the cross section but different longitudinal shape configurations (Xiaowan event in 2009 and an assuming event in real topography). The two-dimensional Saint-Venant equation and dry-wet boundary treatment method are used to simulate the wave generation and propagation processes. The simulation is based on an open source code called `Basilisk' and the adaptive mesh refinement technique is used to achieve enough precision with affordable computational resources. The sensitivity of the parameters representing bed drag and the vortex viscosity is discussed. We found that the damping is relatively not sensitive to the bed drag coefficient, which is natural as the water depth is large compared with wave height. While the vortex viscosity needs to be chosen carefully as it is related to cross sectional velocity distribution. It is also found that the longitudinal shape, i.e. the number of turning points and branches, is the key factor influencing the wave damping. The wave height at the far field could be only one seventh comparing with the initial wave in the case with complex longitudinal shape, while the damping is much weaker in the straight channel case. We guess that this phenomenon is due to the increasing sloshing at these abruptly changed positions. This work could provide a deeper

  2. Integrated seismic studies at the Rye Patch Geothermal Reservoir, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Gritto, Roland; Daley, Thomas M.; Majer, Ernest L.

    2002-05-23

    A 3-D surface seismic reflection survey, covering an area of over 3 square miles, was conducted at the Rye Patch geothermal reservoir (Nevada) to explore the structural features that may control geothermal production in the area. In addition to the surface sources and receivers, a high-temperature three-component seismometer was deployed in a borehole at a depth of 3900 ft within the basement below the reservoir, which recorded the waves generated by all surface sources. A total of 1959 first-arrival travel times were determined out of 2134 possible traces. Two-dimensional ray tracing was performed to simulate wave propagation from the surface sources to the receiver at depth. Travel time differences between observed and calculated times were mapped to topographic changes in the elevation of the interface between the carbonate basement and the sedimentary and volcanic unit above. Results indicate the presence of two dominant geologic features. The first confirms the regional trend of the geologic units in the Basin and Range province with a north-south strike and dip to the west, as expected for normal faulting encountered in an extensional regime. The second is a local disturbance of this regional pattern in form of an elevation of the interface between the carbonate basement and the overlying sedimentary sequence, striking east-west. The geometry of the structure is corroborated by results from a seismic-reflection survey, and by results of tomographic studies conducted as part of the seismic survey. Seismic waves, generated from far-offset shots during the 3-D surface survey, exhibit a sudden decrease in amplitudes while propagating across the boundaries of the elevation high. This apparent boundary correlates spatially with the location of the Rye Patch fault as interpreted from the 3-D seismic reflection data. Finite-difference modeling of elastic wave propagation is performed to estimate the structural parameters of the fault. Questions to be answered are

  3. Full Waveform Inversion for Reservoir Characterization - A Synthetic Study

    KAUST Repository

    Zabihi Naeini, E.

    2017-05-26

    Most current reservoir-characterization workflows are based on classic amplitude-variation-with-offset (AVO) inversion techniques. Although these methods have generally served us well over the years, here we examine full-waveform inversion (FWI) as an alternative tool for higher-resolution reservoir characterization. An important step in developing reservoir-oriented FWI is the implementation of facies-based rock physics constraints adapted from the classic methods. We show that such constraints can be incorporated into FWI by adding appropriately designed regularization terms to the objective function. The advantages of the proposed algorithm are demonstrated on both isotropic and VTI (transversely isotropic with a vertical symmetry axis) models with pronounced lateral and vertical heterogeneity. The inversion results are explained using the theoretical radiation patterns produced by perturbations in the medium parameters.

  4. Studies Regarding the Safety in Operation of Ezer Reservoir

    Directory of Open Access Journals (Sweden)

    Balan Isabela

    2014-05-01

    Full Text Available The dam of the non-permanent reservoir Ezer, located on Jijia river is an earth dam with a maximum height of 6.18 m, which provides a global retention to the canopy of 10.330 million cubic meters. The dam founded on weak, muddy soils suffered in the years 1989 and 1992 downstream slope failures of the fillings. It was found that hydrostatic levels were high in the piezometric wells and that consolidation of the foundation soil was reduced. This paper presents a brief history of the dam and aspects regarding the behaviour monitoring of Ezer non-permanent reservoir during the years 2000-2012.

  5. PRELIMINARY RESULTS OF QUALITY STUDY OF WATER FROM SMALL MICHALICE RESERVOIR ON WIDAWA RIVER

    Directory of Open Access Journals (Sweden)

    Mirosław Wiatkowski

    2014-10-01

    Full Text Available The paper presents an analysis of water quality of the small Michalice reservoir. A preliminary assessment of the reservoir water quality and its usability was made. The quality of water in the reservoir is particularly important as the main functions of the reservoir are agricultural irrigation, recreation and flood protection . The following physico-chemical parameters of the Widawa River were analyzed: NO3 -, NO2 -, NH4 +, PO4 3-, COD, water temperature, pH and electrolytic conductivity. Main descriptive statistical data were presented for the analyzed water quality indicators. The research results indicate that the reservoir contributed to the reduced concentrations of the following water quality indicators: nitrates, nitrites, phosphates, electrolytic conductivity and COD (in the outflowing water – St.3 in comparison to the water flowing into the reservoir – St.1. In the water flowing out of the Psurów reservoir higher values of the remaining indicators were observed if compared with the inflowing water. It was stated, as well, that analised waters are not vulnerable to nitrogen compounds pollution coming from the agricultural sources and are eutrophic. For purpose obtaining of the précised information about condition of Michalice reservoir water purity as well as river Widawa it becomes to continue the hydrological monitoring and water quality studies.

  6. Research Note:An approach to integrated assessement of reservoir siltation: the Joaquín Costa reservoir as a case study

    Directory of Open Access Journals (Sweden)

    A. Navas

    2004-01-01

    Full Text Available In 1932, the Esera river was dammed at the foothills of the Pyrenean External Ranges; since then, sedimentation has reduced its water storage capacity by a third. This study of the sediments in the Joaquín Costa reservoir has been based on detailed sedimentological examination and other analysis of mineralogy, grain size distribution and the chemical components of the materials accumulated at the bottom of the reservoir. Interpretations are based on results from four sediment cores collected at sites representative of the main environments in the reservoir. Records of known flood events and of reservoir management data have been combined with a 137Cs-derived chronology. Thus, it has been possible to ascribe the sedimentary record at the different reservoir environments to specific years, as well as some main changes in the facies types and sediment components. This methodology is a first approach to assessing siltation processes and dynamics in Mediterranean mountain reservoirs. Keywords: reservoir siltation, mineralogy, sedimentology,sedimentation rates, 137Cs, sediment tracing, mountain reservoir, central Spanish Pyrenees

  7. CTR plasma engineering studies

    International Nuclear Information System (INIS)

    Miley, G.H.

    1991-01-01

    Ash (e.g. thermalized helium from D-T) buildup in a tokamak can potentially prevent ignition and seriously degrade the fusion energy gain from driven system. This problem is most pronounced as the ratio of particle/energy confinement time increases towards the neoclassical limit. Yet much improved confinement of the fuel ions is desirable for a fusion reactor. The goals of the work described here were two fold: to study the effect of helium buildup on the energy balance for a tokamak, and consider methods of active control that might be employed to alleviate the problem. We examine ash buildup effect for both D-T and D- 3 He systems. Most examples used apply to the ARIES 1 D-T reactor design and to the ARIES 3 D- 3 He design since part of this was in support of these two designs. Then we report on brief studies of two potentially attractive control methods, namely controlled sawtooth and fishbone instabilities. The concept is that sawteeth or fishbones would be used on purpose periodically in order to ''flush'' out excess ash from the fusion core. Both methods are shown to feasible and attractive. More study is needed, however, since the phenomenona in which are physically complex. Still the pay off, namely, reduced ash buildup, is exceedingly important so that such studies desires strong attention

  8. An integrated study of the Grayburg/San Andres reservoir, Foster and South Cowden fields, Ector County, Texas, Class II

    Energy Technology Data Exchange (ETDEWEB)

    Trentham, DGS, Robert C.; Robinson, M.S., William C.; Wider, Kevin; Weinbrandt, Ph.D.,PE, Richard

    2000-04-14

    A project to recover economic amounts of oil from a very mature oil field is being conducted by Laguna Petroleum Corporation of Midland, Texas, with partial funding from a U. S. Department of Energy (DOE) grant to study shallow carbonate rock reservoirs. The objectives of the project are to use modern engineering methods to optimize oil field management and to use geological and geophysical data to recover untapped potential within the petroleum reservoirs. The integration of data and techniques from these disciplines has yielded results greater than those achievable without their cooperation. The cost of successfully accomplishing these goals is to be low enough for even small independent operators to afford. This article is a report describing accomplishments for the fiscal year 1998-1999.

  9. An Integrated Study of the Grayburg/San Andres Reservoir, Foster and South Cowden Fields, Ector County, Texas

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, William C.; Trentham, Robert C.; Widner, Kevin; Wienbrandt, Richard

    1999-06-22

    A project to recover economic amounts of oil from a very mature oil field is being conducted by Laguna Petroleum Corporation of Midland, Texas, with partial funding from a U. S. Department of Energy grant to study shallow carbonate rock reservoirs. The objectives of the project are to use modern engineering methods to optimize oil field management and to use geological and geophysical data to recover untapped potential within the petroleum reservoirs. The integration of data and techniques from these disciplines has yielded results greater than those achievable without their cooperation. The cost of successfully accomplishing these goals is to be low enough for even small independent operators to afford. This article is a report describing accomplishments for the fiscal year 1997-1998.

  10. RESEARCH STUDY ON THE BREEDING AVIFAUNA OF THE BASCOV RESERVOIR

    Directory of Open Access Journals (Sweden)

    Maria Denisa Conete

    2015-12-01

    Full Text Available The author conducted an ornithological study in the Bascov Reservoir area (a square of 2x2 km and observed 102 breeding species; 83 (81% of them are certain breeding species and 19 (19% are probable breeding species. The results of the research were cumulated with those found in the Atlas of the breeding species of Romania. By relating them with the Atlas data, we noted that 83 of the 100 breeding species cited in the Atlas were again recorded during our study. Nineteen new breeding species were identified. Among the species dependent on wetlands, mention should be made of Ixobrychus minutus, Anas platyrhynchos, Fulica atra, Gallinula chloropus, Aythya ferina, etc., with relatively large numbers of individuals. The analysis showed a relatively larger number (66 of euconstant and constant species, which confirmed the wealth of food resources in the area during the nesting period. The specific richness on the Bascov Lake is represented by 119 species, a number that is consistent with the availability of the food resources and nesting places, as well as the somewhat fluctuating presence of predators (stray dogs, and the anthropocentric disturbance (sound and chemical pollution, etc.. The yearly increase in the number of reed clusters, the expansion of the surface of the islets, the emergence of bushes and trees, the ageing of the existing trees have led to a certain yearly increase in the number of breeding individuals in 45 species. But the anthropogenic influence in the area has eventually contributed to a decrease in the number of birds, both as a number of species and as a number of individuals. The study has also shown that in the farmland bird species the number of individuals is in decline. Most of the breeding species - 75 (representing 74% in the area under research are migratory. Eighteen breeding species (17.64% are listed in Annex I of the Birds Directive. The presence of the key breeding species in the area under research must be

  11. Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams.

    Directory of Open Access Journals (Sweden)

    Mohammad Heydari

    Full Text Available Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam's location (Series and parallel, conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands.

  12. Optimization of Multiple and Multipurpose Reservoir System Operations by Using Matrix Structure (Case Study: Karun and Dez Reservoir Dams).

    Science.gov (United States)

    Heydari, Mohammad; Othman, Faridah; Taghieh, Mahmood

    2016-01-01

    Optimal operation of water resources in multiple and multipurpose reservoirs is very complicated. This is because of the number of dams, each dam's location (Series and parallel), conflict in objectives and the stochastic nature of the inflow of water in the system. In this paper, performance optimization of the system of Karun and Dez reservoir dams have been studied and investigated with the purposes of hydroelectric energy generation and providing water demand in 6 dams. On the Karun River, 5 dams have been built in the series arrangements, and the Dez dam has been built parallel to those 5 dams. One of the main achievements in this research is the implementation of the structure of production of hydroelectric energy as a function of matrix in MATLAB software. The results show that the role of objective function structure for generating hydroelectric energy in weighting method algorithm is more important than water supply. Nonetheless by implementing ε- constraint method algorithm, we can both increase hydroelectric power generation and supply around 85% of agricultural and industrial demands.

  13. Quantum reservoir engineering through quadratic optomechanical interaction in the reversed dissipation regime

    Science.gov (United States)

    Lee, Jae Hoon; Seok, H.

    2018-01-01

    We explore an electromagnetic field coupled to a mechanical resonator via quadratic optomechanical interaction in the reversed dissipation regime where the mechanical damping rate is much higher than the cavity-field dissipation rate. It is shown that in this regime, the cavity field effectively acquires an additional reservoir which is conditioned by the temperature of the mechanical bath as well as the mechanical damping rate. We analytically find the steady-state mean photon number and the critical temperature of the mechanical oscillator to cool or heat the coupled electromagnetic field. We also show that in the case of quadratic coupling, the temperature of the mechanical oscillator can be estimated in the quantum regime by observing the noise spectrum of the cavity field.

  14. Thermal mapping studies at Kadra reservoir near Kaiga generating station site

    International Nuclear Information System (INIS)

    Ravi, P.M.; Nayak, P.D.; Sudhakar, J.; Mishra, D.G.; Hegde, A.G.

    2007-01-01

    An inherent problem in nuclear and thermal power plants are the release of heat energy into the environment through cooling system to water bodies such as lakes, rivers, estuaries and oceans. Two NPPs of Kaiga Generating Station, discharge the thermal effluent to the nearby Kadra reservoir. This paper presents the results of three year long comprehensive thermal mapping studies conducted by ESL, KGS as part of the Thermal Ecological Studies sponsored by Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy. Present studies clearly demonstrate that the thermally influenced zone in the reservoir is limited to a small volume of the reservoir and is not likely to lead any irreversible adverse impact on the ecosystem of the reservoir. (author)

  15. Estimating irrigation water demand using an improved method and optimizing reservoir operation for water supply and hydropower generation: a case study of the Xinfengjiang reservoir in southern China

    Science.gov (United States)

    Wu, Yiping; Chen, Ji

    2013-01-01

    The ever-increasing demand for water due to growth of population and socioeconomic development in the past several decades has posed a worldwide threat to water supply security and to the environmental health of rivers. This study aims to derive reservoir operating rules through establishing a multi-objective optimization model for the Xinfengjiang (XFJ) reservoir in the East River Basin in southern China to minimize water supply deficit and maximize hydropower generation. Additionally, to enhance the estimation of irrigation water demand from the downstream agricultural area of the XFJ reservoir, a conventional method for calculating crop water demand is improved using hydrological model simulation results. Although the optimal reservoir operating rules are derived for the XFJ reservoir with three priority scenarios (water supply only, hydropower generation only, and equal priority), the river environmental health is set as the basic demand no matter which scenario is adopted. The results show that the new rules derived under the three scenarios can improve the reservoir operation for both water supply and hydropower generation when comparing to the historical performance. Moreover, these alternative reservoir operating policies provide the flexibility for the reservoir authority to choose the most appropriate one. Although changing the current operating rules may influence its hydropower-oriented functions, the new rules can be significant to cope with the increasingly prominent water shortage and degradation in the aquatic environment. Overall, our results and methods (improved estimation of irrigation water demand and formulation of the reservoir optimization model) can be useful for local watershed managers and valuable for other researchers worldwide.

  16. Play Analysis and Digital Portfolio of Major Oil Reservoirs in the Permian Basin: Application and Transfer of Advanced Geological and Engineering Technologies for Incremental Production Opportunities

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; Caroline L. Breton; William D. Raatz; Stephen C. Ruppel; Charles Kerans

    2004-01-13

    A play portfolio is being constructed for the Permian Basin in west Texas and southeast New Mexico, the largest onshore petroleum-producing basin in the United States. Approximately 1,300 reservoirs in the Permian Basin have been identified as having cumulative production greater than 1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of oil through 2000. Of these significant-sized reservoirs, approximately 1,000 are in Texas and 300 in New Mexico. There are 32 geologic plays that have been defined for Permian Basin oil reservoirs, and each of the 1,300 major reservoirs was assigned to a play. The reservoirs were mapped and compiled in a Geographic Information System (GIS) by play. The final reservoir shapefile for each play contains the geographic location of each reservoir. Associated reservoir information within the linked data tables includes RRC reservoir number and district (Texas only), official field and reservoir name, year reservoir was discovered, depth to top of the reservoir, production in 2000, and cumulative production through 2000. Some tables also list subplays. Play boundaries were drawn for each play; the boundaries include areas where fields in that play occur but are smaller than 1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of cumulative production. Oil production from the reservoirs in the Permian Basin having cumulative production of >1 MMbbl (1.59 x 10{sup 5} m{sup 3}) was 301.4 MMbbl (4.79 x 10{sup 7} m{sup 3}) in 2000. Cumulative Permian Basin production through 2000 was 28.9 Bbbl (4.59 x 10{sup 9} m{sup 3}). The top four plays in cumulative production are the Northwest Shelf San Andres Platform Carbonate play (3.97 Bbbl [6.31 x 10{sup 8} m{sup 3}]), the Leonard Restricted Platform Carbonate play (3.30 Bbbl [5.25 x 10{sup 8} m{sup 3}]), the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play (2.70 Bbbl [4.29 x 10{sup 8} m{sup 3}]), and the San Andres Platform Carbonate play (2.15 Bbbl [3.42 x 10{sup 8} m{sup 3}]). Detailed studies of three reservoirs

  17. Study on the enhancement of hydrocarbon recovery by characterization of the reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Tae-Jin; Kwak, Young-Hoon; Huh, Dae-Gee [Korea Institute of Geology Mining and Materials, Taejon (KR)] (and others)

    1999-12-01

    The reservoir geochemistry is to understand the origin of these heterogeneities and distributions of the bitumens within the reservoir and to use them not only for exploration but for the development of the petroleums. Methods and principles of the reservoir geochemistry, which are applicable to the petroleum exploration and development, are reviewed in the study. In addition, a case study was carried out on the gas, condensate, water and bitumen samples in the reservoir, taken from the Haenam, Pohang areas and the Ulleung Basin offshore Korea. Mineral geothermometers were studied to estimate the thermal history in sedimentary basins and successfully applied to the Korean onshore and offshore basins. The opal silica-to-quartz transformation was investigated in the Pohang basin as a geothermometer. In Korean basins, the smectite-to-illite changes indicate that smectite and illite can act as the geothermometer to estimate the thermal history of the basins. The albitization reaction was also considered as a temperature indicator. Naturally fractured reservoir is an important source of oil and gas throughout the world. The properties of matrix and fracture are the key parameters in predicting the performances of naturally fractured reservoirs. A new laboratory equipment has been designed and constructed by pressure pulse method to determine the properties, which are (1) the porosity of matrix, (2) the permeability of matrix, (3) the effective width of the fractures, and the permeability of the fractures. (author). 97 refs.

  18. CO2 storage in depleted gas reservoirs: A study on the effect of residual gas saturation

    Directory of Open Access Journals (Sweden)

    Arshad Raza

    2018-03-01

    Full Text Available Depleted gas reservoirs are recognized as the most promising candidate for carbon dioxide storage. Primary gas production followed by injection of carbon dioxide after depletion is the strategy adopted for secondary gas recovery and storage practices. This strategy, however, depends on the injection strategy, reservoir characteristics and operational parameters. There have been many studies to-date discussing critical factors influencing the storage performance in depleted gas reservoirs while little attention was given to the effect of residual gas. In this paper, an attempt was made to highlight the importance of residual gas on the capacity, injectivity, reservoir pressurization, and trapping mechanisms of storage sites through the use of numerical simulation. The results obtained indicated that the storage performance is proportionally linked to the amount of residual gas in the medium and reservoirs with low residual fluids are a better choice for storage purposes. Therefore, it would be wise to perform the secondary recovery before storage in order to have the least amount of residual gas in the medium. Although the results of this study are useful to screen depleted gas reservoirs for the storage purpose, more studies are required to confirm the finding presented in this paper.

  19. Experimental studies of low salinity water flooding in carbonate reservoirs: A new promising approach

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Skauge, Arne

    2012-01-01

    Low salinity water flooding is well studied for sandstone reservoirs, both laboratory and field tests have showed improvement in the oil recovery in many cases. Up to very recently, the low salinity effect has been indeterminated for carbonates. Most recently, Saudi Aramco reported that substantial...... reservoirs. In this paper, we have experimentally investigated the oil recovery potential of low salinity water flooding for carbonate rocks. We used both reservoir carbonate and outcrop chalk core plugs. The flooding experiments were carried out initially with the seawater, and afterwards additional oil...... both at ambient and high temperature. No low salinity effect was observed for the reservoir carbonate core plug at the ambient temperature, but increase of the pressure drop over the core plug was detected. On the contrary, a significant increase in oil recovery was observed under low salinity flooding...

  20. New Approach for Evaluation of a Watershed Ecosystem Service for Avoiding Reservoir Sedimentation and Its Economic Value: A Case Study from Ertan Reservoir in Yalong River, China

    Directory of Open Access Journals (Sweden)

    Bilige Sude

    2011-01-01

    Full Text Available A model was established to simulate an ecosystem service of avoiding reservoir sedimentation and its economic value based on the process of sediment delivery in a watershed. The model included fabricating the watershed of the study reservoir. The sediment retention coefficient of different land cover types were used to simulate the spatial patterns of the annual quantity of the sediment that were prevented from entering the reservoir by the vegetation in each cell followed the flow path in watershed. The economic value of the ecosystem service in this model was determined by the marginal cost of reservoir desilting. This study took the Ertan reservoir as an example. The results showed that most eroded soil was intercepted by different types of ecosystems in the process of sediment delivery in a watershed. The region with a higher quantity of sediment retention was around the reservoir. The absolute quantity of average sediment retention in forestland was lower, so the sediment retention ability of forestland failed to be brought into fullest play in watershed.

  1. Analysis of real-time reservoir monitoring : reservoirs, strategies, & modeling.

    Energy Technology Data Exchange (ETDEWEB)

    Mani, Seethambal S.; van Bloemen Waanders, Bart Gustaaf; Cooper, Scott Patrick; Jakaboski, Blake Elaine; Normann, Randy Allen; Jennings, Jim (University of Texas at Austin, Austin, TX); Gilbert, Bob (University of Texas at Austin, Austin, TX); Lake, Larry W. (University of Texas at Austin, Austin, TX); Weiss, Chester Joseph; Lorenz, John Clay; Elbring, Gregory Jay; Wheeler, Mary Fanett (University of Texas at Austin, Austin, TX); Thomas, Sunil G. (University of Texas at Austin, Austin, TX); Rightley, Michael J.; Rodriguez, Adolfo (University of Texas at Austin, Austin, TX); Klie, Hector (University of Texas at Austin, Austin, TX); Banchs, Rafael (University of Texas at Austin, Austin, TX); Nunez, Emilio J. (University of Texas at Austin, Austin, TX); Jablonowski, Chris (University of Texas at Austin, Austin, TX)

    2006-11-01

    The project objective was to detail better ways to assess and exploit intelligent oil and gas field information through improved modeling, sensor technology, and process control to increase ultimate recovery of domestic hydrocarbons. To meet this objective we investigated the use of permanent downhole sensors systems (Smart Wells) whose data is fed real-time into computational reservoir models that are integrated with optimized production control systems. The project utilized a three-pronged approach (1) a value of information analysis to address the economic advantages, (2) reservoir simulation modeling and control optimization to prove the capability, and (3) evaluation of new generation sensor packaging to survive the borehole environment for long periods of time. The Value of Information (VOI) decision tree method was developed and used to assess the economic advantage of using the proposed technology; the VOI demonstrated the increased subsurface resolution through additional sensor data. Our findings show that the VOI studies are a practical means of ascertaining the value associated with a technology, in this case application of sensors to production. The procedure acknowledges the uncertainty in predictions but nevertheless assigns monetary value to the predictions. The best aspect of the procedure is that it builds consensus within interdisciplinary teams The reservoir simulation and modeling aspect of the project was developed to show the capability of exploiting sensor information both for reservoir characterization and to optimize control of the production system. Our findings indicate history matching is improved as more information is added to the objective function, clearly indicating that sensor information can help in reducing the uncertainty associated with reservoir characterization. Additional findings and approaches used are described in detail within the report. The next generation sensors aspect of the project evaluated sensors and packaging

  2. Bibliography of U.S. Geological Survey studies of lakes and reservoirs; the first 100 years

    Science.gov (United States)

    Winter, Thomas C.

    1982-01-01

    For more than 100 years, the U.S. Geological Survey has pursued its mission of assessing and mapping the earth resources of the United States, including assessment of the Nation's water resources. Although the Survey has never been a water-management or development agency, it has assisted agencies that are responsible for such developments, and commonly provides data and information for such purposes. Because reservoirs are an intergral part of most water-development projects, the Survey has been involved in reservoir-related studies since the 1880's. The largest and longest involvement has centered on providing information on streamflows and sediment transport related to existing and proposed reservoirs. During the late 1940's, the Survey greatly expanded its activities in evaporation research. More recently, ground water, including bank storage, has gained increased attention. Most of these studies were related primarily to questions of water quantity, and the Survey continues to be involved in studies of physical hydrology. In addition, in response to the increased concern with environmental quality during the past 20 years, the number of Survey studies of the chemical and biological aspects of lakes and reservoirs have increased considerably. Prompted by the recent Centennial (1879-1979) of the U.S. Geological Survey, it is appropriate to assess the Survey's contributions to the hydrology of lakes and reservoirs. Both natural lakes and manmade reservoirs are included in this report. 1 This report includes studies in which lakes or reservoirs are the principal topics. It does not include reports of general water resources of an area in which lakes are discussed as part of that area. This report also does not include data reports in which the data are merely tabulated. The types of reports listed herein include studies of existing or proposed water bodies and associated fluxes of water to and from these water bodies. This report does not include geological or

  3. A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

    Directory of Open Access Journals (Sweden)

    Iskahar

    2018-01-01

    Full Text Available Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

  4. A Study of Sedimentation at the River Estuary on the Change of Reservoir Storage

    Science.gov (United States)

    Iskahar; Suripin; Isdiyana

    2018-02-01

    Estuary of the river that leads to the reservoir has characteristics include: relatively flat, there is a change in the increase of wet cross-sectional area and backwater. The backwater will cause the flow velocity to be reduced, so that the grains of sediment with a certain diameter carried by the flow will settle in the estuary of the river. The purpose of this research is to know the distribution and sedimentation pattern at the river estuary that leads to the reservoir with the change of water level in the reservoir storage, so the solution can be found to remove / reduce sediment before entering the reservoir. The method used is the experimental, by making the physical model of the river estuary leading to the reservoir. This study expects a solution to reduce sedimentation, so that sedimentation can be removed / minimized before entering the reservoir. This research tries to apply bypass channel to reduce the sedimentation at the river estuary. Bypass channels can be applied to overcome sedimentation at the river estuary, but in order for the sediment to be removed optimally, it is necessary to modify the mouth of bypass channel and channel angle.

  5. Protein Engineering: Case Studies of Commercialized Engineered Products

    Science.gov (United States)

    Walsh, Gary

    2007-01-01

    Programs in biochemistry invariably encompass the principles of protein engineering. Students often display increased understanding and enthusiasm when theoretical concepts are underpinned by practical example. Herein are presented five case studies, each focusing upon a commercial protein product engineered to enhance its application-relevant…

  6. Environmental-impact assessment of dams and reservoir projects (review and a case study)

    International Nuclear Information System (INIS)

    Shah, S.M.

    2009-01-01

    Dams and reservoirs are among one of the most sensitive of all development Project, in terms of pervasiveness of their influence in altering the environmental conditions and resources. In the present study, major dams and reservoir projects are reviewed, from the environmental point of view. Dams and Reservoir projects bring about major changes in the immediate environment, thus affecting public health, settlements, farmlands, roads and historical sites. Impacts on human population and wildlife may be profound. Tropical diseases, involving fresh-water hosts or vectors in their transmission, are often common around new reservoirs. Large lakes create limnological changes, excessive evaporation, seepage, disturbance in water-table and increased tendencies of landslides and earthquakes. Micro climatic changes are possible, such as fog formation, increased cloudiness and modified rainfall-patterns. Retention of sediment results in silting up of reservoirs. Water shortages on mountain rivers may leave unsightly dry river-beds below a dam. Sediment deposition and growth of vegetation in reservoir affects the water-extraction for navigation power-generation and fishing. Various dams and reservoir projects in the world are critically studied, in terms of creating environmental impacts. The Kala Bagh Dam project (Pakistan), which is ready for construction, has been analysed as a case study, by matrix method. Analyses show that adverse effects of this dam are less than the benefits. It is recommended that based on the experience, appropriate lines and strategies may be drawn up to evaluate the local projects. Multidisciplinary experts need to be involved, for assessing environmental impacts and suggesting mitigation measures, to combat the adverse effects. (author)

  7. PLAY ANALYSIS AND DIGITAL PORTFOLIO OF MAJOR OIL RESERVOIRS IN THE PERMIAN BASIN: APPLICATION AND TRANSFER OF ADVANCED GEOLOGICAL AND ENGINEERING TECHNOLOGIES FOR INCREMENTAL PRODUCTION OPPORTUNITIES

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; William Raatz; Cari Breton; Stephen C. Ruppel; Charles Kerans; Mark H. Holtz

    2003-04-01

    A play portfolio is being constructed for the Permian Basin in west Texas and southeast New Mexico, the largest petroleum-producing basin in the US. Approximately 1300 reservoirs in the Permian Basin have been identified as having cumulative production greater than 1 MMbbl of oil through 2000. Of these major reservoirs, approximately 1,000 are in Texas and 300 in New Mexico. On a preliminary basis, 32 geologic plays have been defined for Permian Basin oil reservoirs and assignment of each of the 1300 major reservoirs to a play has begun. The reservoirs are being mapped and compiled in a Geographic Information System (GIS) by play. Detailed studies of three reservoirs are in progress: Kelly-Snyder (SACROC unit) in the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play, Fullerton in the Leonardian Restricted Platform Carbonate play, and Barnhart (Ellenburger) in the Ellenburger Selectively Dolomitized Ramp Carbonate play. For each of these detailed reservoir studies, technologies for further, economically viable exploitation are being investigated.

  8. NASA Software Engineering Benchmarking Study

    Science.gov (United States)

    Rarick, Heather L.; Godfrey, Sara H.; Kelly, John C.; Crumbley, Robert T.; Wifl, Joel M.

    2013-01-01

    To identify best practices for the improvement of software engineering on projects, NASA's Offices of Chief Engineer (OCE) and Safety and Mission Assurance (OSMA) formed a team led by Heather Rarick and Sally Godfrey to conduct this benchmarking study. The primary goals of the study are to identify best practices that: Improve the management and technical development of software intensive systems; Have a track record of successful deployment by aerospace industries, universities [including research and development (R&D) laboratories], and defense services, as well as NASA's own component Centers; and Identify candidate solutions for NASA's software issues. Beginning in the late fall of 2010, focus topics were chosen and interview questions were developed, based on the NASA top software challenges. Between February 2011 and November 2011, the Benchmark Team interviewed a total of 18 organizations, consisting of five NASA Centers, five industry organizations, four defense services organizations, and four university or university R and D laboratory organizations. A software assurance representative also participated in each of the interviews to focus on assurance and software safety best practices. Interviewees provided a wealth of information on each topic area that included: software policy, software acquisition, software assurance, testing, training, maintaining rigor in small projects, metrics, and use of the Capability Maturity Model Integration (CMMI) framework, as well as a number of special topics that came up in the discussions. NASA's software engineering practices compared favorably with the external organizations in most benchmark areas, but in every topic, there were ways in which NASA could improve its practices. Compared to defense services organizations and some of the industry organizations, one of NASA's notable weaknesses involved communication with contractors regarding its policies and requirements for acquired software. One of NASA's strengths

  9. Monitoring of endangered Roanoke logperch (Percina rex) in Smith River upstream from the Philpott Reservoir on U.S. Army Corps of Engineers property near Martinsville, Virginia

    Science.gov (United States)

    Roberts, James H.; Angermeier, Paul L.

    2012-01-01

    The purpose of this study was to continue annual monitoring of Roanoke logperch (Percina rex), an endangered fish, in the Smith River immediately upstream from Philpott Reservoir. This river reach is owned by the U.S. Army Corps of Engineers (USACE), which must ensure that appropriate actions are undertaken to aid in recovery of logperch. Monitoring of fish abundance and habitat conditions provides a means for assessing the species’ status and its responses to USACE management actions. The Roanoke logperch is a large darter (Percidae: Etheostomatinae) endemic to the Roanoke, Dan, and Nottoway River basins of Virginia and North Carolina, where it occupies third- to sixth-order streams containing relatively silt-free substrate (Jenkins and Burkhead, 1994). Because of its rarity, small range, and vulnerability to siltation, the Roanoke logperch was listed in 1989 as endangered under the U.S. Endangered Species Act (ESA) (U.S. Federal Register 54:34468-34472). Within the Dan basin, Roanoke logperch have long been known to occupy the Smith River and one of its largest tributaries, Town Creek (Jenkins and Burkhead, 1994). Logperch also recently were discovered in other tributaries of the Dan River, including North Carolina segments of the Mayo River, Cascade Creek, Big Beaver Island Creek, Wolf Island Creek (William Hester, U.S. Fish and Wildlife Service, personal commun., 2012). Within the Smith River, Roanoke logperch are present both upstream and downstream from Philpott Reservoir, a hydroelectric and water storage project owned and operated by the USACE. Although logperch have not been observed in the reservoir itself, the species is relatively abundant in a free-flowing, ≈ 2.5-km-long segment of Smith River upstream from the reservoir on USACE property (Lahey and Angermeier, 2006). This segment is bounded on the downstream end by the lentic conditions of the reservoir and on the upstream end by White Falls, a natural waterfall that presumably allows fish passage

  10. Fracture density determination using a novel hybrid computational scheme: a case study on an Iranian Marun oil field reservoir

    International Nuclear Information System (INIS)

    Nouri-Taleghani, Morteza; Mahmoudifar, Mehrzad; Shokrollahi, Amin; Tatar, Afshin; Karimi-Khaledi, Mina

    2015-01-01

    Most oil production all over the world is from carbonated reservoirs. Carbonate reservoirs are abundant in the Middle East, the Gulf of Mexico and in other major petroleum fields that are regarded as the main oil producers. Due to the nature of such reservoirs that are associated with low matrix permeability, the fracture is the key parameter that governs the fluid flow in porous media and consequently oil production. Conventional methods to determine the fracture density include utilizing core data and the image log family, which are both time consuming and costly processes. In addition, the cores are limited to certain intervals and there is no image log for the well drilled before the introduction of this tool. These limitations motivate petroleum engineers to try to find appropriate alternatives. Recently, intelligent systems on the basis of machine learning have been applied to various branches of science and engineering. The objective of this study is to develop a mathematical model to predict the fracture density using full set log data as inputs based on a combination of three intelligent systems namely, the radial basis function neural network, the multilayer perceptron neural network and the least square supported vector machine. The developed committee machine intelligent system (CMIS) is the weighted average of the individual results of each expert. Proper corresponding weights are determined using a genetic algorithm (GA). The other important feature of the proposed model is its generalization capability. The ability of this model to predict data that have not been introduced during the training stage is very good. (paper)

  11. INTEGRATED OUTCROP AND SUBSURFACE STUDIES OF THE INTERWELL ENVIRONMENT OF CARBONATE RESERVOIRS: CLEAR FORK (LEONARDIAN-AGE) RESERVOIRS, WEST TEXAS AND NEW MEXICO

    Energy Technology Data Exchange (ETDEWEB)

    F. Jerry Lucia

    2002-01-31

    This is the final report of the project ''Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonardian-Age) Reservoirs, West Texas and New Mexico'', Department of Energy contract no. DE-AC26-98BC15105 and is the third in a series of similar projects funded jointly by the U.S. Department of Energy and The University of Texas at Austin, Bureau of Economic Geology, Reservoir Characterization Research Laboratory for Carbonates. All three projects focus on the integration of outcrop and subsurface data for the purpose of developing improved methods for modeling petrophysical properties in the interwell environment. The first project, funded by contract no. DE-AC22-89BC14470, was a study of San Andres outcrops in the Algerita Escarpment, Guadalupe Mountains, Texas and New Mexico, and the Seminole San Andres reservoir, Permian Basin. This study established the basic concepts for constructing a reservoir model using sequence-stratigraphic principles and rock-fabric, petrophysical relationships. The second project, funded by contract no. DE-AC22-93BC14895, was a study of Grayburg outcrops in the Brokeoff Mountains, New Mexico, and the South Cowden Grayburg reservoir, Permian Basin. This study developed a sequence-stratigraphic succession for the Grayburg and improved methods for locating remaining hydrocarbons in carbonate ramp reservoirs. The current study is of the Clear Fork Group in Apache Canyon, Sierra Diablo Mountains, West Texas, and the South Wasson Clear Fork reservoir, Permian Basin. The focus was on scales of heterogeneity, imaging high- and low-permeability layers, and the impact of fractures on reservoir performance. In this study (1) the Clear Fork cycle stratigraphy is defined, (2) important scales of petrophysical variability are confirmed, (3) a unique rock-fabric, petrophysical relationship is defined, (4) a porosity method for correlating high-frequency cycles and defining rock

  12. Study on the enhancement of hydrocarbon recovery by characterization of the reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Young Hoon; Son, Jin Dam; Oh, Jae Ho [Korea Institute of Geology Mining and Materials, Taejon (Korea)] [and others

    1998-12-01

    Three year project is being carried out on the enhancement of hydrocarbon recovery by the reservoir characterization. This report describes the results of the second year's work. This project deals with characterization of fluids, bitumen ad rock matrix in the reservoir. New equipment and analytical solutions for naturally fractured reservoir were also included in this study. Main purpose of the reservoir geochemistry is to understand the origin of fluids (gas, petroleum and water) and distribution of the bitumens within the reservoir and to use them not only for exploration but development of the petroleum. For the theme of reservoir geochemistry, methods and principles of the reservoir gas and bitumen characterization, which is applicable to the petroleum development, are studied. and case study was carried out on the gas, water and bitumen samples in the reservoir taken form Haenam area and Ulleung Basin offshore Korea. Gases taken form the two different wells indicate the different origin. Formation water analyses show the absence of barrier within the tested interval. With the sidewall core samples from a well offshore Korea, the analysis using polarizing microscope, scanning electron microscope with EDX and cathodoluminoscope was performed for the study on sandstone diagenesis. The I/S changes were examined on the cuttings samples from a well, offshore Korea to estimate burial temperature. Oxygen stable isotope is used to study geothermal history in sedimentary basin. Study in the field is rare in Korea and basic data are urgently needed especially in continental basins to determine the value of formation water. In the test analyses, three samples from marine basins indicate final temperature from 55 deg.C to 83 deg.C and one marine sample indicate the initial temperature of 36 deg.C. One sample from continental basin represented the final temperature from 53 and 80 deg.C. These temperatures will be corrected because these values were based on assumed

  13. Study on fine geological modelling of the fluvial sandstone reservoir in Daqing oilfield

    Energy Technology Data Exchange (ETDEWEB)

    Zhoa Han-Qing [Daqing Research Institute, Helongjiang (China)

    1997-08-01

    These paper aims at developing a method for fine reservoir description in maturing oilfields by using close spaced well logging data. The main productive reservoirs in Daqing oilfield is a set of large fluvial-deltaic deposits in the Songliao Lake Basin, characterized by multi-layers and serious heterogeneities. Various fluvial channel sandstone reservoirs cover a fairly important proportion of reserves. After a long period of water flooding, most of them have turned into high water cut layers, but there are considerable residual reserves within them, which are difficult to find and tap. Making fine reservoir description and developing sound a geological model is essential for tapping residual oil and enhancing oil recovery. The principal reason for relative lower precision of predicting model developed by using geostatistics is incomplete recognition of complex distribution of fluvial reservoirs and their internal architecture`s. Tasking advantage of limited outcrop data from other regions (suppose no outcrop data available in oilfield) can only provide the knowledge of subtle changing of reservoir parameters and internal architecture. For the specific geometry distribution and internal architecture of subsurface reservoirs (such as in produced regions) can be gained only from continuous infilling logging well data available from studied areas. For developing a geological model, we think the first important thing is to characterize sandbodies geometries and their general architecture`s, which are the framework of models, and then the slight changing of interwell parameters and internal architecture`s, which are the contents and cells of the model. An excellent model should possess both of them, but the geometry is the key to model, because it controls the contents and cells distribution within a model.

  14. Application of integrated reservoir management and reservoir characterization to optimize infill drilling

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This project has used a multi-disciplinary approach employing geology, geophysics, and engineering to conduct advanced reservoir characterization and management activities to design and implement an optimized infill drilling program at the North Robertson (Clearfork) Unit in Gaines County, Texas. The activities during the first Budget Period consisted of developing an integrated reservoir description from geological, engineering, and geostatistical studies, and using this description for reservoir flow simulation. Specific reservoir management activities were identified and tested. The geologically targeted infill drilling program currently being implemented is a result of this work. A significant contribution of this project is to demonstrate the use of cost-effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability shallow-shelf carbonate (SSC) reservoirs. The techniques that are outlined for the formulation of an integrated reservoir description apply to all oil and gas reservoirs, but are specifically tailored for use in the heterogeneous, low permeability carbonate reservoirs of West Texas.

  15. [Ribosome engineering of streptomyces sp. FJ3 from Three Gorges reservoir area and metabolic product of the selected mutant strain].

    Science.gov (United States)

    Hai, Le; Huang, Yuqi; Liao, Guojian; Hu, Changhua

    2011-07-01

    To explore new resource from inactive actinomycete strains, we screened resistant mutant strains by ribosome engineering, and analyzed the products derived from the selected mutant strains. Three Gorges reservoir area-derived actinomycete strains including BD20, FJ3, WZ20 and FJ5 were used as initial strains, which showed no-antibacterial activities. The streptomycin-resistant (str(R)) mutants and rifampicin-resistant (rif(R)) mutants were screened by single colony isolation on streptomycin-containing plates and rifampicin-containing plates according to the method for obtaining drug-resistant mutants in ribosome engineering. The four initial strains and their str(R)-mutants and rif(R)-mutants were fermented in a liquid medium with the same composition. Mutants with anti-Staphylococcus aureus activity were obtained by paper chromatography. The components of fermentation broth were analyzed by high performance liquid chromatography (HPLC) and high performance liquid chromatography-mass spectrometry (LC-MS). Furthermore, FJ3 strain was identified by 16S rDNA and morphology. The minimal inhibitory concentration (MIC) of streptomycin and rifampicin for FJ3 was: 0.5 microg/mL and 110 microg/mL, respectively. Twenty-four strR-mutant strains and 20 rif(R)-mutant strains of FJ3 mutant strains were selected for bioassay. The result of the antibacterial activity screening demonstrated that six strains inhibited bacteria. Two strains (FJ3-2 and FJ3-6) were screened from the streptomycin-resistance mutants of inactive strain FJ3. The result of bioassay showed that the fermentation broth of FJ3-2 and FJ3-6 exhibited obvious anti-Staphylococcus aureus activity. The assay of paper chromatography showed that the active substance may be nucleic acid class antibiotic via using solvent system Doskochilova. Moreover, the results of HPLC and LC-MS exhibited that this substance may be thiolutin. Ribosome engineering for changing the secondary metabolic function of the inactive wild

  16. Experimental studies of low salinity water flooding in carbonate reservoirs: A new promising approach

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Skauge, Arne

    2012-01-01

    reservoirs. In this paper, we have experimentally investigated the oil recovery potential of low salinity water flooding for carbonate rocks. We used both reservoir carbonate and outcrop chalk core plugs. The flooding experiments were carried out initially with the seawater, and afterwards additional oil......Low salinity water flooding is well studied for sandstone reservoirs, both laboratory and field tests have showed improvement in the oil recovery in many cases. Up to very recently, the low salinity effect has been indeterminated for carbonates. Most recently, Saudi Aramco reported that substantial...... recovery was evaluated by sequential injection of various diluted seawater. The experiments applied stepwise increase in flow rate to eliminate the influence of possible capillary end effect. The total oil recovery, interaction of the different ions with the rock, and the wettability changes were studied...

  17. An experimental study of tracers for labelling of injection gas in oil reservoirs

    International Nuclear Information System (INIS)

    Dugstad, Oe.

    1992-01-01

    This work demonstrates the feasibility of the PMCP and PMCH as tracers in field experiments. These compounds have properties which make them as well suited for well to well studies as the more common tracers CH 3 T and 85 Kr. In an injection project carried out at the Gullfaks field in the North Sea the two PFCs verified communication between wells. This implies communication between different geological layers in the reservoir and also communication across faults within the same layers. Laboratory studies carried out have focused on the retention of the tracers in dynamic flooding experiments under conditions comparable with those in the petroleum reservoirs. Simultaneous injection of a variety of tracers has shown individual variations in tracer retention which are caused by important reservoir parameters as fluid saturation and rock properties. By proper design of field injection programs the tracers response may therefore be used to estimate fluid saturation if actual rock properties are known. 45 refs., 20 figs., 13 tabs

  18. Trophic State Evolution and Nutrient Trapping Capacity in a Transboundary Subtropical Reservoir: A 25-Year Study

    Science.gov (United States)

    Cunha, Davi Gasparini Fernandes; Benassi, Simone Frederigi; de Falco, Patrícia Bortoletto; do Carmo Calijuri, Maria

    2016-03-01

    Artificial reservoirs have been used for drinking water supply, other human activities, flood control and pollution abatement worldwide, providing overall benefits to downstream water quality. Most reservoirs in Brazil were built during the 1970s, but their long-term patterns of trophic status, water chemistry, and nutrient removal are still not very well characterized. We aimed to evaluate water quality time series (1985-2010) data from the riverine and lacustrine zones of the transboundary Itaipu Reservoir (Brazil/Paraguay). We examined total phosphorus and nitrogen, chlorophyll a concentrations, water transparency, and phytoplankton density to look for spatial and temporal trends and correlations with trophic state evolution and nutrient retention. There was significant temporal and spatial water quality variation ( P Itaipu and led to relatively low removal percentages. Our study suggested that water quality problems may be more pronounced immediately after the filling phase of the artificial reservoirs, associated with the initial decomposition of drowned vegetation at the very beginning of reservoir operation.

  19. Study on Transfer Rules of Coal Reservoir Pressure Drop Based on Coalbed Methane Well Drainage Experiments

    Science.gov (United States)

    Yuhang, X.

    2017-12-01

    A pumping test was carried out to explore the transfer rules of pressure drop in coal reservoir during the drainage. The experiment was divided into three stages. In the first stage, the pump displacement of 3m3/h was used to reduce the bottom hole flowing pressure and stopped until the continuous gas phase was produced; Undertaking the first stage, in the second stage, when the gas phase was continuously produced, the pump was stopped immediately. As the bottom hole flowing pressure going up without gas phase, pumping started again for a week. In the third stage ,the well pumping was carried out at the bottom hole pressure drop rate of 30Kpa/d after two months' recovery. Combined with the data of regional geology and fractured well, taking the characteristics of macroscopic coal rocks, development of pore and fracture in coal and isothermal adsorption test as the background, the features of reservoir output in each stage of the experiment were analyzed and compared, and then the transfer rules of pressure drop contained in the differences of the output was studied further. In the first and third stage of the experiment, the output of liquid phase was much larger than the space volume of coal reservoir pore and fracture in the range of 100m2. In the second stage, the output of the continuous gas phase appeared around 0.7Mpa when the continuous gas phase appears below the critical desorption pressure of 0.25Mpa during the whole experiment. The results indicate that, the transfer of pressure drop in the coal reservoir of this well is mainly horizontal, and the liquid phase produced in the reservoir mainly comes from the recharge of the reservoir at the far end of the relative high pressure area; the adsorption space of coalbed methane in the coal matrix as well as the main migration channel of fluid in the reservoir doesn't belong to the same pressure system and there exists the communication barrier between them. In addition, the increasing of the effective stress

  20. Simulation study of huff-n-puff air injection for enhanced oil recovery in shale oil reservoirs

    Directory of Open Access Journals (Sweden)

    Hu Jia

    2018-03-01

    Full Text Available This paper is the first attempt to evaluate huff-n-puff air injection in a shale oil reservoir using a simulation approach. Recovery mechanisms and physical processes of huff-n-puff air injection in a shale oil reservoir are investigated through investigating production performance, thermal behavior, reservoir pressure and fluid saturation features. Air flooding is used as the basic case for a comparative study. The simulation study suggests that thermal drive is the main recovery mechanism for huff-n-puff air injection in the shale oil reservoir, but not for simple air flooding. The synergic recovery mechanism of air flooding in conventional light oil reservoirs can be replicated in shale oil reservoirs by using air huff-n-puff injection strategy. Reducing huff-n-puff time is better for performing the synergic recovery mechanism of air injection. O2 diffusion plays an important role in huff-n-puff air injection in shale oil reservoirs. Pressure transmissibility as well as reservoir pressure maintenance ability in huff-n-puff air injection is more pronounced than the simple air flooding after primary depletion stage. No obvious gas override is exhibited in both air flooding and air huff-n-puff injection scenarios in shale reservoirs. Huff-n-puff air injection has great potential to develop shale oil reservoirs. The results from this work may stimulate further investigations.

  1. GHG budget in a young subtropical hydroelectric reservoir: Nam Theun 2 case study

    Science.gov (United States)

    Deshmukh, C.; Guérin, F.; Serça, D.; Descloux, S.; Chanudet, V.; Guédant, P.

    2012-04-01

    Dynamics of major greenhouse gases (CO2, CH4 and N2O) has been studied in a new subtropical hydroelectric reservoir (impounded in 2009), Nam Theun 2 (NT2), in Lao PDR, Asia. The main pathways of emission were quantified, i.e., ebullition (bubbling), surface diffusion, downstream emissions (diffusion and degassing) and emissions from the drawdown area (up to 370 km2 for a 450km2 in the case of NT2). All presented results are coming from five field campaigns conducted from May 2009 to June 2011, and a monthly monitoring on 35 stations. Additional laboratory work in controlled conditions helped to assess production rates of CH4, CO2 and N2O, and aerobic CH4 oxidation rates. The ebullition of CH4 is in the same order as from other tropical reservoirs, varying with depth and atmospheric pressure. Measured diffusive fluxes of CH4 and CO2 cover the whole range of reported fluxes for other tropical reservoirs, depending on the season. Diffusive fluxes of N2O, and CH4 downstream (degassing and diffusion) emissions are in the lower range as reported before for tropical reservoirs. On the opposite, the drawdown area would represent a significant contribution to N2O emission. Our results for the year 2010 show that diffusive emission from the reservoir surface is the main contributor (46%) to total GHG emissions from the NT2 reservoir. With 25% and 19% of total GHG emissions, bubbling and drawdown area emissions also contributed significantly respectively. Downstream emissions from NT2 reservoir contributed around 10% of total GHG emissions, a percentage lower than reported for other reservoirs. With 963 Gg CO2eq yr-1 and 986 Gg CO2eq yr-1respectively, CH4 and CO2 have almost the same contributions (48 and 49%) of the total GHG budget, N2O accounting for less than 3% with 64 Gg CO2eq yr-1. With a total emissions from NT2 reservoir of 2013 Gg CO2eq yr-1, gross NT2 emission are about an order of magnitude higher than pre-impoundment emissions (276 Gg CO2eq yr-1). Net emission

  2. Simulation studies to evaluate the effect of fracture closure on the performance of fractured reservoirs; Final report

    Energy Technology Data Exchange (ETDEWEB)

    Howrie, I.; Dauben, D.

    1994-03-01

    A three-year research program to evaluate the effect of fracture closure on the recovery of oil and gas from naturally fractured reservoirs has been completed. The overall objectives of the study were to: (1) evaluate the reservoir conditions for which fracture closure is significant, and (2) evaluate innovative fluid injection techniques capable of maintaining pressure within the reservoir. The evaluations of reservoir performance were made by a modern dual porosity simulator, TETRAD. This simulator treats both porosity and permeability as functions of pore pressure. The Austin Chalk in the Pearsall Field in of South Texas was selected as the prototype fractured reservoir for this work. During the first year, simulations of vertical and horizontal well performance were made assuming that fracture permeability was insensitive to pressure change. Sensitivity runs indicated that the simulator was predicting the effects of critical reservoir parameters in a logical and consistent manner. The results confirmed that horizontal wells could increase both rate of oil recovery and total oil recovery from naturally fractured reservoirs. In the second year, the performance of the same vertical and horizontal wells was reevaluated with fracture permeability treated as a function of reservoir pressure. To investigate sensitivity to in situ stress, differing loading conditions were assumed. Simulated natural depletions confirm that pressure sensitive fractures degrade well performance. The severity of degradation worsens when the initial reservoir pressure approaches the average stress condition of the reservoir, such as occurs in over pressured reservoirs. Simulations with water injection indicate that degradation of permeability can be counteracted when reservoir pressure is maintained and oil recovery can be increased when reservoir properties are favorable.

  3. Remote Sensing of Water Quality in Multipurpose Reservoirs: Case Study Applications in Indonesia, Mexico, and Uruguay

    Science.gov (United States)

    Miralles-Wilhelm, F.; Serrat-Capdevila, A.; Rodriguez, D.

    2017-12-01

    This research is focused on development of remote sensing methods to assess surface water pollution issues, particularly in multipurpose reservoirs. Three case study applications are presented to comparatively analyze remote sensing techniquesforo detection of nutrient related pollution, i.e., Nitrogen, Phosphorus, Chlorophyll, as this is a major water quality issue that has been identified in terms of pollution of major water sources around the country. This assessment will contribute to a better understanding of options for nutrient remote sensing capabilities and needs and assist water agencies in identifying the appropriate remote sensing tools and devise an application strategy to provide information needed to support decision-making regarding the targeting and monitoring of nutrient pollution prevention and mitigation measures. A detailed review of the water quality data available from ground based measurements was conducted in order to determine their suitability for a case study application of remote sensing. In the first case study, the Valle de Bravo reservoir in Mexico City reservoir offers a larger database of water quality which may be used to better calibrate and validate the algorithms required to obtain water quality data from remote sensing raw data. In the second case study application, the relatively data scarce Lake Toba in Indonesia can be useful to illustrate the value added of remote sensing data in locations where water quality data is deficient or inexistent. The third case study in the Paso Severino reservoir in Uruguay offers a combination of data scarcity and persistent development of harmful algae blooms. Landsat-TM data was obteined for the 3 study sites and algorithms for three key water quality parameters that are related to nutrient pollution: Chlorophyll-a, Total Nitrogen, and Total Phosphorus were calibrated and validated at the study sites. The three case study applications were developed into capacity building/training workshops

  4. Vortices in dam reservoir: A case study of Karun III dam

    Indian Academy of Sciences (India)

    The present study focuses on the effect of vortex formation on plane velocities in a reservoir. Velocity measurements are performed in the hydraulic model of Karun III dam and hydropower plant. Different vortices were produced at the horizontal intake by changing the submerged depth. Tangential velocities were measured ...

  5. Study on detailed geological modelling for fluvial sandstone reservoir in Daqing oil field

    Energy Technology Data Exchange (ETDEWEB)

    Zhao Hanqing; Fu Zhiguo; Lu Xiaoguang [Institute of Petroleum Exploration and Development, Daqing (China)

    1997-08-01

    Guided by the sedimentation theory and knowledge of modern and ancient fluvial deposition and utilizing the abundant information of sedimentary series, microfacies type and petrophysical parameters from well logging curves of close spaced thousands of wells located in a large area. A new method for establishing detailed sedimentation and permeability distribution models for fluvial reservoirs have been developed successfully. This study aimed at the geometry and internal architecture of sandbodies, in accordance to their hierarchical levels of heterogeneity and building up sedimentation and permeability distribution models of fluvial reservoirs, describing the reservoir heterogeneity on the light of the river sedimentary rules. The results and methods obtained in outcrop and modem sedimentation studies have successfully supported the study. Taking advantage of this method, the major producing layers (PI{sub 1-2}), which have been considered as heterogeneous and thick fluvial reservoirs extending widely in lateral are researched in detail. These layers are subdivided into single sedimentary units vertically and the microfacies are identified horizontally. Furthermore, a complex system is recognized according to their hierarchical levels from large to small, meander belt, single channel sandbody, meander scroll, point bar, and lateral accretion bodies of point bar. The achieved results improved the description of areal distribution of point bar sandbodies, provide an accurate and detailed framework model for establishing high resolution predicting model. By using geostatistic technique, it also plays an important role in searching for enriched zone of residual oil distribution.

  6. Depth limit of littoral vegetation in a storage reservoir: A case study of Lipno Reservoir (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Krolová, M.; Čížková, Hana; Hejzlar, Josef

    2012-01-01

    Roč. 42, č. 2 (2012), s. 165-174 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GA206/09/1764 EU Projects: European Commission(XE) 244121 - REFRESH Institutional research plan: CEZ:AV0Z60170517; CEZ:AV0Z60870520 Keywords : macrophyte * littoral * reservoir * shore erosion * ecological potential * European Water Framework Directive Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.565, year: 2012

  7. Bubble generation and venous air filtration by hard-shell venous reservoirs: a comparative study.

    Science.gov (United States)

    Mitchell, S J; Willcox, T; Gorman, D F

    1997-09-01

    We have previously shown significant bubble formation in Medtronic Maxima hard-shell venous reservoirs (HSVRs). In the present study, we not only investigated the mechanism of this bubble formation, but also the extent of bubble clearance by membrane oxygenators and arterial line filters. In addition, we also compared the performance of five HSVRs with respect to bubble formation and venous air filtration. Salvaged clinical CPB circuits containing different HSVRs were studied by downstream Doppler monitoring under fixed flow-decreasing volume, fixed volume-increasing flow, and entrained venous air conditions. Bubbles formed in the Medtronic Maxima top entry HSVR at volumes below 800 ml and flows above 3.5 l min-1, and were incompletely removed by a membrane oxygenator and arterial line filter. Decreased bubbling was seen when the reservoir atmosphere was flushed with CO2, suggesting that these bubbles formed in a fountain at the venous inflow. The Medtronic Maxima Forte HSVR formed significantly fewer bubbles at low volumes, and filtered venous air effectively. Negligible bubble formation occurred in the Sorin, Terumo, or Baxter reservoirs. The minimum recommended operating volume for the Medtronic Maxima top entry reservoir should be reset at 600 ml and this device should always be used with an arterial filter. Bubble formation is substantially reduced in the new Medtronic Maxima Forte HSVR and this device is a good filter for venous air.

  8. A study of relations between physicochemical properties of crude oils and microbiological characteristics of reservoir microflora

    Science.gov (United States)

    Yashchenko, I. G.; Polishchuk, Yu. M.; Peremitina, T. O.

    2015-10-01

    The dependence of the population and activity of reservoir microflora upon the chemical composition and viscosity of crude oils has been investigated, since it allows the problem of improvement in the technologies and enhancement of oil recovery as applied to production of difficult types of oils with anomalous properties (viscous, heavy, waxy, high resin) to be solved. The effect of the chemical composition of the oil on the number, distribution, and activity of reservoir microflora has been studied using data on the microbiological properties of reservoir water of 16 different fields in oil and gas basins of Russia, Mongolia, China, and Vietnam. Information on the physicochemical properties of crude oils of these fields has been obtained from the database created at the Institute of Petroleum Chemistry, Siberian Branch on the physicochemical properties of oils throughout the world. It has been found that formation water in viscous oil reservoirs is char acterized by a large population of heterotrophic and sulfate reducing bacteria and the water of oil fields with a high paraffin content, by population of denitrifying bacteria.

  9. A study of well test data interpretation model for waterbearing reservoirs with phase redistribution

    Science.gov (United States)

    Zhang, Junxiang; Deng, Rui; Liang, Haipeng; Yang, Jing

    2017-05-01

    In China, plentiful marine reservoirs exist. Net pay thickness in individual gas reservoirs where partial penetration was performed can be hundreds of meters. Due to the influence of condensate water and formation, water phase separation phenomenon, where gas rose up and liquid moved down, and a morsel of water production emerged in some gas wells, which makes the build-up curves distorted and thus unable to be interpreted. On the basis of seepage theory and Laplace transformation, a seepage mathematical model and a well test interpretation model for gas wells with phase separation considered are developed to analyze the impact of such various elements as phase separation and partial penetration on the pressure and pressure derivative log-log plot. With practical data of well test in Xihu Sag, reliability analysis of the mathematical model mentioned above was demonstrated. Theoretical research results proposed in our study substantially improved the accuracy of well test interpretation for thick water-bearing gas reservoirs and laid a technical foundation of development of the similar oil & gas reservoirs.

  10. Geothermal reservoir assessment case study: Northern Dixie Valley, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Denton, J.M.; Bell, E.J.; Jodry, R.L.

    1980-11-01

    Two 1500 foot temperature gradient holes and two deep exploratory wells were drilled and tested. Hydrologic-hydrochemical, shallow temperature survey, structural-tectonic, petrologic alteration, and solid-sample geochemistry studies were completed. Eighteen miles of high resolution reflection seismic data were gathered over the area. The study indicates that a geothermal regime with temperatures greater than 400/sup 0/F may exist at a depth of approximately 7500' to 10,000' over an area more than ten miles in length.

  11. Parametric studies for the fusion engineering device

    International Nuclear Information System (INIS)

    Reid, R.L.; Steiner, D.

    1983-01-01

    Parametric studies were conducted using the Fusion Engineering Design Center (FEDC) systems code to investigate the cost, performance, and engineering sensitivity of variations within the fusion engineering device (FED) design space. Candidate FED missions and the associated fusion devices required to achieve the missions are compared. A brief description of the FEDC systems code and the results of the parametric studies that helped to define the FED baseline design are presented

  12. Reservoir operation using El Niño forecasts-case study of Daule Peripa and Baba, Ecuador

    DEFF Research Database (Denmark)

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan

    2014-01-01

    Reservoir operation is studied for the Daule Peripa and Baba system in Ecuador, where El Niño events cause anomalously heavy precipitation. Reservoir inflow is modelled by a Markov-switching model using El Niño-Southern Oscillation (ENSO) indices as input. Inflow is forecast using 9-month lead time...

  13. Trap-efficiency study, Highland Creek flood-retarding reservoir near Kelseyville, California, water years 1966-77

    Science.gov (United States)

    Trujillo, L.F.

    1982-01-01

    This investigation is part of a nationwide study of trap efficiency of detention reservoirs. In this report, trap efficiency was computed from reservoir inflow and outflow sediment data and from reservoir survey and outflow data. Highland Creek Reservoir is a flood-retarding reservoir located in Lake County, near Kelseyville, California. This reservoir has a maximum storage capacity of 3,199 acre-feet and permanent pool storage of 921 acre-feet. Mean annual rainfall for the 14.1 square-mile drainage area above Highland Creek Dam was 29 inches during the December 1965 to September 1977 study period. Resultant mean annual runoff was 17,100 acre-feet. Total reservoir inflow for the 11.8 yea r study period was 202,000 acre-feet, transporting an estimated 126,000 tons (10,700 tons per year) of suspended sediment. Total reservoir outflow for the same period was 188,700 acre-feet, including 15 ,230 tons (1,290 tons per year) of sediment. Estimated trap efficiency for the study period was 88 percent, based on estimated sediment inflow and measured sediment outflow.

  14. Reservoir and civil engineering geophysics (CD-Rom); Geophysique de gisement et de genie civil (CD-Rom)

    Energy Technology Data Exchange (ETDEWEB)

    Mari, J.L.; Chapellier, D.

    1999-07-01

    This CD-Rom is a pedagogical tool developed from the book 'field and civil engineering geophysics' (Technip ed., 1998). It presents the geophysical methods (surface and well geophysical surveys, radar surveys and well logging) and their application in the study of oil fields and also in civil engineering. Several cartoons illustrate the principle of methods, their domain of use and their limitations. It covers the following topics: surface seismic surveys (waves propagation, equipments, reflexion and refraction seismic surveys, surface waves); well seismic surveys (operation, data processing, imaging); well logging (acoustic, nuclear,electrical and others, methods of interpretation); radar surveys (principle, surface, wells, possibilities and limitations). (J.S.)

  15. Marine Vibrionaceae as a reservoir for bioprospecting and ecology studies

    DEFF Research Database (Denmark)

    Giubergia, Sonia

    emerged as an untapped source of biodiversity, and this study investigated the marine bacterial family Vibrionaceae (“vibrios”) for its potential as reservoir of novel biodiversity and of species relevant for the ecology of the marine environment. The characterization of a novel species, Vibrio galatheae...... is required to elucidate whether they are produced to antagonize competitors or to communicate with other colonizers and/or a potential host. In conclusion, this PhD study adds to the knowledge of Vibrionaceae as an untapped reservoir of biodiversity and important players in the ecology of the marine...... environment. Studying microbial eco-physiology is important not only for the development of ecological models, but also as foundation for bioprospecting studies, where this knowledge may be used, for example, to elicit silent biosynthetic gene clusters during natural product discovery....

  16. Field Studies of Geothermal Reservoirs Rio Grande Rift, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    James C Witcher

    2002-07-30

    The Rio Grande rift provides an excellent field laboratory to study the nature of geothermal systems in an extensional environment. Much of the geologic complexity that is found in the Basin and Range is absent because the rift is located on cratonic crust with a thin and well-characterized Phanerozoic stratigraphy and tectonic history. On the other hand, the Neogene thermo-tectonic history of the rift has many parallels with the Basin and Range to the west. The geology of the southern Rio Grande rift is among the best characterized of any rift system in the world. Also, most geologic maps for the region are rather unique in that detailed analyses of Quaternary stratigraphic and surficial unit are added in concert with the details of bedrock geology. Pleistocene to Holocene entrenchment of the Rio Grande and tributaries unroofs the alteration signatures and permeability attributes of paleo outflow plumes and upflow zones, associated with present-day, but hidden or ''blind,'' hydrothermal systems at Rincon and San Diego Mountain.

  17. Responses of spatial-temporal dynamics of bacterioplankton community to large-scale reservoir operation: a case study in the Three Gorges Reservoir, China

    OpenAIRE

    Li, Zhe; Lu, Lunhui; Guo, Jinsong; Yang, Jixiang; Zhang, Jiachao; He, Bin; Xu, Linlin

    2017-01-01

    Large rivers are commonly regulated by damming, yet the effects of such disruption on bacterioplankton community structures have not been adequately studied. The aim of this study was to explore the biogeographical patterns present under dam regulation and to uncover the major drivers structuring bacterioplankton communities. Bacterioplankton assemblages in the Three Gorges Reservoir (TGR) were analyzed using Illumina Miseq sequencing by comparing seven sites located within the TGR before and...

  18. Evaluation of sediment management strategies on reservoir storage depletion rate: a case study

    NARCIS (Netherlands)

    Ali, M.; Sterk, G.

    2010-01-01

    Sedimentation aspects have a major role during the design of new reservoir projects because life of the reservoir mainly depends upon sediment handling during reservoir operation. Therefore, proper sediment management strategies should be adopted to enhance the life span of reservoirs. Basha

  19. Imaging fluid/solid interactions in hydrocarbon reservoir rocks.

    Science.gov (United States)

    Uwins, P J; Baker, J C; Mackinnon, I D

    1993-08-01

    The environmental scanning electron microscope (ESEM) has been used to image liquid hydrocarbons in sandstones and oil shales. Additionally, the fluid sensitivity of selected clay minerals in hydrocarbon reservoirs was assessed via three case studies: HCl acid sensitivity of authigenic chlorite in sandstone reservoirs, freshwater sensitivity of authigenic illite/smectite in sandstone reservoirs, and bleach sensitivity of a volcanic reservoir containing abundant secondary chlorite/corrensite. The results showed the suitability of using ESEM for imaging liquid hydrocarbon films in hydrocarbon reservoirs and the importance of simulating in situ fluid-rock interactions for hydrocarbon production programmes. In each case, results of the ESEM studies greatly enhanced prediction of reservoir/borehole reactions and, in some cases, contradicted conventional wisdom regarding the outcome of potential engineering solutions.

  20. Manage Short-term Flood Events and Long-term Water Needs via Reservoir Operation: A Risk Analysis Study

    Science.gov (United States)

    Cheng, W.; Hsu, N.; Wei, C.; Cheng, W.

    2010-12-01

    This study proposes a methodology to assess the risk of the water shortage during a drought period and the risk of the downstream over-levee flows during a flood period based on the reservoir operation rules for flood control. These rules are defined by upper limits (or flood control storage zone).Through a Monte Carlo simulation, a series of hydrographs are generated to represent the reservoir inflow during a flood period based on historic typhoon events. This series of generated hydrographs are then applied to a reservoir flood operation simulation model. The simulation model calculates the water levels of reservoir at the end of a flood period and the reservoir release during the typhoon the events. Reservoir release is used to calculate the water level at downstream control locations for evaluation of a short-term over-levee risk. The ending water level of the reservoir is used as the initial condition for a water distribution optimization model that evaluates drought conditions for long-term water supply. By applying risk analysis, an assessment is made on the risk of both the water shortage during a drought and over-levee flows during flooding seasons. Based on the results of the risk analysis, we evaluate the relationship among upper-limit sets, shortage risk, and over-levee risk and also provide reservoir operation suggestions based on the risk evaluation.

  1. Managing Injected Water Composition To Improve Oil Recovery: A Case Study of North Sea Chalk Reservoirs

    DEFF Research Database (Denmark)

    Zahid, Adeel; Shapiro, Alexander; Stenby, Erling Halfdan

    2012-01-01

    imbibition, which has been applied in most of the previous studies. Two different flooding schemes (with and without aging) were used for flooding North Sea reservoir chalk samples. For comparison, two tests were also carried out with Stevns Klint core plugs. The flooding tests were carried out...... composition but also the formation water composition affected the oil recovery at high temperatures from the Stevns Klint chalk rock....

  2. Makerspaces in Engineering Education: A Case Study

    DEFF Research Database (Denmark)

    Jensen, Lasse Skovgaard; Özkil, Ali Gürcan; Mougaard, Krestine

    2016-01-01

    it by opening makerspaces and adopting elements of the Maker Movement in their offerings. This paper investigates how university driven makerspaces can affect engineering design and product development education trough a case study. We provide our findings based on interviews and data collected from educators...... engineering design education....

  3. KE Basin water dispositioning engineering study

    International Nuclear Information System (INIS)

    Hunacek, G.S.; Gahir, S.S.

    1994-01-01

    This engineering study is a feasibility study of KE Basin water treatment to an acceptable level and dispositioning the treated water to Columbia River, ground through ETF or to air through evaporation

  4. Preliminary Assessment on Autecological Studies of Beardless Barb, Cyclocheilichthys apogon (Valenciennes, 1842) from Muda Reservoir of Kedah, Malaysia.

    Science.gov (United States)

    Rosli, Nor Aziella Mohd; Zain, Khaironizam Md

    2016-11-01

    Like many other countries, reservoirs in Malaysia are primarily built for various functions such as hydroelectric power generation, drinking water supply, flood mitigation and irrigation for agricultural purposes. Artisanal fisheries activities were also performed in these reservoirs. The freshwater fish are a requisite source of protein for the rural population. Consequently, the fish resources in reservoirs should be carefully maintained at sustainable level. Present study elucidates the preliminary assessment on autecological studies of beardless barb, Cyclocheilichthys apogon as a model of fish biota in Muda Reservoir. This research investigates the growth pattern of C. apogon using length-weight relationship and their condition factor. A total of 307 specimens were captured using cast net for six consecutive months from March 2014 until August 2014. The growth coefficient (b) from the length-weight equation (W = aL b ) for male and female of C. apogon were 3.150 and 3.185, respectively, indicating positive allometric growth. The condition factor values of male and female of C. apogon were 1.023 ± 0.111 and 1.026 ± 0.100, respectively, suggesting that C. apogon is in good condition in Muda Reservoir. The paucity of research on the autecological study in the Muda Reservoir contributes to the main reason of performing this research. The findings will serve as baseline information of this species in Muda Reservoir, as well as for comparative study in the future.

  5. Game theory and fuzzy programming approaches for bi-objective optimization of reservoir watershed management: a case study in Namazgah reservoir.

    Science.gov (United States)

    Üçler, N; Engin, G Onkal; Köçken, H G; Öncel, M S

    2015-05-01

    In this study, game theory and fuzzy programming approaches were used to balance economic and environmental impacts in the Namazgah reservoir, Turkey. The main goals identified were to maximize economic benefits of land use and to protect water quality of reservoir and land resources. Total phosphorous load (kg ha(-1) year(-1)) and economic income (USD ha(-1) year(-1)) from land use were determined as environmental value and economic value, respectively. The surface area of existing land use types, which are grouped under 10 headings according to the investigations on the watershed area, and the constraint values for the watershed were calculated using aerial photos, master plans, and basin slope map. The results of fuzzy programming approach were found to be very close to the results of the game theory model. It was concluded that the amount of fertilizer used in the current situation presents a danger to the reservoir and, therefore, unnecessary fertilizer use should be prevented. Additionally, nuts, fruit, and vegetable cultivation, instead of wheat and corn cultivation, was found to be more suitable due to their high economic income and low total phosphorus (TP) load. Apart from agricultural activities, livestock farming should also be considered in the area as a second source of income. It is believed that the results obtained in this study will help decision makers to identify possible problems of the watershed.

  6. Impact of an Engineering Case Study in a High School Pre-Engineering Course

    Science.gov (United States)

    Rutz, Eugene; Shafer, Michelle

    2011-01-01

    Students at an all-girls high school who were enrolled in an introduction to engineering course were presented an engineering case study to determine if the case study affected their attitudes toward engineering and their abilities to solve engineering problems. A case study on power plants was implemented during a unit on electrical engineering.…

  7. Application of integrated reservoir management and reservoir characterization to optimize infill drilling. Annual report, June 13, 1994--June 12, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Pande, P.K.

    1996-11-01

    This project has used a multi-disciplinary approach employing geology, geophysics, and engineering to conduct advanced reservoir characterization and management activities to design and implement an optimized infill drilling program at the North Robertson (Clearfork) Unit in Gaines County, Texas. The activities during the first Budget Period have consisted of developing an integrated reservoir description from geological, engineering, and geostatistical studies, and using this description for reservoir flow simulation. Specific reservoir management activities are being identified and tested. The geologically targeted infill drilling program will be implemented using the results of this work. A significant contribution of this project is to demonstrate the use of cost-effective reservoir characterization and management tools that will be helpful to both independent and major operators for the optimal development of heterogeneous, low permeability shallow-shelf carbonate (SSC) reservoirs. The techniques that are outlined for the formulation of an integrated reservoir description apply to all oil and gas reservoirs, but are specifically tailored for use in the heterogeneous, low permeability carbonate reservoirs of West Texas.

  8. Trap-efficiency study, Highland Creek flood retarding reservoir near Kelseyville, California, water years 1966-77

    Science.gov (United States)

    Trujillo, L.F.

    1980-01-01

    This investigation is part of a nationwide study of trap efficiency of detention reservoirs. In this report, trap efficiency was computed from reservoir inflow and outflow sediment data and from reservoir survey and outflow data. Highland Creek Reservoir is a flood retarding reservoir located in Lake County, near Kelseyville, California. This reservoir has a maximum storage capacity of 3,199 acre-feet and permanent pool storage of 921 acre-feet. Mean annual rainfall for the 14.1-square-mile drainage area above Highland Creek Dam was 29 inches during the December 1965 to September 1977 study period. Resultant mean annual runoff was 17,100 acre-feet. Total reservoir inflow for the 11.8-year study period was 202,000 acre-feet, transporting an estimated 126,000 tons (10,700 tons per year) of suspended sediment. Total reservoir outflow for the same period was 188,700 acre-feet, including 15,230 tons (1,290 tons per year) of sediment. Estimated trap efficiency for the study period was 88%, based on estimated sediment inflow and measured sediment outflow. Reservoir surveys made in December 1965 and April 1972 revealed a storage capacity loss of 35.8 acre-feet during the 6.3-year period. Computed by using an estimated specific weight, this loss represents 54,600 tons of deposited sediment. Sediment outflow during the same period was 8,890 tons. Trap efficiency for the survey period was 86%. (USGS)

  9. Improved characterization of reservoir behavior by integration of reservoir performances data and rock type distributions

    Energy Technology Data Exchange (ETDEWEB)

    Davies, D.K.; Vessell, R.K. [David K. Davies & Associates, Kingwood, TX (United States); Doublet, L.E. [Texas A& M Univ., College Station, TX (United States)] [and others

    1997-08-01

    An integrated geological/petrophysical and reservoir engineering study was performed for a large, mature waterflood project (>250 wells, {approximately}80% water cut) at the North Robertson (Clear Fork) Unit, Gaines County, Texas. The primary goal of the study was to develop an integrated reservoir description for {open_quotes}targeted{close_quotes} (economic) 10-acre (4-hectare) infill drilling and future recovery operations in a low permeability, carbonate (dolomite) reservoir. Integration of the results from geological/petrophysical studies and reservoir performance analyses provide a rapid and effective method for developing a comprehensive reservoir description. This reservoir description can be used for reservoir flow simulation, performance prediction, infill targeting, waterflood management, and for optimizing well developments (patterns, completions, and stimulations). The following analyses were performed as part of this study: (1) Geological/petrophysical analyses: (core and well log data) - {open_quotes}Rock typing{close_quotes} based on qualitative and quantitative visualization of pore-scale features. Reservoir layering based on {open_quotes}rock typing {close_quotes} and hydraulic flow units. Development of a {open_quotes}core-log{close_quotes} model to estimate permeability using porosity and other properties derived from well logs. The core-log model is based on {open_quotes}rock types.{close_quotes} (2) Engineering analyses: (production and injection history, well tests) Material balance decline type curve analyses to estimate total reservoir volume, formation flow characteristics (flow capacity, skin factor, and fracture half-length), and indications of well/boundary interference. Estimated ultimate recovery analyses to yield movable oil (or injectable water) volumes, as well as indications of well and boundary interference.

  10. Study of different factors affecting the electrical properties of natural gas reservoir rocks based on digital cores

    International Nuclear Information System (INIS)

    Jiang, Liming; Sun, Jianmeng; Wang, Haitao; Liu, Xuefeng

    2011-01-01

    The effects of the wettability and solubility of natural gas in formation water on the electrical properties of natural gas reservoir rocks are studied using the finite element method based on digital cores. The results show that the resistivity index of gas-wet reservoir rocks is significantly higher than that of water-wet reservoir rocks in the entire range of water saturation. The difference between them increases with decreasing water saturation. The resistivity index of natural gas reservoir rocks decreases with increasing additional conduction of water film. The solubility of natural gas in formation water has a dramatic effect on the electrical properties of reservoir rocks. The resistivity index of reservoir rocks increases as the solubility of natural gas increases. The effect of the solubility of natural gas on the resistivity index is very obvious under conditions of low water saturation, and it becomes weaker with increasing water saturation. Therefore, the reservoir wettability and the solubility of natural gas in formation water should be considered in defining the saturation exponent

  11. Enhanced heavy oil recovery for carbonate reservoirs integrating cross-well seismic–a synthetic Wafra case study

    KAUST Repository

    Katterbauer, Klemens

    2015-07-14

    Heavy oil recovery has been a major focus in the oil and gas industry to counter the rapid depletion of conventional reservoirs. Various techniques for enhancing the recovery of heavy oil were developed and pilot-tested, with steam drive techniques proven in most circumstances to be successful and economically viable. The Wafra field in Saudi Arabia is at the forefront of utilizing steam recovery for carbonate heavy oil reservoirs in the Middle East. With growing injection volumes, tracking the steam evolution within the reservoir and characterizing the formation, especially in terms of its porosity and permeability heterogeneity, are key objectives for sound economic decisions and enhanced production forecasts. We have developed an integrated reservoir history matching framework using ensemble based techniques incorporating seismic data for enhancing reservoir characterization and improving history matches. Examining the performance on a synthetic field study of the Wafra field, we could demonstrate the improved characterization of the reservoir formation, determining more accurately the position of the steam chambers and obtaining more reliable forecasts of the reservoir’s recovery potential. History matching results are fairly robust even for noise levels up to 30%. The results demonstrate the potential of the integration of full-waveform seismic data for steam drive reservoir characterization and increased recovery efficiency.

  12. Hydrodynamic influence on reservoir sustainability in semi-arid climate: A physicochemical and environmental isotopic study.

    Science.gov (United States)

    Ammar, Rawaa; Kazpard, Véronique; El Samrani, Antoine G; Amacha, Nabil; Saad, Zeinab; Chou, Lei

    2017-07-15

    Water scarcity and increasing water demand require the development of water management plans such as establishing artificial lakes and dams. Plans to meet water needs are faced by uprising challenges to improve water quality and to ensure the sustainability of hydro-projects. Environmental isotopes coupled to water physicochemical characteristics were investigated over a biennial cycle to assess both geomorphological and environmental impacts on the water quality of a reservoir situated in an intensively used agricultural watershed under a Mediterranean semi-arid climate. The particularity of the semi-arid climate and the diverse topography generate a continental and orographic rain effect on the isotopic composition of precipitation and the water recharged sources. The studied reservoir responds quickly to land-use activities and climatic changes as reflected by temporal and spatial variations of water chemistry and isotopic composition. Increasing changes in precipitation rate and dry periods significantly modified the water isotopic composition in the reservoir. During the first year, hydrogen (δD) and oxygen (δ 18 O) isotopes are depleted by 6 and 2‰ between dry and wet season, respectively. While a shift of -2‰ for δD and -1‰ for δ 18 O was detected during the second annual cycle. Environmental isotopic compositions demonstrate for the first time the occurrence of groundwater inflow to the central (Cz) and dam (Dz) zones of the Qaraaoun reservoir. The Cz and Dz can be considered as open water bodies subjected to dilution by groundwater inflow, which induces vertical mixing and reverse isotopic stratification of the water column. In the contrary, the river mouth zone acts as a closed system without groundwater intrusion, where heavy water accumulates and may act as a sink for contaminants during dry season. Groundwater influx acts as a dilution factor that renews the hypolimnion, and minimizes the perturbations induced by both internal

  13. STUDI KOLEKSI REFERENSI RESERVOIR PENYAKIT DI DAERAH ENZOOTIK PES DI JAWA BARAT DAN JAWA TIMUR

    Directory of Open Access Journals (Sweden)

    Ristiyanto -

    2011-12-01

    Full Text Available ENGLISHReservoir Reference Study Collection Disease, particularly rats have been conducted in several areas such as the enzootic plague area in the district of Nongkojajar, Pasuruan, East Java and Ciwidey district, Bandung regency, West Java. These were organized in May-October 2007. The method used for the collection and reference reservoir of disease is rodentia survey methods. Result of the reference collection reservoir of disease is the house rat Rattus tanezumi Nongkojajar found either in the of Pasuruan, East Java (3 rats and the District of Ciwidey (4 rats. Polynesian rat R. exulans, three rats were only found in the District Nongkojajar, whereas three rats R. tiomanicus, three rats were found in Ciwidey. In addition another types of mice were also found 1 Insectivora mice Suncus murinus in the District Ciwidey. Type of rats captured in habitat homes in the District Ciwidey Bandung regency, West Java and Pasuruan, East Java is the same type, namely house rat Rattus tanezumi. Types of mice caught in the habitat garden in the District Ciwidey Bandung regency, West Java (tiomanicus R. tree rats were different from mice found in Pasuruan, East Java (Polynesian rat R. exulans. Local environment in plague enzootic area in Pasuruan, East Java is mountainous and forest conservation area Bromo-Tengger, while District Ciwidey, Bandung is the highland tourism areas / mountainous and agricultural areas.INDONESIAKoleksi referensi reservoir penyakit khususnya tikus telah dilakukan di beberapa daerah enzootik pes seperti di Kecamatan Nongkojajar, Kabupaten Pasuruan, Jawa Timur dan Kecamatan Ciwidey, Kabupaten Bandung, Jawa Barat. Kegiatan tersebut dilaksanakan pada bulan Mei-Oktober 2007. Metode yang digunakan untuk koleksi dan referensi reservoir penyakit adalah metode survei rodensia. Hasil koleksi referensi reservoir penyakit adalah tikus rumah Rattus tanezumi ditemukan baik di Kecamatan Nongkojajar, Kabupaten Pasuruan, Jawa Timur (3 ekor maupun

  14. Genesis Analysis of High-Gamma Ray Sandstone Reservoir and Its Log Evaluation Techniques: A Case Study from the Junggar Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Liang Wang

    2013-01-01

    Full Text Available In the Junggar basin, northwest China, many high gamma-ray (GR sandstone reservoirs are found and routinely interpreted as mudstone non-reservoirs, with negative implications for the exploration and exploitation of oil and gas. Then, the high GR sandstone reservoirs’ recognition principles, genesis, and log evaluation techniques are systematically studied. Studies show that the sandstone reservoirs with apparent shale content greater than 50% and GR value higher than 110API can be regarded as high GR sandstone reservoir. The high GR sandstone reservoir is mainly and directly caused by abnormally high uranium enrichment, but not the tuff, feldspar or clay mineral. Affected by formation’s high water sensitivity and poor borehole quality, the conventional logs can not recognize reservoir and evaluate the physical property of reservoirs. Then, the nuclear magnetic resonance (NMR logs is proposed and proved to be useful in reservoir recognition and physical property evaluation.

  15. Integrated reservoir assessment and characterization: Final report, October 1, 1985--September 30, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Honarpour, M.; Szpakiewicz, M.; Sharma, B.; Chang, Ming-Ming; Schatzinger, R.; Jackson, S.; Tomutsa, L.; Maerefat, N.

    1989-05-01

    This report covers the development of a generic approach to reservoir characterization, the preliminary studies leading to the selection of an appropriate depositional system for detailed study, the application of outcrop studies to quantified reservoir characterization, and the construction of a quantified geological/engineering model used to screen the effects and scales of various geological heterogeneities within a reservoir. These heterogeneities result in large production/residual oil saturation contrasts over small distances. 36 refs., 124 figs., 38 tabs.

  16. DEVELOPMENT OF RESERVOIR CHARACTERIZATION TECHNIQUES AND PRODUCTION MODELS FOR EXPLOITING NATURALLY FRACTURED RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Michael L. Wiggins; Raymon L. Brown; Faruk Civan; Richard G. Hughes

    2002-12-31

    For many years, geoscientists and engineers have undertaken research to characterize naturally fractured reservoirs. Geoscientists have focused on understanding the process of fracturing and the subsequent measurement and description of fracture characteristics. Engineers have concentrated on the fluid flow behavior in the fracture-porous media system and the development of models to predict the hydrocarbon production from these complex systems. This research attempts to integrate these two complementary views to develop a quantitative reservoir characterization methodology and flow performance model for naturally fractured reservoirs. The research has focused on estimating naturally fractured reservoir properties from seismic data, predicting fracture characteristics from well logs, and developing a naturally fractured reservoir simulator. It is important to develop techniques that can be applied to estimate the important parameters in predicting the performance of naturally fractured reservoirs. This project proposes a method to relate seismic properties to the elastic compliance and permeability of the reservoir based upon a sugar cube model. In addition, methods are presented to use conventional well logs to estimate localized fracture information for reservoir characterization purposes. The ability to estimate fracture information from conventional well logs is very important in older wells where data are often limited. Finally, a desktop naturally fractured reservoir simulator has been developed for the purpose of predicting the performance of these complex reservoirs. The simulator incorporates vertical and horizontal wellbore models, methods to handle matrix to fracture fluid transfer, and fracture permeability tensors. This research project has developed methods to characterize and study the performance of naturally fractured reservoirs that integrate geoscience and engineering data. This is an important step in developing exploitation strategies for

  17. Surface Reservoir Characterization and Stratigraphic Studies Using Rock Magnetism and EPR in Venezuela: A Review

    Science.gov (United States)

    Aldana, M.; Diaz, M.; Costanzo-Alvarez, V.

    2007-05-01

    During the last years, the Paleomagnetic and Rock Magnetic Laboratory at the Simon Bolivar University has incorporated studies of rock magnetism and non conventional techniques in geophysics (as Electronic Paramagnetic Resonance or EPR) to solve diverse problems at the Venezuelan oil industry. Particularly, surface reservoir characterization and EPR-Magnetostratigraphic studies have been performed. At some Venezuelan oil fields (Guafita, La Victoria and Furrial) rock magnetic properties studies (e.g. Magnetic Susceptibility (MS)), extractable organic matter (EOM) and organic matter free radical concentration (OMFRC obtained via EPR) analysis have been applied trying to identified, at shallow levels, the "oil magnetic signature" of subjacent reservoirs. The results obtained in non consolidated samples from the first 1500 m of producers and non producers wells, show the existence of MS, EOM and OMFRC anomalies at shallow levels that are associated with an underlying reservoir and/or oil migration. Authigenic spherical aggregates of submicronic FE-rich magnetic crystals, observed by Scanning Electron Microscopy (SEM), are responsible for the detected MS anomalies. These studies allowed to establish a set of criteria (i.e. EPR, EOM and SEM) in order to link, with a minimum uncertainty, near-surface MS anomalies with the underlying reservoir. We have also explored the application of EPR, combined with petrographic, MS analysis, Qn and S-ratios, to characterize stratigraphic facies and identifying depositional environments at various sections in southwestern Venezuela. The different paramagnetic species that have been identified (e.g. manganese, free radicals and different Fe forms) together with the rock magnetic parameters, seem to give valuable information regarding the lithological characteristics of the studied sections. According to our results, as manganese content is related with the redox conditions, it can be used as a paleoenvironmental change index in

  18. Engineering a segmented dual-reservoir polyurethane intravaginal ring for simultaneous prevention of HIV transmission and unwanted pregnancy.

    Directory of Open Access Journals (Sweden)

    Justin T Clark

    Full Text Available The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and unwanted pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems.

  19. Engineering a Segmented Dual-Reservoir Polyurethane Intravaginal Ring for Simultaneous Prevention of HIV Transmission and Unwanted Pregnancy

    Science.gov (United States)

    Clark, Justin T.; Clark, Meredith R.; Shelke, Namdev B.; Johnson, Todd J.; Smith, Eric M.; Andreasen, Andrew K.; Nebeker, Joel S.; Fabian, Judit; Friend, David R.; Kiser, Patrick F.

    2014-01-01

    The HIV/AIDS pandemic and its impact on women prompt the investigation of prevention strategies to interrupt sexual transmission of HIV. Long-acting drug delivery systems that simultaneously protect womenfrom sexual transmission of HIV and unwanted pregnancy could be important tools in combating the pandemic. We describe the design, in silico, in vitro and in vivo evaluation of a dual-reservoir intravaginal ring that delivers the HIV-1 reverse transcriptase inhibitor tenofovir and the contraceptive levonorgestrel for 90 days. Two polyether urethanes with two different hard segment volume fractions were used to make coaxial extruded reservoir segments with a 100 µm thick rate controlling membrane and a diameter of 5.5 mm that contain 1.3 wt% levonorgestrel. A new mechanistic diffusion model accurately described the levonorgestrel burst release in early time points and pseudo-steady state behavior at later time points. As previously described, tenofovir was formulated as a glycerol paste and filled into a hydrophilic polyurethane, hollow tube reservoir that was melt-sealed by induction welding. These tenofovir-eluting segments and 2 cm long coaxially extruded levonorgestrel eluting segments were joined by induction welding to form rings that released an average of 7.5 mg tenofovir and 21 µg levonorgestrel per day in vitro for 90 days. Levonorgestrel segments placed intravaginally in rabbits resulted in sustained, dose-dependent levels of levonorgestrel in plasma and cervical tissue for 90 days. Polyurethane caps placed between segments successfully prevented diffusion of levonorgestrel into the tenofovir-releasing segment during storage.Hydrated rings endured between 152 N and 354 N tensile load before failure during uniaxial extension testing. In summary, this system represents a significant advance in vaginal drug delivery technology, and is the first in a new class of long-acting multipurpose prevention drug delivery systems. PMID:24599325

  20. Environmental Impact Assessment of reservoir construction: new perspectives for restoration economy, and development: the Belo Monte Power Plant case study.

    Science.gov (United States)

    Tundisi, J G; Matsumura-Tundisi, T; Tundisi, J E M

    2015-08-01

    The Environmental Impact Assessment of reservoir construction can be viewed as a new strategic perspective for the economic development of a region. Based on the principles of a watershed approach a interdisciplinary and multidisciplinary systemic view including biogeophysiographical, economic and socio environmental studies the new vision of a EIA provides a basic substratum for the restoration economy and an advanced model for the true development much well ahead of the modernization aspects of the project of a reservoir construction.

  1. Local Water Management of Small Reservoirs: Lessons from Two Case Studies in Burkina Faso

    Directory of Open Access Journals (Sweden)

    Hilmy Sally

    2011-10-01

    Full Text Available Burkina Faso is actively pursuing the implementation of Integrated Water Resources Management (IWRM in its development plans. Several policy and institutional mechanisms have been put in place, including the adoption of a national IWRM action plan (PAGIRE and the establishment so far of 30 local water management committees (Comités Locaux de l’Eau, or CLE. The stated purpose of the CLE is to take responsibility for managing water at sub-basin level. The two case studies discussed in this paper illustrate gaps between the policy objective of promoting IWRM on the one hand, and the realities associated with its practical on-the-ground implementation on the other. A significant adjustment that occurred in practice is the fact that the two CLE studied have been set up as entities focused on reservoir management, whereas it is envisioned that a CLE would constitute a platform for sub-basin management. This reflects a concern to minimise conflict and optimally manage the country’s primary water resource and illustrates the type of pragmatic actions that have to be taken to make IWRM a reality. It is also observed that the local water management committees have not been able to satisfactorily address questions regarding access to, and allocation of, water, which are crucial for the satisfactory functioning of the reservoirs. Water resources in the reservoirs appear to be controlled by the dominant user. In order to correct this trend, measures to build mutual trust and confidence among water users 'condemned' to work together to manage their common resource are suggested, foremost of which is the need to collect and share reliable data. Awareness of power relationships among water user groups and building on functioning, already existing formal or informal arrangements for water sharing are key determinants for successful implementation of the water reform process underway.

  2. The effects of intercooling and regeneration on the thermo-ecological performance analysis of an irreversible-closed Brayton heat engine with variable-temperature thermal reservoirs

    International Nuclear Information System (INIS)

    Sogut, Oguz Salim; Ust, Yasin; Sahin, Bahri

    2006-01-01

    A thermo-ecological performance analysis of an irreversible intercooled and regenerated closed Brayton heat engine exchanging heat with variable-temperature thermal reservoirs is presented. The effects of intercooling and regeneration are given special emphasis and investigated in detail. A comparative performance analysis considering the objective functions of an ecological coefficient of performance, an ecological function proposed by Angulo-Brown and power output is also carried out. The results indicate that the optimal total isentropic temperature ratio and intercooling isentropic temperature ratio at the maximum ecological coefficient of performance conditions (ECOP max ) are always less than those of at the maximum ecological function ( E-dot max ) and the maximum power output conditions ( W-dot max ) leading to a design that requires less investment cost. It is also concluded that a design at ECOP max conditions has the advantage of higher thermal efficiency and a lesser entropy generation rate, but at the cost of a slight power loss

  3. Study Strategies for Engineering Students at DTU

    DEFF Research Database (Denmark)

    Christensen, Hans Peter

    2002-01-01

    The study strategies of first year Master students are investigated at DTU fall 1999 - spring 2002. The results show that the students study less than their teachers expect. And they spend most time on activities not leading to deep understanding and engineering competencies. The students spend...... activated the students, but not significantly increased their independent studying....

  4. Remedial investigation/feasibility study report for lower Watts Bar Reservoir Operable Unit

    International Nuclear Information System (INIS)

    1994-08-01

    This document is the combined Remedial Investigation and Feasibility Study Report for the Lower Watts Bar Reservoir (LWBR) Operable Unit (OU). The LWBR is located in Roane, Rhea, and Meigs counties, Tennessee, and consists of Watts Bar Reservoir downstream of the Clinch River. This area has received hazardous substances released over a period of 50 years from the U.S. Department of Energy's Oak Ridge Reservation (ORR), a National Priority List site established under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). As required by this law, the ORR and all off-site areas that have received containments, including LWBR, must be investigated to determine the risk to human health and the environment resulting from these releases, the need for any remedial action to reduce these risks, and the remedial actions that are most feasible for implementation in this OU. Contaminants from the ORR are primarily transported to the LWBR via the Clinch River. Water-soluble contaminants released to ORR surface waters are rapidly diluted upon entering the Clinch River and then quickly transported downstream to the Tennessee River where further dilution occurs. Almost the entire quantity of these diluted contaminants rapidly flows through LWBR. In contrast, particle-associated contaminants tend to accumulate in the lower Clinch River and in LWBR in areas of sediment deposition. Those particle-associated contaminants that were released in peak quantities during the early years of ORR operations (e.g., mercury and 137 Cs) are buried under as much as 80 cm of cleaner sediment in LWBR. Certain contaminants, most notably polychlorinated biphenyls (PCBs), have accumulated in LWBR biota. The contamination of aquatic biota with PCBs is best documented for certain fish species and extends to reservoirs upstream of the ORR, indicating a contamination problem that is regional in scope and not specific to the ORR

  5. FED baseline engineering studies report

    Energy Technology Data Exchange (ETDEWEB)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept.

  6. FED baseline engineering studies report

    International Nuclear Information System (INIS)

    Sager, P.H.

    1983-04-01

    Studies were carried out on the FED Baseline to improve design definition, establish feasibility, and reduce cost. Emphasis was placed on cost reduction, but significant feasibility concerns existed in several areas, and better design definition was required to establish feasibility and provide a better basis for cost estimates. Design definition and feasibility studies included the development of a labyrinth shield ring concept to prevent radiation streaming between the torus spool and the TF coil cryostat. The labyrinth shield concept which was developed reduced radiation streaming sufficiently to permit contact maintenance of the inboard EF coils. Various concepts of preventing arcing between adjacent shield sectors were also explored. It was concluded that installation of copper straps with molybdenum thermal radiation shields would provide the most reliable means of preventing arcing. Other design studies included torus spool electrical/structural concepts, test module shielding, torus seismic response, poloidal conditions in the magnets, disruption characteristics, and eddy current effects. These additional studies had no significant impact on cost but did confirm the feasibility of the basic FED Baseline concept

  7. TNS engineering trade study analysis

    International Nuclear Information System (INIS)

    Chapin, D.L.; Gibson, G.

    1977-01-01

    The computer code, ground rules, and plasma scalings used in the trade studies are briefly discussed. The results of these analyses are presented in detail. The results are summarized and pertinent conclusions and recommendations regarding the TNS design options are discussed

  8. Upper Khami reservoir study using microscopic thin sections, core and mud lost data and modeling, Bibi Hakimeh oil field

    Directory of Open Access Journals (Sweden)

    B., Soleimani,

    2012-01-01

    Full Text Available The present study is an evaluation of diagenetic processes and reservoir quality of the upper Khami Group in Bibi Hakimeh oil field. The Khami Group is divided into upper (Fahliyan, Gadvan and Dariyan formations and lower parts (Surmeh and Haith formations. Lithologically, Fahliyan and Dariyan formations and Khalij Member of the Gadvan Formation are carbonate and Gadvan Formation is shale. The determined diagenetic processes are dolomitization, glauconitization, anhydritization, mechanical compaction and stylolitization, chertification, pyritization in the upper Khami. Reservoir geological model for describing the structure and fault effects, iso-grade mud loss and fracture maps were constructed by reservoir management system (RMS software. The results revealed that fractures development and as well as the effect of diagenetic processes such as dolomitization and dissolution seem to have increased the reservoir quality. There is good development of fractures in this reservoir. In general, existence of fractures and effects of processes such as dolomitization and dissolution seem to increase the reservoir quality in this field.

  9. Model Studies on the Effectiveness of MBBR Reactors for the Restoration of Small Water Reservoirs

    Science.gov (United States)

    Nowak, Agata; Mazur, Robert; Panek, Ewa; Chmist, Joanna

    2018-02-01

    The authors present the Moving Bed Biofilm Reactor (MBBR) model with a quasi-continuous flow for small water reservoir restoration, characterized by high concentrations of organic pollutants. To determine the efficiency of wastewater treatment the laboratory analysis of physic-chemical parameters were conducted for the model on a semi-technical scale of 1:3. Wastewater treatment process was carried out in 24 h for 1 m3 for raw sewage. The startup period was 2 weeks for all biofilters (biological beds). Approximately 50% reduction in COD and BOD5 was obtained on average for the studied bioreactors. Significant improvements were achieved in theclarity of the treated wastewater, with the reduction of suspension by 60%. The oxygen profile has improved significantly in 7 to 9 hours of the process, and a diametric reduction in the oxidative reduction potential was recorded. A preliminary model of biological treatment effectiveness was determined based on the conducted studies. In final stages, the operation mode was set in real conditions of polluted water reservoirs.

  10. Study on fracture identification of shale reservoir based on electrical imaging logging

    Science.gov (United States)

    Yu, Zhou; Lai, Fuqiang; Xu, Lei; Liu, Lin; Yu, Tong; Chen, Junyu; Zhu, Yuantong

    2017-05-01

    In recent years, shale gas exploration has made important development, access to a major breakthrough, in which the study of mud shale fractures is extremely important. The development of fractures has an important role in the development of gas reservoirs. Based on the core observation and the analysis of laboratory flakes and laboratory materials, this paper divides the lithology of the shale reservoirs of the XX well in Zhanhua Depression. Based on the response of the mudstone fractures in the logging curve, the fracture development and logging Response to the relationship between the conventional logging and electrical imaging logging to identify the fractures in the work, the final completion of the type of fractures in the area to determine and quantify the calculation of fractures. It is concluded that the fracture type of the study area is high and the microstructures are developed from the analysis of the XX wells in Zhanhua Depression. The shape of the fractures can be clearly seen by imaging logging technology to determine its type.

  11. Study on Compatibility of Polymer Hydrodynamic Size and Pore Throat Size for Honggang Reservoir

    Directory of Open Access Journals (Sweden)

    Dan-Dan Yin

    2014-01-01

    Full Text Available Long core flow experiment was conducted to study problems like excessive injection pressure and effective lag of oil wells during the polymer flooding in Honggang reservoir in Jilin oilfield. According to the changes in viscosity and hydrodynamic dimensions before and after polymer solution was injected into porous media, the compatibility of polymer hydrodynamic dimension and the pore throat size was studied in this experiment. On the basis of the median of radius R of pore throats in rocks with different permeability, dynamic light scattering method (DLS was adopted to measure the hydrodynamic size Rh of polymer solution with different molecular weights. The results state that three kinds of 1500 mg/L concentration polymer solution with 2000 × 104, 1500 × 104, and 1000 × 104 molecular weight matched well with the pore throat in rocks with permeability of 300 mD, 180 mD, and 75 mD in sequence. In this case, the ratios of core pore throat radius median to the size of polymer molecular clew R/Rh are 6.16, 5.74, and 6.04. For Honggang oil reservoir in Jilin, when that ratio ranges from 5.5 to 6.0, the compatibility of polymer and the pore structure will be relatively better.

  12. Reservoir sedimentation; a literature survey

    NARCIS (Netherlands)

    Sloff, C.J.

    1991-01-01

    A survey of literature is made on reservoir sedimentation, one of the most threatening processes for world-wide reservoir performance. The sedimentation processes, their impacts, and their controlling factors are assessed from a hydraulic engineering point of view with special emphasis on

  13. Remedial investigation/feasibility study report for Lower Watts Bar Reservoir Operable Unit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    This document is the combined Remedial Investigation and Feasibility Study Report for the lower Watts Bar Reservoir (LWBR) Operable Unit (OU). The LWBR is located in Roane, Rhea, and Meigs counties, Tennessee, and consists of Watts Bar Reservoir downstream of the Clinch river. This area has received hazardous substances released over a period of 50 years from the US Department of Energy`s Oak Ridge Reservation (ORR), a National Priority List site established under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). As required by this law, the ORR and all off-site areas that have received contaminants, including LWBR, must be investigated to determine the risk to human health and the environment resulting from these releases, the need for any remedial action to reduce these risks, and the remedial actions that are most feasible for implementation in this OU. Contaminants from the ORR are primarily transported to the LWBR via the Clinch River. There is little data regarding the quantities of most contaminants potentially released from the ORR to the Clinch River, particularly for the early years of ORR operations. Estimates of the quantities released during this period are available for most radionuclides and some inorganic contaminants, indicating that releases 30 to 50 years ago were much higher than today. Since the early 1970s, the release of potential contaminants has been monitored for compliance with environmental law and reported in the annual environmental monitoring reports for the ORR.

  14. Remedial investigation/feasibility study report for Lower Watts Bar Reservoir Operable Unit

    International Nuclear Information System (INIS)

    1995-03-01

    This document is the combined Remedial Investigation and Feasibility Study Report for the lower Watts Bar Reservoir (LWBR) Operable Unit (OU). The LWBR is located in Roane, Rhea, and Meigs counties, Tennessee, and consists of Watts Bar Reservoir downstream of the Clinch river. This area has received hazardous substances released over a period of 50 years from the US Department of Energy's Oak Ridge Reservation (ORR), a National Priority List site established under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). As required by this law, the ORR and all off-site areas that have received contaminants, including LWBR, must be investigated to determine the risk to human health and the environment resulting from these releases, the need for any remedial action to reduce these risks, and the remedial actions that are most feasible for implementation in this OU. Contaminants from the ORR are primarily transported to the LWBR via the Clinch River. There is little data regarding the quantities of most contaminants potentially released from the ORR to the Clinch River, particularly for the early years of ORR operations. Estimates of the quantities released during this period are available for most radionuclides and some inorganic contaminants, indicating that releases 30 to 50 years ago were much higher than today. Since the early 1970s, the release of potential contaminants has been monitored for compliance with environmental law and reported in the annual environmental monitoring reports for the ORR

  15. Identifying Relevant Studies in Software Engineering

    DEFF Research Database (Denmark)

    Zhang, He; Ali Babar, Muhammad; Tell, Paolo

    2011-01-01

    Context: Systematic literature review (SLR) has become an important research methodology in software engineering since the introduction of evidence-based software engineering (EBSE) in 2004. One critical step in applying this methodology is to design and execute appropriate and effective search....... Objective: The main objective of the research reported in this paper is to improve the search step of undertaking SLRs in software engineering (SE) by devising and evaluating systematic and practical approaches to identifying relevant studies in SE. Method: We have systematically selected and analytically...... serve as a supplement to the guidelines for SLRs in EBSE. We plan to further evaluate the proposed approach using a series of case studies on varying research topics in SE....

  16. Photonic engineering for biological study

    Science.gov (United States)

    Wu, Fei

    My dissertation focuses on designing and developing prototypes of optical tools in the laboratory that can facilitate practical medical therapies. More specifically, this dissertation examines two novel biophotonic techniques: (1) a frequency multiplexed confocal microscope with the potential to provide rational therapy of congestive heart failure (CHF), and (2) the "optical comb" with the potential to improve results of retina reattachment surgery and accelerate post surgical recovery. Next, I will discuss the background, design and initial experimental results of each study individually. Part I: The Frequency Multiplexed Confocal Microscope. To overcome the limitations of existing confocal microscope technology, this dissertation proposes a non-scanning, real-time, high resolution technique (a multi-point frequency multiplexed confocal microscope) to measure 3-D intracellular calcium ion concentration in a living cardiac myocyte. This method can be also applied to measure the intracellular sodium ion concentration, or other ions in which high quantum-yield fluorescent probes are available. The novelty of the proposed research lies in the introduction of carrier frequency multiplexing techniques which can differentiate fluorescence emitted at different spatial locations in cardiac myocyte by their modulated frequency. It therefore opens the possibility to visualize the transient dynamics of intracellular dynamics at multiple locations in cells simultaneously, which will shine a new light on our understanding of CHF. The procedure for frequency multiplexing proposed is described below. Multiple incident laser beams are focused onto different locations in an isolated rat cardiac myocyte with each beam modulated at a different carrier frequency. The fluorescence emission at each location therefore bears the same modulated frequency as the stimulation laser beam. Each fluorescence signal is sent to the photo multiplier tube (PMT) after being spatially filtered by a

  17. Simulation of the mulltizones clastic reservoir: A case study of Upper Qishn Clastic Member, Masila Basin-Yemen

    Science.gov (United States)

    Khamis, Mohamed; Marta, Ebrahim Bin; Al Natifi, Ali; Fattah, Khaled Abdel; Lashin, Aref

    2017-06-01

    The Upper Qishn Clastic Member is one of the main oil-bearing reservoirs that are located at Masila Basin-Yemen. It produces oil from many zones with different reservoir properties. The aim of this study is to simulate and model the Qishn sandstone reservoir to provide more understanding of its properties. The available, core plugs, petrophysical, PVT, pressure and production datasets, as well as the seismic structural and geologic information, are all integrated and used in the simulation process. Eclipse simulator was used as a powerful tool for reservoir modeling. A simplified approach based on a pseudo steady-state productivity index and a material balance relationship between the aquifer pressure and the cumulative influx, is applied. The petrophysical properties of the Qishn sandstone reservoir are mainly investigated based on the well logging and core plug analyses. Three reservoir zones of good hydrocarbon potentiality are indicated and named from above to below as S1A, S1C and S2. Among of these zones, the S1A zone attains the best petrophysical and reservoir quality properties. It has an average hydrocarbon saturation of more than 65%, high effective porosity up to 20% and good permeability record (66 mD). The reservoir structure is represented by faulted anticline at the middle of the study with a down going decrease in geometry from S1A zone to S2 zone. It is limited by NE-SW and E-W bounding faults, with a weak aquifer connection from the east. The analysis of pressure and PVT data has revealed that the reservoir fluid type is dead oil with very low gas liquid ratio (GLR). The simulation results indicate heterogeneous reservoir associated with weak aquifer, supported by high initial water saturation and high water cut. Initial oil in place is estimated to be around 628 MM BBL, however, the oil recovery during the period of production is very low (<10%) because of the high water cut due to the fractures associated with many faults. Hence, secondary and

  18. Limno-reservoirs as a new landscape, environmental and touristic resource: Pareja Limno-reservoir as a case of study (Guadalajara, Spain)

    Science.gov (United States)

    Díaz-Carrión, I.; Sastre-Merlín, A.; Martínez-Pérez, S.; Molina-Navarro, E.; Bienes-Allas, R.

    2012-04-01

    A limno-reservoir is a hydrologic infrastructure with the main goal of generating a body of water with a constant level in the riverine zone of a reservoir, building a dam that makes de limno-reservoir independent from the main body of water. This dam can be built in the main river supplying the reservoir or any tributary as well flowing into it. Despite its novel conception and design, around a dozen are already operative in some Spanish reservoirs. This infrastructure allows the new water body to be independent of the main reservoir management, so the water level stability is its main distinctive characteristic. It leads to the development of environmental, sports and cultural initiatives; which may be included in a touristic exploitation in a wide sense. An opinion poll was designed in 2009 to be carried out the Pareja Limno-reservoir (Entrepeñas reservoir area, Tajo River Basin, central Spain). The results showed that for both, Pareja inhabitants and occasional visitors, the limno-reservoir has become an important touristic resource, mainly demanded during summer season. The performance of leisure activities (especially swimming) are being the main brand of this novel hydraulic and environmental infrastructure, playing a role as corrective and/or compensatory action which is needed to apply in order to mitigate the environmental impacts of the large hydraulic constructions.

  19. Study Of Rock Physics And Seismic Attributes Of Hydrocarbon Reservoirs In Sabah Basin

    Science.gov (United States)

    anak Penguang, Adelynna Shirley; Almanna Lubis, Luluan; Hermana, Maman; Deva Prasad Ghosh, Dr., Prof.

    2017-10-01

    Elastic moduli are known to discriminate fluid and lithology for effective reservoir characterization. However, in some cases, the elastic modulus can also show the same response for different type of fluid and lithology. In our study area, a few elastic moduli were used to evaluate the hydrocarbon sands, water sand and shale as identified based on well log response. Seismic attributes such as Relative Acoustic Impedance attribute and RMS amplitude attribute are also applied to confirm the well log analysis and investigate the seismic response. Based on the results, the effective elastic moduli for our study area is the Lambda-Mu-Rho, Velocity Ratio (Vp/Vs), Poisson's ratio and Scaled Inverse Quality (Q) Ratio. The seismic attributes such as the Relative Acoustic Impedance highlights the impedance difference between the formations while RMS amplitude shows the hydrocarbon presence. The workflow of this study is applicable for other areas for effective fluid and lithology delineation.

  20. Tokamak Engineering Technology Facility scoping study

    Energy Technology Data Exchange (ETDEWEB)

    Stacey, W.M. Jr.; Abdou, M.A.; Bolta, C.C.

    1976-03-01

    A scoping study for a Tokamak Engineering Technology Facility (TETF) is presented. The TETF is a tokamak with R = 3 m and I/sub p/ = 1.4 MA based on the counterstreaming-ion torus mode of operation. The primary purpose of TETF is to demonstrate fusion technologies for the Experimental Power Reactor (EPR), but it will also serve as an engineering and radiation test facility. TETF has several technological systems (e.g., superconducting toroidal-field coil, tritium fuel cycle, impurity control, first wall) that are prototypical of EPR.

  1. Diesel engine emission deterioration - a preliminary study

    CSIR Research Space (South Africa)

    Pretorius, Cecilia J

    2016-04-01

    Full Text Available The objective of this study was to find a parameter in diesel and oil analysis of underground mining vehicles that can be correlated with personal diesel particulate matter (DPM) exposure and used as part of an engine maintenance programme. A number...

  2. Studying Design Engineers Use Of Information Systems

    DEFF Research Database (Denmark)

    Restrepo-Giraldo, John Dairo

    2006-01-01

    Studying information usage by design engineers involves considering technical, social, cognitive and volitional factors. This makes it challenging, especially for researchers without a cognitive psychology background. This paper presents a summary of key findings in researching information use...... and processing in design, discusses important issues on the selection of a research strategy and sums up the important variables that need to be controlled for....

  3. Development of Reservoir Characterization Techniques and Production Models for Exploiting Naturally Fractured Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, M.L.; Evans, R.D.; Brown, R.L.; Gupta, A.

    2001-03-28

    This report focuses on integrating geoscience and engineering data to develop a consistent characterization of the naturally fractured reservoirs. During this reporting period, effort was focused on relating seismic data to reservoir properties of naturally fractured reservoirs, scaling well log data to generate interwell descriptors of these reservoirs, enhancing and debugging a naturally fractured reservoir simulator, and developing a horizontal wellbore model for use in the simulator.

  4. Interactions of structurally modified surfactants with reservoir minerals: Calorimetric, spectroscopic and electrokinetic study

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaran, P.; Sivakumar, A.; Xu, Q.

    1991-03-01

    The objective of this project is to elucidate mechanisms of adsorption of structurally modified surfactants on reservoir minerals and to develop a full understanding of the effect of the surfactant structure on the nature of the adsorbed layers at the molecular level. An additional aim is to study the adsorption of surfactant mixtures on simple well-characterized minerals and on complex minerals representing real conditions. The practical goal of these studies is the identification of the optimum surfactant structures and their combinations for micellar flooding. In this work, the experiments on adsorption were focussed on the position of sulfonate and methyl groups on the aromatic ring of alkyl xylene sulfonates. A multi-pronged approach consisting of calorimetry, electrokinetics, wettability and spectroscopy is planned to elucidate the adsorption mechanism of surfactants and their mixtures on minerals such as alumina and kaolinite. 32 refs., 15 figs., 7 tabs.

  5. Vortices in dam reservoir: A case study of Karun III dam

    Indian Academy of Sciences (India)

    Vertical anti-vortex walls and anti-vortex plates are usually considered to be among the effective means for eliminating a vortex. The possibility of vortex formation can be observed by its velocity in the reservoir, vθ , which is defined as the tangential velocity on an arbitrary point in the reservoir. As the tangential velocity of ...

  6. Lacustrine Environment Reservoir Properties on Sandstone Minerals and Hydrocarbon Content: A Case Study on Doba Basin, Southern Chad

    Science.gov (United States)

    Sumery, N. F. Mohd; Lo, S. Z.; Salim, A. M. A.

    2017-10-01

    The contribution of lacustrine environment as the hydrocarbon reservoir has been widely known. However, despite its growing importance, the lacustrine petroleum geology has received far less attention than marine due to its sedimentological complexity. This study therefore aims in developing an understanding of the unique aspects of lacustrine reservoirs which eventually impacts the future exploration decisions. Hydrocarbon production in Doba Basin, particularly the northern boundary, for instance, has not yet succeeded due to the unawareness of its depositional environment. The drilling results show that the problems were due to the: radioactive sand and waxy oil/formation damage, which all are related to the lacustrine depositional environment. Detailed study of geological and petrophysical integration on wireline logs and petrographic thin sections analysis of this environment helps in distinguishing reservoir and non-reservoir areas and determining the possible mechanism causing the failed DST results. The interpretations show that the correlation of all types> of logs and rho matrix analysis are capable in identifying sand and shale bed despite of the radioactive sand present. The failure of DST results were due to the presence of arkose in sand and waxy oil in reservoir bed. This had been confirmed by the petrographic thin section analysis where the arkose has mineral twinning effect indicate feldspar and waxy oil showing bright colour under fluorescent light. Understanding these special lacustrine environment characteristics and features will lead to a better interpretation of hydrocarbon prospectivity for future exploration.

  7. A Percolation Study of Wettability Effect on the Electrical Properties of Reservoir Rocks

    DEFF Research Database (Denmark)

    Zhou, Dengen; Arbabi, Sepehr; Stenby, Erling Halfdan

    1997-01-01

    Measurements of the electrical resistivity of oil reservoirs are commonly used to estimate other properties of reservoirs, such as porosity and hydrocarbon reserves. However, the interpretation of the measurements is based on empirical correlations, because the underlying mechanisms that control...... the electrical properties of oil bearing rocks have not been well understood. In this paper, we employ percolation concepts to investigate the effect of wettability on the electrical conductivity of a reservoir formation. A three-dimensional simple cubic network is used to represent an ideal reservoir formation...... behavior of reservoir resistivities of different wettabilities. It demonstrates that the resistivity index depends on saturation history and wettability. For strongly oil-wet systems, significant hysteresis is expected, while there is little hysteresis for strongly water-wet systems, and some hysteresis...

  8. Preliminary study of a potential CO2 reservoir area in Hungary

    Science.gov (United States)

    Sendula, Eszter; Király, Csilla; Szabó, Zsuzsanna; Falus, György; Szabó, Csaba; Kovács, István; Füri, Judit; Kónya, Péter; Páles, Mariann; Forray, Viktória

    2014-05-01

    Since the first international agreement in 1997 (the Kyoto Protocol) the reduction of greenhouse gas emission has a key role in the European Union's energy and climate change policy. Following the Directive 2009/31/EC we are experiencing a significant change in the Hungarian national activity. Since the harmonization procedure, which was completed in May 2012, the national regulation obligates the competent authority to collect and regularly update all geological complexes that are potential for CO2 geological storage. In Hungary the most abundant potential storage formations are mostly saline aquifers of the Great Hungarian Plain (SE-Hungary), with sandstone reservoir and clayey caprock. The Neogene basin of the Great Hungarian Plain was subsided and then filled by a prograding delta system from NW and NE during the Late Miocene, mostly in the Pannonian time. The most potential storage rock was formed as a fine-grained sandy turbidite interlayered by thin argillaceous beds in the deepest part of the basin. It has relatively high porosity, depth and more than 1000 m thickness. Providing a regional coverage for the sandy turbidite, a 400-500 m thick argillaceous succession was formed in the slope environment. The composition, thickness and low permeability is expected to make it a suitable, leakage-safe caprock of the storage system. This succession is underlain by argillaceous rocks that were formed in the basin, far from sediment input and overlain by interfingering siltstone, sandstone and claystone succession formed in delta and shoreline environments and in the alluvial plain. Core samples have been collected from the potential reservoir rock and its cap rock in the Great Hungarian Plain's succession. The water compositions of the studied depth were known from well-log database. Using the information, acquired from these archive documents, we have constructed input data for geochemical modeling in order to to study the effect of pCO2 injection in the potential

  9. Geochemical monitoring using noble gases and carbon isotopes: study of a natural reservoir

    International Nuclear Information System (INIS)

    Jeandel, E.

    2008-12-01

    To limit emissions of greenhouse gases in the atmosphere, CO 2 geological sequestration appears as a solution in the fight against climate change. The development of reliable monitoring tools to ensure the sustainability and the safety of geological storage is a prerequisite for the implementation of such sites. In this framework, a geochemical method using noble gas and carbon isotopes geochemistry has been tested on natural and industrial analogues. The study of natural analogues from different geological settings showed systematic behaviours of the geochemical parameters, depending on the containment sites, and proving the effectiveness of these tools in terms of leak detection and as tracers of the behaviour of CO 2 . Moreover, an experience of geochemical tracing on a natural gas storage has demonstrated that it is possible to identify the physical-chemical processes taking place in the reservoir to a human time scale, increasing interest in the proposed tool and providing general information on its use. (author)

  10. Experimental study on the mechanism of hydraulic fracture growth in a glutenite reservoir

    Science.gov (United States)

    Ma, Xinfang; Zou, Yushi; Li, Ning; Chen, Ming; Zhang, Yinuo; Liu, Zizhong

    2017-04-01

    Glutenite reservoirs are frequently significantly heterogeneous because of their unique depositional environment. The presence of gravel in this type of formation complicates the growth path of hydraulic fracture (HF). In this study, laboratory fracturing experiments were conducted on six large natural glutenite specimens (300 mm × 300 mm × 300 mm) using a true triaxial hydraulic fracturing system to investigate the growth law of HF in glutenite reservoirs. Before the experiments were performed, the rock properties of the gravel particles and matrix in the glutenite specimens were determined using various apparatuses. The effects of gravel size, horizontal differential stress, fracturing fluid type (or viscosity), and flow rate on the HF growth pattern, fracture width, and injection pressure were examined in detail. Similar to previous studies, four types of HF intersections with gravel particles, namely, termination, penetration, deflection, and attraction, were observed. The HF growth path in the glutenite specimens with large gravel (40 mm-100 mm) is likely branched and tortuous even under high horizontal differential stress. The HF growth path in the glutenite specimens with small gravel (less than 20 mm) is simple, but a process zone with multiple thin fractures may be created. Breakdown pressure may increase significantly when HF initiates from high-strength gravel particles, which are mainly composed of quartz. HF propagation is likely limited within high-strength gravel particles, thereby resulting in narrow fractures and even termination. The use of low-viscosity fluids, such as slickwater, and the low injection rate can further limit HF growth, particularly its width. As a response, high extension pressure builds up during fracturing.

  11. Global Hawk Systems Engineering. Case Study

    Science.gov (United States)

    2010-01-01

    Charles Garland, whose support was integral in guiding me throughout this case study. Bill Kinzig Global Hawk Systems Engineering Case Study...necessary to characterize the system’s utility. 3.2.3.2 First Flight AV-1 rolled out of the TRA facility on February 20, 1997. While at Lindbergh Field... Lindbergh Field, but its delivery to Edwards AFB, California, was already late. Thus, the air vehicle was disassembled and trucked to Edwards AFB on

  12. Conceptual study of advanced VTOL transport aircraft engine

    OpenAIRE

    Saito, Yoshio; Endo, Masanori; Matsuda, Yukio; Sugiyama, Nanahisa; Watanabe, Minoru; Sugahara, Noboru; Yamamoto, Kazuomi; 齊藤 喜夫; 遠藤 征紀; 松田 幸雄; 杉山 七契; 渡辺 実; 菅原 昇; 山本 一臣

    1996-01-01

    A new concept for a quiet engine for high subsonic VTOL transport aircraft is studied and presented. The concept engine, which is called the separated core turbofan engine, is effectively applied. It is composed of three core engines, two cruise fan engines and six lift fan engines. The cruise fan engines are optimized for high subsonic cruise, and the lift fan engines produce about 98 kN (10,000 kgf) of thrust and can realize highly quiet operation. In this study, no technical problems have ...

  13. Sensitivity analysis and economic optimization studies of inverted five-spot gas cycling in gas condensate reservoir

    Science.gov (United States)

    Shams, Bilal; Yao, Jun; Zhang, Kai; Zhang, Lei

    2017-08-01

    Gas condensate reservoirs usually exhibit complex flow behaviors because of propagation response of pressure drop from the wellbore into the reservoir. When reservoir pressure drops below the dew point in two phase flow of gas and condensate, the accumulation of large condensate amount occurs in the gas condensate reservoirs. Usually, the saturation of condensate accumulation in volumetric gas condensate reservoirs is lower than the critical condensate saturation that causes trapping of large amount of condensate in reservoir pores. Trapped condensate often is lost due to condensate accumulation-condensate blockage courtesy of high molecular weight, heavy condensate residue. Recovering lost condensate most economically and optimally has always been a challenging goal. Thus, gas cycling is applied to alleviate such a drastic loss in resources. In gas injection, the flooding pattern, injection timing and injection duration are key parameters to study an efficient EOR scenario in order to recover lost condensate. This work contains sensitivity analysis on different parameters to generate an accurate investigation about the effects on performance of different injection scenarios in homogeneous gas condensate system. In this paper, starting time of gas cycling and injection period are the parameters used to influence condensate recovery of a five-spot well pattern which has an injection pressure constraint of 3000 psi and production wells are constraint at 500 psi min. BHP. Starting injection times of 1 month, 4 months and 9 months after natural depletion areapplied in the first study. The second study is conducted by varying injection duration. Three durations are selected: 100 days, 400 days and 900 days. In miscible gas injection, miscibility and vaporization of condensate by injected gas is more efficient mechanism for condensate recovery. From this study, it is proven that the application of gas cycling on five-spot well pattern greatly enhances condensate recovery

  14. Evaluating National Weather Service Seasonal Forecast Products in Reservoir Operation Case Studies

    Science.gov (United States)

    Nielson, A.; Guihan, R.; Polebistki, A.; Palmer, R. N.; Werner, K.; Wood, A. W.

    2014-12-01

    Forecasts of future weather and streamflow can provide valuable information for reservoir operations and water management. A challenge confronting reservoir operators today is how to incorporate both climate and streamflow products into their operations and which of these forecast products are most informative and useful for optimized water management. This study incorporates several reforecast products provided by the Colorado Basin River Forecast Center (CBRFC) which allows a complete retrospective analysis of climate forecasts, resulting in an evaluation of each product's skill in the context of water resources management. The accuracy and value of forecasts generated from the Climate Forecast System version 2 (CFSv2) are compared to the accuracy and value of using an Ensemble Streamflow Predictions (ESP) approach. Using the CFSv2 may offer more insight when responding to climate driven extremes than the ESP approach because the CFSv2 incorporates a fully coupled climate model into its forecasts rather than using all of the historic climate record as being equally probable. The role of forecast updating frequency will also be explored. Decision support systems (DSS) for both Salt Lake City Parley's System and the Snohomish County Public Utility Department's (SnoPUD) Jackson project will be used to illustrate the utility of forecasts. Both DSS include a coupled simulation and optimization model that will incorporate system constraints, operating policies, and environmental flow requirements. To determine the value of the reforecast products, performance metrics meaningful to the managers of each system are to be identified and quantified. Without such metrics and awareness of seasonal operational nuances, it is difficult to identify forecast improvements in meaningful ways. These metrics of system performance are compared using the different forecast products to evaluate the potential benefits of using CFSv2 seasonal forecasts in systems decision making.

  15. Construction of a carbonate reservoir model using pressure transient data : field case study

    Energy Technology Data Exchange (ETDEWEB)

    Taheri, S. [Petro-Iran, (Iran, Islamic Republic of); Ghanizadeh, M. [Tehran Energy, (Iran, Islamic Republic of); Haghighi, M. [Tehran Univ., (Iran, Islamic Republic of)

    2004-07-01

    Pressure transient data was integrated with other reservoir information to create a geological model of a carbonate reservoir in the Salaman offshore field in Iran. The model was created using seismic and well log data as well as the interpretation of 99 well tests performed in this field. Several features such as sealing faults, aquifer, fracturing and layering systems were observed. Two faults were identified in the northern part of the reservoir. The distance between the major fault and well number 27 was less than predicted from seismic data. An active aquifer and minor fault were also identified near well number 6. A fracture system was identified around well number 22. Most well tests showed communication between different layers of the reservoirs, suggesting interconnected layers in terms of geology. All calculated permeabilities from the well tests were found to be significantly higher than those from core analysis, suggesting that discrete fractures exist throughout the reservoir. The northern region of the reservoir has the highest permeability values and the lowest values are observed in the central part of the reservoir. 18 refs., 6 figs.

  16. Numerical study of sediment and137Cs discharge out of reservoirs during various scale rainfall events.

    Science.gov (United States)

    Kurikami, Hiroshi; Funaki, Hironori; Malins, Alex; Kitamura, Akihiro; Onishi, Yasuo

    2016-11-01

    Contamination of reservoirs with radiocesium is one of the main concerns in Fukushima Prefecture, Japan. We performed simulations using the three-dimensional finite volume code FLESCOT to understand sediment and radiocesium transport in generic models of reservoirs with parameters similar to those in Fukushima Prefecture. The simulations model turbulent water flows, transport of sediments with different grain sizes, and radiocesium migration both in dissolved and particulate forms. To demonstrate the validity of the modeling approach for the Fukushima environment, we performed a test simulation of the Ogaki Dam reservoir over Typhoon Man-yi in September 2013 and compared the results with field measurements. We simulated a set of generic model reservoirs systematically varying features such as flood intensity, reservoir volume and the radiocesium distribution coefficient. The results ascertain how these features affect the amount of sediment or 137 Cs discharge downstream from the reservoirs, and the forms in which 137 Cs is discharged. Silt carries the majority of the radiocesium in the larger flood events, while the clay-sorbed followed by dissolved forms are dominant in smaller events. The results can be used to derive indicative values of discharges from Fukushima reservoirs under arbitrary flood events. For example the generic model simulations indicate that about 30% of radiocesium that entered the Ogaki Dam reservoir over the flood in September 2015 caused by Typhoon Etau discharged downstream. Continued monitoring and numerical predictions are necessary to quantify future radiocesium migration in Fukushima Prefecture and evaluate possible countermeasures since reservoirs can be a sink of radiocesium. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Reservoir characterization of the Snorre Field

    OpenAIRE

    Gjestvang, Jørgen

    2016-01-01

    Master's thesis in Petroleum engineering The fluvial sandstone in the Snorre field consists of braided to meander streams deposited in arid and in humid climate that show a clear differences in the sedimentology and reservoir properties, especially the silt content in large part of the reservoir which decrease the reservoir properties and water saturation. The heterogeneity of these fluvial formations combined with the faulting history makes this reservoir highly complex with many local an...

  18. Reviving Abandoned Reservoirs with High-Pressure Air Injection: Application in a Fractured and Karsted Dolomite Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Robert Loucks; Stephen C. Ruppel; Dembla Dhiraj; Julia Gale; Jon Holder; Jeff Kane; Jon Olson; John A. Jackson; Katherine G. Jackson

    2006-09-30

    Engineering (both at The University of Texas at Austin) to define the controls on fluid flow in the reservoir as a basis for developing a reservoir model. The successful development of HPAI technology has tremendous potential for increasing the flow of oil from deep carbonate reservoirs in the Permian Basin, a target resource that can be conservatively estimated at more than 1.5 billion barrels. Successful implementation in the field chosen for demonstration, for example, could result in the recovery of more than 34 million barrels of oil that will not otherwise be produced. Geological and petrophysical analysis of available data at Barnhart field reveals the following important observations: (1) the Barnhart Ellenburger reservoir is similar to most other Ellenburger reservoirs in terms of depositional facies, diagenesis, and petrophysical attributes; (2) the reservoir is characterized by low to moderate matrix porosity much like most other Ellenburger reservoirs in the Permian Basin; (3) karst processes (cave formation, infill, and collapse) have substantially altered stratigraphic architecture and reservoir properties; (4) porosity and permeability increase with depth and may be associated with the degree of karst-related diagenesis; (5) tectonic fractures overprint the reservoir, improving overall connectivity; (6) oil-saturation profiles show that the oil-water contact (OWC) is as much as 125 ft lower than previous estimations; (7) production history and trends suggest that this reservoir is very similar to other solution-gas-drive reservoirs in the Permian Basin; and (8) reservoir simulation study showed that the Barnhart reservoir is a good candidate for HPAI and that application of horizontal-well technology can improve ultimate resource recovery from the reservoir.

  19. Effect of pore structure on the seepage characteristics of tight sandstone reservoirs: A case study of Upper Jurassic Penglaizhen Fm reservoirs in the western Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Liqiang Sima

    2017-01-01

    Full Text Available Tight sandstone reservoirs are characterized by complex pore structures and strong heterogeneity, and their seepage characteristics are much different from those of conventional sandstone reservoirs. In this paper, the tight sandstone reservoirs of Upper Jurassic Penglaizhen Fm in western Sichuan Basin were analyzed in terms of their pore structures by using the data about physical property, mercury injection and nuclear magnetic resonance (NMR tests. Then, the seepage characteristics and the gas–water two-phase migration mechanisms and distribution of tight sandstone reservoirs with different types of pore structures in the process of hydrocarbon accumulation and development were simulated by combining the relative permeability experiment with the visual microscopic displacement model. It is shown that crotch-like viscous fingering occurs in the process of gas front advancing in reservoirs with different pore structures. The better the pore structure is, the lower the irreducible water saturation is; the higher the gas-phase relative permeability of irreducible water is, the more easily the gas reservoir can be developed. At the late stage of development, the residual gas is sealed in reservoirs in the forms of bypass, cutoff and dead end. In various reservoirs, the interference between gas and water is stronger, so gas and water tends to be produced simultaneously. The sealed gas may reduce the production rate of gas wells significantly, and the existence of water phase may reduce the gas permeability greatly; consequently, the water-bearing low-permeability tight sandstone gas reservoirs reveal serious water production, highly-difficult development and low-recovery percentage at the late stage, which have adverse impacts on the effective production and development of gas wells.

  20. Reservoir Maintenance and Development Task Report for the DOE Geothermal Technologies Office GeoVision Study.

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, Thomas Stephen [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Finger, John T. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carrigan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Foris, Adam [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kennedy, Mack B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Corbet, Thomas F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Doughty, Christine A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pye, Steven [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sonnenthal, Eric L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    This report documents the key findings from the Reservoir Maintenance and Development (RM&D) Task of the U.S. Department of Energy's (DOE), Geothermal Technologies Office (GTO) Geothermal Vision Study (GeoVision Study). The GeoVision Study had the objective of conducting analyses of future geothermal growth based on sets of current and future geothermal technology developments. The RM&D Task is one of seven tasks within the GeoVision Study with the others being, Exploration and Confirmation, Potential to Penetration, Institutional Market Barriers, Environmental and Social Impacts, Thermal Applications, and Hybrid Systems. The full set of findings and the details of the GeoVision Study can be found in the final GeoVision Study report on the DOE-GTO website. As applied here, RM&D refers to the activities associated with developing, exploiting, and maintaining a known geothermal resource. It assumes that the site has already been vetted and that the resource has been evaluated to be of sufficient quality to move towards full-scale development. It also assumes that the resource is to be developed for power generation, as opposed to low-temperature or direct use applications. This document presents the key factors influencing RM&D from both a technological and operational standpoint and provides a baseline of its current state. It also looks forward to describe areas of research and development that must be pursued if the development geothermal energy is to reach its full potential.

  1. Iodine-129 chronological study of brines from an Ordovician paleokarst reservoir in the Lunnan oilfield, Tarim Basin

    International Nuclear Information System (INIS)

    Chen, Jian; Liu, Dayong; Peng, Ping'an; Ning, Chen; Xiaolin, Hou; Baoshou, Zhang; Zhongyao, Xiao

    2016-01-01

    Previous studies have shown that brines in an Ordovician paleokarst reservoir of the Lunnan oilfield in the Tarim Basin, China, are the product of mixing of paleo-evaporated seawater in the east with paleometeoric waters in the west. In order to put time constraints on the brine and related hydrocarbons in this field, 10 brine samples were collected, for which the iodine concentrations and 129 I/I ratios were measured and discussed. The iodine concentration (3.70–31.2 mg/L) and the 129 I/I ratio (189–897 × 10 −15 ) show that the iodine in the paleoseawater and meteoric water (MW) had different origins and 129 I characteristics. The paleoseawater has a high iodine content (∼31 mg/L), indicating that iodine was introduced into the reservoir along with thermally generated hydrocarbons, possibly in the Cretaceous, from the Caohu Sag in the eastern area. Based on consideration of all possible origins of iodine and 129 I in the brines, it is suggested that the meteoric water maintained its initial iodine content (0.01 mg/L) and 129 I/I ratio (1500 × 10 −15 ), whereas the iodine-enriched paloseawater (IPSW) exhibited a secular 129 I equilibrium (N sq  = 39 atom/μL) as a result of fissiogenic 129 I input in the reservoir over a long period of time. The model of brine evolution developed on that basis confirmed that meteoric water entered the reservoir in the Miocene at about 10 Ma, and partially mixed with the iodine-enriched paleoseawater. The movement of meteoric water was facilitated by faults created during the Himalayan orogeny, then became more dense after dissolving Paleogene halite and infiltrated into the reservoir at high pressure. The iodine and 129 I concentration in the brine contains information about the path and history of the fluid in the reservoir. This may be useful in oil exploration, since the movement of water was, to some extent, related to hydrocarbon migration. - Highlights: • A 129 I chronological study of deep oilfield

  2. Theoretical and experimental study of thermoacoustic engines

    Science.gov (United States)

    Raspet, Richard; Bass, Henry E.; Arnott, W. P.

    1992-12-01

    A three year study of thermoacoustic engines operating as prime movers and refrigerators was completed. The major thrust of this effort was the use and theoretical description of ceramic honeycomb structures as the active element in thermoacoustic engines. An air-filled demonstration prime mover was constructed and demonstrated at Acoustical Society of America and IEE meetings. A helium-filled test prime mover was designed and built an is being employed in studies of the threshold of oscillation as a function of temperature difference and pressure. In addition, acoustically based theories of the thermoacoustic engine have been developed and tested for a parallel plate stack at the Naval Postgraduate School and for a honeycomb stack at the University of Mississippi. Most of this work is described in detail in the attached publications. In this report we will give an overview of the research completed to date and its relationship to work performed at the Naval Postgraduate School and to future work at the University of Mississippi.

  3. Radioecological study of the open reservoirs of the North Kazakhstan area uranium-mining deposits

    International Nuclear Information System (INIS)

    Kazymbet, P.K.; Bakhtin, M.M.; Imasheva, B.S.; Bud'ko, O.G.

    2003-01-01

    In the paper the radiological data of open reservoirs in the former uranium-mining enterprise territory and settlements are given. The received data show, that both the Kutunguz river and reservoirs close to uranium-mining enterprise are polluted by radionuclides. On the received data it is possible to assume, that the essential contribution to the Kutunguz river contamination by radioactive substances the acting mine 11 water is giving. (author)

  4. A successful case study on development of a giant, highly fractured carbonate heavy-oil reservoir in Iran

    Energy Technology Data Exchange (ETDEWEB)

    Tabibi, M.; Mousavi Mirkalaei, S.M. [National Iranian Oil Co., Tehran (Iran, Islamic Republic of)

    2005-11-01

    Most Iranian heavy oil fields occur in carbonate reservoirs. Consequently, research from other types of reservoirs needs to be carefully tested and applied, as some in situ combustion methods can be dangerous and harmful to carbonate reservoirs. This paper presented results from a case study and planned pilot on an oil field with 3.6 billion barrels of oil in place. Pressure was 1408 psi at 1119 measured drilled depth. Details of previous studies in the field were presented, including a 3-D seismic and side view seismic location study. Details of a fracture study were also presented. A swabbing operation was conducted on a single well in order to identify rock and fluid properties. A progressing cavity pump (PCP) was planned for the well. Stimulation methods for enhanced oil recovery were reviewed, and included cold production such as gas lift or solvent treatment and thermal recovery such as steam injection and cyclic steam stimulation. It was estimated that the planned pilot study would last approximately 5 years. Results indicate that gas lifting methods are a suitable cold stimulation technique option for the carbonate reservoir. Challenges and technical considerations include a geological study; drilling operation; reservoir characterization and various techniques of production. Results gained from cores and surface studies have shown that the field was highly fractured, and that most of the fractures were vertical or sub-vertical. Results of the swabbing operation showed that the use of surface pumps would help to increase flow rate in continuous production.18 refs., 3 tabs., 6 figs.

  5. Sediment management for reservoir

    International Nuclear Information System (INIS)

    Rahman, A.

    2005-01-01

    All natural lakes and reservoirs whether on rivers, tributaries or off channel storages are doomed to be sited up. Pakistan has two major reservoirs of Tarbela and Managla and shallow lake created by Chashma Barrage. Tarbela and Mangla Lakes are losing their capacities ever since first impounding, Tarbela since 1974 and Mangla since 1967. Tarbela Reservoir receives average annual flow of about 62 MAF and sediment deposits of 0.11 MAF whereas Mangla gets about 23 MAF of average annual flows and is losing its storage at the rate of average 34,000 MAF annually. The loss of storage is a great concern and studies for Tarbela were carried out by TAMS and Wallingford to sustain its capacity whereas no study has been done for Mangla as yet except as part of study for Raised Mangla, which is only desk work. Delta of Tarbala reservoir has advanced to about 6.59 miles (Pivot Point) from power intakes. In case of liquefaction of delta by tremor as low as 0.12g peak ground acceleration the power tunnels I, 2 and 3 will be blocked. Minimum Pool of reservoir is being raised so as to check the advance of delta. Mangla delta will follow the trend of Tarbela. Tarbela has vast amount of data as reservoir is surveyed every year, whereas Mangla Reservoir survey was done at five-year interval, which has now been proposed .to be reduced to three-year interval. In addition suspended sediment sampling of inflow streams is being done by Surface Water Hydrology Project of WAPDA as also some bed load sampling. The problem of Chasma Reservoir has also been highlighted, as it is being indiscriminately being filled up and drawdown several times a year without regard to its reaction to this treatment. The Sediment Management of these reservoirs is essential and the paper discusses pros and cons of various alternatives. (author)

  6. Biotelemetry study of spring and summer habitat selection by striped bass in Cherokee Reservoir, Tennessee, 1978. [Morone saxatilis

    Energy Technology Data Exchange (ETDEWEB)

    Schaich, B.A.; Coutant, C.C.

    1980-08-01

    Habitat selection of 31 adult striped bass was monitored by temperature sensing ultrasonic and radio transmitters in Cherokee Reservoir, Tennessee, from March through October 1978. This study sought to corroborate summer data obtained by Waddle (1979) in 1977 and to examine mechanisms of habitat selection by observing establishment of the summer distribution. During the spring and early summer months the striped bass ranged throughout the study area in the downstream half of the reservoir. Fish stayed near the bottom at the preferred temperatures throughout the whole study, and no individuals were observed in open water. Movement rates of up to 2.6 km/day were estimated, and rates of 1 km/day were common in the spring. By late July they were apparently avoiding low dissolved oxygen (D.O.) concentrations (<3 mg/l) near the bottom of the main reservoir and epilimnion temperatures greater than 22/sup 0/C, and they moved into cool, oxygenated spring or creek channels (refuges). Low movement rates of 0 to 25 m/day within these refuges occurred. The rates of the few migrations between refuges could not be estimated. Tagged fish moved out of the refuges 3 to 4 weeks after the fall overturn when reservoir temperatures approximated 22 to 24/sup 0/C.

  7. Nuclear thermal propulsion engine cost trade studies

    International Nuclear Information System (INIS)

    Paschall, R.K.

    1993-01-01

    The NASA transportation strategy for the Mars Exploration architecture includes the use of nuclear thermal propulsion as the primary propulsion system for Mars transits. It is anticipated that the outgrowth of the NERVA/ROVER programs will be a nuclear thermal propulsion (NTP) system capable of providing the propulsion for missions to Mars. The specific impulse (Isp) for such a system is expected to be in the 870 s range. Trade studies were conducted to investigate whether or not it may be cost effective to invest in a higher performance (Isp>870 s) engine for nuclear thermal propulsion for missions to Mars. The basic cost trades revolved around the amount of mass that must be transported to low-earth orbit prior to each Mars flight and the cost to launch that mass. The mass required depended on the assumptions made for Mars missions scenarios including piloted/cargo flights, number of Mars missions, and transit time to Mars. Cost parameters included launch cost, program schedule for development and operations, and net discount rate. The results were very dependent on the assumptions that were made. Under some assumptions, higher performance engines showed cost savings in the billions of dollars; under other assumptions, the additional cost to develop higher performance engines was not justified

  8. Hydrocarbon Potential in Sandstone Reservoir Isolated inside Low Permeability Shale Rock (Case Study: Beruk Field, Central Sumatra Basin)

    Science.gov (United States)

    Diria, Shidqi A.; Musu, Junita T.; Hasan, Meutia F.; Permono, Widyo; Anwari, Jakson; Purba, Humbang; Rahmi, Shafa; Sadjati, Ory; Sopandi, Iyep; Ruzi, Fadli

    2018-03-01

    Upper Red Bed, Menggala Formation, Bangko Formation, Bekasap Formation and Duri Formationare considered as the major reservoirs in Central Sumatra Basin (CSB). However, Telisa Formation which is well-known as seal within CSB also has potential as reservoir rock. Field study discovered that lenses and layers which has low to high permeability sandstone enclosed inside low permeability shale of Telisa Formation. This matter is very distinctive and giving a new perspective and information related to the invention of hydrocarbon potential in reservoir sandstone that isolated inside low permeability shale. This study has been conducted by integrating seismic data, well logs, and petrophysical data throughly. Facies and static model are constructed to estimate hydrocarbon potential resource. Facies model shows that Telisa Formation was deposited in deltaic system while the potential reservoir was deposited in distributary mouth bar sandstone but would be discontinued bedding among shale mud-flat. Besides, well log data shows crossover between RHOB and NPHI, indicated that distributary mouth bar sandstone is potentially saturated by hydrocarbon. Target area has permeability ranging from 0.01-1000 mD, whereas porosity varies from 1-30% and water saturation varies from 30-70%. The hydrocarbon resource calculation approximates 36.723 MSTB.

  9. Dam break flood wave under different reservoir's capacities and ...

    Indian Academy of Sciences (India)

    Dam failure has been the subject of many hydraulic engineering studies due to its complicated physics with many uncertainties involved and the potential to cause many ... This paper presents an experimental study on instantaneous dam failure flood under different reservoir's capacities and lengths in which the side slopes ...

  10. Methods for estimating petrophysical parameters from well logs in tight oil reservoirs: a case study

    International Nuclear Information System (INIS)

    Zhao, Peiqiang; Zhuang, Wen; Mao, Zhiqiang; Tong, Zemin; Sun, Zhongchun; Wang, Zhenlin; Luo, Xingping

    2016-01-01

    Estimating petrophysical parameters from well logs plays a significant role in the exploration and development of tight oil resources, but faces challenges. What’s more, the methods for petrophysical parameters from well logs are paid little attention at present. In this paper, the typical tight oil reservoirs of Northwest China are used as an example. Based on the characteristics of mineralogy and fluids in the study field, the rock is assumed into five components which are clays, quartz and feldspar, carbonates, kerogen and pore fluids (porosity). The sum of kerogen content and porosity is defined as the apparent porosity. Then, two porosity log response equations are established. Once the clay content is determined by an individual method, the quartz and feldspar content, carbonate content and apparent porosity are calculated through the established equations. The kerogen content is the difference of the apparent porosity and porosity from nuclear magnetic resonance (NMR) logs. This paper also presents a new approach that combines the complex refractive index method (CRIM) and pseudo Archie method to compute saturation from dielectric logs, which avoids selection for the dielectric constants of each of the minerals. The effectiveness and reliability of these methods are verified by the successful application in the study of the target tight oil play in Northwest China. (paper)

  11. Study of reservoir properties and operational parameters influencing in the steam assisted gravity drainage process in heavy oil reservoirs by numerical simulation

    Directory of Open Access Journals (Sweden)

    Farshad Dianatnasab

    2016-09-01

    Full Text Available This study was originally aimed at suggesting a two-dimensional program for the Steam Assisted Gravity Drainage (SAGD process based on the correlations proposed by Heidari and Pooladi, using the MATLAB software. In fact, the work presented by Chung and Butler was used as the basis for this study. Since the steam chamber development process and the SAGD production performance are functions of reservoir properties and operational parameters, the new model is capable of analyzing the effects of parameters such as height variation at constant length, length variation at constant height, permeability variation, thermal diffusivity coefficient variation and well location on the production rate and the oil recovery among which, the most important one is the thermal diffusivity coefficient analysis. To investigate the accuracy and authenticity of the model outcomes, they were compared with the results obtained by Chung and Butler. The privilege of this method over that proposed by Heidari and Pooladi lies in its ability to investigate the effect of thermal diffusivity coefficient on recovery and analyzing the effect of temperature distribution changes on thickness diffusivity. Based on the observations, results reveal that the proposed model gives more accurate predictions compared to the old model proposed by Chung & Butler.

  12. Responses of spatial-temporal dynamics of bacterioplankton community to large-scale reservoir operation: a case study in the Three Gorges Reservoir, China.

    Science.gov (United States)

    Li, Zhe; Lu, Lunhui; Guo, Jinsong; Yang, Jixiang; Zhang, Jiachao; He, Bin; Xu, Linlin

    2017-02-13

    Large rivers are commonly regulated by damming, yet the effects of such disruption on bacterioplankton community structures have not been adequately studied. The aim of this study was to explore the biogeographical patterns present under dam regulation and to uncover the major drivers structuring bacterioplankton communities. Bacterioplankton assemblages in the Three Gorges Reservoir (TGR) were analyzed using Illumina Miseq sequencing by comparing seven sites located within the TGR before and after impoundment. This approach revealed ecological and spatial-temporal variations in bacterioplankton community composition along the longitudinal axis. The community was dynamic and dominated by Proteobacteria and Actinobacteria phyla, encompassing 39.26% and 37.14% of all sequences, respectively, followed by Bacteroidetes (8.67%) and Cyanobacteria (3.90%). The Shannon-Wiener index of the bacterioplankton community in the flood season (August) was generally higher than that in the impoundment season (November). Principal Component Analysis of the bacterioplankton community compositions showed separation between different seasons and sampling sites. Results of the relationship between bacterioplankton community compositions and environmental variables highlighted that ecological processes of element cycling and large dam disturbances are of prime importance in driving the assemblages of riverine bacterioplankton communities.

  13. Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms.

    Directory of Open Access Journals (Sweden)

    Chaohua Guo

    Full Text Available Development of unconventional shale gas reservoirs (SGRs has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no systematical work has been conducted considering all reasonable transport mechanisms. And there are very few works on sensitivity studies of uncertain parameters using real parameter ranges. Hence, a detailed and systematic study of reservoir simulation with MsFHW is still necessary. In this paper, a dual porosity model was constructed to estimate the effect of parameters on shale gas production with MsFHW. The simulation model was verified with the available field data from the Barnett Shale. The following mechanisms have been considered in this model: viscous flow, slip flow, Knudsen diffusion, and gas desorption. Langmuir isotherm was used to simulate the gas desorption process. Sensitivity analysis on SGRs' production performance with MsFHW has been conducted. Parameters influencing shale gas production were classified into two categories: reservoir parameters including matrix permeability, matrix porosity; and hydraulic fracture parameters including hydraulic fracture spacing, and fracture half-length. Typical ranges of matrix parameters have been reviewed. Sensitivity analysis have been conducted to analyze the effect of the above factors on the production performance of SGRs. Through comparison, it can be found that hydraulic

  14. Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms.

    Science.gov (United States)

    Guo, Chaohua; Wei, Mingzhen; Liu, Hong

    2018-01-01

    Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hydraulic fracture properties. However, rare simulation work has been conducted for multi-stage hydraulic fractured SGRs. Most of them use well testing methods, which have too many unrealistic simplifications and assumptions. Also, no systematical work has been conducted considering all reasonable transport mechanisms. And there are very few works on sensitivity studies of uncertain parameters using real parameter ranges. Hence, a detailed and systematic study of reservoir simulation with MsFHW is still necessary. In this paper, a dual porosity model was constructed to estimate the effect of parameters on shale gas production with MsFHW. The simulation model was verified with the available field data from the Barnett Shale. The following mechanisms have been considered in this model: viscous flow, slip flow, Knudsen diffusion, and gas desorption. Langmuir isotherm was used to simulate the gas desorption process. Sensitivity analysis on SGRs' production performance with MsFHW has been conducted. Parameters influencing shale gas production were classified into two categories: reservoir parameters including matrix permeability, matrix porosity; and hydraulic fracture parameters including hydraulic fracture spacing, and fracture half-length. Typical ranges of matrix parameters have been reviewed. Sensitivity analysis have been conducted to analyze the effect of the above factors on the production performance of SGRs. Through comparison, it can be found that hydraulic fracture

  15. [Studies on seasonal variation and sources of nitrogen and phosphorus in a canyon reservoir used as water source].

    Science.gov (United States)

    Huang, Ting-lin; Qin, Chang-hai; Li, Xuan

    2013-09-01

    According to a continuous survey on Shibianyu Reservoir located north of the Qinling Mountains which lasted for about one and a half years and a simulation study in laboratory, conclusions were drawn as follows. The average concentrations of total nitrogen (TN) and total phosphorus (TP) were 2. 67 mg x L(-1) and 0.04 mg x L(-1), respectively, and the highest values were recorded in the high flow period followed by the median water period, while the lowest values were found in the dry period. The reservoir was in severe eutrophication and the content of chlorophyll a and algal cell density reached 50 mg x m(-3) and 10,000 x 10(4) cells x L(-1), respectively. The yearly input and output of TN was respectively 203.1 t and 181.3 t, while the yearly input and output of TP was respectively 4. 2 t and 4.1 t. Exogenous pollution accounted for more than 90% of the total load. The sediment in reservoir showed an accumulation tendency all year round and the net annual accumulation of TN and TP was 20.2 t and 0. 8 t, respectively. The key of controlling reservoir pollution is to control the endogenous pollution.

  16. Geochemical assessment of a subtropical reservoir: a case study in curitiba, Southern Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Godoi, Ricardo Henrique Moreton; Hirata, Patricia Y.; Godoi, Ana F.L.; Cunha, Cynara L.N.; Soares, Ana P.K.; Gobbi, Eduardo F. [Environmental Engineering Department, Federal University of Parana/UFPR, Curitiba, Parana (Brazil); Bitterncourt, Andre V.L. [Department of Geology, Federal University of Parana/UFPR, Curitiba, Parana (Brazil); Jafelicci, Miguel Jr.; Santos, Francisco J. dos; Bini, Rafael [Chemistry Institute, Sao Paulo State University UNESP, Araraquara, Sao Paulo (Brazil); Zara, Liuz F.; Gardolinski, Jose E.F.C.; Reis Neto, Jose M. [University of Brasilia, Planaltina, DC (Brazil); Potgieter-Vermaak, Sanja [Division of Chemistry and Environmental Science, School of Science and the Environment, Manchester Metropolitan University, Manchester (United Kingdom); Department of Chemistry, Micro and Trace Analysis Centre, University of Antwerp, Antwerp (Belgium); Molecular Science Institute, School of Chemistry, University of the Witwatersrand, Johannesburg (South Africa); Rotondo, Giuliana Gatto; Grieken, Rene van [Department of Chemistry, Micro and Trace Analysis Centre, University of Antwerp, Antwerp (Belgium)

    2012-04-15

    Suspended particles and dissolved substances in water provide reactive surfaces, influence metabolic activity and contribute to the net sediment deposition. It therefore plays an important part in the ecology and quality of the water mass. The water quality in reservoirs is crucial and it is naturally maintained by flushing and sedimentation, which continuously remove phosphorus from the water. In some reservoirs, however, these removal processes are countered by recycling of ions which could play a key role to start and/or maintain the eutrophic state. The combination of macro-, trace- and microanalysis techniques can be useful to trace pollution sources through a chemical fingerprint, whether be during an acute environmental disaster or a long-term release of pollutants. The water quality and total metal content of reservoir sediments were assessed in a reservoir, situated in the capital of the Parana State, in the South-Eastern part of Brazil. The goal of this paper was to determine the metal presence in the sediment and metal and ionic speciation in the Green River reservoir water. Water and bed sediment samples, collected from various sites during 2008 and 2009, were investigated using XRF, ICP-OES, ICP-MS, XRD and zeta potential measurements. Based on the results, the heavy metal concentration and chemical composition of the suspended matter in the water samples, as well as the sediment's chemical composition will be discussed. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  17. A combination of streamtube and geostatical simulation methodologies for the study of large oil reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarty, A.; Emanuel, A.S.; Bernath, J.A. [Chevron Petroleum Technology Company, LaHabra, CA (United States)

    1997-08-01

    The application of streamtube models for reservoir simulation has an extensive history in the oil industry. Although these models are strictly applicable only to fields under voidage balance, they have proved to be useful in a large number of fields provided that there is no solution gas evolution and production. These models combine the benefit of very fast computational time with the practical ability to model a large reservoir over the course of its history. These models do not, however, directly incorporate the detailed geological information that recent experience has taught is important. This paper presents a technique for mapping the saturation information contained in a history matched streamtube model onto a detailed geostatistically derived finite difference grid. With this technique, the saturation information in a streamtube model, data that is actually statistical in nature, can be identified with actual physical locations in a field and a picture of the remaining oil saturation can be determined. Alternatively, the streamtube model can be used to simulate the early development history of a field and the saturation data then used to initialize detailed late time finite difference models. The proposed method is presented through an example application to the Ninian reservoir. This reservoir, located in the North Sea (UK), is a heterogeneous sandstone characterized by a line drive waterflood, with about 160 wells, and a 16 year history. The reservoir was satisfactorily history matched and mapped for remaining oil saturation. A comparison to 3-D seismic survey and recently drilled wells have provided preliminary verification.

  18. Study of Carrying Capacity Assesment for Natural Fisheries in Jatibarang Reservoir In Semarang City

    Science.gov (United States)

    Sujono, Bambang; Anggoro, Sutrisno

    2018-02-01

    Jatibarang reservoir serves as water supply in dry season and controlling flood in Semarang City. This reservoir is stem Kreo River which cathment areas of 54 km2, pool of area 110 ha and volume is 20 billion m3. This reservoir is potential to develop as natural fisheries area. The goals of this research were to explore existing condition of physical, biological as well as chemical parameter; carrying capacity assessment for natural fisheries; determining appropriate fish species to be developed in Jatibarang reservoir. This research was done in descriptive explorative scheme. Field survey and laboratory analyses were conducted to identify physical, chemical and biological parameters of the water. Physical parameters measured were temperature and water brightness. Chemical parameters measured were pH, DO, phosphate, Ammonia, nitrites and nitrate, while biological parameter measured were chlorophyll-a concentration. Carrying capacity analyses was done referred to the Government Regulation Number 82, 2001 that regulate the management of water quality and water pollution control. Based on the research, it showed that the existing condition of physical, chemical and biological parameters were still good to be used for natural fisheries. Based on TSI index, it classified as eutrofic water. Furthermore, tilapia fish (Oreochromis mossambicus), nile tilapia (Oreochromis niloticus) tawes (Barbonymus gonionotus) and carper fish (Cyprinus carpio) were considered as best species for natural fisheries in Jatibarang Reservoir.

  19. Fault assessment for basement reservoir compartmentalization: Case study at Northeast Betara gas field, South Sumatra Basin

    Science.gov (United States)

    Risyad, M.; Suta, I. N.; Haris, A.

    2017-07-01

    Northeast Betara field is situated on the northern part of prolific South Sumatra Basin. It has produced gas from Lower Talang Akar Formation sandstone and over 90 wells have been drilled. A 3D seismic data was acquired in 2000 and reprocessed in 2012 to enhance the subsurface image. In 2013 an exploratory well NEB Base-1 was drilled and made gas and condensate discovery from the subsequent pre-tertiary basement which is confirmed as granite. The well proved fractured basement reservoir play on paleo high of the structure. The absence of full-diameter conventional core prompts well logs and seismic data analysis by using a workstation. Main methods for fracture prediction have been seismic attributes extraction and structural geology studies of basement provided by image logs on a few exploration wells. Ant tracking attribute is widely employed to image seismic event discontinuities due to extensive faults which generated the natural fractures. Delineations well NEB Base-2 was drilled on second paleo high and unfortunately, it did not find any gas indication from pre-tertiary basement target. Seismic structural interpretation and seismic attributes are conducted to image distribution of event discontinuities related to faults or fracture. We found that compartmentalization on basement involved old faults and both paleo high have undergone different structural history and stress character which resulted in separated fractures distribution.

  20. HIV reservoirs and immune surveillance evasion cause the failure of structured treatment interruptions: a computational study.

    Directory of Open Access Journals (Sweden)

    Emiliano Mancini

    Full Text Available Continuous antiretroviral therapy is currently the most effective way to treat HIV infection. Unstructured interruptions are quite common due to side effects and toxicity, among others, and cannot be prevented. Several attempts to structure these interruptions failed due to an increased morbidity compared to continuous treatment. The cause of this failure is poorly understood and often attributed to drug resistance. Here we show that structured treatment interruptions would fail regardless of the emergence of drug resistance. Our computational model of the HIV infection dynamics in lymphoid tissue inside lymph nodes, demonstrates that HIV reservoirs and evasion from immune surveillance themselves are sufficient to cause the failure of structured interruptions. We validate our model with data from a clinical trial and show that it is possible to optimize the schedule of interruptions to perform as well as the continuous treatment in the absence of drug resistance. Our methodology enables studying the problem of treatment optimization without having impact on human beings. We anticipate that it is feasible to steer new clinical trials using computational models.

  1. Phytoplankton functional groups for ecological assessment in young sub-tropical reservoirs: case study of the Nam-Theun 2 Reservoir, Laos, South-East Asia

    Directory of Open Access Journals (Sweden)

    Joanna Martinet

    2014-05-01

    Full Text Available The early stages following the creation of reservoirs are typically physical and biological unstable periods due to the conversion from a lotic to a lentic ecosystem. The sub-tropical Nam Theun 2 Reservoir (Laos was impounded in 2008. Several limnological parameters were monitored from March 2009 to December 2011 in order to understand the evolution of the phytoplankton community. A strong inter annual variability of hydrodynamic pattern was observed. Rainfall and hydraulic balance were the main physical factors driving the community structure. Periods of highest hydraulic stability led to a phytoplankton biomasses increase. The first assemblages were dominated by the S-C-strategists reaching high biomasses but low diversity. Over the three years, phytoplankton became more diverse due to a diversification of ecological niches, mostly explained by a greater water transparency and a more stable thermal stratification. The applicability of functional groups for biomonitoring in this young sub-tropical reservoir was investigated and compared to a classical taxonomical approach. The dominant functional groups (Lo, A, E, F, N and P characterized the NT2 Reservoir as meso-oligotrophic with a tolerance to low nutrients supply. Our results support the hypothesis that a functional group approach is more informative than a species-based approach to assess trophic level and dissolved organic carbon concentrations in such reservoirs.

  2. Aquarius study - engineering and economic considerations

    International Nuclear Information System (INIS)

    Griffin, Roger F.

    1970-01-01

    The two previous papers described the scope of the Aquarius Study and the various applications considered in evaluating the use of nuclear explosives for the development of water resources in Arizona. Surface storage behind a dam created with the use of nuclear explosives was selected for the major effort, primarily because it could afford the most valid direct comparison between nuclear and conventional methods. In this paper I will focus on the engineering and economic considerations involved in developing and evaluating three concepts for constructing a rockfill dam using nuclear explosives. Engineering development and economic evaluation of the concepts was the principal responsibility of Bechtel Corporation as a consultant in the study to the Arizona Atomic Energy Commission. We depended heavily on information supplied by the Federal participants, notably the U.S. Bureau of Reclamation for site data and the U.S. AEC*s Lawrence Radiation Laboratory for information on nuclear explosives effects. Since the study report has not yet been published and additional material is still forthcoming, some of the information I will present, such as the cost estimates, may be subject to change and should be considered preliminary. (author)

  3. Understanding and Mitigating Reservoir Compaction: an Experimental Study on Sand Aggregates

    Science.gov (United States)

    Schimmel, M.; Hangx, S.; Spiers, C. J.

    2016-12-01

    Fossil fuels continue to provide a source for energy, fuels for transport and chemicals for everyday items. However, adverse effects of decades of hydrocarbons production are increasingly impacting society and the environment. Production-driven reduction in reservoir pore pressure leads to a poro-elastic response of the reservoir, and in many occasions to time-dependent compaction (creep) of the reservoir. In turn, reservoir compaction may lead to surface subsidence and could potentially result in induced (micro)seismicity. To predict and mitigate the impact of fluid extraction, we need to understand production-driven reservoir compaction in highly porous siliciclastic rocks and explore potential mitigation strategies, for example, by using compaction-inhibiting injection fluids. As a first step, we investigate the effect of chemical environment on the compaction behaviour of sand aggregates, comparable to poorly consolidated, highly porous sandstones. The sand samples consist of loose aggregates of Beaujean quartz sand, sieved into a grainsize fraction of 180-212 µm. Uniaxial compaction experiments are performed at an axial stress of 35 MPa and temperature of 80°C, mimicking conditions of reservoirs buried at three kilometres depth. The chemical environment during creep is either vacuum-dry or CO2-dry, or fluid-saturated, with fluids consisting of distilled water, acid solution (CO2-saturated water), alkaline solution (pH 9), aluminium solution (pH 3) and solution with surfactants (i.e., AMP). Preliminary results show that compaction of quartz sand aggregates is promoted in a wet environment compared to a dry environment. It is inferred that deformation is controlled by subcritical crack growth when dry and stress corrosion cracking when wet, both resulting in grain failure and subsequent grain rearrangement. Fluids inhibiting these processes, have the potential to inhibit aggregate compaction.

  4. Lithofacies paleogeography mapping and reservoir prediction in tight sandstone strata: A case study from central Sichuan Basin, China

    Directory of Open Access Journals (Sweden)

    Yuan Zhong

    2017-09-01

    Full Text Available Sand-rich tight sandstone reservoirs are potential areas for oil and gas exploration. However, the high ratio of sandstone thickness to that of the strata in the formation poses many challenges and uncertainties to traditional lithofacies paleogeography mapping. Therefore, the prediction of reservoir sweet spots has remained problematic in the field of petroleum exploration. This study provides new insight into resolving this problem, based on the analyses of depositional characteristics of a typical modern sand-rich formation in a shallow braided river delta of the central Sichuan Basin, China. The varieties of sand-rich strata in the braided river delta environment include primary braided channels, secondary distributary channels and the distribution of sediments is controlled by the successive superposed strata deposited in paleogeomorphic valleys. The primary distributary channels have stronger hydrodynamic forces with higher proportions of coarse sand deposits than the secondary distributary channels. Therefore, lithofacies paleogeography mapping is controlled by the geomorphology, valley locations, and the migration of channels. We reconstructed the paleogeomorphology and valley systems that existed prior to the deposition of the Xujiahe Formation. Following this, rock-electro identification model for coarse skeletal sand bodies was constructed based on coring data. The results suggest that skeletal sand bodies in primary distributary channels occur mainly in the valleys and low-lying areas, whereas secondary distributary channels and fine deposits generally occur in the highland areas. The thickness distribution of skeletal sand bodies and lithofacies paleogeography map indicate a positive correlation in primary distributary channels and reservoir thickness. A significant correlation exists between different sedimentary facies and petrophysical properties. In addition, the degree of reservoir development in different sedimentary facies

  5. PLAY ANALYSIS AND DIGITAL PORTFOLIO OF MAJOR OIL RESERVOIRS IN THE PERMIAN BASIN: APPLICATION AND TRANSFER OF ADVANCED GEOLOGICAL AND ENGINEERING TECHNOLOGIES FOR INCREMENTAL PRODUCTION OPPORTUNITIES

    Energy Technology Data Exchange (ETDEWEB)

    Shirley P. Dutton; Eugene M. Kim; Ronald F. Broadhead; Caroline L. Breton; William D. Raatz; Stephen C. Ruppel; Charles Kerans

    2004-05-01

    The Permian Basin of west Texas and southeast New Mexico has produced >30 Bbbl (4.77 x 10{sup 9} m{sup 3}) of oil through 2000, most of it from 1,339 reservoirs having individual cumulative production >1 MMbbl (1.59 x 10{sup 5} m{sup 3}). These significant-sized reservoirs are the focus of this report. Thirty-two Permian Basin oil plays were defined, and each of the 1,339 significant-sized reservoirs was assigned to a play. The reservoirs were mapped and compiled in a Geographic Information System (GIS) by play. Associated reservoir information within linked data tables includes Railroad Commission of Texas reservoir number and district (Texas only), official field and reservoir name, year reservoir was discovered, depth to top of the reservoir, production in 2000, and cumulative production through 2000. Some tables also list subplays. Play boundaries were drawn for each play; the boundaries include areas where fields in that play occur but are <1 MMbbl (1.59 x 10{sup 5} m{sup 3}) of cumulative production. This report contains a summary description of each play, including key reservoir characteristics and successful reservoir-management practices that have been used in the play. The CD accompanying the report contains a pdf version of the report, the GIS project, pdf maps of all plays, and digital data files. Oil production from the reservoirs in the Permian Basin having cumulative production >1 MMbbl (1.59 x 10{sup 5} m{sup 3}) was 301.4 MMbbl (4.79 x 10{sup 7} m{sup 3}) in 2000. Cumulative Permian Basin production through 2000 from these significant-sized reservoirs was 28.9 Bbbl (4.59 x 10{sup 9} m{sup 3}). The top four plays in cumulative production are the Northwest Shelf San Andres Platform Carbonate play (3.97 Bbbl [6.31 x 10{sup 8} m{sup 3}]), the Leonard Restricted Platform Carbonate play (3.30 Bbbl 5.25 x 10{sup 8} m{sup 3}), the Pennsylvanian and Lower Permian Horseshoe Atoll Carbonate play (2.70 Bbbl [4.29 x 10{sup 8} m{sup 3}]), and the San Andres

  6. Elementary teachers' perceptions of engineering, engineering design, and their abilities to teach engineering: A mixed methods study

    Science.gov (United States)

    Hammack, Rebekah Jane

    This explanatory sequential mixed methods study explores elementary teachers' preparedness to teach engineering and engineering design as prescribed by the Next Generation Science Standards (NGSS). The data analyzed included the NGSS document, responses to an online survey that was completed by 542 Oklahoma K-5 teachers responsible for the science instruction of their students, and interview and focus group transcripts from a subset of survey participants. The results are organized into three distinct manuscripts, each devoted to a specific set of research questions. As a whole, the dissertation findings indicate that elementary teachers are not prepared to incorporate engineering practices into their classrooms. Study participants were found to have limited understanding of engineering and engineering design, as well as low engineering self-efficacy and engineering teaching efficacy related to pedagogical content knowledge. While participants recognized the benefits of including engineering activities in their classrooms, they reported that barriers such as lack of time, lack of training, lack of materials, and lack of support inhibited their abilities to infuse engineering into their curriculum.

  7. Assessment of Water Quality Improvements Using the Hydrodynamic Simulation Approach in Regulated Cascade Reservoirs: A Case Study of Drinking Water Sources of Shenzhen, China

    Directory of Open Access Journals (Sweden)

    Ruixiang Hua

    2017-10-01

    Full Text Available Water quality safety is of critical importance in environmental improvement, particularly with respect to drinking water resources worldwide. As the main drinking water sources in Shenzhen, China, the cascade reservoirs comprising the Shiyan, Tiegang, and Xili Reservoirs are highly regulated and have experienced water quality deterioration in recent years. In this study, a three-dimensional hydrodynamic and water quality model was established using the Environmental Fluid Dynamics Code (EFDC for the cascade reservoirs. The relationships between water quality and improvement measures were quantified and the main pollution sources for individual reservoirs were identified. Results showed that the hydrodynamic and water quality model well captured the spatial and temporal variations of water level, the permanganate concentration index (CODMn, and total nitrogen (TN, with high resolution in the cascade reservoirs. The correlation coefficients between simulations and observations were close to 1.00 for water levels, and over 0.50 for CODMn and TN concentrations. The most effective methods for water quality improvement were the reduction of the runoff load for TN and transferred water load for CODMn in the Shiyan Reservoir, reduction of the transferred water load in the Tiegang Reservoir, and an increase in transfer water volume, especially in the flood season, in the Xili Reservoir. Internal pollution sources also played an important role in water pollution, and thus sedimentation should be cleaned up regularly. This study is expected to provide scientific support for drinking water source protection and promote the application of hydrodynamic model in water quality management.

  8. Stochastic reservoir optimization using El Niño information: case study of Daule Peripa, Ecuador

    DEFF Research Database (Denmark)

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan

    2011-01-01

    , each corresponding to a hidden climate state. Climatic information is used as exogenous input and to condition state transitions. We apply the model to the inflow of the Daule Peripa reservoir in western Ecuador, where El Niño events cause anomalously heavy rainfall. El Niño–Southern Oscillation (ENSO...

  9. A welfare study into capture fisheries in cirata reservoir: a bio-economic model

    Science.gov (United States)

    Anna, Z.; Hindayani, P.

    2018-04-01

    Capture fishery in inland such as reservoirs can be a source of food security and even the economy and public welfare of the surrounding community. This research was conducted on Cirata reservoir fishery in West Java, to see how far reservoir capture fishery can contribute economically in the form of resource rents. The method used is the bioeconomic model Copes, which can analyze the demand and supply functions to calculate the optimization of stakeholders’ welfare in various management regimes. The results showed that the management of capture fishery using Maximum Economic Yield regime (MEY) gave the most efficient result, where fewer inputs would produce maximum profit. In the MEY management, the producer surplus obtained is IDR 2,610.203.099, - per quarter and IDR 273.885.400,- of consumer surplus per quarter. Furthermore, researches showed that sustainable management regime policy MEY result in the government rent/surplus ofIDR 217.891,345, - per quarter with the average price of fish per kg being IDR 13.929. In open access fishery, it was shown that the producer surplus becomesIDR 0. Thus the implementation of the MEY-based instrument policy becomes a necessity for Cirata reservoir capture fishery.

  10. Vortices in dam reservoir: A case study of Karun III dam

    Indian Academy of Sciences (India)

    Typical problems may occur when free surface vortex is present in the reservoir which includes decreasing the efficiency of turbines and their vibration, increasing hydraulic losses at the entrance of power intakes, entraining debris which may cause blockage of trash racks, entraining air into the power tunnel, and reducing ...

  11. A National Probabilistic Study of Polybrominated Diphenyl Ethers in Fish from US Lakes and Reservoirs

    Science.gov (United States)

    National estimates were developed for polybrominated diphenyl ethers (PBDEs) in fish from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake) using an unequal probability design. Predator (fillet) and bottom-dweller (w...

  12. Environmental impact assessments of the Xiaolangdi Reservoir on the most hyperconcentrated laden river, Yellow River, China.

    Science.gov (United States)

    Kong, Dongxian; Miao, Chiyuan; Wu, Jingwen; Borthwick, Alistair G L; Duan, Qingyun; Zhang, Xiaoming

    2017-02-01

    The Yellow River is the most hyperconcentrated sediment-laden river in the world. Throughout recorded history, the Lower Yellow River (LYR) experienced many catastrophic flood and drought events. To regulate the LYR, a reservoir was constructed at Xiaolangdi that became operational in the early 2000s. An annual water-sediment regulation scheme (WSRS) was then implemented, aimed at flood control, sediment reduction, regulated water supply, and power generation. This study examines the eco-environmental and socioenvironmental impacts of Xiaolangdi Reservoir. In retrospect, it is found that the reservoir construction phase incurred huge financial cost and required large-scale human resettlement. Subsequent reservoir operations affected the local geological environment, downstream riverbed erosion, evolution of the Yellow River delta, water quality, and aquatic biodiversity. Lessons from the impact assessment of the Xiaolangdi Reservoir are summarized as follows: (1) The construction of large reservoirs is not merely an engineering challenge but must also be viewed in terms of resource exploitation, environmental protection, and social development; (2) long-term systems for monitoring large reservoirs should be established, and decision makers involved at national policy and planning levels must be prepared to react quickly to the changing impact of large reservoirs; and (3) the key to solving sedimentation in the LYR is not Xiaolangdi Reservoir but instead soil conservation in the middle reaches of the Yellow River basin. Proper assessment of the impacts of large reservoirs will help promote development strategies that enhance the long-term sustainability of dam projects.

  13. Application of Multispectral Sensors Carried on Unmanned Aerial Vehicle (UAV to Trophic State Mapping of Small Reservoirs: A Case Study of Tain-Pu Reservoir in Kinmen, Taiwan

    Directory of Open Access Journals (Sweden)

    Tung-Ching Su

    2015-08-01

    Full Text Available Multispectral, as well as multi-temporal, satellite images, coupled with measurements, in situ, have been widely applied to the water quality monitoring of reservoirs. However, the spatial resolutions of the current multispectral satellite imageries are inadequate for trophic state mapping of small reservoirs which merely cover several hectares. Moreover, the temporal gap between effective satellite imaging and measurements, in situ, is usually a few days or weeks; this time lag hampers the establishment of regression models between band ratios and water quality parameters. In this research, the RGB and NIR sensors carried on an unmanned aerial vehicle (UAV were applied to the trophic state mapping of Tain-Pu reservoir, which is one of the small reservoirs in Kinmen, Taiwan. Due to the limited sampling points and the uncertainty of water fluidity, the average method and the matching pixel-by-pixel (MPP method were employed to search for the optimal regression models. The experimental results indicate that the MPP method can lead to better regression models than the average method, and the trophic state maps show that the averages of Chl-a, TP, and SD are 179.7 μg·L−1, 108.4 μg·L−1, and 1.4 m, respectively.

  14. An integrated study of the Grayburg/San Andres reservoir, Foster and south Cowden fields, Ector County, Texas. Quarterly report, January 1--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Trentham, R.C.; Weinbrandt, R.; Reeves, J.J.

    1996-06-17

    The principal objective of this research is to demonstrate in the field that 3D seismic data can be used to aid in identifying porosity zones, permeability barriers and thief zones and thereby improve waterflood design. Geologic and engineering data will be integrated with the geophysical data to result in a detailed reservoir characterization. Reservoir simulation will then be used to determine infill drilling potential and the optimum waterflood design for the project area. This design will be implemented and the success of the waterflood evaluated.

  15. Optimized reservoir operation model of regional wind and hydro power integration case study: Zambezi basin and South Africa

    International Nuclear Information System (INIS)

    Gebretsadik, Yohannes; Fant, Charles; Strzepek, Kenneth; Arndt, Channing

    2016-01-01

    Highlights: • The study introduced reliability assessment method of integrated wind–hydropower operation. • The method identifies optimum target power operations that maximizes the firm generation. • We test the proposed method on interconnected system of reservoirs in Southern Africa region. • Results indicate that higher penetration of wind power can be achieved through the proposed frame work of operation. - Abstract: The present study develops a reliability assessment method of wind resource using optimum reservoir target power operations that maximizes the firm generation of integrated wind and hydropower. A combination of water resources model for a system of reservoirs that implements a demand–priority based linear programing algorithm and a single node power grid system model is implemented on hourly time step. This model was accompanied by a global genetic algorithm solver to determine optimum operation targets for each storage reservoir aiming at maximizing the 90th percentile power generation produced by the integration of wind and hydro over the entire simulation period. This model was applied on the reservoir storages and hydropower system in the Zambezi river basin to test if the storage reservoirs could be efficiently be used to offset wind power intermittence in South Africa subjected to the different physical and policy constraints. Based on the optimized target operation and hourly annual real data for the year 2010, the water resources system and power interconnection system were simulated together to assess the maximum firm generation of power as a result of the new wind and hydro combination target for storage hydropower plants. The result obtained indicates that high regulation of wind and hydro can be achieved as a result of combined operation and showed 45% increase in the level of wind penetration in South Africa’s power system over the reference scenario. The result also indicated a reduced level of coal power utilization and

  16. Evaluation of optimal reservoir prospectivity using acoustic-impedance model inversion: A case study of an offshore field, western Niger Delta, Nigeria

    Directory of Open Access Journals (Sweden)

    Kehinde D. Oyeyemi

    2017-12-01

    Full Text Available The evaluation of economic potential of any hydrocarbon field involves the understanding of the reservoir lithofacies and porosity variations. This in turns contributes immensely towards subsequent reservoir management and field development. In this study, integrated 3D seismic data and well log data were employed to assess the quality and prospectivity of the delineated reservoirs (H1–H5 within the OPO field, western Niger Delta using a model-based seismic inversion technique. The model inversion results revealed four distinct sedimentary packages based on the subsurface acoustic impedance properties and shale contents. Low acoustic impedance model values were associated with the delineated hydrocarbon bearing units, denoting their high porosity and good quality. Application of model-based inverted velocity, density and acoustic impedance properties on the generated time slices of reservoirs also revealed a regional fault and prospects within the field. Keywords: Acoustic impedance, Reservoir characterization, Seismic inversion, Hydrocarbon exploration, Niger Delta

  17. Perspectives and Plans for Graduate Studies. 11, Engineering 1974-75; F. Civil Engineering.

    Science.gov (United States)

    Ontario Council on Graduate Studies, Toronto. Advisory Committee on Academic Planning.

    A series of studies carried out by the Advisory Committee on Academic Planning (ACAP) published by the Council of Ontario Universities (COU) dealt with a planning study of doctoral work in engineering that was conducted in several parts corresponding to the various disciplines within engineering. This document, which is one part of that study,…

  18. Preliminary study of the aquatic macrophytes of selected fish ponds and reservoirs in Makurdi, Benue State, Nigeria

    OpenAIRE

    Okayi, R.G.; Abe, O.M.

    2003-01-01

    A five months survey was conducted to identify the aquatic macrophytes in fishponds and reservoirs in Makurdi (Benue State, Nigeria) between August and December 1999. A total of 3-prominent aquatic macrophytes were identified: Ipomoea aquatica, Nymphae lotus and Echinochloa pyramidalis at two-study sites (site 1, receives organic manure effluent from a cattle ranch, site 2, receives inorganic fertilizer through application). Ipomoea aquatica were found restricted to site l, while Nymphae lotu...

  19. Fundamental Study of Disposition and Release of Methane in a Shale Gas Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yifeng [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Xiong, Yongliang [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Repository Performance; Criscenti, Louise J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geochemistry; Ho, Tuan Ahn [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geochemistry; Weck, Philippe F. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Storage and Transportation Technology; Ilgen, Anastasia G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geochemistry; Matteo, Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Kruichak, Jessica N. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Mills, Melissa M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Nuclear Waste Disposal Research and Analysis; Dewers, Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Geomechanics; Gordon, Margaret E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Dept. of Materials, Devices and Energy Technologies; Akkutlu, Yucel [Texas A & M Univ., College Station, TX (United States). Dept. of Petroleum Engineering

    2016-09-01

    simulations also indicate that a significant fraction (3 - 35%) of methane deposited in kerogen can potentially become trapped in isolated nanopores and thus not recoverable. We have successfully established experimental capabilities for measuring gas sorption and desorption on shale and model materials under a wide range of physical and chemical conditions. Both low and high pressure measurements show significant sorption of CH4 and CO2 onto clays, implying that methane adsorbed on clay minerals could contribute a significant portion of gas-in-place in an unconventional reservoir. We have also studied the potential impact of the interaction of shale with hydrofracking fluid on gas sorption. We have found that the CH4-CO2 sorption capacity for the reacted sample is systematically lower (by a factor of ~2) than that for the unreacted (raw) sample. This difference in sorption capacity may result from a mineralogical or surface chemistry change of the shale sample induced by fluid-rock interaction. Our results shed a new light on mechanistic understanding gas release and production decline in unconventional reservoirs.

  20. A prediction study of a spark ignition supercharged hydrogen engine

    International Nuclear Information System (INIS)

    Al-Baghdadi, Maher A.R. Sadiq.; Al-Janabi, Haroun A.K. Shahad

    2003-01-01

    Hydrogen is found to be a suitable alternative fuel for spark ignition engines with certain drawbacks, such as high NO x emission and small power output. However, supercharging may solve such problems. In this study, the effects of equivalence ratio, compression ratio and inlet pressure on the performance and NO x emission of a four stroke supercharged hydrogen engine have been analyzed using a specially developed computer program. The results are verified and compared with experimental data obtained from tests on a Ricardo E6/US engine. A chart specifying the safe operation zone of the hydrogen engine has been produced. The safe operation zone means no pre-ignition, acceptable NO x emission, high engine efficiency and lower specific fuel consumption in comparison with the gasoline engine. The study also shows that supercharging is a more effective method to increase the output of a hydrogen engine rather than increasing the compression ratio of the engine at the knock limited equivalence ratio

  1. Consequences of eutrophication in the management of water resources in Mediterranean reservoirs: A case study of Lake Cedrino (Sardinia, Italy

    Directory of Open Access Journals (Sweden)

    Bachisio Mario Padedda

    2017-10-01

    Full Text Available One of the primary detrimental effects of eutrophication is the tendency of nuisance cyanobacterial species to increase in number and biomass in freshwater ecosystems. The aim of this study was to investigate possible management actions to control eutrophication and assure water use of a eutrophic deep Mediterranean climate reservoir, dominated by cyanobacteria. With this goal, we defined the trophic state of Lake Cedrino (Sardinia, Italy and studied its phytoplankton, paying particular attention to cyanobacteria, and to seasonal variation of phytoplankton in relation to seasonal variation of environmental variables. The water samples were collected monthly from September 2010 to August 2011 at differing depths from the surface of the water to the bottom at a station located in the deeper portion of the reservoir. Physical, chemical, nutrient, qualitative and quantitative analyses of phytoplankton were performed, and the trophic state was evaluated based on the Trophic State Index and the OECD model. Abundance of nutrients and phytoplankton (cell density, biomass and chlorophyll a indicated a eutrophic condition of the reservoir. In summer, phytoplankton species composition was dominated by nuisance cyanobacteria, particularly Aphanizomenon flosaquae, thereby requiring management plans for harmful blooms. On the base of lake features, we propose management actions at different scales and levels to resolve eutrophication and to allow water use: from nutrient load reduction in the watershed (primarily from point-sources to deep water aeration, to immediately face an attenuation of eutrophic effects. This study is the first explorative step in planning restoration of Lake Cedrino.

  2. Reservoir optimisation using El Niño information. Case study of Daule Peripa (Ecuador)

    Science.gov (United States)

    Gelati, Emiliano; Madsen, Henrik; Rosbjerg, Dan

    2010-05-01

    The optimisation of water resources systems requires the ability to produce runoff scenarios that are consistent with available climatic information. We approach stochastic runoff modelling with a Markov-modulated autoregressive model with exogenous input, which belongs to the class of Markov-switching models. The model assumes runoff parameterisation to be conditioned on a hidden climatic state following a Markov chain, whose state transition probabilities depend on climatic information. This approach allows stochastic modeling of non-stationary runoff, as runoff anomalies are described by a mixture of autoregressive models with exogenous input, each one corresponding to a climate state. We calibrate the model on the inflows of the Daule Peripa reservoir located in western Ecuador, where the occurrence of El Niño leads to anomalously heavy rainfall caused by positive sea surface temperature anomalies along the coast. El Niño - Southern Oscillation (ENSO) information is used to condition the runoff parameterisation. Inflow predictions are realistic, especially at the occurrence of El Niño events. The Daule Peripa reservoir serves a hydropower plant and a downstream water supply facility. Using historical ENSO records, synthetic monthly inflow scenarios are generated for the period 1950-2007. These scenarios are used as input to perform stochastic optimisation of the reservoir rule curves with a multi-objective Genetic Algorithm (MOGA). The optimised rule curves are assumed to be the reservoir base policy. ENSO standard indices are currently forecasted at monthly time scale with nine-month lead time. These forecasts are used to perform stochastic optimisation of reservoir releases at each monthly time step according to the following procedure: (i) nine-month inflow forecast scenarios are generated using ENSO forecasts; (ii) a MOGA is set up to optimise the upcoming nine monthly releases; (iii) the optimisation is carried out by simulating the releases on the

  3. Rapid differentiation in a sill-like magma reservoir: a case study from the campi flegrei caldera

    Science.gov (United States)

    Pappalardo, Lucia; Mastrolorenzo, Giuseppe

    2012-01-01

    In recent decades, geophysical investigations have detected wide magma reservoirs beneath quiescent calderas. However, the discovery of partially melted horizons inside the crust is not sufficient to put constraints on capability of reservoirs to supply cataclysmic eruptions, which strictly depends on the chemical-physical properties of magmas (composition, viscosity, gas content etc.), and thus on their differentiation histories. In this study, by using geochemical, isotopic and textural records of rocks erupted from the high-risk Campi Flegrei caldera, we show that the alkaline magmas have evolved toward a critical state of explosive behaviour over a time span shorter than the repose time of most volcanic systems and that these magmas have risen rapidly toward the surface. Moreover, similar results on the depth and timescale of magma storage were previously obtained for the neighbouring Somma-Vesuvius volcano. This consistency suggests that there might be a unique long-lived magma pool beneath the whole Neapolitan area. PMID:23050096

  4. Retrospective study of malaria prevalence and Anopheles genus in the area of influence of the Binational Itaipu Reservoir.

    Science.gov (United States)

    Falavigna-Guilherme, Ana Lucia; Silva, Allan Martins da; Guilherme, Edson Valdemar; Morais, Dina Lúcia

    2005-01-01

    The importance of hydroelectric dams beside the human interchange in the maintenance of malarious foci and the occurrence of the Anopheles genus on the Binational Itaipu Reservoir were the main points of this retrospective study. Data were collected from existing registrations at National, State and Municipal Health Departments and literature systematic overview, from January 1984 to December 2003. The occurrence of some outbreak of malaria, mainly by Plasmodium vivax, and the prevalence of species of the Anopheles genus different from Anopheles darlingi in the region are discussed. The malaria in the left bank of Paraná River is a focal problem, which must be approached locally through health, educational and social actions to prevent the continuity of outbreaks in the area. Concomitantly, it is necessary to plan and apply effective surveillance measures in the influence area of the Itaipu Reservoir.

  5. Assessing the Habitat Suitability of Dam Reservoirs: A Quantitative Model and Case Study of the Hantan River Dam, South Korea

    Directory of Open Access Journals (Sweden)

    Hyeongsik Kang

    2016-11-01

    Full Text Available The main objective of this study was to investigate ecologically healthy regions near a dam reservoir. This study developed a model for assessing habitat suitability as a proxy for the ecological value of reservoirs. Three main factors comprising nine assessment variables were selected and classified as having a habitat suitability (HS between 0 and 1: (1 geomorphic factors of altitude, slope steepness, and slope aspect; (2 vegetation factors of forest physiognomy, vegetation type, and tree age; and (3 ecological factors of land cover, ecological quality index, and environmental conservation value assessment. The spatial distribution of the nine HS indices was determined using geographic information systems and combined into one HS index value to determine ecologically healthy regions. The assessment model was applied to areas surrounding the Hantan River Dam, South Korea. To verify the model, wildlife location data from the national ecosystem survey of the Ministry of Environment were used. Areas with an HS index between 0.73 and 1 were found to contain 72% of observed wildlife locations. Ecologically healthy areas were identified by adding the indices of each variable. The methods shown here will be useful for establishing ecological restoration plans for dam reservoirs in South Korea.

  6. Case studies for developing globally responsible engineers

    OpenAIRE

    Global Dimension in Engineering Education

    2015-01-01

    Document realitzat amb un ajut financer de la Unió Europea. Per poder accedir al material complementari per a docents dels 28 casos estudi que formen el llibre, activeu el "Document relacionat" Col·lecció de 28 casos estudi per a professors d'enginyeria: 1. Rural development and planning in LDCs: the “Gamba Deve – Licoma axis”,district of Caia, Mozambique 2. Reducing the impact of soil erosion and reservoir siltation on agricultural production and water availability: the case stu...

  7. Small nonroad engine and equipment industry study. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-01

    The purpose of the report is to describe and analyze the structure, conduct, and performance of the small nonroad engine and equipment industry and to assess the technologies represented by the most common engines and equipment. The small nonroad engine and equipment industry is defined as the market or markets, in which engines under 50 horsepower are produced and/or incorporated into new or used nonroad equipment. Examples of the types of equipment in which utility engines are installed include lawnmowers, cement mixers, 2-wheel tractors, generator sets, all terrain vehicles, and many other types of equipment used in various applications. Engine below 50 horsepower are also found in many marine applications, such as outboard sailboat auxiliary engines. However, marine engines are excluded from the study.

  8. Comparative analysis of measures of viral reservoirs in HIV-1 eradication studies.

    Directory of Open Access Journals (Sweden)

    Susanne Eriksson

    2013-02-01

    Full Text Available HIV-1 reservoirs preclude virus eradication in patients receiving highly active antiretroviral therapy (HAART. The best characterized reservoir is a small, difficult-to-quantify pool of resting memory CD4(+ T cells carrying latent but replication-competent viral genomes. Because strategies targeting this latent reservoir are now being tested in clinical trials, well-validated high-throughput assays that quantify this reservoir are urgently needed. Here we compare eleven different approaches for quantitating persistent HIV-1 in 30 patients on HAART, using the original viral outgrowth assay for resting CD4(+ T cells carrying inducible, replication-competent viral genomes as a standard for comparison. PCR-based assays for cells containing HIV-1 DNA gave infected cell frequencies at least 2 logs higher than the viral outgrowth assay, even in subjects who started HAART during acute/early infection. This difference may reflect defective viral genomes. The ratio of infected cell frequencies determined by viral outgrowth and PCR-based assays varied dramatically between patients. Although strong correlations with the viral outgrowth assay could not be formally excluded for most assays, correlations achieved statistical significance only for integrated HIV-1 DNA in peripheral blood mononuclear cells and HIV-1 RNA/DNA ratio in rectal CD4(+ T cells. Residual viremia was below the limit of detection in many subjects and did not correlate with the viral outgrowth assays. The dramatic differences in infected cell frequencies and the lack of a precise correlation between culture and PCR-based assays raise the possibility that the successful clearance of latently infected cells may be masked by a larger and variable pool of cells with defective proviruses. These defective proviruses are detected by PCR but may not be affected by reactivation strategies and may not require eradication to accomplish an effective cure. A molecular understanding of the discrepancy

  9. A Molecular Epidemiological Study of var Gene Diversity to Characterize the Reservoir of Plasmodium falciparum in Humans in Africa

    Science.gov (United States)

    Leliwa-Sytek, Aleksandra; Smith, Terry-Ann; Peterson, Ingrid; Brown, Stuart M.; Migot-Nabias, Florence; Deloron, Philippe; Kortok, Moses M.; Marsh, Kevin; Daily, Johanna P.; Ndiaye, Daouda; Sarr, Ousmane; Mboup, Souleymane; Day, Karen P.

    2011-01-01

    Background The reservoir of Plasmodium infection in humans has traditionally been defined by blood slide positivity. This study was designed to characterize the local reservoir of infection in relation to the diverse var genes that encode the major surface antigen of Plasmodium falciparum blood stages and underlie the parasite's ability to establish chronic infection and transmit from human to mosquito. Methodology/Principal Findings We investigated the molecular epidemiology of the var multigene family at local sites in Gabon, Senegal and Kenya which differ in parasite prevalence and transmission intensity. 1839 distinct var gene types were defined by sequencing DBLα domains in the three sites. Only 76 (4.1%) var types were found in more than one population indicating spatial heterogeneity in var types across the African continent. The majority of var types appeared only once in the population sample. Non-parametric statistical estimators predict in each population at minimum five to seven thousand distinct var types. Similar diversity of var types was seen in sites with different parasite prevalences. Conclusions/Significance Var population genomics provides new insights into the epidemiology of P. falciparum in Africa where malaria has never been conquered. In particular, we have described the extensive reservoir of infection in local African sites and discovered a unique var population structure that can facilitate superinfection through minimal overlap in var repertoires among parasite genomes. Our findings show that var typing as a molecular surveillance system defines the extent of genetic complexity in the reservoir of infection to complement measures of malaria prevalence. The observed small scale spatial diversity of var genes suggests that var genetics could greatly inform current malaria mapping approaches and predict complex malaria population dynamics due to the import of var types to areas where no widespread pre-existing immunity in the population

  10. Experimental study of dual fuel engine performance using variable LPG composition and engine parameters

    International Nuclear Information System (INIS)

    Elnajjar, Emad; Selim, Mohamed Y.E.; Hamdan, Mohammad O.

    2013-01-01

    Highlights: • The effect of using variable LPG is studied. • Five fuels with propane to butane % volume ratio are: 100-70-55-25-0. • 100% Propane composition shows the highest noise levels with similar performance. • At 45° BTDC injection timing 55% Propane LPG the only fuel experience knocking. • LPG fuels gave similar engine performance, with differences in levels of noise. - Abstract: The present work investigates experimentally the effect of LPG fuel with different composition and engine parameters on the performance of a dual compression engine. Five different blends of LPG fuels are used with Propane to Butane volume ratio of 100:0, 70:30, 55:45, 25:75, and 0:100. A single cylinder, naturally aspirated, four strokes, indirectly injected, water cooled modified Ricardo E6 engine, is used in this study. The study is carried out by measuring the cylinder pressure, engine load, engine speed, crank angle, and the fuel’s flow rate. The engine performance under variable LPG fuel composition, engine load, pilot fuel injection timing, compression ratio, pilot fuel mass and engine speed, are estimated by comparing the following engine parameters: the cylinder maximum pressure, the indicated mean effective pressure, the maximum rate of pressure rise, and the thermal efficiency. The experimental data indicates that the engine parameters are playing a major role on the engine’s performance. Different LPG fuel composition did not show a major effect on the engine efficiency but directly impacted the levels of generated combustion noise

  11. A study of coupled thermoacoustic engines

    Science.gov (United States)

    Gillman, Brenna Jane

    In the development of thermoacoustic energy conversion from heat to electricity, an array configuration of heat engines can yield high acoustic power output. Arrays consisting of multiple thermoacoustic engines have been constructed in such a way that the heat driven acoustic engines radiate sound into a common cavity where a piezoelectric transducer is used to convert acoustic power into electrical signal. Coupling effects between two or more self-sustaining thermoacoustic engines, operating near 2.5 kHz, have been observed and considered in terms of synchronization. Two types of coupling were observed to be present in the system: mass coupling and acoustic coupling. It was found that for a weaker mass coupling, in the absence of acoustic coupling, anti-phase synchronization was observed. In-phase synchronization was observed for stronger mass coupling. To vary the acoustic coupling present in this system, the volume of the cavity, and the separation distance between engines were varied. In-phase synchronization was observed for each combination of two engines tested at every cavity volume and separation distance, however the average phase difference measured between oscillators was not the same for each cavity volume tested. It was found that the cavity volume with 228 cm3 was the only cavity tested to result in synchronization with an average phase difference of approximately zero degrees, and also maintain oscillations in a stable acoustic cavity mode for each array tested. Acoustic pressure amplitude was measured to be proportional to the number of engines in the array when scaled by the amplitude of each single engine operating alone for arrays up to four engines. Since an array consisting of four engines was shown to synchronize and produce coherent sound, the coupling between engines was identified as global coupling. To determine the threshold of frequency difference for synchronization, two coupled engines were detuned. It was found that the threshold

  12. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 8: Design approaches: UPH. Appendix A: Upper reservoir

    Science.gov (United States)

    1981-04-01

    Overriding considerations including operating range, volume and lining of reservoir, embankment design, intake/outlet arrangements and filling and make up water provisions were studied within the context of minimizing facility costs and optimizing the plant layout. The study led to the selection of a reservoir formed by embankment of compacted rockfill together with an intake/outlet structure located in the embankment. The reservoir floor and upstream slopes of the embankment will have an asphalt lining to prevent leakage. The material and cost estimates presented are based on the requirements for a 2000 MW plant providing 20,000 MWh of storage with a nominal head of 4600 ft.

  13. Simulation study to determine the feasibility of injecting hydrogen sulfide, carbon dioxide and nitrogen gas injection to improve gas and oil recovery oil-rim reservoir

    Science.gov (United States)

    Eid, Mohamed El Gohary

    This study is combining two important and complicated processes; Enhanced Oil Recovery, EOR, from the oil rim and Enhanced Gas Recovery, EGR from the gas cap using nonhydrocarbon injection gases. EOR is proven technology that is continuously evolving to meet increased demand and oil production and desire to augment oil reserves. On the other hand, the rapid growth of the industrial and urban development has generated an unprecedented power demand, particularly during summer months. The required gas supplies to meet this demand are being stretched. To free up gas supply, alternative injectants to hydrocarbon gas are being reviewed to support reservoir pressure and maximize oil and gas recovery in oil rim reservoirs. In this study, a multi layered heterogeneous gas reservoir with an oil rim was selected to identify the most optimized development plan for maximum oil and gas recovery. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked. The development scheme is identified, in which the pattern and completion of the wells are optimized to best adapt to the heterogeneity of the reservoir. Lateral and maximum block contact holes will be investigated. The non-hydrocarbon gases considered for this study are hydrogen sulphide, carbon dioxide and nitrogen, utilized to investigate miscible and immiscible EOR processes. In November 2010, re-vaporization study, was completed successfully, the first in the UAE, with an ultimate objective is to examine the gas and condensate production in gas reservoir using non hydrocarbon gases. Field development options and proces schemes as well as reservoir management and long term business plans including phases of implementation will be identified and assured. The development option that maximizes the ultimate recovery factor will be evaluated and selected. The study achieved satisfactory results in integrating gas and oil

  14. Production Characteristics with Different Superimposed Modes Using Variogram: A Case Study of a Super-Giant Carbonate Reservoir in the Middle East

    Directory of Open Access Journals (Sweden)

    Chenji Wei

    2017-02-01

    Full Text Available Heterogeneity of permeability is an important factor affecting the production of a carbonate reservoir. How to correctly characterize the heterogeneity of permeability has become a key issue for carbonate reservoir development. In this study, the reservoirs were categorized into four superimposed modes based on the actual logging data from a super-giant heterogeneous carbonate reservoir in the Middle East. A modified permeability formula in terms of the variogram method was presented to reflect the heterogeneity of the reservoirs. Furthermore, the models of oil production and water cut were established and the analytical solutions were obtained. The calculation results show that the present model can predict the productivity of wells with different heterogeneous layers more accurately and rapidly. The larger the varigoram value, the stronger the heterogeneity of the reservoirs, and the faster the decline of production owing to a quicker reduction of formation pressure. With the increase in variogram value, the relative permeability of the oil phase is smaller and the water phase larger, and the water cut becomes larger. This study has provided a quick and reasonable prediction model for heterogeneous reservoir.

  15. Improved recovery from Gulf of Mexico reservoirs. Quarterly status report, January 1--March 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kimbrell, W.C.; Bassiouni, Z.A.; Bourgoyne, A.T.

    1996-04-30

    On February 18, 1992, Louisiana State University with two technical subcontractors, BDM, Inc. and ICF, Inc., began a research program to estimate the potential oil and gas reserve additions that could result from the application of advanced secondary and enhanced oil recovery technologies and the exploitation of undeveloped and attic oil zones in the Gulf of Mexico oil fields that are related to piercement salt domes. This project is a one year continuation of this research and will continue work in reservoir description, extraction processes, and technology transfer. Detailed data will be collected for two previously studies reservoirs: a South Marsh Island reservoir operated by Taylor Energy and one additional Gulf of Mexico reservoir operated by Mobil. Additional reservoirs identified during the project will also be studied if possible. Data collected will include reprocessed 2-D seismic data, newly acquired 3-D data, fluid data, fluid samples, pressure data, well test data, well logs, and core data/samples. The new data will be used to refine reservoir and geologic characterization of these reservoirs. Further laboratory investigation will provide additional simulation input data in the form of PVT properties, relative permeabilities, capillary pressure, and water compatibility. Geological investigations will be conducted to refine the models of mud-rich submarine fan architectures used by seismic analysts and reservoir engineers. Research on advanced reservoir simulation will also be conducted. This report describes a review of fine-grained submarine fans and turbidite systems.

  16. Evaluation of mineral-aqueous chemical equilibria of felsic reservoirs with low-medium temperature: A comparative study in Yangbajing geothermal field and Guangdong geothermal fields

    Science.gov (United States)

    Li, Jiexiang; Sagoe, Gideon; Yang, Guang; Lu, Guoping

    2018-02-01

    Classical geothermometers are useful tools for estimating reservoir temperatures of geothermal systems. However, their application to low-medium temperature reservoirs is limited because large variations of temperatures calculated by different classical geothermometers are usually observed. In order to help choose the most appropriate classical geothermometer for calculating the temperatures of low-medium temperature reservoirs, this study evaluated the mineral-aqueous equilibria of typical low-medium temperature felsic reservoirs in the Yangbajing geothermal field and Guangdong geothermal fields. The findings of this study support that reservoirs in the Guangdong geothermal fields have no direct magma influence. Also, natural reservoirs may represent the intermediate steady state before reaching full equilibrium, which rarely occurs. For the low-medium temperature geothermal systems without the influence of magma, even with seawater intrusion, the process of minerals reaching mineral-aqueous equilibrium is sequential: chlorite and chalcedony are the first, then followed by K-feldspar, kaolinite and K-mica. Chlorite may reach equilibrium at varying activity values, and the equilibrium between K-feldspar and kaolinite or K-feldspar and K-mica can fix the contents of K and Al in the solutions. Although the SiO2 and Al attain equilibrium state, albite and laumontite remain unsaturated and thus may affect low-medium temperature calculations. In this study, the chalcedony geothermometer was found to be the most suitable geothermometer for low-medium temperature reservoirs. The results of K-Mg geothermometer may be useful to complement that of the chalcedony geothermometer in low-medium temperature reservoir systems. Na-K geothermometer will give unreliable results at low-medium temperatures; and Na-K-Ca will also be unsuitable to calculate reservoir temperatures lower than 180 °C, probably caused by the chemical imbalance of laumontite.

  17. Study on the evolution of nuclear engineering professions

    International Nuclear Information System (INIS)

    2008-01-01

    Based on interviews of experts belonging to different companies and institutions (EDF, AREVA, CEA, ASN, IRSN, INSTN), subcontractors, engineers and technicians of the nuclear sector, persons in charge of education, pupils and students, this study gives a synthetic vision of the general context of the needs for nuclear engineering professionals, at the world scale, in the French context, the perceived difficulties faced by this sector, the use of subcontracting, the recruitment needs, the educational profile of engineers and technicians, their revenues, their opinion about their work, the adequacy between education and employment in this sector. It gives estimated figures for engineer and technician recruitment needs for different abilities in the French nuclear engineering

  18. Study Regarding the Identification of an Internal Combustion Engine

    Directory of Open Access Journals (Sweden)

    Ioan Ruja

    2016-10-01

    Full Text Available The paper presents the results of the scientific investigations performed on an Otto engine. One conducted surveys on the analytic and experimental modelling of the internal combustion engine, considered as automated system element. The results of the analytical study are concretised in the mathematical model of the engine, expressed in the operational. The experimental results are concretised in the indicial response in rotating speed, as well as in the determination of the constants of interest. The investigation methods used in conducting the survey were: experimental identification based on the indicial response of the engine and the analytical identification based on the mathematical models of diverse engine subsystems.

  19. Researching primary engineering education: UK perspectives, an exploratory study

    Science.gov (United States)

    Clark, Robin; Andrews, Jane

    2010-10-01

    This paper draws attention to the findings of an exploratory study that critically identified and analysed relevant perceptions of elementary level engineering education within the UK. Utilising an approach based upon grounded theory methodology, 30 participants including teachers, representatives of government bodies and non-profit providers of primary level engineering initiatives were interviewed. Three main concepts were identified during the analysis of findings, each relevant to primary engineering education. These were pedagogic issues, exposure to engineering within the curriculum and children's interest. The paper concludes that the opportunity to make a real difference to children's education by stimulating their engineering imagination suggests this subject area is of particular value.

  20. 49 CFR 393.50 - Reservoirs required.

    Science.gov (United States)

    2010-10-01

    ... depressing the brake pedal or treadle valve to the limit of its travel. (c) Safeguarding of air and vacuum... NECESSARY FOR SAFE OPERATION Brakes § 393.50 Reservoirs required. (a) Reservoir capacity for air-braked... driver to make a full service brake application with the engine stopped without depleting the air...

  1. Study of the Effect of Clay Particles on Low Salinity Water Injection in Sandstone Reservoirs

    Directory of Open Access Journals (Sweden)

    Sina Rezaei Gomari

    2017-03-01

    Full Text Available The need for optimal recovery of crude oil from sandstone and carbonate reservoirs around the world has never been greater for the petroleum industry. Water-flooding has been applied to the supplement primary depletion process or as a separate secondary recovery method. Low salinity water injection is a relatively new method that involves injecting low salinity brines at high pressure similar to conventional water-flooding techniques, in order to recover crude oil. The effectiveness of low salinity water injection in sandstone reservoirs depends on a number of parameters such as reservoir temperature, pressure, type of clay particle and salinity of injected brine. Clay particles present on reservoir rock surfaces adsorb polar components of oil and modify wettability of sandstone rocks to the oil-wet state, which is accountable for the reduced recovery rates by conventional water-flooding. The extent of wettability alteration caused by three low salinity brines on oil-wet sandstone samples containing varying clay content (15% or 30% and type of clay (kaolinite/montmorillonite were analyzed in the laboratory experiment. Contact angles of mica powder and clay mixture (kaolinite/montmorillonite modified with crude oil were measured before and after injection with three low salinity sodium chloride brines. The effect of temperature was also analyzed for each sample. The results of the experiment indicate that samples with kaolinite clay tend to produce higher contact angles than samples with montmorillonite clay when modified with crude oil. The highest degree or extent of wettability alteration from oil-wet to intermediate-wet state upon injection with low salinity brines was observed for samples injected with brine having salinity concentration of 2000 ppm. The increase in temperature tends to produce contact angles values lying in the higher end of the intermediate-wet range (75°–115° for samples treated at 50 °C, while their corresponding

  2. Applying 1D Sediment Models to Reservoir Flushing Studies: Measuring, Monitoring, and Modeling the Spencer Dam Sediment Flush with HEC-RAS

    Science.gov (United States)

    2016-07-01

    by Paul Boyd and Stanford Gibson PURPOSE: The purposes of this Coastal and Hydraulics Engineering Technical Note (CHETN) are (1) to summarize the...Kansas River) (Gibson and Boyd 2014; Davis et al. 2014; Shelley and Gibson 2015). However, because these reservoir management strategies are still...as sediment and represented the dam in the model as an inline structure with time-series controlled gates. The unsteady equations required 6-second

  3. Case Study Research in Software Engineering Guidelines and Examples

    CERN Document Server

    Runeson, Per; Rainer, Austen; Regnell, Bjorn

    2012-01-01

    Based on their own experiences of in-depth case studies of software projects in international corporations, in this book the authors present detailed practical guidelines on the preparation, conduct, design and reporting of case studies of software engineering.  This is the first software engineering specific book on the case study research method.

  4. Upscaling verticle permeability within a fluvio-aeolian reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.D.; Corbett, P.W.M.; Jensen, J.L. [Heriot-Watt Univ., Edinburgh (United Kingdom)

    1997-08-01

    Vertical permeability (k{sub v}) is a crucial factor in many reservoir engineering issues. To date there has been little work undertaken to understand the wide variation of k{sub v} values measured at different scales in the reservoir. This paper presents the results of a study in which we have modelled the results of a downhole well tester using a statistical model and high resolution permeability data. The work has demonstrates and quantifies a wide variation in k{sub v} at smaller, near wellbore scales and has implications for k{sub v} modelling at larger scales.

  5. Assessment of Reservoir Water Quality Using Multivariate Statistical Techniques: A Case Study of Qiandao Lake, China

    Directory of Open Access Journals (Sweden)

    Qing Gu

    2016-03-01

    Full Text Available Qiandao Lake (Xin’an Jiang reservoir plays a significant role in drinking water supply for eastern China, and it is an attractive tourist destination. Three multivariate statistical methods were comprehensively applied to assess the spatial and temporal variations in water quality as well as potential pollution sources in Qiandao Lake. Data sets of nine parameters from 12 monitoring sites during 2010–2013 were obtained for analysis. Cluster analysis (CA was applied to classify the 12 sampling sites into three groups (Groups A, B and C and the 12 monitoring months into two clusters (April-July, and the remaining months. Discriminant analysis (DA identified Secchi disc depth, dissolved oxygen, permanganate index and total phosphorus as the significant variables for distinguishing variations of different years, with 79.9% correct assignments. Dissolved oxygen, pH and chlorophyll-a were determined to discriminate between the two sampling periods classified by CA, with 87.8% correct assignments. For spatial variation, DA identified Secchi disc depth and ammonia nitrogen as the significant discriminating parameters, with 81.6% correct assignments. Principal component analysis (PCA identified organic pollution, nutrient pollution, domestic sewage, and agricultural and surface runoff as the primary pollution sources, explaining 84.58%, 81.61% and 78.68% of the total variance in Groups A, B and C, respectively. These results demonstrate the effectiveness of integrated use of CA, DA and PCA for reservoir water quality evaluation and could assist managers in improving water resources management.

  6. Reservoir Simulations of Low-Temperature Geothermal Reservoirs

    Science.gov (United States)

    Bedre, Madhur Ganesh

    The eastern United States generally has lower temperature gradients than the western United States. However, West Virginia, in particular, has higher temperature gradients compared to other eastern states. A recent study at Southern Methodist University by Blackwell et al. has shown the presence of a hot spot in the eastern part of West Virginia with temperatures reaching 150°C at a depth of between 4.5 and 5 km. This thesis work examines similar reservoirs at a depth of around 5 km resembling the geology of West Virginia, USA. The temperature gradients used are in accordance with the SMU study. In order to assess the effects of geothermal reservoir conditions on the lifetime of a low-temperature geothermal system, a sensitivity analysis study was performed on following seven natural and human-controlled parameters within a geothermal reservoir: reservoir temperature, injection fluid temperature, injection flow rate, porosity, rock thermal conductivity, water loss (%) and well spacing. This sensitivity analysis is completed by using ‘One factor at a time method (OFAT)’ and ‘Plackett-Burman design’ methods. The data used for this study was obtained by carrying out the reservoir simulations using TOUGH2 simulator. The second part of this work is to create a database of thermal potential and time-dependant reservoir conditions for low-temperature geothermal reservoirs by studying a number of possible scenarios. Variations in the parameters identified in sensitivity analysis study are used to expand the scope of database. Main results include the thermal potential of reservoir, pressure and temperature profile of the reservoir over its operational life (30 years for this study), the plant capacity and required pumping power. The results of this database will help the supply curves calculations for low-temperature geothermal reservoirs in the United States, which is the long term goal of the work being done by the geothermal research group under Dr. Anderson at

  7. Session: Reservoir Technology

    Energy Technology Data Exchange (ETDEWEB)

    Renner, Joel L.; Bodvarsson, Gudmundur S.; Wannamaker, Philip E.; Horne, Roland N.; Shook, G. Michael

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of five papers: ''Reservoir Technology'' by Joel L. Renner; ''LBL Research on the Geysers: Conceptual Models, Simulation and Monitoring Studies'' by Gudmundur S. Bodvarsson; ''Geothermal Geophysical Research in Electrical Methods at UURI'' by Philip E. Wannamaker; ''Optimizing Reinjection Strategy at Palinpinon, Philippines Based on Chloride Data'' by Roland N. Horne; ''TETRAD Reservoir Simulation'' by G. Michael Shook

  8. A Historical Systems Study of Liquid Rocket Engine Throttling Capabilities

    Science.gov (United States)

    Betts, Erin M.; Frederick, Robert A., Jr.

    2010-01-01

    This is a comprehensive systems study to examine and evaluate throttling capabilities of liquid rocket engines. The focus of this study is on engine components, and how the interactions of these components are considered for throttling applications. First, an assessment of space mission requirements is performed to determine what applications require engine throttling. A background on liquid rocket engine throttling is provided, along with the basic equations that are used to predict performance. Three engines are discussed that have successfully demonstrated throttling. Next, the engine system is broken down into components to discuss special considerations that need to be made for engine throttling. This study focuses on liquid rocket engines that have demonstrated operational capability on American space launch vehicles, starting with the Apollo vehicle engines and ending with current technology demonstrations. Both deep throttling and shallow throttling engines are discussed. Boost and sustainer engines have demonstrated throttling from 17% to 100% thrust, while upper stage and lunar lander engines have demonstrated throttling in excess of 10% to 100% thrust. The key difficulty in throttling liquid rocket engines is maintaining an adequate pressure drop across the injector, which is necessary to provide propellant atomization and mixing. For the combustion chamber, cooling can be an issue at low thrust levels. For turbomachinery, the primary considerations are to avoid cavitation, stall, surge, and to consider bearing leakage flows, rotordynamics, and structural dynamics. For valves, it is necessary to design valves and actuators that can achieve accurate flow control at all thrust levels. It is also important to assess the amount of nozzle flow separation that can be tolerated at low thrust levels for ground testing.

  9. Influence of Large Reservoir Operation on Water-Levels and Flows in Reaches below Dam: Case Study of the Three Gorges Reservoir.

    Science.gov (United States)

    Yang, Yunping; Zhang, Mingjin; Zhu, Lingling; Liu, Wanli; Han, Jianqiao; Yang, Yanhua

    2017-11-15

    The Three Gorges Project (TGP) is the world's largest water conservation project. The post-construction low-flow water level at the same discharge below the dam has declined, but there remains disagreement over whether the flood level has increased. Measured water levels and upstream and downstream flow data from 1955 to 2016 show that, post-construction: (1) the low-flow water level at the same discharge decreased, and the lowest water level increased due to dry-season reservoir discharge; (2) the decline of the low-flow water level below the dam was less than the undercutting value of the flow channel of the river; (3) the flood level at the same discharge below the dam was slightly elevated, although peak water levels decreased; (4) flood characteristics changed from a high discharge-high flood level to a medium discharge - high flood level; and (5) an expected decline in the flood level downstream was not observed. Channel erosion and the adjustment of rivers and lakes tend to reduce flood levels, while river bed coarsening, vegetation, and human activities downstream increase the flood level. Although the flood control benefits of the Three Gorges Dam (TGD) and the upstream reservoirs are obvious, increased elevation of the downstream flood level remains a concern.

  10. Fluvial facies reservoir productivity prediction method based on principal component analysis and artificial neural network

    Directory of Open Access Journals (Sweden)

    Pengyu Gao

    2016-03-01

    Full Text Available It is difficult to forecast the well productivity because of the complexity of vertical and horizontal developments in fluvial facies reservoir. This paper proposes a method based on Principal Component Analysis and Artificial Neural Network to predict well productivity of fluvial facies reservoir. The method summarizes the statistical reservoir factors and engineering factors that affect the well productivity, extracts information by applying the principal component analysis method and approximates arbitrary functions of the neural network to realize an accurate and efficient prediction on the fluvial facies reservoir well productivity. This method provides an effective way for forecasting the productivity of fluvial facies reservoir which is affected by multi-factors and complex mechanism. The study result shows that this method is a practical, effective, accurate and indirect productivity forecast method and is suitable for field application.

  11. Environmental quality assessment of reservoirs impacted by Hg from chlor-alkali technologies: case study of a recovery.

    Science.gov (United States)

    Le Faucheur, Séverine; Vasiliu, Dan; Catianis, Irina; Zazu, Mariana; Dranguet, Perrine; Beauvais-Flück, Rebecca; Loizeau, Jean-Luc; Cosio, Claudia; Ungureanu, Costin; Ungureanu, Viorel Gheorghe; Slaveykova, Vera I

    2016-11-01

    Mercury (Hg) pollution legacy of chlor-alkali plants will be an important issue in the next decades with the planned phase out of Hg-based electrodes by 2025 within the Minamata convention. In such a context, the present study aimed to examine the extent of Hg contamination in the reservoirs surrounding the Oltchim plant and to evaluate the possible improvement of the environmental quality since the closure of its chlor-alkali unit. This plant is the largest chlor-alkali plant in Romania, which partly switched to Hg-free technology in 1999 and definitely stopped the use of Hg electrolysis in May 2012. Total Hg (THg) and methylmercury (CH 3 Hg) concentrations were found to decrease in the surface waters and sediments of the reservoirs receiving the effluents of the chlor-alkali platform since the closure of Hg units. Hence, calculated risk quotients (RQ) indicated no adverse effect of Hg for aquatic organisms from the ambient water exposure. RQ of Hg in sediments were mostly all higher than 1, showing important risks for benthic organisms. However, ecotoxicity testing of water and sediments suggest possible impact of other contaminants and their mixtures. Hg hotspots were found in soils around the platform with RQ values much higher than 1. Finally, THg and CH 3 Hg concentrations in fish were below the food safety limit set by the WHO, which contrasts with previous measurements made in 2007 revealing that 92 % of the studied fish were of high risk of consumption. Discontinuing the use of Hg electrodes greatly improved the surrounding environment of chlor-alkali plants within the following years and led to the decrease environmental exposure to Hg through fish consumption. However, sediment and soil still remained highly contaminated and problematic for the river reservoir management. The results of this ecological risk assessment study have important implications for the evaluation of the benefits as well as limits of the Minamata Convention implementation.

  12. Orbit Transfer Vehicle Engine Study. Phase A, extension 1: Study plan update

    Science.gov (United States)

    Mellish, J. A.

    1979-01-01

    The updated study plan for the Space Transportation System orbit transfer vehicle (OTV) engine study is presented. The study program consists of engine system, programmatic, cost, and risk analyses of OTV engine concepts. Detailed task descriptions for the advanced expander cycle engine optimization, alternate low thrust capability, and safety, reliability, and cost comparisons are given.

  13. Assessment of Water Quality Improvements Using the Hydrodynamic Simulation Approach in Regulated Cascade Reservoirs: A Case Study of Drinking Water Sources of Shenzhen, China

    OpenAIRE

    Ruixiang Hua; Yongyong Zhang

    2017-01-01

    Water quality safety is of critical importance in environmental improvement, particularly with respect to drinking water resources worldwide. As the main drinking water sources in Shenzhen, China, the cascade reservoirs comprising the Shiyan, Tiegang, and Xili Reservoirs are highly regulated and have experienced water quality deterioration in recent years. In this study, a three-dimensional hydrodynamic and water quality model was established using the Environmental Fluid Dynamics Code (EFDC)...

  14. K Basin sludge dissolution engineering study

    International Nuclear Information System (INIS)

    Westra, A.G.

    1998-01-01

    The purpose of this engineering study is to investigate the available technology related to dissolution of the K Basin sludge in nitric acid. The conclusion of this study along with laboratory and hot cell tests with actual sludge samples will provide the basis for beginning conceptual design of the sludge dissolver. The K Basin sludge contains uranium oxides, fragments of metallic U, and some U hydride as well as ferric oxyhydroxide, aluminum oxides and hydroxides, windblown sand that infiltrated the basin enclosure, ion exchange resin, and miscellaneous materials. The decision has been made to dispose of this sludge separate from the fuel elements stored in the basins. The sludge will be conditioned so that it meets Tank Waste Remediation System waste acceptance criteria and can be sent to one of the underground storage tanks. Sludge conditioning will be done by dissolving the fuel constituents in nitric acid, separating the insoluble material, adding neutron absorbers for criticality safety, and then reacting the solution with caustic to co-precipitate the uranium and plutonium. There will be five distinct feed streams to the sludge conditioning process two from the K East (KE) Basin and three from the K West (KW) Basin. The composition of the floor and pit sludges which contain more iron oxides and sand than uranium is much different than the canister sludges which are composed of mostly uranium oxides. The sludge conditioning equipment will be designed to process all of the sludge streams, but some of the operating parameters will be adjusted as necessary to handle the different sludge stream compositions. The volume of chemical additions and the amount of undissolved solids will be much different for floor and pit sludge than for canister sludge. Dissolution of uranium metal and uranium dioxide has been studied quite thoroughly and much information is available. Both uranium metal and uranium dioxide have been dissolved on a large scale in nuclear fuel

  15. Quality engineering as a discipline of study.

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, Rachel R.; Hoover, Marcey L.

    2012-12-01

    The current framework for quality scholarship in the United States ranges from the training and education of future quality engineers, managers, and professionals to focused and sustained research initiatives that, through academic institutions and other organizations, aim to improve the knowledge and application of quality across a variety of sectors. Numerous quality journals also provide a forum for professional dissemination of information.

  16. Will building new reservoirs always help increase the water supply reliability? - insight from a modeling-based global study

    Science.gov (United States)

    Zhuang, Y.; Tian, F.; Yigzaw, W.; Hejazi, M. I.; Li, H. Y.; Turner, S. W. D.; Vernon, C. R.

    2017-12-01

    More and more reservoirs are being build or planned in order to help meet the increasing water demand all over the world. However, is building new reservoirs always helpful to water supply? To address this question, the river routing module of Global Change Assessment Model (GCAM) has been extended with a simple yet physical-based reservoir scheme accounting for irrigation, flood control and hydropower operations at each individual reservoir. The new GCAM river routing model has been applied over the global domain with the runoff inputs from the Variable Infiltration Capacity Model. The simulated streamflow is validated at 150 global river basins where the observed streamflow data are available. The model performance has been significantly improved at 77 basins and worsened at 35 basins. To facilitate the analysis of additional reservoir storage impacts at the basin level, a lumped version of GCAM reservoir model has been developed, representing a single lumped reservoir at each river basin which has the regulation capacity of all reservoir combined. A Sequent Peak Analysis is used to estimate how much additional reservoir storage is required to satisfy the current water demand. For basins with water deficit, the water supply reliability can be improved with additional storage. However, there is a threshold storage value at each basin beyond which the reliability stops increasing, suggesting that building new reservoirs will not help better relieve the water stress. Findings in the research can be helpful to the future planning and management of new reservoirs.

  17. Quantification of pore size distribution in reservoir rocks using MRI logging: A case study of South Pars Gas Field.

    Science.gov (United States)

    Ghojogh, Jalal Neshat; Esmaili, Mohammad; Noruzi-Masir, Behrooz; Bakhshi, Puyan

    2017-12-01

    Pore size distribution (PSD) is an important factor for controlling fluid transport through porous media. The study of PSD can be applicable in areas such as hydrocarbon storage, contaminant transport, prediction of multiphase flow, and analysis of the formation damage by mud infiltration. Nitrogen adsorption, centrifugation method, mercury injection, and X-ray computed tomography are commonly used to measure the distribution of pores. A core sample is occasionally not available because of the unconsolidated nature of reservoirs, high cost of coring operation, and program limitations. Magnetic resonance imaging logging (MRIL) is a proper logging technique that allows the direct measurement of the relaxation time of protons in pore fluids and correlating T 2 distribution to PSD using proper mathematical equations. It is nondestructive and fast and does not require core samples. In this paper, 8 core samples collected from the Dalan reservoir in South Pars Gas Field were studied by processing MRIL data and comparing them by PSD determined in the laboratory. By using the MRIL method, variation in PSD corresponding to the depth for the entire logged interval was determined. Moreover, a detailed mineralogical composition of the reservoir samples related to T 2 distribution was obtained. A good correlation between MRIL and mercury injection data was observed. High degree of similarity was also observed between T 2 distribution and PSD (R 2 = 0.85 to 0.91). Based on the findings from the MRIL method, the obtained values for clay bond water varied between 1E-6 and 1E-3µm, a range that is comprehended from an extra peak on the PSD curve. The frequent pore radius was determined to be 1µm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Evaluation of optimal reservoir prospectivity using acoustic-impedance model inversion: A case study of an offshore field, western Niger Delta, Nigeria

    Science.gov (United States)

    Oyeyemi, Kehinde D.; Olowokere, Mary T.; Aizebeokhai, Ahzegbobor P.

    2017-12-01

    The evaluation of economic potential of any hydrocarbon field involves the understanding of the reservoir lithofacies and porosity variations. This in turns contributes immensely towards subsequent reservoir management and field development. In this study, integrated 3D seismic data and well log data were employed to assess the quality and prospectivity of the delineated reservoirs (H1-H5) within the OPO field, western Niger Delta using a model-based seismic inversion technique. The model inversion results revealed four distinct sedimentary packages based on the subsurface acoustic impedance properties and shale contents. Low acoustic impedance model values were associated with the delineated hydrocarbon bearing units, denoting their high porosity and good quality. Application of model-based inverted velocity, density and acoustic impedance properties on the generated time slices of reservoirs also revealed a regional fault and prospects within the field.

  19. Engineering geophysical study of the convocation square, Kaduna ...

    African Journals Online (AJOL)

    Geophysical investigation for engineering studies was carried out at the convocation square of Kaduna State University (KASU) main campus, Kaduna state, which falls within the Basement Complex of North-Western Nigeria. The study is aimed at assisting in the planning and development process of civil engineering ...

  20. Support vector regression for porosity prediction in a heterogeneous reservoir: A comparative study

    Science.gov (United States)

    Al-Anazi, A. F.; Gates, I. D.

    2010-12-01

    In wells with limited log and core data, porosity, a fundamental and essential property to characterize reservoirs, is challenging to estimate by conventional statistical methods from offset well log and core data in heterogeneous formations. Beyond simple regression, neural networks have been used to develop more accurate porosity correlations. Unfortunately, neural network-based correlations have limited generalization ability and global correlations for a field are usually less accurate compared to local correlations for a sub-region of the reservoir. In this paper, support vector machines are explored as an intelligent technique to correlate porosity to well log data. Recently, support vector regression (SVR), based on the statistical learning theory, have been proposed as a new intelligence technique for both prediction and classification tasks. The underlying formulation of support vector machines embodies the structural risk minimization (SRM) principle which has been shown to be superior to the traditional empirical risk minimization (ERM) principle employed by conventional neural networks and classical statistical methods. This new formulation uses margin-based loss functions to control model complexity independently of the dimensionality of the input space, and kernel functions to project the estimation problem to a higher dimensional space, which enables the solution of more complex nonlinear problem optimization methods to exist for a globally optimal solution. SRM minimizes an upper bound on the expected risk using a margin-based loss function ( ɛ-insensitivity loss function for regression) in contrast to ERM which minimizes the error on the training data. Unlike classical learning methods, SRM, indexed by margin-based loss function, can also control model complexity independent of dimensionality. The SRM inductive principle is designed for statistical estimation with finite data where the ERM inductive principle provides the optimal solution (the

  1. unconventional natural gas reservoirs

    International Nuclear Information System (INIS)

    Correa G, Tomas F; Osorio, Nelson; Restrepo R, Dora P

    2009-01-01

    This work is an exploration about different unconventional gas reservoirs worldwide: coal bed methane, tight gas, shale gas and gas hydrate? describing aspects such as definition, reserves, production methods, environmental issues and economics. The overview also mentioned preliminary studies about these sources in Colombia.

  2. Oxidation Catalyst Studies on a Diesel Engine

    OpenAIRE

    Ye, Shifei

    2010-01-01

    In this thesis, the experimental test facilities consisted of a well instrumented live Ford 2.0 litre turbocharged diesel engine connected to a specially made exhaust can, which contained a diesel oxidation catalyst (DOC). Experiments were performed on DOCs, which were specially prepared by Johnson Matthey, and had thermocouples mounted in their walls to measure axial temperature profiles. These DOCs consisted of a Pt catalyst dispersed in an alumina washcoat on a cordierite monolith supports...

  3. Oxygen uptake during mineralization of photosynthesized carbon from phytoplankton of the Barra Bonita Reservoir: a mesocosm study

    Directory of Open Access Journals (Sweden)

    MB. Cunha-Santino

    Full Text Available This study aimed to discuss and describe the oxygen consumption during aerobic mineralization of organic products (cells and excretion products from five unialgal cultures: Cryptomonas sp., Microcystis aeruginosa, Anabaena spiroides, Thalassiosira sp. and Aulacoseira granulata. These species were isolated from Barra Bonita reservoir (22º 29’ S and 48º 34’ W and cultivated in the laboratory. From each culture, two decomposition chambers were prepared; each chamber contained about 130 mg.L-1 of carbon from water samples of the reservoir. The chambers were aerated and incubated in the dark at 20.0 ºC. The concentration of dissolved oxygen, pH values and electrical conductivity of the solutions were determined during a period of 10 days. The results indicated increases in oxygen consumption for all the solutions studied and also for electrical conductivity. The pH values presented a decreasing tendency throughout the experiment. Oxygen consumption varied from 43 (Aulacoseira granulata chamber to 345 mg O2 g-1 C (Anabaena spiroides chamber. Decrease in pH values was probably due to increase in CO2 concentration from microbial respiration. Increase in electrical conductivity might be due to the liberation of ions during decomposition. The results demonstrate the potentiality of the studied genera in influencing oxygen availability followed by a die-off event. It also indicates the possibility of changing of the electrical conductivity and pH values in the water column due the aerobic algae mineralization.

  4. Computational studies of an intake manifold for restricted engine application

    Science.gov (United States)

    Prasetyo, Bagus Dwi; Ubaidillah, Maharani, Elliza Tri; Setyohandoko, Gabriel; Idris, Muhammad Idzdihar

    2018-02-01

    The Formula Society of Automotive Engineer (FSAE) student competition is an international contest for a vehicle that entirely designed and built by students from various universities. The engine design in the Formula SAE competition has to comply a tight regulation. Concerning the engine intake line, an air restrictor of circular cross-section less than 20 mm must be fitted between the throttle valve and the engine inlet. The throat is aimed to limit the engine air flow rate as it strongly influences the volumetric efficiency and then the maximum power. This article focuses on the design of the engine intake system of the Bengawan FSAE team vehicle to optimize the engine power output and its stability. The performance of engine intake system is studied through computational fluid dynamics (CFD). The objective of CFD is to know the pressure, velocity, and airflow of the air intake manifold for the best performance of the engine. The three-dimensional drawing of the intake manifold was made, and CFD simulation was conducted using ANSYS FLUENT. Two models were studied. The result shows that the different design produces a different value of the velocity of airflow and the kind of flow type.

  5. Technical difficulties of logging while drilling in carbonate reservoirs and the countermeasures: A case study from the Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Shudong Zhang

    2015-12-01

    Full Text Available In the Sichuan Basin, carbonate reservoirs are characterized by deep burial depth and strong heterogeneity, so it is difficult to conduct structure steering, pore space reservoir tracking and trajectory control in the process of geosteering logging while drilling. In this paper, a series of corresponding techniques for structure, reservoir and formation tracking were proposed after analysis was conducted on multiple series of carbonate strata in terms of their geologic and logging response characteristics. And investigation was performed on the adaptabilities of the following logging technologies to geosteering while drilling, including gamma ray imaging while drilling, resistivity imaging while drilling, density imaging while drilling, gamma ray logging while drilling, resistivity logging while drilling, neutron logging while drilling and density logging while drilling. After while drilling information was thoroughly analyzed, the logging suites for four common types of complicated reservoirs (thin layered reservoirs, thick massive reservoirs, denuded karst reservoirs and shale gas reservoirs were optimized, and five logging combinations suitable for different formations and reservoirs were proposed, including gamma ray logging + porosity + resistivity imaging, gamma ray logging + resistivity imaging, gamma ray logging + porosity + resistivity logging, gamma ray imaging + resistivity logging, and gamma ray logging. Field application indicates that it is of great reference and application value to use this method for the first time to summarize logging while drilling combinations for different types of carbonate reservoirs.

  6. Estimating Water Levels with Google Earth Engine

    Science.gov (United States)

    Lucero, E.; Russo, T. A.; Zentner, M.; May, J.; Nguy-Robertson, A. L.

    2016-12-01

    Reservoirs serve multiple functions and are vital for storage, electricity generation, and flood control. For many areas, traditional ground-based reservoir measurements may not be available or data dissemination may be problematic. Consistent monitoring of reservoir levels in data-poor areas can be achieved through remote sensing, providing information to researchers and the international community. Estimates of trends and relative reservoir volume can be used to identify water supply vulnerability, anticipate low power generation, and predict flood risk. Image processing with automated cloud computing provides opportunities to study multiple geographic areas in near real-time. We demonstrate the prediction capability of a cloud environment for identifying water trends at reservoirs in the US, and then apply the method to data-poor areas in North Korea, Iran, Azerbaijan, Zambia, and India. The Google Earth Engine cloud platform hosts remote sensing data and can be used to automate reservoir level estimation with multispectral imagery. We combine automated cloud-based analysis from Landsat image classification to identify reservoir surface area trends and radar altimetry to identify reservoir level trends. The study estimates water level trends using three years of data from four domestic reservoirs to validate the remote sensing method, and five foreign reservoirs to demonstrate the method application. We report correlations between ground-based reservoir level measurements in the US and our remote sensing methods, and correlations between the cloud analysis and altimetry data for reservoirs in data-poor areas. The availability of regular satellite imagery and an automated, near real-time application method provides the necessary datasets for further temporal analysis, reservoir modeling, and flood forecasting. All statements of fact, analysis, or opinion are those of the author and do not reflect the official policy or position of the Department of Defense or any

  7. Double Compression Expansion Engine: A Parametric Study on a High-Efficiency Engine Concept

    KAUST Repository

    Bhavani Shankar, Vijai Shankar

    2018-04-03

    The Double compression expansion engine (DCEE) concept has exhibited a potential for achieving high brake thermal efficiencies (BTE). The effect of different engine components on system efficiency was evaluated in this work using GT Power simulations. A parametric study on piston insulation, convection heat transfer multiplier, expander head insulation, insulation of connecting pipes, ports and tanks, and the expander intake valve lift profiles was conducted to understand the critical parameters that affected engine efficiency. The simulations were constrained to a constant peak cylinder pressure of 300 bar, and a fixed combustion phasing. The results from this study would be useful in making technology choices that will help realise the potential of this engine concept.

  8. Engineering Students' Views of Corporate Social Responsibility: A Case Study from Petroleum Engineering.

    Science.gov (United States)

    Smith, Jessica M; McClelland, Carrie J; Smith, Nicole M

    2017-12-01

    The mining and energy industries present unique challenges to engineers, who must navigate sometimes competing responsibilities and codes of conduct, such as personal senses of right and wrong, professional ethics codes, and their employers' corporate social responsibility (CSR) policies. Corporate social responsibility (CSR) is the current dominant framework used by industry to conceptualize firms' responsibilities to their stakeholders, yet has it plays a relatively minor role in engineering ethics education. In this article, we report on an interdisciplinary pedagogical intervention in a petroleum engineering seminar that sought to better prepare engineering undergraduate students to critically appraise the strengths and limitations of CSR as an approach to reconciling the interests of industry and communities. We find that as a result of the curricular interventions, engineering students were able to expand their knowledge of the social, rather than simply environmental and economic dimensions of CSR. They remained hesitant, however, in identifying the links between those social aspects of CSR and their actual engineering work. The study suggests that CSR may be a fruitful arena from which to illustrate the profoundly sociotechnical dimensions of the engineering challenges relevant to students' future careers.

  9. Fault seal analysis to predict the compartmentalization of gas reservoir: Case study of Steenkool formation Bintuni Basin

    Science.gov (United States)

    Ginanjar, W. C. B.; Haris, A.; Riyanto, A.

    2017-07-01

    This study is aimed to analyze the mechanism of hydrocarbons trapping in the field on a relatively new play in the Bintuni basin particularly Steenkool formation. The first well in this field has been drilled with a shallow target in the Steenkool formation and the drilling is managed to find new gas reserves in the shale-sandstone layer. In the structure of this gas discovery, there is the potential barrier for compartmentalization that draws attention to analyze how the patterns of structural of fault become a part of reservoir compartment. In order to measure the risk associated with prospects on a field bounded by faults, it is important to understand the processes that contribute to fault seal. The method of Fault Seal Analysis (FSA) is one of the methods used for the analysis of the nature of a fault whether the fault is sealing or leaking the fluid flow in the reservoir. Trapping systems that are limited by faults play an important role in creating a trap of hydrocarbon. The ability of a fault to seal fluid is quantitatively reflected by the value of Shale Gouge Ratio (SGR). SGR is the calculation of the amount of fine-grained material that fills fault plane (fault gouge) as a result of the movement mechanism of fault. The result of this study is a valuable resource for the systematic evaluation of the analysis of hydrocarbon prospects in the field.

  10. Multi-objective Optimization of the Mississippi Headwaters Reservoir System

    Science.gov (United States)

    Faber, B. A.; Harou, J. J.

    2006-12-01

    The Hydrologic Engineering Center (HEC) of the U.S. Army Corps of Engineers is participating in a re- operation study of the Mississippi Headwaters reservoir system. The study, termed ROPE (Reservoir Operation Plan Evaluation), will develop a new operation policy for the reservoir system in a Shared Vision Planning effort. The current operating plan is 40 years old and does not account for the diverse objectives of the system altered by increased development and resource awareness. Functions of the six-reservoir system include flood damage reduction, recreation, fish and wildlife habitat considerations, tribal resources, water quality, water supply, erosion and sedimentation control, and hydropower production. Experience has shown that a modeling approach using both optimization, which makes decisions based on their value to objectives, and simulation, which makes decisions that follow operating instructions or rules, is an effective way to improve or develop new operating policies. HEC's role in this study was to develop a multi- objective optimization model of the system using HEC-PRM (Prescriptive Reservoir Model), a generalized computer program that performs multi-period deterministic network-flow optimization of reservoir systems. The optimization model's purpose is to enable stakeholders and decision makers to select appropriate tradeoffs between objectives, and have these tradeoffs reflected in proposed rules. Initial single-objective optimizations allow stakeholders to verify that the penalty functions developed by experts accurately represent their interests. Once penalty functions are confirmed, trade-off curves between pairs of system objectives are developed, and stakeholders and decision makers choose a desired balance between the two objectives. These chosen balance points are maintained in optimizations that consider all objectives. Finally, optimal system decisions are studied to infer operating patterns that embody the chosen tradeoffs. The

  11. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements

    Energy Technology Data Exchange (ETDEWEB)

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  12. Installation of a Devonian Shale Reservoir Testing Facility and acquisition of reservoir property measurements. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Locke, C.D.; Salamy, S.P.

    1991-09-01

    In October, a contract was awarded for the Installation of a Devonian Shale Reservoir Testing Facility and Acquisition of Reservoir Property measurements from wells in the Michigan, Illinois, and Appalachian Basins. Geologic and engineering data collected through this project will provide a better understanding of the mechanisms and conditions controlling shale gas production. This report summarizes the results obtained from the various testing procedures used at each wellsite and the activities conducted at the Reservoir Testing Facility.

  13. Riparian Buffers for Runoff Control and Sensitive Species Habitat on U.S. Army Corps of Engineers Lake and Reservoir Projects

    Science.gov (United States)

    2016-10-01

    significant fluctuations in water levels (Allen and Klimas 1986) based on a variety of factors , including hydropower, recreation, and water supply...Development Center. REFERENCES Allen, H. H., and C. V . Klimas. 1986. Reservoir shoreline revegetation guidelines. Technical Report E-86-13. Vicksburg...103–113). Backhuys, Leiden , the Netherlands. Brodhead, K. M. S. H. Stoleson, and D. M. Finch. 2007. Southwestern Willow Flycatchers (Empidonax traillii

  14. Feasibility study of low-head hydrolectric power on Carlyle Reservoir for the Carlyle, Illinois Municipal Electric Utility - City of Carlyle, Illinois

    Energy Technology Data Exchange (ETDEWEB)

    1979-03-01

    The feasibility of the city of Carlyle, Illinois developing hydroelectric power on Carlyle Reservoir was determined. The hydrologic conditions under which the proposed project would operate were investigated herein along with the marketability of production from the facility and the facility's compatability with present reservoir functions as well as with the environment. A conceptual plant design has been developed in detail for a power plant consisting of two horizontal shaft, adjustable blade, fixed vane hydroelectric turbines each connected through speed increasing gear boxes to 4375 kW generators. The site selected is west of and immediately adjacent to the stilling basin of the spillway for Carlyle Reservoir. Two 13.5 penstocks would be bored through the existing concrete non-overflow dam adjacent to the present gated spillway structure. The total estimated project cost is $7,550,000 or an average of $863.00 per installed kilowatt. The development of the proposed project is believed to require 45 months and will produce an estimated average annual output of approximately 21,500,000 kWh. The conceptual design herein developed is believed to have the capability of an eventual detailed engineering design which will be acceptable to all approving authorities, and particularly the U.S. Corps of Engineers.

  15. A study of CO2 flooding on wave velocities in the Naharkatiya oil reservoir of Upper Assam Basin

    Directory of Open Access Journals (Sweden)

    Subrata Borgohain Gogoi

    2017-03-01

    Full Text Available This paper studies the compressional-wave and shear-wave velocities in the laboratory in six conventional core plugs. These plugs were obtained from a depth of more than 3000 m from the producing horizons of Naharkatiya oil reservoir of Upper Assam Basin, India. The porosities of the conventional core plugs were from 9.67 to 25.8% and that of unconsolidated sand pack was 47%. These plugs and sand pack were saturated with n-hexadecane before CO2 flooding. It was observed that during flooding compressional-wave velocities decreased more than the shear wave velocities. These decreases in wave velocity depend on confining pressure, pore pressure, porosity and temperature of the plugs. Increasing pore pressure at constant confining pressure not only keeps the pores and cracks open but also reduces the confining pressure effect and increases the CO2 density. Higher pore pressures causes larger decrease in both compressional and shear wave velocities. In case of conventional core plugs which are consolidated, having lower porosities tends to decrease the CO2 effect. In unconsolidated sand pack the flooding effect is large even though porosity is high because the bulk modulus of the sand is low. The experimental and the theoretical analyses in this paper show that the decrease in compressional-wave velocities caused by CO2 flooding makes it possible to track CO2 front movements and monitor CO2 flooding process in the reservoir.

  16. Wild-Caught and Farm-Reared Amphibians are Important Reservoirs of Salmonella, A Study in North-East Thailand.

    Science.gov (United States)

    Ribas, A; Poonlaphdecha, S

    2017-03-01

    The role of amphibians as Salmonella reservoirs has not been as well studied as in reptiles, where the literature is abundant. Recent outbreaks of salmonellosis associated with exotic pet frogs have occurred in United States. Frog farming and wild frog harvesting have increased the international trade in these species. This necessitates a better understanding of the risk of salmonellosis transmission from amphibians to humans. We explored the presence of Salmonella in amphibians (frogs and toads) in Thailand, where farmed and wild frogs as well as toads are present. These live animals are easily found in the local markets and are used as food. Exportation of frog meat from Thailand is common. During March-June 2014, ninety-seven frogs were collected from several habitats, including frog farms, urban areas and protected natural areas. The collected amphibians were tested for the presence of Salmonella. The overall prevalence of Salmonella was 69.07% (90.00% in farm animals, 0% in urban area animals and 44.83% in protected area animals). Eight serovars of Salmonella were isolated: subsp. diarizonae ser. 50:k:z, Hvittingfoss, Muenchen, Newport, Stanley, Thompson, Panama and Wandsworth. Six of the identified serovars, Hvittingfoss, Newport, Panama, Stanley, Thompson and Wandsworth, have been detected in humans in Thailand. According to our results, amphibians are reservoirs of Salmonella and can be a public health concern when used as a source of protein for humans. © 2016 Blackwell Verlag GmbH.

  17. USE OF POM AND ARTIFICIAL NEURAL NETWORKS IN THE THREEDIMENSIONAL MODELING OF LAKES : GOKPINAR DAM RESERVOIR AS A CASE STUDY

    Directory of Open Access Journals (Sweden)

    Mahmut FIRAT

    2006-01-01

    Full Text Available The circulation pattern in lakes and reservoirs varies according to many external factors. In situ measurement of the occuring flow pattern in every point of the lake is a very costly and hard task. For this reason, models determining the velocities and surface fluctuations are developed by using computers. The use of these models enables the generation of the foundation for the prediction of possible environmental problems and water pollution concentrations. Today, three dimensional models are widely used in the modelling of lakes and reservoirs. In this study, the velocity profiles and surface fluctuation values generated under various wind speed and directions at some sections in Gokpinar Lake in Denizli are obtained by applying artificial neural networks (ANN on the results of three dimensional hydrodynamic model of the lake made with Princeton Ocean Model (POM. The developed ANN model is applied to the same sections for different wind conditions and it is found that the results are in accordance with the results of POM. As a result of the comparisons of the models, the superiorities of the models on each other at the model generation and solution phases are determined and mentioned.

  18. Modelling earthquake location errors at a reservoir scale: a case study in the Upper Rhine Graben

    Science.gov (United States)

    Kinnaert, X.; Gaucher, E.; Achauer, U.; Kohl, T.

    2016-08-01

    Earthquake absolute location errors which can be encountered in an underground reservoir are investigated. In such an exploitation context, earthquake hypocentre errors can have an impact on the field development and economic consequences. The approach using the state-of-the-art techniques covers both the location uncertainty and the location inaccuracy—or bias—problematics. It consists, first, in creating a 3-D synthetic seismic cloud of events in the reservoir and calculating the seismic traveltimes to a monitoring network assuming certain propagation conditions. In a second phase, the earthquakes are relocated with assumptions different from the initial conditions. Finally, the initial and relocated hypocentres are compared. As a result, location errors driven by the seismic onset time picking uncertainties and inaccuracies are quantified in 3-D. Effects induced by erroneous assumptions associated with the velocity model are also modelled. In particular, 1-D velocity model uncertainties, a local 3-D perturbation of the velocity and a 3-D geostructural model are considered. The present approach is applied to the site of Rittershoffen (Alsace, France), which is one of the deep geothermal fields existing in the Upper Rhine Graben. This example allows setting realistic scenarios based on the knowledge of the site. In that case, the zone of interest, monitored by an existing seismic network, ranges between 1 and 5 km depth in a radius of 2 km around a geothermal well. Well log data provided a reference 1-D velocity model used for the synthetic earthquake relocation. The 3-D analysis highlights the role played by the seismic network coverage and the velocity model in the amplitude and orientation of the location uncertainties and inaccuracies at subsurface levels. The location errors are neither isotropic nor aleatoric in the zone of interest. This suggests that although location inaccuracies may be smaller than location uncertainties, both quantities can have a

  19. Modeling Alpine hydropower reservoirs management to study the water-energy nexus under change.

    Science.gov (United States)

    Castelletti, A.; Giuliani, M.; Fumagalli, E.; Weber, E.

    2014-12-01

    Climate change and growing population are expected to severely affect freshwater availability by the end of 21th century. Many river basins, especially in the Mediterranean region, are likely to become more prone to periods of reduced water supply, risking considerable impacts on the society, the environment, and the economy, thus emphasizing the need to rethink the way water resources are distributed, managed, and used at the regional and river basin scale. This paradigm shift will be essential to cope with the undergoing global change, characterized by growing water demands and by increasingly uncertain hydrologic regimes. Most of the literature traditionally focused on predicting the impacts of climate change on water resources, while our understanding of the human footprint on the hydrological cycle is limited. For example, changes in the operation of the Alpine hydropower reservoirs induced by socio-economic drivers (e.g., development of renewable energy) were already observed over the last few years and produced relevant impacts on multiple water uses due to the altered distribution of water volumes in time and space. Modeling human decisions as well as the links between society and environmental systems becomes key to develop reliable projections on the co-evolution of the coupled human-water systems and deliver robust adaptation strategies This work contributes a preliminary model-based analysis of the behaviour of hydropower operators under changing energy market and climate conditions. The proposed approach is developed for the San Giacomo-Cancano reservoir system, Italy. The identification of the current operating policy is supported by input variable selection methods to select the most relevant hydrological and market based drivers to explain the observed release time series.. The identified model is then simulated under a set of future scenarios, accounting for both climate and socio-economic change (e.g. expansion of the electric vehicle sector, load

  20. Study of gas production from shale reservoirs with multi-stage hydraulic fracturing horizontal well considering multiple transport mechanisms

    OpenAIRE

    Guo, Chaohua; Wei, Mingzhen; Liu, Hong

    2018-01-01

    Development of unconventional shale gas reservoirs (SGRs) has been boosted by the advancements in two key technologies: horizontal drilling and multi-stage hydraulic fracturing. A large number of multi-stage fractured horizontal wells (MsFHW) have been drilled to enhance reservoir production performance. Gas flow in SGRs is a multi-mechanism process, including: desorption, diffusion, and non-Darcy flow. The productivity of the SGRs with MsFHW is influenced by both reservoir conditions and hyd...

  1. Enhancing Systems Engineering Education Through Case Study Writing

    Science.gov (United States)

    Stevens, Jennifer Stenger

    2016-01-01

    Developing and refining methods for teaching systems engineering is part of Systems Engineering grand challenges and agenda for research in the SE research community. Retention of systems engineering knowledge is a growing concern in the United States as the baby boom generation continues to retire and the faster pace of technology development does not allow for younger generations to gain experiential knowledge through years of practice. Government agencies, including the National Aeronautics and Space Administration (NASA), develop their own curricula and SE leadership development programs to "grow their own" systems engineers. Marshall Space Flight Center (MSFC) conducts its own Center-focused Marshall Systems Engineering Leadership Development Program (MSELDP), a competitive program consisting of coursework, a guest lecture series, and a rotational assignment into an unfamiliar organization engaged in systems engineering. Independently, MSFC developed two courses to address knowledge retention and sharing concerns: Real World Marshall Mission Success course and its Case Study Writers Workshop and Writers Experience. Teaching case study writing and leading students through a hands-on experience at writing a case study on an SE topic can enhance SE training and has the potential to accelerate the transfer of experiential knowledge. This paper is an overview of the pilot experiences with teaching case study writing, its application in case study-based learning, and identifies potential areas of research and application for case study writing in systems engineering education.

  2. How to solve the technical problems in CBM development: A case study of a CBM gas reservoir in the southern Qinshui Basin

    Directory of Open Access Journals (Sweden)

    Qingzhong Zhu

    2015-03-01

    Full Text Available The low average single-well production, resulting in low economic benefit, has become the main bottleneck of CBM development in China. In view of this issue, through case study of a CBM gas reservoir in the southern Qinshui Basin, we summarized the present status of CBM technology and development there and also pointed out some major problems in CBM development: (1 the engineering technology for the CBM development needs to adapt to the particular geological characteristics; (2 a large number of inefficient zones still exist in mature blocks in the southern Qinshui Basin; (3 single-well production can not be effectively enhanced only by increasing the fracturing scale; (4 the production of multi-lateral wells is higher, but the fulfillment rate of production capacity overall is still low; and (5 on-site management lacks scientific evidence. On this basis, we present the following suggestions for subsequent coalbed gas development: (1 the production construction mode should be changed, and the fulfillment rate of production capacity construction should be improved; (2 CBM geological research should be improved and well types and locations should be designed reasonably and scientifically; (3 main technologies should be built in a dialectical thinking mode; (4 horizontal well design should be optimized to improve the applicability of relevant technologies; (5 fracturing mode should be changed to improve single-well production; and (6 the drainage technology should be changed to improve economic efficiency.

  3. Reservoir Cannulas for Pediatric Oxygen Therapy: A Proof-of-Concept Study

    Directory of Open Access Journals (Sweden)

    Grace Wu

    2016-01-01

    Full Text Available Hypoxemia is a complication of pneumonia—the leading infectious cause of death in children worldwide. Treatment generally requires oxygen-enriched air, but access in low-resource settings is expensive and unreliable. We explored use of reservoir cannulas (RCs, which yield oxygen savings in adults but have not been examined in children. Toddler, small child, and adolescent breathing profiles were simulated with artificial lung and airway models. An oxygen concentrator provided flow rates of 0 to 5 L/min via a standard nasal cannula (NC or RC, and delivered oxygen fraction (FdO2 was measured. The oxygen savings ratio (SR and absolute flow savings (AFS were calculated, comparing NC and RC. We demonstrated proof-of-concept that pendant RCs could conserve oxygen during pediatric therapy. SR mean and standard deviation were 1.1±0.2 to 1.4±0.4, 1.1±0.1 to 1.7±0.3, and 1.3±0.1 to 2.4±0.3 for toddler, small child, and adolescent models, respectively. Maximum AFS observed were 0.3±0.3, 0.2±0.1, and 1.4±0.3 L/min for the same models. RCs have the potential to reduce oxygen consumption during treatment of hypoxemia in children; however, further evaluation of products is needed, followed by clinical analysis in patients.

  4. CDIO Projects in Civil Engineering Study Program at DTU

    DEFF Research Database (Denmark)

    Krogsbøll, Anette; Simonsen, Claus; Christensen, Jørgen Erik

    2011-01-01

    In 2008 all Bachelor of engineering study programs at the Technical University of Denmark (DTU) have been adopted to the “Conceive – Design – Implement – Operate” approach. As part of the necessary changes it was decided that all seven study programs should have a cross disciplinary project...... or a design build project on each of the first four semesters. In this paper the four projects in the civil engineering study program are described along with a brief description of the entire study program. The aim is to provide additional information and documentation to accompany an exposition where...... students present their projects. Learning outcomes, training and assessment of personal, professional and social engineering skills are described from a project point of view. Progression of engineering skills is discussed from a study program perspective. The interrelation between the various elements...

  5. Reservoir Characterisation Using Wireline Evaluation And Poststack Seismic Inversion: A Lancelot Field, Southern North Sea, U.K. case study

    International Nuclear Information System (INIS)

    Mojisola, A.

    2002-01-01

    Improved reservoir characterization has been a major factor in the worldwide gain in oil recovery efficiencies over the last decades. This is because inadequate reservoir characterization, usually due to lack of appropriate tools can cause significant errors in petroleum reservoir performance prediction thereby preventing the full potential of a reservoir from being achieved. This work employs the use of wireline logs and the seismic inversion process to characterize the reservoirs in the Lancelot field. An initial reservoir analysis was carried out using the wireline evaluation. Five potential reservoirs were delineated. Thereafter reservoir parameters such as porosity, water saturation, water saturation, net-to-gross ratio of the delineated reservoirs were estimated. The seismic inversion process depends on four factors; the wavelet, the tie between the well logs and the seismic, the inversion algorithm employed and the initial model. Therefore before the main inversion, parameter tests were carried out to determine the best wavelet extraction algorithm and best inversion algorithm suited for he available data. A wavelet with a length of 70ms and a taper length of 20ms gave a close approximation of a zero phase wavelet with a stable spectrum and high dominant frequency. Based on quantitative assessment of the available inversion algorithms, the constrained blocky inversion produced the best result. Acoustic impedance, velocity and porosity sections were produced from the inverted input seismic. By incorporating geological and wireline evaluation results as constraints, the output from the inversion process were analysed. The result shows lateral variation in the reservoirs qualities of the delineated reservoirs. The seismic inversion process confirmed the Rotliegend sandstone as a prospect with a range of porosity predicted from the inversion

  6. Numerical Simulation Study on Steam-Assisted Gravity Drainage Performance in a Heavy Oil Reservoir with a Bottom Water Zone

    Directory of Open Access Journals (Sweden)

    Jun Ni

    2017-12-01

    Full Text Available In the Pikes Peak oil field near Lloydminster, Canada, a significant amount of heavy oil reserves is located in reservoirs with a bottom water zone. The properties of the bottom water zone and the operation parameters significantly affect oil production performance via the steam-assisted gravity drainage (SAGD process. Thus, in order to develop this type of heavy oil resource, a full understanding of the effects of these properties is necessary. In this study, the numerical simulation approach was applied to study the effects of properties in the bottom water zone in the SAGD process, such as the initial gas oil ratio, the thickness of the reservoir, and oil saturation of the bottom water zone. In addition, some operation parameters were studied including the injection pressure, the SAGD well pair location, and five different well patterns: (1 two corner wells, (2 triple wells, (3 downhole water sink well, (4 vertical injectors with a horizontal producer, and (5 fishbone well. The numerical simulation results suggest that the properties of the bottom water zone affect production performance extremely. First, both positive and negative effects were observed when solution gas exists in the heavy oil. Second, a logarithmical relationship was investigated between the bottom water production ratio and the thickness of the bottom water zone. Third, a non-linear relation was obtained between the oil recovery factor and oil saturation in the bottom water zone, and a peak oil recovery was achieved at the oil saturation rate of 30% in the bottom water zone. Furthermore, the operation parameters affected the heavy oil production performance. Comparison of the well patterns showed that the two corner wells and the triple wells patterns obtained the highest oil recovery factors of 74.71% and 77.19%, respectively, which are almost twice the oil recovery factors gained in the conventional SAGD process (47.84%. This indicates that the optimized SAGD process

  7. Study of temperature distribution in a Stirling engine regenerator

    International Nuclear Information System (INIS)

    Gheith, R.; Aloui, F.; Ben Nasrallah, S.

    2014-01-01

    Highlights: • A Gamma-Stirling engine is experimented to determine the optimal operation parameters. • A set of experiment reveals a difference of temperature between regenerator sides. • A phenomenon which consumes a part of the produced energy by the engine is highlighted. • A multi-objectif study based on experimental design methodology is developed. • The optimal set of operation parameters maximizing the engine power is proposed. - Abstract: A gamma Stirling engine is studied in this paper. A special care was accorded to the instrumentation of this engine and especially the instrumentation of the regenerator. A preliminarily set of experimental measurement reveals a difference of temperature between both regenerator sides. A second set of experiments was proposed to detect the influence of this phenomenon on Stirling engine performances. The asymmetry of heat transfer inside the Stirling engine regenerator’s is one of the important phenomenons which consume a part of the produced energy. Two experiments are made to find out the causes of this asymmetry. In order to know the influence of the different operation parameters on this new phenomenon the experimental design method is adopted. The experimental design is an alternative to identify the parameters sets allowing optimal Stirling engine performances. A central composite rotatable design was adopted for minimizing the asymmetry of temperature between both regenerator sides and maximizes the engine brake power. The selected four independent parameters are: heating temperature (300 °C–500 °C), initial filling pressure (3 bar–8 bar), cooling water flow rate (0.2 l/m–3 l/min) and operation time (4–20 min after study regime). The four adopted factors are experimentally varied. The results show that the heating temperature is the most significant factor for the studied phenomenon. The major damages caused by this phenomenon will be presented too

  8. Exploratory Simulation Studies of Caprock Alteration Induced byStorage of CO2 in Depleted Gas Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Gherardi, Fabrizio; Xu, Tianfu; Pruess, Karsten

    2005-11-23

    This report presents numerical simulations of isothermalreactive flows which might be induced in the caprock of an Italiandepleted gas reservoir by the geological sequestration of carbon dioxide.Our objective is to verify that CO2 geological disposal activitiesalready planned for the study area are safe and do not induce anyundesired environmental impact.Gas-water-rock interactions have beenmodelled under two different intial conditions, i.e., assuming that i)caprock is perfectly sealed, or ii) partially fractured. Field conditionsare better approximated in terms of the "sealed caprock model". Thefractured caprock model has been implemented because it permits toexplore the geochemical beahvior of the system under particularly severeconditions which are not currently encountered in the field, and then todelineate a sort of hypothetical maximum risk scenario.Major evidencessupporting the assumption of a sealed caprock stem from the fact that nogas leakages have been detected during the exploitation phase, subsequentreservoir repressurization due to the ingression of a lateral aquifer,and during several cycles of gas storage in the latest life of reservoirmanagement.An extensive program of multidisciplinary laboratory tests onrock properties, geochemical and microseismic monitoring, and reservoirsimulation studies is underway to better characterize the reservoir andcap-rock behavior before the performance of a planned CO2 sequestrationpilot test.In our models, fluid flow and mineral alteration are inducedin the caprock by penetration of high CO2 concentrations from theunderlying reservoir, i.e., it was assumed that large amounts of CO2 havebeen already injected at depth. The main focus is on the potential effectof these geochemical transformations on the sealing efficiency of caprockformations. Batch and multi-dimensional 1D and 2D modeling has been usedto investigate multicomponent geochemical processes. Our simulationsaccount for fracture-matrix interactions, gas

  9. Study of shale reservoir nanometer-sized pores in Member 1 of Shahejie Formation in JX area, Liaozhong sag

    Science.gov (United States)

    Cheng, Yong; Zhang, Yu; Wen, Yiming

    2018-02-01

    The microscopic pore structure is the key of the shale reservoir study; however, traditional Scanning Electron Microscopy (SEM) methods cannot identify the irregular morphology caused by mechanical polishing. In this work, Scanning Electron Microscopy combined argon ion polishing technology was taken to study the characteristics of shale reservoir pores of Member 1 of Shahejie Formation (E3s1) located in JX1-1 area of Liaozhong Sag. The results show that pores between clay platelets, intraplatelet pores within clay aggregates and organic-matter pores are very rich in the area and with good pore connectivity, so these types of pores are of great significance for oil-gas exporation. Pores between clay platelets are formed by directional or semi-directional contact between edge and surface, edge and edge or surface and surface of laminated clay minerals, whose shapes are linear, mesh, and irregular with the size of 500 nm to 5 μm. The intraplatelet pores within clay aggregates are formed in the process of the transformation and compaction of clay minerals, whose shapes are usually linear with the width of 30 to 500 nm and the length of 2 to 50 μm. The organic-matter pores are from the process of the conversion from organic matters to the hydrocarbon under thermal evolution, whose shapes are gneissic, irregular, pitted and elliptical with the size of 100 nm to 2 μm. This study is of certain guiding significance to selecting target zones, evaluating resource potential and exploring & developing of shale gas in this region.

  10. Reservoir drawdown: Case study in flow changes to potentially improve fisheries

    International Nuclear Information System (INIS)

    Wik, S.J.

    1995-01-01

    Salmon populations in the Columbia River Basin have declined, and several species are now protected under the Endangered Species Act. Many factors have contributed to the decline, including overharvest, loss of habit, degradation of water quality, and construction of dams. Many measures have been implemented to reduce the impact of the dams, but additional measures are being considered. Lowering water-surface elevations behind four lower Snake River dams has been proposed as a measure to improve juvenile salmonid survival. The Corps of Engineers has determined preliminary costs, schedules, and required modifications for several drawdown alternatives. Initial estimates of the ability of this type of operation to improve salmonid survival are controversial

  11. Study of sustainable production in two-phase liquid dominated with steam cap underlying brine reservoir by numerical simulation

    Science.gov (United States)

    Pratama, Heru Berian; Miryani Saptadji, Nenny

    2017-12-01

    The main issue in the management of the two-phase liquid-dominated geothermal field is rapid decline pressure in the reservoir so that the supply of steam to the power plant cannot be fulfilled. To understanding that, modelling and numerical simulation used reservoir simulators. The model is developed on liquid-dominated geothermal fields are assessed in various scenarios of production strategies (focusing only steam cap, brine reservoir and a combination) and injection strategies (deep and shallow injection, centered and dispersed injection), with the calculation using separated steam cycle method. The simulation results of the model for sustainable production are production 25% from steam cap + 75% from brine reservoir, dispersed and deep reinjection with make-up wells from steam cap results 9 make-up well number. The implementation of production-injection strategy needs to be planned right from the beginning of exploitation so that the strategy can adapt to changes in reservoir characteristics.

  12. Ethical Considerations in Tissue Engineering Research: Case Studies in Translation

    Science.gov (United States)

    Baker, Hannah B.; McQuilling, John P.

    2016-01-01

    Tissue engineering research is a complex process that requires investigators to focus on the relationship between their research and anticipated gains in both knowledge and treatment improvements. The ethical considerations arising from tissue engineering research are similarly complex when addressing the translational progression from bench to bedside, and investigators in the field of tissue engineering act as moral agents at each step of their research along the translational pathway, from early benchwork and preclinical studies to clinical research. This review highlights the ethical considerations and challenges at each stage of research, by comparing issues surrounding two translational tissue engineering technologies: the bioartificial pancreas and a tissue engineered skeletal muscle construct. We present relevant ethical issues and questions to consider at each step along the translational pathway, from the basic science bench to preclinical research to first-in-human clinical trials. Topics at the bench level include maintaining data integrity, appropriate reporting and dissemination of results, and ensuring that studies are designed to yield results suitable for advancing research. Topics in preclinical research include the principle of “modest translational distance” and appropriate animal models. Topics in clinical research include key issues that arise in early-stage clinical trials, including selection of patient-subjects, disclosure of uncertainty, and defining success. The comparison of these two technologies and their ethical issues brings to light many challenges for translational tissue engineering research and provides guidance for investigators engaged in development of any tissue engineering technology. PMID:26282436

  13. Air–water CO2 and CH4 fluxes along a river–reservoir continuum: Case study in the Pengxi River, a tributary of the Yangtze River in the Three Gorges Reservoir, China

    Science.gov (United States)

    Water surface greenhouse gas (GHG) emissions in freshwater reservoirs are closely related to limnological processes in the water column. Affected by both reservoir operation and seasonal changes, variations in the hydro-morphological conditions in the river–reservoir continuum will create distinctiv...

  14. Constraints on Water Reservoir Lifetimes From Catchment-Wide 10Be Erosion Rates—A Case Study From Western Turkey

    Science.gov (United States)

    Heineke, Caroline; Hetzel, Ralf; Akal, Cüneyt; Christl, Marcus

    2017-11-01

    The functionality and retention capacity of water reservoirs is generally impaired by upstream erosion and reservoir sedimentation, making a reliable assessment of erosion indispensable to estimate reservoir lifetimes. Widely used river gauging methods may underestimate sediment yield, because they do not record rare, high-magnitude events and may underestimate bed load transport. Hence, reservoir lifetimes calculated from short-term erosion rates should be regarded as maximum values. We propose that erosion rates from cosmogenic 10Be, which commonly integrate over hundreds to thousands of years, are useful to complement short-term sediment yield estimates and should be employed to estimate minimum reservoir lifetimes. Here we present 10Be erosion rates for the drainage basins of six water reservoirs in Western Turkey, which are located in a tectonically active region with easily erodible bedrock. Our 10Be erosion rates for these catchments are high, ranging from ˜170 to ˜1,040 t/km2/yr. When linked to reservoir volumes, they yield minimum reservoir lifetimes between 25 ± 5 and 1,650 ± 360 years until complete filling, with four reservoirs having minimum lifespans of ≤110 years. In a neighboring region with more resistant bedrock and less tectonic activity, we obtain much lower catchment-wide 10Be erosion rates of ˜33 to ˜95 t/km2/yr, illustrating that differences in lithology and tectonic boundary conditions can cause substantial variations in erosion even at a spatial scale of only ˜50 km. In conclusion, we suggest that both short-term sediment yield estimates and 10Be erosion rates should be employed to predict the lifetimes of reservoirs.

  15. Tissue-Engineering for the Study of Cardiac Biomechanics

    Science.gov (United States)

    Ma, Stephen P.; Vunjak-Novakovic, Gordana

    2016-01-01

    The notion that both adaptive and maladaptive cardiac remodeling occurs in response to mechanical loading has informed recent progress in cardiac tissue engineering. Today, human cardiac tissues engineered in vitro offer complementary knowledge to that currently provided by animal models, with profound implications to personalized medicine. We review here recent advances in the understanding of the roles of mechanical signals in normal and pathological cardiac function, and their application in clinical translation of tissue engineering strategies to regenerative medicine and in vitro study of disease. PMID:26720588

  16. Thermoelastic properties of the Rotokawa Andesite: A geothermal reservoir constraint

    Science.gov (United States)

    Siratovich, P. A.; von Aulock, F. W.; Lavallée, Y.; Cole, J. W.; Kennedy, B. M.; Villeneuve, M. C.

    2015-08-01

    Knowledge of the thermal properties of geothermal reservoir rocks is essential to constraining important engineering concerns such as wellbore stability, reservoir forecasting and stimulation procedures. The thermo-mechanical evolution of geological material is also important to assess when considering natural processes such as magmatic dyke propagation, contact metamorphism and magma/lava emplacement and cooling effects. To better constrain these properties in the geothermal reservoir, thermal measurements were carried out on core samples from production wells drilled in the Rotokawa Andesite geothermal reservoir, located in the Taupo Volcanic Zone, New Zealand. Linear thermal expansion testing, thermogravimetric analysis, and differential scanning calorimetry were used, employing experimental heating rates of 2, 5 and 20 °C/min. Thermal property analyses can elucidate whether thermal expansion values measured under varied heating (and cooling) rates are rate dependent and if thermo-chemical reactions influence the resultant expansivity. Measured thermal expansion coefficients of the Rotokawa Andesite are shown not to be heating rate dependent. We have also found that significant thermochemical reactions occur during heating above 500 °C resulting in non-reversible changes to the thermomechanical properties. The combined thermogravimetric, calorimetric and thermomechanical analysis allows insight to the reactions occurring and how the thermomechanical properties are affected at high temperature. We incorporated results of tensile strength testing on the Rotokawa Andesite to apply our thermal property measurements to a one-dimensional thermal stress model. The developed model provides a failure criterion for the Rotokawa Andesite under thermal stress. The importance of this study is to further understand the critical heating and cooling rates at which thermal stress may cause cracking within the Rotokawa reservoir. Thermal cracking in the reservoir can be

  17. Stonemeal of Amazon soils with sediments from reservoirs: a case study of remineralization of the Tucuruí degraded land for agroforest reclamation.

    Science.gov (United States)

    Theodoro, Suzi H; Leonardos, Othon H; Rocha, Eduardo; Macedo, Iris; Rego, Kleysson G

    2013-03-01

    This study suggests the employment of accumulated sediments in the reservoir of Tucuruí (Pará /Brazil) to remineralize the surrounding degraded soils. The approach was based on the principles of stonemeal technology. It suggests that the soil can be rejuvenated by crushed rocks rich in macro and micronutrients. Removal of the sediments for agricultural use will bring benefits to family farmers and increase the life cycle of the reservoir and, therefore, energy generation. Geochemical data on retained sediments, soils and rocks in the area of influence of the reservoir were evaluated regarding nutrient transport mechanisms and soil-fertility potential. Results show that sediments from the reservoir contain nutrients levels at least one order of magnitude greater than average Amazon region soils. Our data on soil use and occupation in the region show the degradation areas which could be recovered by stonemeal techniques. Thence, an Agroforestry System was installed, with 12 plots where different mixtures of sediments removed from the reservoir were used, along with crushed rock with or without the addition of NPK and manure. The experiments showed that maximum crop yield and plant growth were attained in the plots where a mixture of sediments, crushed rocks and manure were added.

  18. Stonemeal of amazon soils with sediments from reservoirs: a case study of remineralization of the tucuruí degraded land for agroforest reclamation

    Directory of Open Access Journals (Sweden)

    SUZI H. THEODORO

    2013-03-01

    Full Text Available This study suggests the employment of accumulated sediments in the reservoir of Tucuruí (Pará /Brazil to remineralize the surrounding degraded soils. The approach was based on the principles of stonemeal technology. It suggests that the soil can be rejuvenated by crushed rocks rich in macro and micronutrients. Removal of the sediments for agricultural use will bring benefits to family farmers and increase the life cycle of the reservoir and, therefore, energy generation. Geochemical data on retained sediments, soils and rocks in the area of influence of the reservoir were evaluated regarding nutrient transport mechanisms and soil-fertility potential. Results show that sediments from the reservoir contain nutrients levels at least one order of magnitude greater than average Amazon region soils. Our data on soil use and occupation in the region show the degradation areas which could be recovered by stonemeal techniques. Thence, an Agroforestry System was installed, with 12 plots where different mixtures of sediments removed from the reservoir were used, along with crushed rock with or without the addition of NPK and manure. The experiments showed that maximum crop yield and plant growth were attained in the plots where a mixture of sediments, crushed rocks and manure were added.

  19. Flow-based dissimilarity measures for reservoir models : a spatial-temporal tensor approach

    NARCIS (Netherlands)

    Insuasty, Edwin; van den Hof, P.M.J.; Weiland, Siep; Jansen, J.D.

    2017-01-01

    In reservoir engineering, it is attractive to characterize the difference between reservoir models in metrics that relate to the economic performance of the reservoir as well as to the underlying geological structure. In this paper, we develop a dissimilarity measure that is based on reservoir

  20. Space engineering modeling and optimization with case studies

    CERN Document Server

    Pintér, János

    2016-01-01

    This book presents a selection of advanced case studies that cover a substantial range of issues and real-world challenges and applications in space engineering. Vital mathematical modeling, optimization methodologies and numerical solution aspects of each application case study are presented in detail, with discussions of a range of advanced model development and solution techniques and tools. Space engineering challenges are discussed in the following contexts: •Advanced Space Vehicle Design •Computation of Optimal Low Thrust Transfers •Indirect Optimization of Spacecraft Trajectories •Resource-Constrained Scheduling, •Packing Problems in Space •Design of Complex Interplanetary Trajectories •Satellite Constellation Image Acquisition •Re-entry Test Vehicle Configuration Selection •Collision Risk Assessment on Perturbed Orbits •Optimal Robust Design of Hybrid Rocket Engines •Nonlinear Regression Analysis in Space Engineering< •Regression-Based Sensitivity Analysis and Robust Design ...

  1. Initial trade and design studies for the fusion engineering device

    International Nuclear Information System (INIS)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-06-01

    The Magnetic Fusion Energy Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. The Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), initiated a program of trade and design studies in October 1980 to support the selection of the FED concept. This document presents the results of these initial trade and design studies. Based on these results, a baseline configuration has been identified and the Design Center effort for the remainder of the fiscal year will be devoted to the development of a self-consistent FED design description

  2. Initial trade and design studies for the fusion engineering device

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, C.A.; Steiner, D.; Smith, G.E.

    1981-06-01

    The Magnetic Fusion Energy Engineering Act of 1980 calls for the operation of a Fusion Engineering Device (FED) by 1990. It is the intent of the Act that the FED, in combination with other testing facilities, will establish the engineering feasibility of magnetic fusion energy. The Fusion Engineering Design Center (FEDC), under the guidance of a Technical Management Board (TMB), initiated a program of trade and design studies in October 1980 to support the selection of the FED concept. This document presents the results of these initial trade and design studies. Based on these results, a baseline configuration has been identified and the Design Center effort for the remainder of the fiscal year will be devoted to the development of a self-consistent FED design description.

  3. A PRELIMINARY STUDY OF HUMOUR IN ENGINEERING EDUCATION

    Directory of Open Access Journals (Sweden)

    SIOW C. LIM

    2017-01-01

    Full Text Available It is commonly known that humour has an implication on the process of teaching and learning. However, there is still limited study done on the implication of humour in teaching and learning engineering courses. This paper studies the perception and experience of engineering lecturers and students towards the incorporation of sense of humour in the teaching and learning of engineering courses. Online and offline surveys were conducted on the students and lecturers from the school of engineering, Taylors’ University respectively. Several interesting insights were drawn from the responses with the general consensus from both students and lecturers that humour helps in enhancing the teaching and learning process. Real case examples of how the lecturers deliver their lectures with humour were also presented.

  4. Advanced Oil Recovery Technologies for Improved Recovery from Slope Basin Clastic Reservoirs, Nash Draw Brushy Canyon Pool, Eddy County, NM

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Mark B.

    1999-02-24

    The Nash Draw Brushy Canyon Pool in Eddy County New Mexico is a cost-shared field demonstration project in the US Department of Energy Class II Program. A major goal of the Class III Program is to stimulate the use of advanced technologies to increase ultimate recovery from slope-basin clastic reservoirs. Advanced characterization techniques are being used at the Nash Draw project to develop reservoir management strategies for optimizing oil recovery from this Delaware reservoir. Analysis, interpretation, and integration of recently acquired geologic, geophysical, and engineering data revealed that the initial reservoir characterization was too simplistic to capture the critical features of this complex formation. Contrary to the initial characterization, a new reservoir description evolved that provided sufficient detail regarding the complexity of the Brushy Canyon interval at Nash Draw. This new reservoir description is being used as a risk reduction tool to identify ''sweet spots'' for a development drilling program as well as to evaluate pressure maintenance strategies. The reservoir characterization, geological modeling, 3-D seismic interpretation, and simulation studies have provided a detailed model of the Brushy Canyon zones. This model was used to predict the success of different reservoir management scenarios and to aid in determining the most favorable combination of targeted drilling, pressure maintenance, well simulation, and well spacing to improve recovery from this reservoir.

  5. Work reservoirs in thermodynamics

    Science.gov (United States)

    Anacleto, Joaquim

    2010-05-01

    We stress the usefulness of the work reservoir in the formalism of thermodynamics, in particular in the context of the first law. To elucidate its usefulness, the formalism is then applied to the Joule expansion and other peculiar and instructive experimental situations, clarifying the concepts of configuration and dissipative work. The ideas and discussions presented in this study are primarily intended for undergraduate students, but they might also be useful to graduate students, researchers and teachers.

  6. Theoretical Analysis of the Mechanism of Fracture Network Propagation with Stimulated Reservoir Volume (SRV) Fracturing in Tight Oil Reservoirs.

    Science.gov (United States)

    Su, Yuliang; Ren, Long; Meng, Fankun; Xu, Chen; Wang, Wendong

    2015-01-01

    Stimulated reservoir volume (SRV) fracturing in tight oil reservoirs often induces complex fracture-network growth, which has a fundamentally different formation mechanism from traditional planar bi-winged fracturing. To reveal the mechanism of fracture network propagation, this paper employs a modified displacement discontinuity method (DDM), mechanical mechanism analysis and initiation and propagation criteria for the theoretical model of fracture network propagation and its derivation. A reasonable solution of the theoretical model for a tight oil reservoir is obtained and verified by a numerical discrete method. Through theoretical calculation and computer programming, the variation rules of formation stress fields, hydraulic fracture propagation patterns (FPP) and branch fracture propagation angles and pressures are analyzed. The results show that during the process of fracture propagation, the initial orientation of the principal stress deflects, and the stress fields at the fracture tips change dramatically in the region surrounding the fracture. Whether the ideal fracture network can be produced depends on the geological conditions and on the engineering treatments. This study has both theoretical significance and practical application value by contributing to a better understanding of fracture network propagation mechanisms in unconventional oil/gas reservoirs and to the improvement of the science and design efficiency of reservoir fracturing.

  7. Theoretical Analysis of the Mechanism of Fracture Network Propagation with Stimulated Reservoir Volume (SRV Fracturing in Tight Oil Reservoirs.

    Directory of Open Access Journals (Sweden)

    Yuliang Su

    Full Text Available Stimulated reservoir volume (SRV fracturing in tight oil reservoirs often induces complex fracture-network growth, which has a fundamentally different formation mechanism from traditional planar bi-winged fracturing. To reveal the mechanism of fracture network propagation, this paper employs a modified displacement discontinuity method (DDM, mechanical mechanism analysis and initiation and propagation criteria for the theoretical model of fracture network propagation and its derivation. A reasonable solution of the theoretical model for a tight oil reservoir is obtained and verified by a numerical discrete method. Through theoretical calculation and computer programming, the variation rules of formation stress fields, hydraulic fracture propagation patterns (FPP and branch fracture propagation angles and pressures are analyzed. The results show that during the process of fracture propagation, the initial orientation of the principal stress deflects, and the stress fields at the fracture tips change dramatically in the region surrounding the fracture. Whether the ideal fracture network can be produced depends on the geological conditions and on the engineering treatments. This study has both theoretical significance and practical application value by contributing to a better understanding of fracture network propagation mechanisms in unconventional oil/gas reservoirs and to the improvement of the science and design efficiency of reservoir fracturing.

  8. A case study of technology transfer: Rehabilitative engineering at Rancho Los Amigos Hospital. [prosthetic devices engineering

    Science.gov (United States)

    Hildred, W.

    1973-01-01

    The transfer of NASA technolgy to rehabilitative applications of artificial limbs is studied. Human factors engineering activities range from orthotic manipulators to tiny dc motors and transducers to detect and transmit voluntary control signals. It is found that bicarbon implant devices are suitable for medical equipment and artificial limbs because of their biological compatibility with human body fluids and tissues.

  9. A remote sensing method for estimating regional reservoir area and evaporative loss

    Science.gov (United States)

    Zhang, Hua; Gorelick, Steven M.; Zimba, Paul V.; Zhang, Xiaodong

    2017-12-01

    Evaporation from the water surface of a reservoir can significantly affect its function of ensuring the availability and temporal stability of water supply. Current estimations of reservoir evaporative loss are dependent on water area derived from a reservoir storage-area curve. Such curves are unavailable if the reservoir is located in a data-sparse region or questionable if long-term sedimentation has changed the original elevation-area relationship. We propose a remote sensing framework to estimate reservoir evaporative loss at the regional scale. This framework uses a multispectral water index to extract reservoir area from Landsat imagery and estimate monthly evaporation volume based on pan-derived evaporative rates. The optimal index threshold is determined based on local observations and extended to unobserved locations and periods. Built on the cloud computing capacity of the Google Earth Engine, this framework can efficiently analyze satellite images at large spatiotemporal scales, where such analysis is infeasible with a single computer. Our study involves 200 major reservoirs in Texas, captured in 17,811 Landsat images over a 32-year period. The results show that these reservoirs contribute to an annual evaporative loss of 8.0 billion cubic meters, equivalent to 20% of their total active storage or 53% of total annual water use in Texas. At five coastal basins, reservoir evaporative losses exceed the minimum freshwater inflows required to sustain ecosystem health and fishery productivity of the receiving estuaries. Reservoir evaporative loss can be significant enough to counterbalance the positive effects of impounding water and to offset the contribution of water conservation and reuse practices. Our results also reveal the spatially variable performance of the multispectral water index and indicate the limitation of using scene-level cloud cover to screen satellite images. This study demonstrates the advantage of combining satellite remote sensing and

  10. Adjustment and prediction of primary behavior of some reservoirs in the Cinco Presidentes field (Mexico)

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, F.C.P.; Mendoza, J.S.

    1974-03-01

    The primary behavior of some reservoirs of the Cinco Presidentes field is analyzed. These are reservoirs in the final stage of exploitation, in which a great decline of pressure and of production has been observed. The principal aspect of the study consists in having carried out, in spite of the scarcity of information, an adjustment that permitted a prediction of behavior. Because of the small amount of bottom-hole pressure information available, the adjustment is basically made as a function of the production data, especially studying the variation of cumulative production of gas with respect to that of oil. This article shows that many times, because of the insufficiency of data, reservoir behavior is evaluated within a very small probability range, and sets out a foundation for insisting on obtaining information, short-and long-term, in reservoir engineering.

  11. 3D Sedimentological and geophysical studies of clastic reservoir analogs: Facies architecture, reservoir properties, and flow behavior within delta front facies elements of the Cretaceous Wall Creek Member, Frontier Formation, Wyoming

    Energy Technology Data Exchange (ETDEWEB)

    Christopher D. White

    2009-12-21

    Significant volumes of oil and gas occur in reservoirs formed by ancient river deltas. This has implications for the spatial distribution of rock types and the variation of transport properties. A between mudstones and sandstones may form baffles that influence productivity and recovery efficiency. Diagenetic processes such as compaction, dissolution, and cementation can also alter flow properties. A better understanding of these properties and improved methods will allow improved reservoir development planning and increased recovery of oil and gas from deltaic reservoirs. Surface exposures of ancient deltaic rocks provide a high-resolution view of variability. Insights gleaned from these exposures can be used to model analogous reservoirs, for which data is sparser. The Frontier Formation in central Wyoming provides an opportunity for high-resolution models. The same rocks exposed in the Tisdale anticline are productive in nearby oil fields. Kilometers of exposure are accessible, and bedding-plane exposures allow use of high-resolution ground-penetrating radar. This study combined geologic interpretations, maps, vertical sections, core data, and ground-penetrating radar to construct geostatistical and flow models. Strata-conforming grids were use to reproduce the observed geometries. A new Bayesian method integrates outcrop, core, and radar amplitude and phase data. The proposed method propagates measurement uncertainty and yields an ensemble of plausible models for calcite concretions. These concretions affect flow significantly. Models which integrate more have different flow responses from simpler models, as demonstrated an exhaustive two-dimensional reference image and in three dimensions. This method is simple to implement within widely available geostatistics packages. Significant volumes of oil and gas occur in reservoirs that are inferred to have been formed by ancient river deltas. This geologic setting has implications for the spatial distribution of

  12. Hybrid vehicle system studies and optimized hydrogen engine design

    Science.gov (United States)

    Smith, J. R.; Aceves, S.

    1995-04-01

    We have done system studies of series hydrogen hybrid automobiles that approach the PNGV design goal of 34 km/liter (80 mpg), for 384 km (240 mi) and 608 km (380 mi) ranges. Our results indicate that such a vehicle appears feasible using an optimized hydrogen engine. We have evaluated the impact of various on-board storage options on fuel economy. Experiments in an available engine at the Sandia CRF demonstrated NO(x) emissions of 10 to 20 ppM at an equivalence ratio of 0.4, rising to about 500 ppm at 0.5 equivalence ratio using neat hydrogen. Hybrid simulation studies indicate that exhaust NO(x) concentrations must be less than 180 ppM to meet the 0.2 g/mile ULEV or Federal Tier II emissions regulations. LLNL has designed and fabricated a first generation optimized hydrogen engine head for use on an existing Onan engine. This head features 15:1 compression ratio, dual ignition, water cooling, two valves and open quiescent combustion chamber to minimize heat transfer losses. Initial testing shows promise of achieving an indicated efficiency of nearly 50% and emissions of less than 100 ppM NO(x). Hydrocarbons and CO are to be measured, but are expected to be very low since their only source is engine lubricating oil. A successful friction reduction program on the Onan engine should result in a brake thermal efficiency of about 42% compared to today's gasoline engines of 32%. Based on system studies requirements, the next generation engine will be about 2 liter displacement and is projected to achieve 46% brake thermal efficiency with outputs of 15 kW for cruise and 40 kW for hill climb.

  13. The Role of Ethnographic Studies in Empirical Software Engineering

    DEFF Research Database (Denmark)

    Sharp, Helen; Dittrich, Yvonne; Souza, Cleidson R. B. de

    2016-01-01

    Ethnography is a qualitative research method used to study people and cultures. It is largely adopted in disciplines outside software engineering, including different areas of computer science. Ethnography can provide an in-depth understanding of the socio-technological realities surrounding...... everyday software development practice, i.e., it can help to uncover not only what practitioners do, but also why they do it. Despite its potential, ethnography has not been widely adopted by empirical software engineering researchers, and receives little attention in the related literature. The main goal...... of this paper is to explain how empirical software engineering researchers would benefit from adopting ethnography. This is achieved by explicating four roles that ethnography can play in furthering the goals of empirical software engineering: to strengthen investigations into the social and human aspects...

  14. An Industrial Case Study: Identification of Competencies of Design Engineers

    DEFF Research Database (Denmark)

    Ahmed, Saeema

    2007-01-01

    This paper describes the findings from an empirical study carried out with engineers in senior roles within a large company manufacturing complex products. This research aimed to identify the types of knowledge that are important for design engineers. Twenty-four knowledge categories were...... identified and the importance of these for design engineers in industry was investigated. In addition, the number of years of relevant experience required to become an expert in these types of knowledge was investigated. Knowledge related to the process was perceived as more important to those related...... to the product. However, the number of years to become an expert in process knowledge was found to be lower than for product knowledge, despite process knowledge being perceived as more important. The findings of this research contribute to the education and training of design engineers....

  15. Motivational Factors of Professional Engineers and Non-Professional Engineers in Applying for License as Professional Engineer: A Comparative Study

    Science.gov (United States)

    Khamis, Nor Kamaliana; Harun, Zambri; Tahir, Mohd Faizal Mat; Wahid, Zaliha; Sabri, Mohd Anas Mohd

    2013-01-01

    All engineering faculties in Malaysia are required to have at least three academics who have engineering competency for each program. Having an engineering competency means academics has obtained the compulsory endorsements from the Boards of Engineers, Malaysia, BEM. Upon approval, academics seeking such competency could carry the suffix Ir. to…

  16. Human leptospirosis in Seychelles: A prospective study confirms the heavy burden of the disease but suggests that rats are not the main reservoir.

    Directory of Open Access Journals (Sweden)

    Leon Biscornet

    2017-08-01

    Full Text Available Leptospirosis is a bacterial zoonosis caused by pathogenic Leptospira for which rats are considered as the main reservoir. Disease incidence is higher in tropical countries, especially in insular ecosystems. Our objectives were to determine the current burden of leptospirosis in Seychelles, a country ranking first worldwide according to historical data, to establish epidemiological links between animal reservoirs and human disease, and to identify drivers of transmission.A total of 223 patients with acute febrile symptoms of unknown origin were enrolled in a 12-months prospective study and tested for leptospirosis through real-time PCR, IgM ELISA and MAT. In addition, 739 rats trapped throughout the main island were investigated for Leptospira renal carriage. All molecularly confirmed positive samples were further genotyped.A total of 51 patients fulfilled the biological criteria of acute leptospirosis, corresponding to an annual incidence of 54.6 (95% CI 40.7-71.8 per 100,000 inhabitants. Leptospira carriage in Rattus spp. was overall low (7.7% but dramatically higher in Rattus norvegicus (52.9% than in Rattus rattus (4.4%. Leptospira interrogans was the only detected species in both humans and rats, and was represented by three distinct Sequence Types (STs. Two were novel STs identified in two thirds of acute human cases while noteworthily absent from rats.This study shows that human leptospirosis still represents a heavy disease burden in Seychelles. Genotype data suggests that rats are actually not the main reservoir for human disease. We highlight a rather limited efficacy of preventive measures so far implemented in Seychelles. This could result from ineffective control measures of excreting animal populations, possibly due to a misidentification of the main contaminating reservoir(s. Altogether, presented data stimulate the exploration of alternative reservoir animal hosts.

  17. Realization of a Brownian engine to study transport phenomena: a semiclassical approach.

    Science.gov (United States)

    Ghosh, Pradipta; Shit, Anindita; Chattopadhyay, Sudip; Chaudhuri, Jyotipratim Ray

    2010-06-01

    Brownian particles moving in a periodic potential with or without external load are often used as good theoretical models for the phenomenological studies of microscopic heat engines. The model that we propose here, assumes the particle to be moving in a nonequilibrium medium and we have obtained the exact expression for the stationary current density. We have restricted our consideration to the overdamped motion of the Brownian particle. We present here a self-consistent theory based on the system-reservoir coupling model, within a microscopic approach, of fluctuation induced transport in the semiclassical limit for a general system coupled with two heat baths kept at different temperatures. This essentially puts forth an approach to semiclassical state-dependent diffusion. We also explore the possibility of observing a current when the temperature of the two baths are different, and also envisage that our system may act as a Carnot engine even when the bath temperatures are the same. The condition for such a construction has been elucidated.

  18. Integrating a reservoir regulation scheme into a spatially distributed hydrological model

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Gang; Gao, Huilin; Naz, Bibi S.; Kao, Shih-Chieh; Voisin, Nathalie

    2016-12-01

    During the past several decades, numerous reservoirs have been built across the world for a variety of purposes such as flood control, irrigation, municipal/industrial water supplies, and hydropower generation. Consequently, natural streamflow timing and magnitude have been altered significantly by reservoir operations. In addition, the hydrological cycle can be modified by land use/land cover and climate changes. To understand the fine scale feedback between hydrological processes and water management decisions, a distributed hydrological model embedded with a reservoir component is of desire. In this study, a multi-purpose reservoir module with predefined complex operational rules was integrated into the Distributed Hydrology Soil Vegetation Model (DHSVM). Conditional operating rules, which are designed to reduce flood risk and enhance water supply reliability, were adopted in this module. The performance of the integrated model was tested over the upper Brazos River Basin in Texas, where two U.S. Army Corps of Engineers reservoirs, Lake Whitney and Aquilla Lake, are located. The integrated DHSVM model was calibrated and validated using observed reservoir inflow, outflow, and storage data. The error statistics were summarized for both reservoirs on a daily, weekly, and monthly basis. Using the weekly reservoir storage for Lake Whitney as an example, the coefficients of determination (R2) and the Nash-Sutcliff Efficiency (NSE) are 0.85 and 0.75, respectively. These results suggest that this reservoir module has promise for use in sub-monthly hydrological simulations. Enabled with the new reservoir component, the DHSVM model provides a platform to support adaptive water resources management under the impacts of evolving anthropogenic activities and substantial environmental changes.

  19. Effect of reservoir heterogeneity on air injection performance in a light oil reservoir

    Directory of Open Access Journals (Sweden)

    Hu Jia

    2018-03-01

    Full Text Available Air injection is a good option to development light oil reservoir. As well-known that, reservoir heterogeneity has great effect for various EOR processes. This also applies to air injection. However, oil recovery mechanisms and physical processes for air injection in heterogeneous reservoir with dip angle are still not well understood. The reported setting of reservoir heterogeneous for physical model or simulation model of air injection only simply uses different-layer permeability of porous media. In practice, reservoir heterogeneity follows the principle of geostatistics. How much of contrast in permeability actually challenges the air injection in light oil reservoir? This should be investigated by using layered porous medial settings of the classical Dykstra-Parsons style. Unfortunately, there has been no work addressing this issue for air injection in light oil reservoir. In this paper, Reservoir heterogeneity is quantified based on the use of different reservoir permeability distribution according to classical Dykstra-Parsons coefficients method. The aim of this work is to investigate the effect of reservoir heterogeneity on physical process and production performance of air injection in light oil reservoir through numerical reservoir simulation approach. The basic model is calibrated based on previous study. Total eleven pseudo compounders are included in this model and ten complexity of reactions are proposed to achieve the reaction scheme. Results show that oil recovery factor is decreased with the increasing of reservoir heterogeneity both for air and N2 injection from updip location, which is against the working behavior of air injection from updip location. Reservoir heterogeneity sometimes can act as positive effect to improve sweep efficiency as well as enhance production performance for air injection. High O2 content air injection can benefit oil recovery factor, also lead to early O2 breakthrough in heterogeneous reservoir. Well

  20. Guidelines for using empirical studies in software engineering education

    Directory of Open Access Journals (Sweden)

    Fabian Fagerholm

    2017-09-01

    Full Text Available Software engineering education is under constant pressure to provide students with industry-relevant knowledge and skills. Educators must address issues beyond exercises and theories that can be directly rehearsed in small settings. Industry training has similar requirements of relevance as companies seek to keep their workforce up to date with technological advances. Real-life software development often deals with large, software-intensive systems and is influenced by the complex effects of teamwork and distributed software development, which are hard to demonstrate in an educational environment. A way to experience such effects and to increase the relevance of software engineering education is to apply empirical studies in teaching. In this paper, we show how different types of empirical studies can be used for educational purposes in software engineering. We give examples illustrating how to utilize empirical studies, discuss challenges, and derive an initial guideline that supports teachers to include empirical studies in software engineering courses. Furthermore, we give examples that show how empirical studies contribute to high-quality learning outcomes, to student motivation, and to the awareness of the advantages of applying software engineering principles. Having awareness, experience, and understanding of the actions required, students are more likely to apply such principles under real-life constraints in their working life.

  1. Pilot study of using UAV to reveal spatial patterns of indicator bacteria concentrations in ponds and reservoirs used for irrigation

    Science.gov (United States)

    Determination of indicator bacteria concentrations in irrigation water recently became mandatory for farmers. These concentrations are known to have large spatial variability in ponds and reservoirs. This variability is partially attributed to affinity of indicator bacteria to algae accumulations. W...

  2. The role of anthropogenic water reservoirs within the landscapes of mining areas – a case study from the western part of the Upper Silesian Coal Basin

    Directory of Open Access Journals (Sweden)

    Jaruchiewicz Ewelina

    2014-03-01

    Full Text Available A few thousand anthropogenic water reservoirs can be found in the area of the Upper Silesian Coal Basis (USCB located in southern Poland. In this paper the role of such anthropogenic lakes in the landscape of the western part of the USCB was presented and illustrated with the example of Knurów, a mining city, and its immediate surrounding area. The study of landscape changes in this area was carried out on the basis of archival and contemporary cartographic materials, historical sources, and interviews with inhabitants and direct field observations. It was found that the origin of the majority of the water reservoirs is related to hard coal, clay and sand mining. They were created primarily as a result of filling subsidence basins and post-mining excavations with water, as well as being the result of the construction of various hydro-technical facilities (settling ponds, fire protection water reservoirs, etc. In the study area the anthropogenic water reservoirs are of different sizes, shapes and durability and play different roles in the environment. Between 1884 and 2001 their number increased 25-fold, while at the same time their total surface area increased more than 8-fold. The role of the newly created water reservoirs in the landscape primarily involves the transformation of the existing terrestrial ecosystems into wetland ecosystems. The agro-forestry landscape of the late 19th century was transformed into a typically anthropogenic landscape with a dominant share of water reservoirs, settlement ponds and mining waste heaps. The most common species of plants around the water reservoirs are Phragmites australis, Typha latifolia, Ceratophyllum demersum, Elodea canadensis, Potamogeton natans, Lemna sp., Acorus calamus, Myriophyllum verticillatum, Sagittaria sagittifolia, Alisma plantago-aquatica and Glyceria aquatica. The most valuable elements of the flora include Trapa natans and Ruppia maritima, species recognized in Poland as threatened

  3. Adoption of value engineering: an attribute study for construction

    International Nuclear Information System (INIS)

    Shaikh, P.

    2015-01-01

    For economic reasons, engineers are compelled to explore low cost methods in construction industry to reduce the overall cost of a project. Research studies have been conducted in this regard throughout the world and value engineering is one of such approaches. Its effective use and applications reduces the project cost without compromising the project quality. Project cost, and efficient design alternatives can be identified using this technique, which will ultimately reduce the overall project cost. Client satisfaction, project reliability and quality can also be improved by the application of value engineering. It is also used for improving managerial performance, project schedule and reduced risks in a project. It is a powerful tool used to identify problems and recommend solutions. This paper highlights the importance of value engineering in general and with specific perspective of Construction Industry in Pakistan. Questionnaire based survey has been conducted by construction managers (i.e. project engineers, construction engineers, project managers, architects, etc.) through online web based system, as a result, random data sampling is achieved. The attributes are mapped to obtain goals for the project. The data has been analyzed through reliability and linear regression using SPSS while Z-Score and Average Index are conducted using MS Excel. The results showed that there is ample need to apply such techniques in initial phases of any project to get project benefits. (author)

  4. Cryostat design case studies, principles and engineering

    CERN Document Server

    2016-01-01

    This book enables the reader to learn the fundamental and applied aspects of practical cryostat design by examining previous design choices and resulting cryostat performance. Through a series of extended case studies the book presents an overview of existing cryostat design covering a wide range of cryostat types and applications, including the magnet cryostats that comprise the majority of the Large Hadron Collider at CERN, space-borne cryostats containing sensors operating below 1 K, and large cryogenic liquid storage vessels. It starts with an introductory section on the principles of cryostat design including practical data and equations. This section is followed by a series of case studies on existing cryostats, describing the specific requirements of the cryostat, the challenges involved and the design choices made along with the resulting performance of the cryostat. The cryostat examples used in the studies are chosen to cover a broad range of cryostat applications and the authors of each case are ...

  5. A Numerical Study on the Effects of Initial Water Saturation of a Geothermal Reservoir on Well Characteristics

    OpenAIRE

    Khasani; Itoi, Ryuichi; Tanaka, Toshiaki; Fukuda, Michihiro

    2004-01-01

    The effects of initial water saturation on well characteristics in two-phase geothermal reservoirs were evaluated. A vertical wellbore model of uniform diameter coupled with a radial horizontal flow in a reservoir of uniform thickness was employed. The momentum equation for two-phase flow in a wellbore was numerically evaluated with a method introduced by Orkiszewski. The energy equation in the wellbore was assumed to be isenthalpic. Mass flow rate and pressure at a feed zone of the well were...

  6. Application of magnetic method to assess the extent of high temperature geothermal reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Soengkono, S.; Hochstein, M.P.

    1995-01-26

    The extent of thermally altered rocks in high temperature geothermal reservoirs hosted by young volcanic rocks can be assessed from magnetic surveys. Magnetic anomalies associated with many geothermal field in New Zealand and Indonesia can be interpreted in terms of thick (up to 1 km) demagnetized reservoir rocks. Demagnetization of these rocks has been confirmed by core studies and is caused by hydrothermal alteration produced from fluid/rock interactions. Models of the demagnetized Wairakei (NZ) and Kamojang (Indonesia) reservoirs are presented which include the productive areas. Magnetic surveys give fast and economical investigations of high temperature prospects if measurements are made from the air. The magnetic interpretation models can provide important constraints for reservoir models. Magnetic ground surveys can also be used to assess the extent of concealed near surface alteration which can be used in site selection of engineering structures.

  7. Investigation of diffusivity coefficient of Asmari reservoir by well test analysis

    Energy Technology Data Exchange (ETDEWEB)

    Shadizadeh, S.R. [Petroleum Univ. of Technology, Tehran (Iran, Islamic Republic of); Amiri, M.; Zaferanieh, M. [National Iranian Oil Co., Tehran (Iran, Islamic Republic of)

    2007-07-01

    One of the greatest challenges facing petroleum engineers is to characterize the physical nature of subterranean reservoirs from which crude oil is produced. The quality of reservoir description determines the results of numerical simulations of reservoir performance. The ways by which information can be obtained include seismic and geological studies; well drilling data; well pressure testing; and analysis of reservoir performance through history matching. This paper presented the results of a study in which the Asmari field in southern onshore Iran was characterized. The field went into production in 1970. To date, a total of 39 wells have been completed in the Asmari and Bangestan groups of this field. Pan System software was used in this study to analyze the well test data. Parameters such as permeability, skin factor, wellbore storage, average reservoir pressure, diffusivity coefficient and productivity index are calculated for each well. In particular, the diffusivity coefficient for the Asmari sedimentary layer was determined. This dimensionless reservoir parameter is a ratio of a medium's capacity for transmissibility of fluid to capacity. Diffusivity offers a quantitative measure for the rate of response during transient fluid flow. All available information such as petrophysical data, PVT data, production data and pressure build up data of the completed wells in Asmari formation were collected. Twenty one data tests were then analyzed. A correlation between productivity index and the diffusivity coefficient for the Asmari formation was subsequently obtained. It was concluded that permeability is one of the most important parameter in reservoir engineering calculations. Different completion of well number 1 showed that the diffusivity coefficient and productivity index of carbonate layer is less than in the sandstone layer. It was determined that the western part of the reservoir is suitable for drilling new wells.13 refs., 5 tabs., 7 figs.

  8. Filtration engineering study to upgrade the ETF

    International Nuclear Information System (INIS)

    McDonald, F.N.N.

    1995-01-01

    Filtration technologies are evaluated which have potential to augment or upgrade the 200 Area Effluent Treatment Facility. The study was written in anticipation of treating future waste waters that have high fouling potentials. The Three ultrafilters judged to be capable of treating future waste waters are: hollow fiber, tubular, and centrifugal

  9. Analytical Study of Component Based Software Engineering

    OpenAIRE

    Iqbaldeep Kaur; Parvinder S. Sandhu; Hardeep Singh; Vandana Saini

    2009-01-01

    This paper is a survey of current component-based software technologies and the description of promotion and inhibition factors in CBSE. The features that software components inherit are also discussed. Quality Assurance issues in componentbased software are also catered to. The feat research on the quality model of component based system starts with the study of what the components are, CBSE, its development life cycle and the pro & cons of CBSE. Various attributes are s...

  10. Application of integrated petroleum reservoir study for intervention and field development program in western onshore field, India

    Directory of Open Access Journals (Sweden)

    Vijai Kumar Baskaran

    2017-12-01

    Full Text Available In this research, an integrated reservoir study is performed in the J#Field (J-Oil Field of western onshore, India to evaluate its additional reserves expectations and implement field developments plan using waterflood pilot program. The target strata includes two formations of Paleogene, which is about 3600 ft, namely G#Fm (G-Formation of the Eocene and T#Fm (T-Formation of Oligocene, subdivided into 11 zones. Based on these results, an attempt was made to construct of an optimization plan to exploit it, taking into account that the field is producing since 1947, with a cumulative production of 183.5 MMbbl and an overall recovery factor of 28% until January 2016. On the basis of the potential evaluation and geological modeling, blocks J48 and J45 were simulated, and the remaining oil distribution characteristics in two blocks were studied after history match. The work includes the stratigraphic studies, seismic study, logging interpretation, sedimentary facies modeling, three dimensional geological modeling, simulations for waterflooding, and future field development plans.

  11. Thermoacoustic engines and refrigerators

    Energy Technology Data Exchange (ETDEWEB)

    Swift, G.

    1996-12-31

    This report is a transcript of a practice lecture given in preparation for a review lecture on the operation of thermoacoustic engines and refrigerators. The author begins by a brief review of the thermodynamic principles underlying the operation of thermoacoustic engines and refrigerators. Remember from thermodynamics class that there are two kinds of heat engines, the heat engine or the prime mover which produces work from heat, and the refrigerator or heat pump that uses work to pump heat. The device operates between two thermal reservoirs at temperatures T{sub hot} and T{sub cold}. In the heat engine, heat flows into the device from the reservoir at T{sub hot}, produces work, and delivers waste heat into the reservoir at T{sub cold}. In the refrigerator, work flows into the device, lifting heat Q{sub cold} from reservoir at T{sub cold} and rejecting waste heat into the reservoir at T{sub hot}.

  12. Engineering study for ISSTRS design concept

    Energy Technology Data Exchange (ETDEWEB)

    Hertzel, J.S.

    1997-01-31

    Los Alamos Technical Associates, Inc., is pleased to transmit the attached Conceptual Design Package for the Initial Single Shell Tank Retrieval System (ISSTRS), 90% Conceptual Design Review. The package includes the following: (1) ISSTRS Trade Studies: (a) Retrieval Facility Cooling Requirements; (b) Equipment Re-usability between Project W-320 and Tanks 241-C-103 and 241-C-1 05; (c) Sluice Line Options; and (d) Options for the Location of Tanks AX-103 and A-1 02 HVAC Equipment; (2) Drawings; (3) Risk Management Plan; (4) 0850 Interface Control Document; (5) Requirements Traceability Report; and (6) Project Design Specification.

  13. Mined salt storage feasibility: Engineering study report

    International Nuclear Information System (INIS)

    1987-07-01

    This study addresses a method of eliminating the surface storage of mined salt at the Deaf Smith repository site. It provides rough estimates of the logistics and costs of transporting 3.7 million tons of salt from the repository to the salt disposal site near Carlsbad, New Mexico and returning it to the repository for decommissioning backfill. The study assumes that a railcar/truck system will be installed and that the excavated salt will be transported from the repository to an existing potash mine located near Carlsbad, New Mexico approximately 300 miles from the repository. The 3.7 million tons of salt required for repository decommissioning backfill can be stored in the potash mines along with the excess salt, with no additional capital costs required for either a railcar or a truck transportation system. The capital cost for facilities to reclaim the 3.7 million tons of salt from the potash mine is estimated to be $4,400,000 with either a rail or truck transportation system. Segregating the 3.7 million tons of backfill salt in a surface storage area at the potash mine requires a capital cost of $13,900,000 with a rail system or $11,400,000 with a truck system. Transportation costs are estimated at $0.08/ton-mile for rail and $0.13/ton-mile for truck. 2 figs., 5 tabs

  14. A Study Of Internet Search Engines Usage By Undergraduate ...

    African Journals Online (AJOL)

    The purpose of this study is to investigate students' ability to use different Internet search engines (ISEs) in Universities in the Niger Delta Region of Nigeria. To reveal the types of ISEs used, and identify the source through which students acquire the skills. The study adopted a descriptive survey method. Questionnaire and ...

  15. Landslide susceptibility modeling applying machine learning methods: A case study from Longju in the Three Gorges Reservoir area, China

    Science.gov (United States)

    Zhou, Chao; Yin, Kunlong; Cao, Ying; Ahmed, Bayes; Li, Yuanyao; Catani, Filippo; Pourghasemi, Hamid Reza

    2018-03-01

    Landslide is a common natural hazard and responsible for extensive damage and losses in mountainous areas. In this study, Longju in the Three Gorges Reservoir area in China was taken as a case study for landslide susceptibility assessment in order to develop effective risk prevention and mitigation strategies. To begin, 202 landslides were identified, including 95 colluvial landslides and 107 rockfalls. Twelve landslide causal factor maps were prepared initially, and the relationship between these factors and each landslide type was analyzed using the information value model. Later, the unimportant factors were selected and eliminated using the information gain ratio technique. The landslide locations were randomly divided into two groups: 70% for training and 30% for verifying. Two machine learning models: the support vector machine (SVM) and artificial neural network (ANN), and a multivariate statistical model: the logistic regression (LR), were applied for landslide susceptibility modeling (LSM) for each type. The LSM index maps, obtained from combining the assessment results of the two landslide types, were classified into five levels. The performance of the LSMs was evaluated using the receiver operating characteristics curve and Friedman test. Results show that the elimination of noise-generating factors and the separated modeling of each landslide type have significantly increased the prediction accuracy. The machine learning models outperformed the multivariate statistical model and SVM model was found ideal for the case study area.

  16. On the Pragmatic Design of Literature Studies in Software Engineering

    DEFF Research Database (Denmark)

    Kuhrmann, Marco; Méndez Fernández, Daniel; Daneva, Maya

    2017-01-01

    Systematic literature studies have received much attention in empirical software engineering in recent years. They have become a powerful tool to collect and structure reported knowledge in a systematic and reproducible way. We distinguish systematic literature reviews to systematically analyze...... reported evidence in depth, and systematic mapping studies to structure a field of interest in a broader, usually quantified manner. Due to the rapidly increasing body of knowledge in software engineering, researchers who want to capture the published work in a domain often face an extensive amount...

  17. Engineering Lipid Bilayer Membranes for Protein Studies

    Science.gov (United States)

    Khan, Muhammad Shuja; Dosoky, Noura Sayed; Williams, John Dalton

    2013-01-01

    Lipid membranes regulate the flow of nutrients and communication signaling between cells and protect the sub-cellular structures. Recent attempts to fabricate artificial systems using nanostructures that mimic the physiological properties of natural lipid bilayer membranes (LBM) fused with transmembrane proteins have helped demonstrate the importance of temperature, pH, ionic strength, adsorption behavior, conformational reorientation and surface density in cellular membranes which all affect the incorporation of proteins on solid surfaces. Much of this work is performed on artificial templates made of polymer sponges or porous materials based on alumina, mica, and porous silicon (PSi) surfaces. For example, porous silicon materials have high biocompatibility, biodegradability, and photoluminescence, which allow them to be used both as a support structure for lipid bilayers or a template to measure the electrochemical functionality of living cells grown over the surface as in vivo. The variety of these media, coupled with the complex physiological conditions present in living systems, warrant a summary and prospectus detailing which artificial systems provide the most promise for different biological conditions. This study summarizes the use of electrochemical impedance spectroscopy (EIS) data on artificial biological membranes that are closely matched with previously published biological systems using both black lipid membrane and patch clamp techniques. PMID:24185908

  18. Reservoir fisheries of Asia

    International Nuclear Information System (INIS)

    Silva, S.S. De.

    1990-01-01

    At a workshop on reservoir fisheries research, papers were presented on the limnology of reservoirs, the changes that follow impoundment, fisheries management and modelling, and fish culture techniques. Separate abstracts have been prepared for three papers from this workshop

  19. Multiobjective reservoir operating rules based on cascade reservoir input variable selection method

    Science.gov (United States)

    Yang, Guang; Guo, Shenglian; Liu, Pan; Li, Liping; Xu, Chongyu

    2017-04-01

    The input variable selection in multiobjective cascade reservoir operation is an important and difficult task. To address this problem, this study proposes the cascade reservoir input variable selection (CIS) method that searches for the most valuable input variables for decision making in multiple-objectivity cascade reservoir operations. From a case study of Hanjiang cascade reservoirs in China, we derive reservoir operating rules based on the combination of CIS and Gaussian radial basis functions (RBFs) methods and optimize the rules through Pareto-archived dynamically dimensioned search (PA-DDS) with two objectives: to maximize both power generation and water supply. We select the most effective input variables and evaluate their impacts on cascade reservoir operations. From the simulated trajectories of reservoir water level, power generation, and water supply, we analyze the multiobjective operating rules with several input variables. The results demonstrate that the CIS method performs well in the selection of input variables for the cascade reservoir operation, and the RBFs method can fully express the nonlinear operating rules for cascade reservoirs. We conclude that the CIS method is an effective and stable approach to identifying the most valuable information from a large number of candidate input variables. While the reservoir storage state is the most valuable information for the Hanjiang cascade reservoir multiobjective operation, the reservoir inflow is the most effective input variable for the single-objective operation of Danjiangkou.

  20. Reservoirs in the United States

    Science.gov (United States)

    Harbeck, G. Earl

    1948-01-01

    Man has engaged in the control of flowing water since history began. Among his early recorded efforts were reservoirs for muncipal water-supplies constructed near ancient Jerusalem to store water which was brought there in masonry conduits. 1/  Irrigation was practiced in Egypt as early as 2000 B. C. There the "basin system" was used from ancient times until the 19th century. The land was divided , into basins of approximately 40,000 acres, separated by earthen dikes. 2/  Flood waters of the Nile generally inundated the basins through canals, many of which were built by the Pharaohs. Even then the economic consequences of a deficient annual flood were recognized. Lake Maeris, which according to Herodotus was an ancient storage reservoir, is said to have had an area of 30,000 acres. In India, the British found at the time of their occupancy of the Presidency of Madras about 50,000 reservoirs for irrigation, many believed to be of ancient construction. 3/ During the period 115-130 A. D. reservoirs were built to improve the water-supply of Athens. Much has been written concerning the elaborate collection and distribution system built to supply Rome, and parts of it remain to this day as monuments to the engineering skill employed by the Romans in solving the problem of large-scale municipal water-supplies.

  1. Fluid design studies of integrated modular engine system

    Science.gov (United States)

    Frankenfield, Bruce; Carek, Jerry

    1993-01-01

    A study was performed to develop a fluid system design and show the feasibility of constructing an integrated modular engine (IME) configuration, using an expander cycle engine. The primary design goal of the IME configuration was to improve the propulsion system reliability. The IME fluid system was designed as a single fault tolerant system, while minimizing the required fluid components. This study addresses the design of the high pressure manifolds, turbopumps and thrust chambers for the IME configuration. A physical layout drawing was made, which located each of the fluid system components, manifolds and thrust chambers. Finally, a comparison was made between the fluid system designs of an IME system and a non-network (clustered) engine system.

  2. Web Search Studies: Multidisciplinary Perspectives on Web Search Engines

    Science.gov (United States)

    Zimmer, Michael

    Perhaps the most significant tool of our internet age is the web search engine, providing a powerful interface for accessing the vast amount of information available on the world wide web and beyond. While still in its infancy compared to the knowledge tools that precede it - such as the dictionary or encyclopedia - the impact of web search engines on society and culture has already received considerable attention from a variety of academic disciplines and perspectives. This article aims to organize a meta-discipline of “web search studies,” centered around a nucleus of major research on web search engines from five key perspectives: technical foundations and evaluations; transaction log analyses; user studies; political, ethical, and cultural critiques; and legal and policy analyses.

  3. Large reservoirs: Chapter 17

    Science.gov (United States)

    Miranda, Leandro E.; Bettoli, Phillip William

    2010-01-01

    Large impoundments, defined as those with surface area of 200 ha or greater, are relatively new aquatic ecosystems in the global landscape. They represent important economic and environmental resources that provide benefits such as flood control, hydropower generation, navigation, water supply, commercial and recreational fisheries, and various other recreational and esthetic values. Construction of large impoundments was initially driven by economic needs, and ecological consequences received little consideration. However, in recent decades environmental issues have come to the forefront. In the closing decades of the 20th century societal values began to shift, especially in the developed world. Society is no longer willing to accept environmental damage as an inevitable consequence of human development, and it is now recognized that continued environmental degradation is unsustainable. Consequently, construction of large reservoirs has virtually stopped in North America. Nevertheless, in other parts of the world construction of large reservoirs continues. The emergence of systematic reservoir management in the early 20th century was guided by concepts developed for natural lakes (Miranda 1996). However, we now recognize that reservoirs are different and that reservoirs are not independent aquatic systems inasmuch as they are connected to upstream rivers and streams, the downstream river, other reservoirs in the basin, and the watershed. Reservoir systems exhibit longitudinal patterns both within and among reservoirs. Reservoirs are typically arranged sequentially as elements of an interacting network, filter water collected throughout their watersheds, and form a mosaic of predictable patterns. Traditional approaches to fisheries management such as stocking, regulating harvest, and in-lake habitat management do not always produce desired effects in reservoirs. As a result, managers may expend resources with little benefit to either fish or fishing. Some locally

  4. Understanding the True Stimulated Reservoir Volume in Shale Reservoirs

    KAUST Repository

    Hussain, Maaruf

    2017-06-06

    Successful exploitation of shale reservoirs largely depends on the effectiveness of hydraulic fracturing stimulation program. Favorable results have been attributed to intersection and reactivation of pre-existing fractures by hydraulically-induced fractures that connect the wellbore to a larger fracture surface area within the reservoir rock volume. Thus, accurate estimation of the stimulated reservoir volume (SRV) becomes critical for the reservoir performance simulation and production analysis. Micro-seismic events (MS) have been commonly used as a proxy to map out the SRV geometry, which could be erroneous because not all MS events are related to hydraulic fracture propagation. The case studies discussed here utilized a fully 3-D simulation approach to estimate the SRV. The simulation approach presented in this paper takes into account the real-time changes in the reservoir\\'s geomechanics as a function of fluid pressures. It is consisted of four separate coupled modules: geomechanics, hydrodynamics, a geomechanical joint model for interfacial resolution, and an adaptive re-meshing. Reservoir stress condition, rock mechanical properties, and injected fluid pressure dictate how fracture elements could open or slide. Critical stress intensity factor was used as a fracture criterion governing the generation of new fractures or propagation of existing fractures and their directions. Our simulations were run on a Cray XC-40 HPC system. The studies outcomes proved the approach of using MS data as a proxy for SRV to be significantly flawed. Many of the observed stimulated natural fractures are stress related and very few that are closer to the injection field are connected. The situation is worsened in a highly laminated shale reservoir as the hydraulic fracture propagation is significantly hampered. High contrast in the in-situ stresses related strike-slip developed thereby shortens the extent of SRV. However, far field nature fractures that were not connected to

  5. Soil erosion and sediment fluxes analysis: a watershed study of the Ni Reservoir, Spotsylvania County, VA, USA.

    Science.gov (United States)

    Pope, Ian C; Odhiambo, Ben K

    2014-03-01

    Anthropogenic forces that alter the physical landscape are known to cause significant soil erosion, which has negative impact on surface water bodies, such as rivers, lakes/reservoirs, and coastal zones, and thus sediment control has become one of the central aspects of catchment management planning. The revised universal soil loss equation empirical model, erosion pins, and isotopic sediment core analyses were used to evaluate watershed erosion, stream bank erosion, and reservoir sediment accumulation rates for Ni Reservoir, in central Virginia. Land-use and land cover seems to be dominant control in watershed soil erosion, with barren land and human-disturbed areas contributing the most sediment, and forest and herbaceous areas contributing the least. Results show a 7 % increase in human development from 2001 (14 %) to 2009 (21.6 %), corresponding to an increase in soil loss of 0.82 Mg ha(-1) year(-1) in the same time period. (210)Pb-based sediment accumulation rates at three locations in Ni Reservoir were 1.020, 0.364, and 0.543 g cm(-2) year(-1) respectively, indicating that sediment accumulation and distribution in the reservoir is influenced by reservoir configuration and significant contributions from bedload. All three locations indicate an increase in modern sediment accumulation rates. Erosion pin results show variability in stream bank erosion with values ranging from 4.7 to 11.3 cm year(-1). These results indicate that urban growth and the decline in vegetative cover has increased sediment fluxes from the watershed and poses a significant threat to the long-term sustainability of the Ni Reservoir as urbanization continues to increase.

  6. Ecological investigations at power plant cooling lakes, reservoirs, and ponds: an annotated bibliography. Final report

    International Nuclear Information System (INIS)

    Yost, F.E.; Talmage, S.S.

    1981-06-01

    Presented as an annotated bibliography are 541 references dealing with ecological investigations at power plants which use cooling lakes, ponds, or reservoirs. The references were obtained from open literature and from environmental reports and impact statements prepared for or by the electric utility industry. The literature covers the period 1950 through mid-1980. Topics covered include site-specific studies at facilities using cooling lakes, ponds, or reservoirs, as well as special studies, engineering studies, and general studies. References are arranged alphabetically by author and indexes are provided to personal and corporate authors, facility names, regions, and taxonomic names

  7. Study on Zipingpu reservoir induced multi-scale porous flows related to 2008 Wenchuan Ms 8.0 earthquake by parallel CPU and GPU computation

    Science.gov (United States)

    Shi, Y.; Zhu, B.

    2010-12-01

    Coulomb failure assumption is used to evaluate the earthquake trigger, and pore pressures play an important part in triggering the earthquake slip. Based on the parallel CPU computation and GPU visualization technology, the relationship between the pore stress accumulation on Zipingpu reservoir and the trigging and propagation mechanism of the Longmenshan coseismic fault slip have been studied on different length scales [Scale I: 30.976E_31.105E, 103.45N_103.577N;Scale II: 30.7E_31.3E, 103.05N_103.76N; Scale III: 29E_33E, 101N_105N]. Longmenshan fault slip of 2008 Wenchuan Ms 8.0 earthquake is obtained by GPS & InSAR inversion technique, it composed with two slips and cross-wised Zipingpu reservoir zone. The relationship between the pore stress accumulation of Zipingpu reservoir and the trigging and propagation of the Longmenshan coseismic fault slip because very important for it direction effect the dynamic real-time security evaluation and monitor of Zipingpu key water control project. Zipingpu reservoir is located on the upstream of Minjiang river, the maximum reservoir storage capacity is 11×109 m3, the adjustable reservoir storage capacity is 8×109 m3, the normal impounded level is 877m, the dam top altitude is 894m and the dam bottom altitude is 728m.The key water control project began Mar.3.2001, stop flow time is Nov.1.2002, storage time is Dec.1.2004 and completed at Dec.1.2006. The total pore stress accumulation time before Wenchuan Ms 8.0 Earthquake (May.12.2008) is 3~4 years. In our physical model, we use the 15000 time steps (10 ts/day) to describe the effect of pore stress of reservoir to the Longmenshan fault slip. From the GPS&InSAR inversion technology, the Longmenshan earthquake fault slip is divided into 673 parts. The results show that the relationship between extended pore strain and stress on Zipingpu reservoir and Longmenshan coseismic fault slip on Scale I under 20000ts. The pore stress accumulation value level is 0.3Mp. The relationship

  8. Assessing spatial uncertainty in reservoir characterization for carbon sequestration planning using public well-log data: A case study

    Science.gov (United States)

    Venteris, E.R.; Carter, K.M.

    2009-01-01

    Mapping and characterization of potential geologic reservoirs are key components in planning carbon dioxide (CO2) injection projects. The geometry of target and confining layers is vital to ensure that the injected CO2 remains in a supercritical state and is confined to the target layer. Also, maps of injection volume (porosity) are necessary to estimate sequestration capacity at undrilled locations. Our study uses publicly filed geophysical logs and geostatistical modeling methods to investigate the reliability of spatial prediction for oil and gas plays in the Medina Group (sandstone and shale facies) in northwestern Pennsylvania. Specifically, the modeling focused on two targets: the Grimsby Formation and Whirlpool Sandstone. For each layer, thousands of data points were available to model structure and thickness but only hundreds were available to support volumetric modeling because of the rarity of density-porosity logs in the public records. Geostatistical analysis based on this data resulted in accurate structure models, less accurate isopach models, and inconsistent models of pore volume. Of the two layers studied, only the Whirlpool Sandstone data provided for a useful spatial model of pore volume. Where reliable models for spatial prediction are absent, the best predictor available for unsampled locations is the mean value of the data, and potential sequestration sites should be planned as close as possible to existing wells with volumetric data. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

  9. A Study of the Fruit Bat (Rousettus sp Brain Anatomy as Natural Reservoir Wild Animal for the Rabies Virus

    Directory of Open Access Journals (Sweden)

    Karina Mayang Sari

    2015-06-01

    Full Text Available Rousettus sp. (Fruit bat is one type of fruit bats in Indonesia and act as a natural reservoir of rabies. Rabies is caused by a virus from genus Lyssavirus, family Rhabdoviridae, which attack central nervous system (CNS.The brain is an organ that is sensitive to rabies infection. The purpose of this study was to determine the anatomical structure of the fruit bat brain macroscopically. Five fruit bat were used in this study, they were anaesthetized using ketamine and xylazin. Animals were perfused using physiological saline and 10% buffered formalin. Brains were taken using tweezers after all the bones of the skull were separated. Analysis of macroscopic brain was done descriptively. The results showed that the fruit bat brain were generally divided into cerebrum, cerebellum and brain stem. Gyrus, sulcus and the paraflokulus lobes of the fruit bat brain were less developed than that of the dogs brain.

  10. A phenomenographic study of students' experiences with transition from pre-college engineering programs to first-year engineering

    Science.gov (United States)

    Salzman, Noah

    Recent national dialogues on the importance of preparing more students for careers in Science, Technology, Engineering, and Mathematics has driven the development of formal and informal learning opportunities for children and adolescents to explore engineering. Despite the growth of these programs, relatively little research exists on how participation in these programs affects students who choose to pursue further study in engineering. The present study addressed this gap through an exploration of the different ways that First-Year Engineering students experience the transition from pre-college engineering to undergraduate engineering studies. Given the focus of this research on students' experiences, phenomenography was chosen to explore the phenomenon of transition from pre-college to first-year engineering at a large, public Midwestern university. This facilitated understanding the range of variation in the ways that students experienced this transition. Twenty-two students with different amounts of participation in a variety of different engineering programs were selected to be interviewed using a purposeful maximum variation sampling strategy. The interviews were guided by a semi-structured interview protocol that encouraged the participants to reflect on their pre-college engineering experiences, their experiences in First-Year Engineering, and the transition between the two domains. The interviews were analyzed using phenomenographic methods to develop an outcome space consisting of five qualitatively different but related ways of experiencing the transition from pre-college to First-Year Engineering. These categories of description included Foreclosure, Frustration, Tedium, Connection, and Engaging Others. With the exception of the first category which was characterized by a lack of passion and commitment to engineering, the remaining four categories formed a hierarchical relationship representing increasing integration in First-Year Engineering. The

  11. Engine Power Turbine and Propulsion Pod Arrangement Study

    Science.gov (United States)

    Robuck, Mark; Zhang, Yiyi

    2014-01-01

    A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing

  12. An environmental data base for all Hydro-Quebec reservoirs

    International Nuclear Information System (INIS)

    Demers, C.

    1988-01-01

    Hydro-Quebec has created two management positions specifically for reservoirs, namely Reservoir Ecology Advisor and Reservoir Management Advisor. To assist management decisions, a means was required of bringing together all existing environmental information for each reservoir operated by Hydro-Quebec, including storage reservoirs, auxiliary reservoirs and forebays. A relational database using Reflex software was developed on a network of Macintosh computers. The database contains five blocks of information: general information, and physical, physiochemical, biologic and socioeconomic characteristics for each reservoir. Data will be collected on over 100 sites, and the tool will form the basis for developing a medium-range study program on reservoir ecology. The program must take into account the physical, biological and socioeconomic aspects of the environment, as well as the concerns of management personnel operating the reservoirs, the local population, reservoir users, and various government departments. 2 figs

  13. Reservoir triggering seismicity in Greece: An evidence based review

    Science.gov (United States)

    Pavlou, Kyriaki; Drakatos, George; Kouskouna, Vasiliki; Makropoulos, Konstantinos

    2017-04-01

    First filling and water fluctuation in artificial lakes and reservoirs are known causes of local seismicity. In Greece, 117 dams were built over the past 60 years, of which, however, only 22 have a capacity greater than 20x206cm3 and could thus affect seismicity in a meaningful way. Most of these larger dams have been constructed and operated by the Greek Public Power Corporation (PPC). The paper aims at a comprehensive review of all relevant studies, undertaken so far, and critically examines the evidence of reservoir triggering seismicity and possible accelerated earthquake occurrence provided. The main reservoirs examined include the Marathon, Kremasta, Pournari, Ilarion and Polyphyto artificial lakes, all of which have recorded seismic events associated with their filling and/or operation for the time period up to 2010. Seismic activity that correlates with maximum or minimum water level fluctuations leads to conclusions about a possible triggering seismicity due to a pore pressure diffusion (drained or un-drained response). In each case we review the cross-correlation coefficients between the reservoir levels and triggered events, and discuss the reasons for their association from an engineering geological (mechanical properties of rocks and formations) and seismological (triggered events) perspective. Our work suggests that, whilst in these cases PCC performs very well the task of hydrological and energy management of the reservoirs, it is crucially important to monitor and validate the daily seismicity at and around the artificial lakes for a better understanding of the upmost limit of triggered seismicity, and possible triggered landslides in the areas surrounding its main reservoirs.

  14. Experimental studies of the air hybrid engine charging operation

    OpenAIRE

    Zhao, H; Ma, T; Lee, CY

    2014-01-01

    Over the last few years, theoretical and modelling studies have been carried out on the feasibility and potential of novel mild air hybrid engine concepts based on production components. These mild air hybrid concepts are able to convert vehicle brake energy into pneumatic energy in the form of compressed air stored in the air tank. The compressed air can then be used to crank-start the engine by either injecting and expanding in the cylinder or driving a production air starter. Thus, the reg...

  15. The experiences of women engineers who have completed one to five years of professional engineering employment: A phenomenological study

    Science.gov (United States)

    White, Susan M.

    Women engineers remain underrepresented in employment in engineering fields in the United States. Feminist theory views this gender disparity beyond equity in numbers for women engineers and looks at structural issues of women's access, opportunities, and quality of experience in the workplace. Research on women's success and persistence in engineering education is diverse; however, there are few studies that focus on the early years of women's careers in engineering and less using a phenomenological research design. Experiences of women engineers who have completed one to five years of professional engineering employment are presented using a phenomenological research design. Research questions explored the individual and composite experiences for the co-researchers of the study as well as challenges and advantages of the phenomenon of having completed one to five years of professional engineering employment. Themes that emanated from the data were a feeling that engineering is a positive profession, liking math and science from an early age, having experiences of attending math and science camps or learning and practicing engineering interests with their fathers for some co-researchers. Other themes included a feeling of being different as a woman in the engineering workplace, taking advantage of opportunities for training, education, and advancement to further their careers, and the role of informal and formal mentoring in developing workplace networks and engineering expertise. Co-researchers negotiated issues of management quality and support, experiences of gender discrimination in the workplace, and having to make decisions balancing their careers and family responsibilities. Finally, the women engineers for this research study expressed intentions to persist in their careers while pursuing expertise and experience in their individual engineering fields.

  16. Staphylococcus aureus reservoirs and transmission routes in a Portuguese Neonatal Intensive Care Unit: a 30-month surveillance study.

    Science.gov (United States)

    Conceição, Teresa; Aires de Sousa, Marta; Miragaia, Maria; Paulino, Elsa; Barroso, Rosalina; Brito, Maria João; Sardinha, Teresa; Sancho, Luísa; Carreiro, Helena; de Sousa, Germano; Machado, Maria do Céu; de Lencastre, Hermínia

    2012-04-01

    Although Staphylococcus aureus is a major cause of outbreaks in neonatal intensive care units (NICUs), there are no studies on the epidemiology of S. aureus isolates responsible for infection in Portuguese NICUs. Between July 2005 and December 2007, a total of 54 methicillin susceptible S. aureus (MSSA) isolates were recovered from 16 infected infants, parents, health care workers (HCWs), and the environment in a level III NICU. Isolates were characterized by pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing. Virulence determinants were detected by multiplex polymerase chain reaction. Three major MSSA clones were endemic in the NICU, representing 70% (n=38) of the isolates: PFGE type A-ST5 (n=17); type B-ST30 (n=12); and type C-ST1 (n=9). Leukotoxins and hemolysins were present in all isolates, although none of them carried PVL. HCWs, plastic folders protecting clinical files, and mothers' nipples were identified as potential reservoirs and/or vehicles of dissemination of S. aureus. Consequently, additional infection control measures were implemented in this NICU.

  17. Use of bias correction techniques to improve seasonal forecasts for reservoirs - A case-study in northwestern Mediterranean.

    Science.gov (United States)

    Marcos, Raül; Llasat, Ma Carmen; Quintana-Seguí, Pere; Turco, Marco

    2018-01-01

    In this paper, we have compared different bias correction methodologies to assess whether they could be advantageous for improving the performance of a seasonal prediction model for volume anomalies in the Boadella reservoir (northwestern Mediterranean). The bias correction adjustments have been applied on precipitation and temperature from the European Centre for Middle-range Weather Forecasting System 4 (S4). We have used three bias correction strategies: two linear (mean bias correction, BC, and linear regression, LR) and one non-linear (Model Output Statistics analogs, MOS-analog). The results have been compared with climatology and persistence. The volume-anomaly model is a previously computed Multiple Linear Regression that ingests precipitation, temperature and in-flow anomaly data to simulate monthly volume anomalies. The potential utility for end-users has been assessed using economic value curve areas. We have studied the S4 hindcast period 1981-2010 for each month of the year and up to seven months ahead considering an ensemble of 15 members. We have shown that the MOS-analog and LR bias corrections can improve the original S4. The application to volume anomalies points towards the possibility to introduce bias correction methods as a tool to improve water resource seasonal forecasts in an end-user context of climate services. Particularly, the MOS-analog approach gives generally better results than the other approaches in late autumn and early winter. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Breathing Life into Engineering: A Lesson Study Life Science Lesson

    Science.gov (United States)

    Lawrence, Maria; Yang, Li-Ling; Briggs, May; Hession, Alicia; Koussa, Anita; Wagoner, Lisa

    2016-01-01

    A fifth grade life science lesson was implemented through a lesson study approach in two fifth grade classrooms. The research lesson was designed by a team of four elementary school teachers with the goal of emphasizing engineering practices consistent with the "Next Generation Science Standards" (NGSS) (Achieve Inc. 2013). The fifth…

  19. Engineering study for closure of 209E facility

    International Nuclear Information System (INIS)

    Brevick, C.H.; Heys, W.H.; Johnson, E.D.

    1997-01-01

    This document is an engineering study for evaluating alternatives to determine the most cost effective closure plan for the 209E Facility, Critical Mass Laboratory. This laboratory is located in the 200 East Area of the Hanford Site and contains a Critical Assembly Room and a Mix room were criticality experiments were once performed

  20. Elements of Motivational Structure for Studying Mechanical Engineering

    Science.gov (United States)

    Dubreta, Nikša; Miloš, Damir

    2017-01-01

    The article presents the findings on students' reasons for studying mechanical engineering. These reasons were covered in terms of extrinsic and intrinsic motivation additionally related to selected independent variables of the sample--students' secondary school Grade Point Average, their gender and the socio-economic status. The research was…

  1. Evaluating Risk Awareness in Undergraduate Students Studying Mechanical Engineering

    Science.gov (United States)

    Langdon, G. S.; Balchin, K.; Mufamadi, P.

    2010-01-01

    This paper examines the development of risk awareness among undergraduate students studying mechanical engineering at a South African university. A questionnaire developed at the University of Liverpool was modified and used on students from the first, second and third year cohorts to assess their awareness in the areas of professional…

  2. Engineering study for closure of 209E facility

    Energy Technology Data Exchange (ETDEWEB)

    Brevick, C.H.; Heys, W.H.; Johnson, E.D.

    1997-07-07

    This document is an engineering study for evaluating alternatives to determine the most cost effective closure plan for the 209E Facility, Critical Mass Laboratory. This laboratory is located in the 200 East Area of the Hanford Site and contains a Critical Assembly Room and a Mix room were criticality experiments were once performed.

  3. Stream, Lake, and Reservoir Management.

    Science.gov (United States)

    Dai, Jingjing; Mei, Ying; Chang, Chein-Chi

    2017-10-01

    This review on stream, lake, and reservoir management covers selected 2016 publications on the focus of the following sections: Stream, lake, and reservoir management • Water quality of stream, lake, and reservoirReservoir operations • Models of stream, lake, and reservoir • Remediation and restoration of stream, lake, and reservoir • Biota of stream, lake, and reservoir • Climate effect of stream, lake, and reservoir.

  4. Integrated seismic study of naturally fractured tight gas reservoirs. Final report, September 1991--January 1995

    Energy Technology Data Exchange (ETDEWEB)

    Mavko, G.; Nur, A.

    1995-01-01

    The approach in this project has been to integrate the principles of rock physics into a quantitative processing and interpretation scheme that exploits, where possible, the broader spectrum of fracture zone signatures: (1) anomalous compressional and shear wave velocity; (2) Q and velocity dispersion; (3) increased velocity anisotropy; (4) amplitude vs. offset (AVO) response, and (5) variations in frequency content. As part of this the authors have attempted to refine some of the theoretical rock physics tools that should be applied in any field study to link the observed seismic signatures to the physical/geologic description of the fractured rock. The project had 3 key elements: (1) rock physics studies of the anisotropic viscoelastic signatures of fractured rocks, (2) acquisition and processing of seismic reflection field data, and (3) interpretation of seismic and well log data. The study site is in a producing field operated by Amoco and Arco at the southern boundary of the Powder River basin in Wyoming. During the winter of 1992--1993 the authors collected about 50 km of 9-component reflection seismic data and obtained existing log data from several wells in the vicinity. The paper gives background information on laboratory studies, seismic field studies of fracture anisotropy, and the problem of upscaling from the laboratory to the field. It discusses fluid effects on seismic anisotropy and a method for predicting stress-induced seismic anisotropy. Then results from the field experiment are presented and discussed: regional geologic framework and site description; seismic data acquisition; shear wave data and validation; and P-wave data analysis. 106 refs., 52 figs.

  5. A Study on Semantic Searching, Semantic Search Engines and Technologies Used for Semantic Search Engines

    OpenAIRE

    Junaid Rashid; Muhammad Wasif Nisar

    2016-01-01

    Semantic search engines(SSE) are more efficient than other web engines because in this era of busy life everyone wants an exact answer to his question which only semantic engines can provide. The immense increase in the volume of data, traditional search engines has increased the number of answers to satisfy the user. This creates the problem to search for the desired answer. To solve this problem, the trend of developing semantic search engines is increasing day by da...

  6. Status of Wheeler Reservoir

    Energy Technology Data Exchange (ETDEWEB)

    1990-09-01

    This is one in a series of status reports prepared by the Tennessee Valley Authority (TVA) for those interested in the conditions of TVA reservoirs. This overview of Wheeler Reservoir summarizes reservoir purposes and operation, reservoir and watershed characteristics, reservoir uses and use impairments, and water quality and aquatic biological conditions. The information presented here is from the most recent reports, publications, and original data available. If no recent data were available, historical data were summarized. If data were completely lacking, environmental professionals with special knowledge of the resource were interviewed. 12 refs., 2 figs.

  7. A Study on the Reservoir Capacity to Control Mud Flood Derived from Mud Volcano: A Phenomenon in Sidoarjo

    Directory of Open Access Journals (Sweden)

    Sholihin Sholihin

    2010-11-01

    Full Text Available This paper is an extended research of Coastal Zone Management of Sidoarjo mud phenomenon. The idea is to find special concept of management to control mud flood using reservoir system. This method, in the mud fluid, is intentionally used to make separation of the solid materials from water. The concept is to calculate sediment velocity in order to find the time of sedimentation then to estimate the volume of mud. Therefore, the reservoir will be determined from this calculation. The result of this research is the dimension of the reservoir: area of 3,704,144.36 m2, the depth of 5.94 m, and the volume 22.018.856.07 m3. The time of sedimentation is calculated of 28.33 hours for 42.2 % of material volume sedimentation. Consequently, the suspension material is 57.8 %. The correction of calculation is depending on the calculation of the velocity of sedimentation, about 2 %.

  8. Study to determine the feasibility of obtaining true samples of oil and gas reservoirs. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ward, C.E.; Sinclair, A.R.

    1977-10-01

    The study concludes that a feasible solution is possible which would provide up to about 90 percent information accuracy under many operating conditions, well within the economic range for most oil and gas operations. The study also concludes that there is potential feasibility for the development of systems to approach 100 percent information accuracy under many operating situations. However, the cost of such a system is far beyond those considered practical within the economics of the competitive oil and gas industry. The justification of such a system has been likened to that of a ''moon shot'' approach and would take several years of development before true feasibility and probability of success could be assessed.

  9. Qualitative simulation of bathymetric changes due to reservoir sedimentation: A Japanese case study.

    Directory of Open Access Journals (Sweden)

    Ahmed Bilal

    Full Text Available Sediment-dynamics modeling is a useful tool for estimating a dam's lifespan and its cost-benefit analysis. Collecting real data for sediment-dynamics analysis from conventional field survey methods is both tedious and expensive. Therefore, for most rivers, the historical record of data is either missing or not very detailed. Available data and existing tools have much potential and may be used for qualitative prediction of future bathymetric change trend. This study shows that proxy approaches may be used to increase the spatiotemporal resolution of flow data, and hypothesize the river cross-sections and sediment data. Sediment-dynamics analysis of the reach of the Tenryu River upstream of Sakuma Dam in Japan was performed to predict its future bathymetric changes using a 1D numerical model (HEC-RAS. In this case study, only annually-averaged flow data and the river's longitudinal bed profile at 5-year intervals were available. Therefore, the other required data, including river cross-section and geometry and sediment inflow grain sizes, had to be hypothesized or assimilated indirectly. The model yielded a good qualitative agreement, with an R2 (coefficient of determination of 0.8 for the observed and simulated bed profiles. A predictive simulation demonstrated that the useful life of the dam would end after the year 2035 (±5 years, which is in conformity with initial detailed estimates. The study indicates that a sediment-dynamic analysis can be performed even with a limited amount of data. However, such studies may only assess the qualitative trends of sediment dynamics.

  10. Periodontal pocket as a potential reservoir of high risk human papilloma virus: A pilot study

    Science.gov (United States)

    Dayakar, Manjunath Mundoor; Shipilova, Anna; Gupta, Dinesh

    2016-01-01

    Aim: Human papilloma viruses (HPVs) are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. HPV detection in periodontium has previously involved DNA detection. This study attempts to: (a) Detect the presence or absence of high risk HPV in marginal periodontiun by identifying E6/E7 messenger RNA (mRNA) in cells from samples obtained by periodontal pocket scraping. (b) Detect the percentage of HPV E6/E7 mRNA in cells of pocket scrapings, which is responsible for producing oncoproteins E6 and E7. Materials and Methods: Pocket scrapings from the periodontal pockets of eight subjects with generalized chronic periodontitis were taken the detection of presence or absence of E6, E7 mRNA was performed using in situ hybridization and flow cytometry. Results: HPV E6/E7 mRNA was detected in four of the eight samples. Conclusion: Presence of high risk human papillomaviruses in periodontal pockets patients of diagnosed with chronic periodontitis, not suffering from head and neck squamous cell carcinoma in the present day could link periodontitis to HPV related squamous cell carcinoma. Prevalence studies are needed detecting the presence of HPV in marginal periodontium as well as prospective studies of HPV positive periodontitis patients are required to explore this possible link. PMID:27143823

  11. Periodontal pocket as a potential reservoir of high risk human papilloma virus: A pilot study

    Directory of Open Access Journals (Sweden)

    Manjunath Mundoor Dayakar

    2016-01-01

    Full Text Available Aim: Human papilloma viruses (HPVs are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. HPV detection in periodontium has previously involved DNA detection. This study attempts to: (a Detect the presence or absence of high risk HPV in marginal periodontiun by identifying E6/E7 messenger RNA (mRNA in cells from samples obtained by periodontal pocket scraping. (b Detect the percentage of HPV E6/E7 mRNA in cells of pocket scrapings, which is responsible for producing oncoproteins E6 and E7. Materials and Methods: Pocket scrapings from the periodontal pockets of eight subjects with generalized chronic periodontitis were taken the detection of presence or absence of E6, E7 mRNA was performed using in situ hybridization and flow cytometry. Results: HPV E6/E7 mRNA was detected in four of the eight samples. Conclusion: Presence of high risk human papillomaviruses in periodontal pockets patients of diagnosed with chronic periodontitis, not suffering from head and neck squamous cell carcinoma in the present day could link periodontitis to HPV related squamous cell carcinoma. Prevalence studies are needed detecting the presence of HPV in marginal periodontium as well as prospective studies of HPV positive periodontitis patients are required to explore this possible link.

  12. Periodontal pocket as a potential reservoir of high risk human papilloma virus: A pilot study.

    Science.gov (United States)

    Dayakar, Manjunath Mundoor; Shipilova, Anna; Gupta, Dinesh

    2016-01-01

    Human papilloma viruses (HPVs) are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. HPV detection in periodontium has previously involved DNA detection. This study attempts to: (a) Detect the presence or absence of high risk HPV in marginal periodontiun by identifying E6/E7 messenger RNA (mRNA) in cells from samples obtained by periodontal pocket scraping. (b) Detect the percentage of HPV E6/E7 mRNA in cells of pocket scrapings, which is responsible for producing oncoproteins E6 and E7. Pocket scrapings from the periodontal pockets of eight subjects with generalized chronic periodontitis were taken the detection of presence or absence of E6, E7 mRNA was performed using in situ hybridization and flow cytometry. HPV E6/E7 mRNA was detected in four of the eight samples. Presence of high risk human papillomaviruses in periodontal pockets patients of diagnosed with chronic periodontitis, not suffering from head and neck squamous cell carcinoma in the present day could link periodontitis to HPV related squamous cell carcinoma. Prevalence studies are needed detecting the presence of HPV in marginal periodontium as well as prospective studies of HPV positive periodontitis patients are required to explore this possible link.

  13. Some practical aspects of reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, M.L.; Young, M.A.; Cole, E.L.; Madden, M.P. [BDM-Oklahoma, Bartlesville, OK (United States)

    1996-09-01

    The practical essence of reservoir management is the optimal application of available resources-people, equipment, technology, and money to maximize profitability and recovery. Success must include knowledge and consideration of (1) the reservoir system, (2) the technologies available, and (3) the reservoir management business environment. Two Reservoir Management Demonstration projects (one in a small, newly-discovered field and one in a large, mature water-flood) implemented by the Department of Energy through BDM-Oklahoma illustrate the diversity of situations suited for reservoir management efforts. Project teams made up of experienced engineers, geoscientists, and other professionals arrived at an overall reservoir management strategy for each field. in 1993, Belden & Blake Corporation discovered a regionally significant oil reservoir (East Randolph Field) in the Cambrian Rose Run formation in Portage County, Ohio. Project objectives are to improve field operational economics and optimize oil recovery. The team focused on characterizing the reservoir geology and analyzing primary production and reservoir data to develop simulation models. Historical performance was simulated and predictions were made to assess infill drilling, water flooding, and gas repressurization. The Citronelle Field, discovered in 1955 in Mobile County, Alabama, has produced 160 million barrels from fluvial sandstones of the Cretaceous Rodessa formation. Project objectives are to address improving recovery through waterflood optimization and problems related to drilling, recompletions, production operations, and regulatory and environmental issues. Initial efforts focused on defining specific problems and on defining a geographic area within the field where solutions might best be pursued. Geologic and reservoir models were used to evaluate past performance and to investigate improved recovery operations.

  14. Conceptual study of advanced VTOL transport aircraft engine; Kosoku VTOL kiyo engine no gainen kento

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Y.; Endo, M.; Matsuda, Y.; Sugiyama, N.; Watanabe, M.; Sugahara, N.; Yamamoto, K. [National Aerospace Laboratory, Tokyo (Japan)

    1996-04-01

    This report proposes the concept of an ultra-low noise engine for advanced high subsonic VTOL transport aircraft, and discusses its technological feasibility. As one of the applications of the previously reported `separated core turbofan engine,` the conceptual engine is composed of 3 core engines, 2 cruise fan engines for high subsonic cruising and 6 lift fan engines producing thrust of 98kN (10000kgf)/engine. The core turbojet engine bleeds a large amount of air at the outlet of a compressor to supply driving high-pressure air for fans to other engines. The lift fan engine is composed of a lift fan, driving combustor, turbine and speed reduction gear, and is featured by not only high operation stability and thin fan engine like a separated core engine but also ultra-low noise operation. The cruise fan engine adopts the same configuration as the lift fan engine. Since this engine configuration has no technological problems difficult to be overcome, its high technological feasibility is expected. 6 refs., 7 figs., 5 tabs.

  15. Study of occupational stress among railway engine pilots

    Science.gov (United States)

    Kumar, Devesh; Singh, Jai Vir; Kharwar, Poonam S.

    2011-01-01

    Background: Traffic volume and speed is going to be increased in Indian Railways successively, leading to higher stress in staff connected with train operations. The jobs of railway engine pilots come under the category of high-strain jobs, necessitating a need to conduct multicentric study to unfold the factors associated with occupational stress and organizational strategies. Materials and Methods: Present study covered 185 railway engine pilots and office clerks working in various railway zones by incidental method. Occupational Stress Index (OSI) test developed by Srivastva and Singh, questionnaire of specific stressors constructed by authors and laboratory test battery for psychological screening of high-speed train pilots were used as tools. Results: Means of OSI and all the 12 occupational stressors of railway engine pilots were found significantly higher to that of office clerks. Means of OSI and occupational stressors of goods train pilots were significantly higher in comparison to high-speed train pilots and passenger train pilots. Study revealed positive correlation of speed perception and complex reaction time tests and negative correlation of other constituent tests of laboratory test battery to OSI test. Highest subgroup of stressor observedwas role overload followed by role conflict. Conclusions: These findings provide a prima facie evidence of higher occupational stress among railway engine pilots because of identified specific stressors prevalent in their job and explore the possible intervention strategies for its reduction. Significant correlation is noticed between OSI and laboratory test results, indicating its relevant utility in preliminary psychological screening. PMID:21808497

  16. Elastostatic effects around a magma reservoir and pathway due to historic earthquakes: a case study of Mt. Fuji, Japan

    Science.gov (United States)

    Hosono, Masaki; Mitsui, Yuta; Ishibashi, Hidemi; Kataoka, Jun

    2016-12-01

    We discuss elastostatic effects on Mt. Fuji, the tallest volcano in Japan, due to historic earthquakes in Japan. The 1707 Hoei eruption, which was the most explosive historic eruption of Mt. Fuji, occurred 49 days after the Hoei earthquake (Mw 8.7) along the Nankai Trough. It was previously suggested that the Hoei earthquake induced compression of a basaltic magma reservoir and unclamping of a dike-intruded region at depth, possibly triggering magma mixing and the subsequent Plinian eruption. Here, we show that the 1707 Hoei earthquake was a special case of induced volumetric strain and normal stress changes around the magma reservoir and pathway of Mt. Fuji. The 2011 Tohoku earthquake (Mw 9), along the Japan Trench, dilated the magma reservoir. It has been proposed that dilation of a magma reservoir drives the ascent of gas bubbles with magma and further depressurization, leading to a volcanic eruption. In fact, seismicity notably increased around Mt. Fuji during the first month after the 2011 Tohoku earthquake, even when we statistically exclude aftershocks, but the small amount of strain change (< 1 μ strain) may have limited the ascent of magma. For many historic earthquakes, the magma reservoir was compressed and the magma pathway was wholly clamped. This type of interaction has little potential to mechanically trigger the deformation of a volcano. Thus, Mt. Fuji may be less susceptible to elastostatic effects because of its location relative to the sources of large tectonic earthquakes. As an exception, a possible local earthquake in the Fujikawa-kako fault zone could induce a large amount of magma reservoir dilation beneath the southern flank of Mt. Fuji.

  17. Evaluating the Implications of Climate Phenomenon Indices in Supporting Reservoir Operation Using the Artificial Neural Network and Decision-Tree Methods: A Case Study on Trinity Lake in Northern California

    Science.gov (United States)

    Yang, T.; Akbari Asanjan, A.; Gao, X.; Sorooshian, S.

    2016-12-01

    Reservoirs are fundamental human-built infrastructures that collect, store, and deliver fresh surface water in a timely manner for all kinds of purposes, including residential and industrial water supply, flood control, hydropower, and irrigation, etc. Efficient reservoir operation requires that policy makers and operators understand how reservoir inflows, available storage, and discharges are changing under different climatic conditions. Over the last decade, the uses of Artificial Intelligence and Data Mining (AI & DM) techniques in assisting reservoir management and seasonal forecasts have been increasing. Therefore, in this study, two distinct AI & DM methods, Artificial Neural Network (ANN) and Random Forest (RF), are employed and compared with respect to their capabilities of predicting monthly reservoir inflow, managing storage, and scheduling reservoir releases. A case study on Trinity Lake in northern California is conducted using long-term (over 50 years) reservoir operation records and 17 known climate phenomenon indices, i.e. PDO and ENSO, etc., as predictors. Results show that (1) both ANN and RF are capable of providing reasonable monthly reservoir storage, inflow, and outflow prediction with satisfactory statistics, and (2) climate phenomenon indices are useful in assisting monthly or seasonal forecasts of reservoir inflow and outflow. It is also found that reservoir storage has a consistent high autocorrelation effect, while inflow and outflow are more likely to be influenced by climate conditions. Using a Gini diversity index, RF method identifies that the reservoir discharges are associated with Southern Oscillation Index (SOI) and reservoir inflows are influenced by multiple climate phenomenon indices during different seasons. Furthermore, results also show that, during the winter season, reservoir discharges are controlled by the storage level for flood-control purposes, while, during the summer season, the flood-control operation is not as

  18. Integrated Outcrop and Subsurface Studies of the Interwell Environment of Carbonate Reservoirs: Clear Fork (Leonaradian Age) Reservoirs, West Texas and New Mexico

    International Nuclear Information System (INIS)

    Lucia, F.J.; Ruppel, S.C.

    2001-01-01

    Characterization of cycle and facies architecture on lower Clear Fork and lowermost upper Clear Fork equivalent outcrops in Apache Canyon of Sierra Diablo was complete. The focus of detailed study in Apache Canyon has been the upper Clear Fork section because this interval contains the productive interval in South Wasson field, the preliminary subsurface study area. Parts of three high-frequency sequences (HFS), each 60 to 100 ft thick, are present on the south wall of Apache Canyon. HFS's display an upper-deepening or backstepping pattern associated with longer-term sea level rise. Each HFS is composed of upward-shallowing cycles whose thickness, facies composition, and continuity vary within and between HFS's

  19. Impacts of boreal hydroelectric reservoirs on seasonal climate and precipitation recycling as simulated by the CRCM5: a case study of the La Grande River watershed, Canada

    Science.gov (United States)

    Irambona, C.; Music, B.; Nadeau, D. F.; Mahdi, T. F.; Strachan, I. B.

    2018-02-01

    Located in northern Quebec, Canada, eight hydroelectric reservoirs of a 9782-km2 maximal area cover 6.4% of the La Grande watershed. This study investigates the changes brought by the impoundment of these reservoirs on seasonal climate and precipitation recycling. Two 30-year climate simulations, corresponding to pre- and post-impoundment conditions, were used. They were generated with the fifth-generation Canadian Regional Climate Model (CRCM5), fully coupled to a 1D lake model (FLake). Seasonal temperatures and annual energy budget were generally well reproduced by the model, except in spring when a cold bias, probably related to the overestimation of snow cover, was seen. The difference in 2-m temperature shows that reservoirs induce localized warming in winter (+0.7 ± 0.02 °C) and cooling in the summer (-0.3 ± 0.02 °C). The available energy at the surface increases throughout the year, mostly due to a decrease in surface albedo. Fall latent and sensible heat fluxes are enhanced due to additional energy storage and availability in summer and spring. The changes in precipitation and runoff are within the model internal variability. At the watershed scale, reservoirs induce an additional evaporation of only 5.9 mm year-1 (2%). We use Brubaker's precipitation recycling model to estimate how much of the precipitation is recycled within the watershed. In both simulations, the maximal precipitation recycling occurs in July (less than 6%), indicating weak land-atmosphere coupling. Reservoirs do not seem to affect this coupling, as precipitation recycling only decreased by 0.6% in July.

  20. Study on temperature distribution along wellbore of fracturing horizontal wells in oil reservoir

    Directory of Open Access Journals (Sweden)

    Junjun Cai

    2015-12-01

    Full Text Available The application of distributed temperature sensors (DTS to monitor producing zones of horizontal well through a real-time measurement of a temperature profile is becoming increasingly popular. Those parameters, such as flow rate along wellbore, well completion method, skin factor, are potentially related to the information from DTS. Based on mass-, momentum-, and energy-balance equations, this paper established a coupled model to study on temperature distribution along wellbore of fracturing horizontal wells by considering skin factor in order to predict wellbore temperature distribution and analyze the factors influencing the wellbore temperature profile. The models presented in this paper account for heat convective, fluid expansion, heat conduction, and viscous dissipative heating. Arriving temperature and wellbore temperature curves are plotted by computer iterative calculation. The non-perforated and perforated sections show different temperature distribution along wellbore. Through the study on the sensitivity analysis of skin factor and flow rate, we come to the conclusion that the higher skin factor generates larger temperature increase near the wellbore, besides, temperature along wellbore is related to both skin factors and flow rate. Temperature response type curves show that the larger skin factor we set, the less temperature augmenter from toe to heel could be. In addition, larger flow rate may generate higher wellbore temperature.

  1. Geo-Chemo-Mechanical Studies for Permanent CO{sub 2} Storage in Geologic Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Kelemen, Peter; Park, Ah-hyung; Matter, Jurg; Gadikota, Greeshma; Lisabeth, Harrison; Zhu, Wenlu

    2013-09-30

    This two-pronged study investigated the rates and mechanisms of formation of Ca and Mg carbonate minerals via reaction of aqueous fluids with silicate minerals and rocks, and the geomechanical effects of such reactions. The kinetic studies focused on the separation of variables, following from previous studies demonstrating rapid formation of carbonates via reaction of the mineral olivine with aqueous fluids rich in NaHCO{sub 3} (plus KHCO{sub 3} and RbHCO{sub 3}) and NaCl at a high partial pressure of CO{sub 2}. We wished to separate and quantify the effects of NaHCO{sub 3} and NaCl, and to investigate whether bicarbonate-rich, aqueous fluids would also cause rapid formation of carbonates via reaction with other minerals and rocks. Further, we wished to improve upon previous work by adding precise characterization of grain size distributions and surface area, and their changes as a result of reaction. We confirmed previous reports of very rapid olivine carbonation. We found that at a given temperature and CO{sub 2} partial pressure the previously observed rate enhancement in olivine carbonation is due mainly to NaHCO{sub 3}, and not to dissolved NaCl. Further, though reaction of the mineral plagioclase, and two rock compositions, were all faster in the presence of NaHCO{sub 3}-rich fluids, compared with saline and de-ionized water, they were all much slower than reaction of olivine. In the experiments showing the fastest reaction rate, average grain size tended to increase during experiments, presumably due to dissolution of small reactant grains plus growth of product phases on reactant surfaces. Porosity/surface area of grains tended to change with reaction progress, due to the formation of dissolution pits and irregular growth of product phases on reactant grain surfaces. Development of a passivating phase (e.g., a layer of silica) due to incongruent dissolution of solid reactants and/or precipitation of solid products was detected, but was relatively minor and

  2. An Integrated Study of the Grayburg/San Andres Reservoir, Foster and South Cowden Fields, Ector County, Texas, Class II

    Energy Technology Data Exchange (ETDEWEB)

    Trentham, Robert C.; Weinbrandt, Richard; Robinson, William C.; Widner, Kevin

    2001-05-03

    The objectives of the project were to: (1) Thoroughly understand the 60-year history of the field. (2) Develop a reservoir description using geology and 3D seismic. (3) Isolate the upper Grayburg in wells producing from multiple intervals to stop cross flow. (4) Re-align and optimize the upper Grayburg waterflood. (5) Determine well condition, identify re-frac candidates, evaluate the effectiveness of well work and obtain bottom hole pressure data for simulation utilizing pressure transient testing field wide. (6) Quantitatively integrate all the data to guide the field operations, including identification of new well locations utilizing reservoir simulation.

  3. The experimental study of heat extraction of supercritical CO2 in the geothermal reservoir

    Directory of Open Access Journals (Sweden)

    Huang Cyun-Jie

    2016-01-01

    Full Text Available The heat transfer phenomena of supercritical CO2 are experimentally investigated in a horizontal tube for improving the efficiency of CO2-EGS.This study discuss the experimental verification of the numerical simulations. The experiment is conducted for the pressure, the flow rate, and particle size 1.54mm. In addition, the experiment and simulation that the maximum heat extraction is occurred at the 9MPa pressure and mass flow rate of 0.00109 kg/s. The maximum specific heat extraction at 9MPa and flow rate of 0.00082 kg/s. The results show that the numerical model has been experimentally verified of the feasibility. Furthermore, the pseudo-critical point had a significant influence on the heat extraction, temperature difference and specific heat extraction.

  4. Geochemical monitoring using noble gases and carbon isotopes: study of a natural reservoir; Monitoring geochimique par couplage entre les gaz rares et les isotopes du carbone: etude d'un reservoir naturel

    Energy Technology Data Exchange (ETDEWEB)

    Jeandel, E

    2008-12-15

    To limit emissions of greenhouse gases in the atmosphere, CO{sub 2} geological sequestration appears as a solution in the fight against climate change. The development of reliable monitoring tools to ensure the sustainability and the safety of geological storage is a prerequisite for the implementation of such sites. In this framework, a geochemical method using noble gas and carbon isotopes geochemistry has been tested on natural and industrial analogues. The study of natural analogues from different geological settings showed systematic behaviours of the geochemical parameters, depending on the containment sites, and proving the effectiveness of these tools in terms of leak detection and as tracers of the behaviour of CO{sub 2}. Moreover, an experience of geochemical tracing on a natural gas storage has demonstrated that it is possible to identify the physical-chemical processes taking place in the reservoir to a human time scale, increasing interest in the proposed tool and providing general information on its use. (author)

  5. Antimisting kerosene JT3 engine fuel system integration study

    Science.gov (United States)

    Fiorentino, A.

    1987-01-01

    An analytical study and laboratory tests were conducted to assist NASA in determining the safety and mission suitability of the modified fuel system and flight tests for the Full-Scale Transport Controlled Impact Demonstration (CID) program. This twelve-month study reviewed and analyzed both the use of antimisting kerosene (AMK) fuel and the incorporation of a fuel degrader on the operational and performance characteristics of the engines tested. Potential deficiencies and/or failures were identified and approaches to accommodate these deficiencies were recommended to NASA Ames -Dryden Flight Research Facility. The result of flow characterization tests on degraded AMK fuel samples indicated levels of degradation satisfactory for the planned missions of the B-720 aircraft. The operability and performance with the AMK in a ground test engine and in the aircraft engines during the test flights were comparable to those with unmodified Jet A. For the final CID test, the JT-3C-7 engines performed satisfactorily while operating on AMK right up to impact.

  6. Reverse Engineering of Gene Regulatory Networks: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Hendrik Hache

    2009-01-01

    Full Text Available Reverse engineering of gene regulatory networks has been an intensively studied topic in bioinformatics since it constitutes an intermediate step from explorative to causative gene expression analysis. Many methods have been proposed through recent years leading to a wide range of mathematical approaches. In practice, different mathematical approaches will generate different resulting network structures, thus, it is very important for users to assess the performance of these algorithms. We have conducted a comparative study with six different reverse engineering methods, including relevance networks, neural networks, and Bayesian networks. Our approach consists of the generation of defined benchmark data, the analysis of these data with the different methods, and the assessment of algorithmic performances by statistical analyses. Performance was judged by network size and noise levels. The results of the comparative study highlight the neural network approach as best performing method among those under study.

  7. Engineering education research: Impacts of an international network of female engineers on the persistence of Liberian undergraduate women studying engineering

    Science.gov (United States)

    Rimer, Sara; Reddivari, Sahithya; Cotel, Aline

    2015-11-01

    As international efforts to educate and empower women continue to rise, engineering educators are in a unique position to be a part of these efforts by encouraging and supporting women across the world at the university level through STEM education and outreach. For the past two years, the University of Michigan has been a part of a grassroots effort to encourage and support the persistence of engineering female students at University of Liberia. This effort has led to the implementation of a leadership camp this past August for Liberian engineering undergraduate women, meant to: (i) to empower engineering students with the skills, support, and inspiration necessary to become successful and well-rounded engineering professionals in a global engineering market; and (ii) to strengthen the community of Liberian female engineers by building cross-cultural partnerships among students resulting in a international network of women engineers. This session will present qualitative research findings on the impact of this grassroots effort on Liberian female students? persistence in engineering, and the future directions of this work.

  8. Geothermal reservoir management

    Energy Technology Data Exchange (ETDEWEB)

    Scherer, C.R.; Golabi, K.

    1978-02-01

    The optimal management of a hot water geothermal reservoir was considered. The physical system investigated includes a three-dimensional aquifer from which hot water is pumped and circulated through a heat exchanger. Heat removed from the geothermal fluid is transferred to a building complex or other facility for space heating. After passing through the heat exchanger, the (now cooled) geothermal fluid is reinjected into the aquifer. This cools the reservoir at a rate predicted by an expression relating pumping rate, time, and production hole temperature. The economic model proposed in the study maximizes discounted value of energy transferred across the heat exchanger minus the discounted cost of wells, equipment, and pumping energy. The real value of energy is assumed to increase at r percent per year. A major decision variable is the production or pumping rate (which is constant over the project life). Other decision variables in this optimization are production timing, reinjection temperature, and the economic life of the reservoir at the selected pumping rate. Results show that waiting time to production and production life increases as r increases and decreases as the discount rate increases. Production rate decreases as r increases and increases as the discount rate increases. The optimal injection temperature is very close to the temperature of the steam produced on the other side of the heat exchanger, and is virtually independent of r and the discount rate. Sensitivity of the decision variables to geohydrological parameters was also investigated. Initial aquifer temperature and permeability have a major influence on these variables, although aquifer porosity is of less importance. A penalty was considered for production delay after the lease is granted.

  9. Investigation of temperature dynamics in small and shallow reservoirs, case study : Lake Binaba, Upper East Region of Ghana

    NARCIS (Netherlands)

    Abbasi, A.; Annor, F.O.; van de Giesen, N.C.

    2016-01-01

    An unsteady fully three-dimensional model of Lake Binaba (a shallow small reservoir) in semi-arid Upper East Region of Ghana has been developed to simulate its temperature dynamics. The model developed is built on the Reynolds Averaged Navier-Stokes (RANS) equations, utilizing the Boussinesq

  10. Gravimetric monitoring of water influx into a gas reservoir: A numerical study based on the ensemble kalman filter

    NARCIS (Netherlands)

    Glegola, M.; Ditmar, P.; Hanea, R.G.; Vossepoel, F.C.; Arts, R.; Klees, R.

    2012-01-01

    Water influx into gas fields can reduce recovery factors by 10-40%. Therefore, information about the magnitude and spatial distribution of water influx is essential for efficient management of waterdrive gas reservoirs. Modern geophysical techniques such as gravimetry may provide a direct measure of

  11. Spatio-temporal study of phytoplankton cell viability in a eutrophic reservoir using SYTOX Green nucleic acid stain

    Czech Academy of Sciences Publication Activity Database

    Rychtecký, Pavel; Znachor, Petr; Nedoma, Jiří

    2014-01-01

    Roč. 740, č. 1 (2014), s. 177-189 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP504/11/2177; GA ČR(CZ) GAP504/11/2182 Institutional support: RVO:60077344 Keywords : phytoplankton * reservoir * cell death * SYTOX Green Subject RIV: DA - Hydrology ; Limnology Impact factor: 2.275, year: 2014

  12. A multi-scale case study of natural fracture systems in outcrops and boreholes with applications to reservoir modelling

    NARCIS (Netherlands)

    Taal-van Koppen, J.K.J.

    2008-01-01

    Fractured reservoirs are notoriously difficult to characterize because the resolution of seismic data is too low to detect fractures whereas borehole data is detailed but sparse. Therefore, outcrops can be of great support in gaining knowledge of the three-dimensional geometry of fracture networks,

  13. Studies and support for the EGS reservoirs at Soultz-sous-Forets. April 2004 - May 2009. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Portier, S.; Vuataz, F.-D. [Centre de Recherche en Geothermie (CREGE), Neuchatel (Switzerland)

    2009-08-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at the activities carried out during the period from April 2004 up to May 2009 at Soultz-sous-Forets, France, in connection with the enhanced geothermal systems (EGS) at that location. The report describes the work performed by the Swiss EGS Research and Development group involved in the Soultz project. The principal target set was to install and operate a power plant, enabling the deep reservoir/heat exchanger to be operated, evaluated and improved under realistic conditions. The Swiss contributors have been participating in several work packages: Short and long term tests and medium-term tests of the three-well reservoir/heat exchanger system, development and up-scaling, technical and economic design of larger, industrial, EGS units and the development of stimulation methodology for EGS. The exchange of findings obtained during this project phase is discussed, as is the state-of-the-art of EGS stimulation methods, the interpretation of logging data. Also, seismic /-hydraulic factors, the evaluation of the production/injection performance of the boreholes and reservoir development strategies are discussed as are the modelling of geochemical impact of forced fluid circulation in the deep geothermal reservoir and the results of chemical stimulation tests performed on site.

  14. Consistent lithological units and its influence on geomechanical stratification in shale reservoir: case study from Baltic Basin, Poland.

    Science.gov (United States)

    Pachytel, Radomir; Jarosiński, Marek; Bobek, Kinga

    2017-04-01

    Geomechanical investigations in shale reservoir are crucial to understand rock behavior during hydraulic fracturing treatment and to solve borehole wall stability problem. Anisotropy should be considered as key mechanical parameter while trying to characterize shale properties in variety of scales. We are developing a concept of step-by-step approach to characterize and upscale the Consistent Lithological Units (CLU) at several scales of analysis. We decided that the most regional scale model, comparable to lithostratigraphic formations, is too general for hydraulic fracture propagation study thus a more detailed description is needed. The CLU's hierarchic model aims in upscale elastic properties with their anisotropy based on available data from vertical borehole. For the purpose of our study we have an access to continuous borehole core profile and full set of geophysical logging from several wells in the Pomeranian part of the Ordovician and Silurian shale complex belongs to the Baltic Basin. We are focused on shale properties that might be crucial for mechanical response to hydraulic fracturing: mineral components, porosity, density, elastic parameters and natural fracture pattern. To prepare the precise CLU model we compare several methods of determination and upscaling every single parameter used for consistent units secretion. Mineralogical data taken from ULTRA log, GEM log, X-ray diffraction and X-ray fluorescence were compared with Young modulus from sonic logs and Triaxial Compressive Strength Tests. The results showed the impact of clay content and porosity increase on Young's modulus reduction while carbonates (both calcite and dolomite) have stronger impact on elastic modulus growth, more than quartz, represented here mostly by detrital particles. Comparing the shales of similar composition in a few wells of different depths we concluded that differences in diagenesis and compaction due to variation in formation depth in a range of 1 km has negligible

  15. Study on the morals of nuclear power engineers

    International Nuclear Information System (INIS)

    Kosaka, Takashi; Kotani, Fumio; Morikawa, Shin'ichi; Hiramoto, Mitsuru; Koya, Masahiko

    2000-01-01

    Regarding the incident that occurred in October 1998 in which records of containers for transporting spent fuel were altered, the morals of engineers was pointed out as one reason for the problem. Since then, much effort has been exerted to prevent the re-occurrence of such an incident and to reform the corporate climate at electric power companies. From an objective point of view the Institute of Nuclear Safety Systems, inc., the Institute of Social Research conducted an analysis regarding of the conditions faced by that engineers are faced with and discussing how the engineers should deal with the issue of morals as professionals under such circumstances. In this research, teaching materials were compiled, such as a checklist and examples of case studies, to be used for morals education/training and others. This will be useful for engineers who are working for an organization and are in a number of complicated relationships, in dealing with a wide variety of moral issues in their day-to-day activities. (author)

  16. Sedimentological and geophysical studies of clastic reservoir analogs: Methods, applications and developments of ground-penetrating radar for determination of reservoir geometries in near-surface settings. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, G.A.; Soegaard, K.

    1998-05-25

    An integrated sedimentologic and GPR investigation has been carried out on a fluvial channel sandstone in the mid-Cretaceous Ferron Sandstone at Coyote Basin along the southwestern flank of the San Rafael Uplift in east-central Utah. This near-surface study, which covers a area of 40 {times} 16.5 meters to a depth of 15 meters, integrates detailed stratigraphic data from outcrop sections and facies maps with multi-frequency 3-D GPR surveys. The objectives of this investigation are two-fold: (1) to develop new ground-penetrating radar (GPR) technology for imaging shallow subsurface sandstone bodies, and (2) to construct an empirical three-dimensional sandstone reservoir model suitable for hydrocarbon flow-simulation by imaging near-surface sandstone reservoir analogs with the use of GPR. The sedimentological data base consists of a geologic map of the survey area and a detailed facies map of the cliff face immediately adjacent to the survey area. Five vertical sections were measured along the cliff face adjacent to the survey area. In addition, four wells were cored within the survey area from which logs were recorded. In the sections and well logs primary sedimentary structures were documented along with textural information and permeability data. Gamma-ray profiles were also obtained for all sections and core logs. The sedimentologic and stratigraphic information serves as the basis from which much of the processing and interpretation of the GPR data was made. Three 3-D GPR data sets were collected over the survey area at frequencies of 50 MHZ, 100 MHZ, and 200 MHZ.

  17. Preliminary design study of underground pumped hydro and compressed-air energy storage in hard rock. Volume 8: Design approaches. UPH. Appendix E: Lower reservoir

    Science.gov (United States)

    1981-04-01

    Operational, construction, and geotechnical requirements were examined. Overriding considerations including operating range, volume, construction methods, cavern cross section and reservoir layout were studied within the context of minimizing facility costs and optimizing the plant layout. The study led to a preliminary arrangement of fourteen parallel caverns, each 60 ft wide by 85 ft high in cross section and 3610 ft in length. The requirements for and preliminary design of the intermediate reservoir in the case of a two step UPH facility is also described. The design and the cost estimates presented are based on the requirements for a 2000 MW plant providing 20,000 MWh of storage at a nominal head of 4600 ft.

  18. Top-Down, Intelligent Reservoir Model

    Science.gov (United States)

    Mohaghegh, Shahab

    2010-05-01

    Conventional reservoir simulation and modeling is a bottom-up approach. It starts with building a geological model of the reservoir that is populated with the best available petrophysical and geophysical information at the time of development. Engineering fluid flow principles are added and solved numerically so as to arrive at a dynamic reservoir model. The dynamic reservoir model is calibrated using the production history of multiple wells and the history matched model is used to strategize field development in order to improve recovery. Top-Down, Intelligent Reservoir Modeling approaches the reservoir simulation and modeling from an opposite angle by attempting to build a realization of the reservoir starting with the measured well production behavior (history). The production history is augmented by core, log, well test and seismic data in order to increase the accuracy of the Top-Down modeling technique. Although not intended as a substitute for the conventional reservoir simulation of large, complex fields, this novel approach to reservoir modeling can be used as an alternative (at a fraction of the cost) to conventional reservoir simulation and modeling in cases where performing conventional modeling is cost (and man-power) prohibitive. In cases where a conventional model of a reservoir already exists, Top-Down modeling should be considered as a compliment to, rather than a competition for the conventional technique, to provide an independent look at the data coming from the reservoir/wells for optimum development strategy and recovery enhancement. Top-Down, Intelligent Reservoir Modeling starts with well-known reservoir engineering techniques such as Decline Curve Analysis, Type Curve Matching, History Matching using single well numerical reservoir simulation, Volumetric Reserve Estimation and calculation of Recovery Factors for all the wells (individually) in the field. Using statistical techniques multiple Production Indicators (3, 6, and 9 months cum

  19. Reservoir-induced seismicity at Castanhao reservoir, NE Brazil

    Science.gov (United States)

    Nunes, B.; do Nascimento, A.; Ferreira, J.; Bezerra, F.

    2012-04-01

    Our case study - the Castanhão reservoir - is located in NE Brazil on crystalline rock at the Borborema Province. The Borborema Province is a major Proterozoic-Archean terrain formed as a consequence of convergence and collision of the São Luis-West Africa craton and the São Francisco-Congo-Kasai cratons. This reservoir is a 60 m high earth-filled dam, which can store up to 4.5 billion m3 of water. The construction begun in 1990 and finished in October 2003.The first identified reservoir-induced events occurred in 2003, when the water level was still low. The water reached the spillway for the first time in January 2004 and, after that, an increase in seismicity occured. The present study shows the results of a campaign done in the period from November 19th, 2009 to December 31th, 2010 at the Castanhão reservoir. We deployed six three-component digital seismographic station network around one of the areas of the reservoir. We analyzed a total of 77 events which were recorded in at least four stations. To determine hypocenters and time origin, we used HYPO71 program (Lee & Lahr, 1975) assuming a half-space model with following parameters: VP= 5.95 km/s and VP/VS=1.73. We also performed a relocation of these events using HYPODD (Waldhauser & Ellsworth, 2000) programme. The input data used we used were catalogue data, with all absolute times. The results from the spatio-temporal suggest that different clusters at different areas and depths are triggered at different times due to a mixture of: i - pore pressure increase due to diffusion and ii - increase of pore pressure due to the reservoir load.

  20. Study of hydrogeological and engineering-geological conditions of deposits

    International Nuclear Information System (INIS)

    1985-01-01

    Methods for hydrogeological and engineering-geological studies are considered as a part of the complex works dUring eXploration of hydrogenic uranium deposits to develop them by Underground ieaching (UL). Problems are enumerated and peculiarities Of hydrogeologic and engipeering-geological works at different stages are outlined (prospeccing - evaluating works, preliminary and detailed survey). Attention is paid to boring and equipment for hydrogeological and engineering - geological boreholes. Testing-filtering works are described, the latter includes: evacuations, fulnesses ( forcings), and tests of fulness-evacuation. The problem on steady-state observations in boreholes and laboratory studies of rocks and underground waters is discussed. Geological and geophysical methods for evaluation of rock and ore filtering properties are presented. Necessity of hydrogeological zonation of deposits as applied to UL is marked

  1. Separation of organic ion exchange resins from sludge -- engineering study

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, J.B.

    1998-08-25

    This engineering study evaluates the use of physical separation technologies to separate organic ion exchange resin from KE Basin sludge prior to nitric acid dissolution. This separation is necessitate to prevent nitration of the organics in the acid dissolver. The technologies under consideration are: screening, sedimentation, elutriation. The recommended approach is to first screen the Sludge and resin 300 microns then subject the 300 microns plus material to elutriation.

  2. Development of gas and gas condensate reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    In the study of gas reservoir development, the first year topics are restricted on reservoir characterization. There are two types of reservoir characterization. One is the reservoir formation characterization and the other is the reservoir fluid characterization. For the reservoir formation characterization, calculation of conditional simulation was compared with that of unconditional simulation. The results of conditional simulation has higher confidence level than the unconditional simulation because conditional simulation considers the sample location as well as distance correlation. In the reservoir fluid characterization, phase behavior calculations revealed that the component grouping is more important than the increase of number of components. From the liquid volume fraction with pressure drop, the phase behavior of reservoir fluid can be estimated. The calculation results of fluid recombination, constant composition expansion, and constant volume depletion are matched very well with the experimental data. In swelling test of the reservoir fluid with lean gas, the accuracy of dew point pressure forecast depends on the component characterization. (author). 28 figs., 10 tabs.

  3. Petroleum Characterisation and Reservoir Dynamics - The Froey Field and the Rind Discovery, Norwegian Continental Shelf

    Energy Technology Data Exchange (ETDEWEB)

    Bhullar, Abid G.

    1999-07-01

    The objective of this thesis is to apply the fundamental principles of petroleum geochemistry integrated with petroleum/reservoir engineering and geological concepts to the dynamics and characterisation of petroleum reservoirs. The study is based on 600 core samples and 9 DST oils from 11 wells in the Froey Field and the Rind Discovery. The work is presented in five papers. Paper 1 is a detailed characterisation of the reservoirs using a petroleum geochemical approach. Paper 2 describes the application of a single reservoir geochemical screening technique to exploration, appraisal and production geology and reservoir/petroleum engineering. Paper 3 compares the Iatroscan TLC-FID screening technique and the extraction efficiency of micro-extraction used in this work with the well-established Rock-Eval geochemical screening method and with the Soxtec extraction method. Paper 4 refines the migration and filling models of Paper 1, and Paper 5 presents a comparison of models of petroleum generation, migration and accumulation based on geochemical data with 1D burial history, a ''pseudo well'' based on actual well data and regional seismic analysis representing the hydrocarbon generative basin conditions.

  4. Studies of fracture network geometry of reservoir outcrop analogues from terrestrial lidar data: attempts to quantify spatial variations of fracture characteristics

    Science.gov (United States)

    Vsemirnova, E. A.; Jones, R. R.; McCaffrey, K. J. W.

    2012-04-01

    We describe studies analysing terrestrial lidar datasets of fracture systems from a range of reservoir analogues in clastic and carbonate lithologies that represent geological analogues of offshore hydrocarbon reservoirs for the UK continental shelf. As fracture networks (observed here from centimetre to kilometre scale) can significantly affect the permeability of a fractured reservoir, the definition of fracture network geometry at various scales has become an important goal of structural analysis. The main aim of the study has been to extend the investigation of fracture networks in order to quantify spatial variations in fracture parameters in a variety of lithologies. The datasets were pre-processed using RiSCAN PRO software, and then re-sampled and filtered to derive characteristics which are traditionally measured from outcrops, including size distributions, fracture spacing and clustering statistics. This type of analysis can significantly reduce the uncertainty associated with some field fracture network measurements. The digitised fracture networks datasets are then used to investigate various aspects of spatial heterogeneity. A series of fracture maps (joints and faults) were generated at different scales, and fracture trends were studied to test scale dependency of fracture orientations. Multiscale trend analysis was then applied to describe the trend structure of the fracture networks.

  5. Structural analysis characterization of permeability pathways across reservoir-seal interface - South-Eastern Utah; Results from integrated sedimentological, structural, and geochemical studies.

    Science.gov (United States)

    Petrie, E. S.; Evans, J. P.; Richey, D.; Flores, S.; Barton, C.; Mozley, P.

    2015-12-01

    Sedimentary rocks in the San Rafael Swell, Utah, were deformed by Laramide compression and subsequent Neogene extension. We evaluate the effect of fault damage zone morphology as a function of structural position, and changes in mechanical stratigraphy on the distribution of secondary minerals across the reservoir-seal pair of the Navajo Sandstone and overlying Carmel Formation. We decipher paleo-fluid migration and examine the effect faults and fractures have on reservoir permeability and efficacy of top seal for a range of geo-engineering applications. Map-scale faults have an increased probability of allowing upward migration of fluids along the fault plane and within the damage zone, potentially bypassing the top seal. Field mapping, mesoscopic structural analyses, petrography, and geochemical observations demonstrate that fault zone thickness increases at structural intersections, fault relay zones, fault-related folds, and fault tips. Higher densities of faults with meters of slip and dense fracture populations are present in relay zones relative to single, discrete faults. Curvature analysis of the San Rafael monocline and fracture density data show that fracture density is highest where curvature is highest in the syncline hinge and near faults. Fractures cross the reservoir-seal interface where fracture density is highest and structural diagensis includes mineralization events and bleaching and calcite and gypsum mineralization. The link between fracture distributions and structural setting implys that transmissive fractures have predictable orientations and density distributions. At the m- to cm- scale, deformation-band faults and joints in the Navajo Sandstone penetrate the reservoir-seal interface and transition into open-mode fractures in the caprock seal. Scanline analysis and petrography of veins provide evidence for subsurface mineralization and fracture reactivation, suggesting that the fractures act as loci for fluid flow through time

  6. Prediction of Gas Injection Performance for Heterogeneous Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Blunt, Martin J.; Orr, Jr., Franklin M.

    1999-12-20

    This report describes research carried out in the Department of Petroleum Engineering at Stanford University from September 1998 - September 1998 under the third year of a three-year Department of Energy (DOE) grant on the ''Prediction of Gas Injection Performance for Heterogeneous Reservoirs''. The research effort is an integrated study of the factors affecting gas injection, from the pore scale to the field scale, and involves theoretical analysis, laboratory experiments and numerical simulation. The research is divided into four main areas: (1) Pore scale modeling of three-phase flow in porous media; (2) Laboratory experiments and analysis of factors influencing gas injection performance at the core scale with an emphasis on the fundamentals of three-phase flow; (3) Benchmark simulations of gas injection at the field scale; and (4) Development of streamline-based reservoir simulator.

  7. Visual study of capabilities of managing IC engine filling degree vs engine ecological indicators

    Science.gov (United States)

    Kołodziej, Szymon; Ligus, Grzegorz

    2017-10-01

    The operation of an internal combustion engine in a transient state is related to constant changes in cylinder filling degree. Managing a steady course of engine torque demands constant corrections in the volume of air delivered to the engine. In this work, different engine throttle management strategies were analyzed. The effect of throttle velocity on emissions was depicted. The research has shown that the greatest value of work density is reached by the IC engine for relatively low values of throttle angle. For shown values, disturbances in air flow in engine intake which may adversely affect emissions due to uneven cylinder filling were researched with the use of Digital Particle Image Velocimetry. The conducted research has shown significant unevennes in air supply to individual cylinders in the engine. This effect may cause discrepancies in air excess ratio for each cylinder, and result in heightened harmful substance emission.

  8. Serological study of vaccinia virus reservoirs in areas with and without official reports of outbreaks in cattle and humans in São Paulo, Brazil.

    Science.gov (United States)

    Peres, Marina Gea; Bacchiega, Thais Silva; Appolinário, Camila Michele; Vicente, Acácia Ferreira; Allendorf, Susan Dora; Antunes, João Marcelo Azevedo Paula; Moreira, Sabrina Almeida; Legatti, Emerson; Fonseca, Clóvis Rinaldo; Pituco, Edviges Maristela; Okuda, Liria Hiromi; Pantoja, José Carlos de Figueiredo; Ferreira, Fernando; Megid, Jane

    2013-12-01

    Vaccinia virus (VACV), the etiological agent of an exanthematic disease, has been associated with several bovine outbreaks in Brazil since the end of the global vaccination campaign against smallpox. It was previously believed that the vaccine virus used for the WHO global campaign had adapted to an unknown wild reservoir and was sporadically re-emerging in outbreaks in cattle and milkers. At present, it is known that Brazilian VACV is phylogenetically different from the vaccinia virus vaccinal strain, but its origin remains unknown. This study assessed the seroprevalence of orthopoxviruses in domestic and wild animals and farmers from 47 farms in three cities in the southwest region of the state of São Paulo with or without official reports of outbreaks in cattle or humans. Our data indicate a low seroprevalence of antibodies in wild animals and raise interesting questions about the real potential of wild rodents and marsupials as VACV reservoirs, suggesting other routes through which VACV can be spread.

  9. Impact of environmental factors on maintaining water quality of Bakreswar reservoir, India

    Directory of Open Access Journals (Sweden)

    Moitreyee Banerjee

    2015-09-01

    Full Text Available Reservoirs and dams are engineered systems designed to serve purposes like supply of drinking water as well as other commercial and industrial use. A thorough assessment of water quality for these systems is thus necessary. The present study is carried out at Bakreswar reservoir, in Birbhum district, which was created by the dam, built on Bakreswar River. The major purpose of the reservoir is the supply of drinking water to the surrounding villages and Bakreswar Thermal Power Station. Water samples were collected fortnightly from three different stations of the reservoir. Physical and chemical factors like dissolved oxygen, atmospheric temperature, pH, conductivity, salinity, solar radiation, water temperature, alkalinity, hardness, chloride, productivity etc. were analysed using standard procedure. Abundance data is calculated for four major groups of zooplanktons (Cladocera, Copepoda, Ostracoda, and Rotifera with the software PAST 2.1. Multivariate statistical analysis like PCA, hierarchical cluster and CCA are performed in order to predict the temporal variation in the water quality factors using SPSS 20. Distinct seasonal variation was found for environmental factors and zooplankton groups. Bakreswar reservoir has good assemblage of zooplankton and distinct temporal variation of environmental factors and its association with zooplankton predicts water quality condition. These results could help in formulating proper strategies for advanced water quality management and conservation of reservoir ecosystem. Key elements for growth and sustenance of the system can then be evaluated and this knowledge can be further applied for management purposes.

  10. A Comparative Study between a Pseudo-Forward Equation (PFE and Intelligence Methods for the Characterization of the North Sea Reservoir

    Directory of Open Access Journals (Sweden)

    Saeed Mojeddifar

    2014-12-01

    Full Text Available This paper presents a comparative study between three versions of adaptive neuro-fuzzy inference system (ANFIS algorithms and a pseudo-forward equation (PFE to characterize the North Sea reservoir (F3 block based on seismic data. According to the statistical studies, four attributes (energy, envelope, spectral decomposition and similarity are known to be useful as fundamental attributes in porosity estimation. Different ANFIS models were constructed using three clustering methods of grid partitioning (GP, subtractive clustering method (SCM and fuzzy c-means clustering (FCM. An experimental equation, called PFE and based on similarity attributes, was also proposed to estimate porosity values of the reservoir. When the validation set derived from training wells was used, the R-square coefficient between two variables (actual and predicted values was obtained as 0.7935 and 0.7404 for the ANFIS algorithm and the PFE model, respectively. But when the testing set derived from testing wells was used, the same coefficients decreased to 0.252 and 0.5133 for the ANFIS algorithm and the PFE model, respectively. According to these results, and the geological characteristics observed in the F3 block, it seems that the ANFIS algorithms cannot estimate the porosity acceptably. By contrast, in the outputs of PFE, the ability to detect geological structures such as faults (gas chimney, folds (salt dome, and bright spots, alongside the porosity estimation of sandstone reservoirs, could help in determining the drilling target locations. Finally, this work proposes that the developed PFE could be a good technique for characterizing the reservoir of the F3 block.

  11. Consolidated View on Space Software Engineering Problems - An Empirical Study

    Science.gov (United States)

    Silva, N.; Vieira, M.; Ricci, D.; Cotroneo, D.

    2015-09-01

    Independent software verification and validation (ISVV) has been a key process for engineering quality assessment for decades, and is considered in several international standards. The “European Space Agency (ESA) ISVV Guide” is used for the European Space market to drive the ISVV tasks and plans, and to select applicable tasks and techniques. Software artefacts have room for improvement due to the amount if issues found during ISVV tasks. This article presents the analysis of the results of a large set of ISVV issues originated from three different ESA missions-amounting to more than 1000 issues. The study presents the main types, triggers and impacts related to the ISVV issues found and sets the path for a global software engineering improvement based on the most common deficiencies identified for space projects.

  12. Promoting Active Learning in Electrical Engineering Basic Studies

    Directory of Open Access Journals (Sweden)

    Anu Lehtovuori

    2013-05-01

    Full Text Available Active learning, project-based teaching, and student collaboration are current trends in engineering education. Incorporating these have also been the goal of the basic studies development project EPOP started at the Aalto University School of Electrical Engineering in 2011. In the project, two obligatory basic courses in circuit analysis and electromagnetic field theory have been taught using interactive engagement during the spring of 2012. This paper presents the implementation of the teaching, including methods and evaluation with several concrete examples. As a result of the novel teaching, motivation and the engagement of students were at a high level during the whole course and learning results were better than those of the students participating the traditional lecture course.

  13. Energy Efficient Engine program advanced turbofan nacelle definition study

    Science.gov (United States)

    Howe, David C.; Wynosky, T. A.

    1985-01-01

    Advanced, low drag, nacelle configurations were defined for some of the more promising propulsion systems identified in the earlier Benefit/Cost Study, to assess the benefits associated with these advanced technology nacelles and formulate programs for developing these nacelles and low volume thrust reversers/spoilers to a state of technology readiness in the early 1990's. The study results established the design feasibility of advanced technology, slim line nacelles applicable to advanced technology, high bypass ratio turbofan engines. Design feasibility was also established for two low volume thrust reverse/spoiler concepts that meet or exceed the required effectiveness for these engines. These nacelle and thrust reverse/spoiler designs were shown to be applicable in engines with takeoff thrust sizes ranging from 24,000 to 60,000 pounds. The reduced weight, drag, and cost of the advanced technology nacelle installations relative to current technology nacelles offer a mission fuel burn savings ranging from 3.0 to 4.5 percent and direct operating cost plus interest improvements from 1.6 to 2.2 percent.

  14. Introducing Knowledge Management in Study Program of Nuclear Engineering

    International Nuclear Information System (INIS)

    Pleslic, S.

    2012-01-01

    Nuclear engineering is the branch of engineering concerning application of the fission as well as the fusion of atomic nuclei, and the application of other sub-atomic physics, based on the principles of nuclear physics. In the sub-field of nuclear fission there are many investigations of interactions and maintaining of systems and components like nuclear reactors and nuclear power plants. The field also includes the study of different applications of ionizing radiation (medicine, agriculture...), nuclear safety, the problems of thermodynamics transport, nuclear materials and nuclear fuels, and other related technologies like radioactive waste management. In the area of nuclear science and engineering a big amount of knowledge has been accumulated over the last decades. Different levels of nuclear knowledge were considered in different ways and they were taught to different parts of population as a general human culture and as a general scientific-technical-technological culture (high schools, nuclear information centres, training centres, universities...). An advanced level of nuclear knowledge has been accumulated by many experienced workers, specialists and experts in all nuclear and nuclear-related fields and applications. In the last 20 years knowledge management has established itself as a discipline of enabling individuals, teams and whole organizations to create, share and apply knowledge collectively and systematically, with goal to better achieve their objectives. Also, knowledge management became key strategic approach for management of intellectual assets and knowledge that can improve safety, efficiency and innovation, and lead to preserve and enhance current knowledge. Knowledge management could be applied in education, training, networking, human resource development and capacity building, sharing, pooling and transferring knowledge form centres of knowledge to centres of growth. Considering the critical importance of nuclear knowledge it is important

  15. Tres Marias Reservoir, Minas Gerais State: Study of the dispersion of suspended sediments in surface waters using orbital images

    Science.gov (United States)

    Dejesusparada, N. (Principal Investigator); Sausen, T. M.

    1980-01-01

    Computer compatible tapes from LANDSAT were used to compartmentalize the Ires Marias reservoir according to respective grey level spectral response. Interactive and automatic, supervised classification, was executed from the IMAGE-100 system. From the simple correlation analysis and graphic representation, it is shown that grey tone levels are inversely proportional to Secchi Depth values. It is further shown that the most favorable period to conduct an analysis of this type is during the rainy season.

  16. Ichthyofauna of the reservoirs of Central Vietnam

    Directory of Open Access Journals (Sweden)

    I. A. Stolbunov

    2012-01-01

    Full Text Available Species composition, distribution and abundance of fish in the pelagic and littoral zone of four reservoirs of Central Vietnam (Suoi Chau, Kam Lam, Da Ban and Suoi Dau were studied first. According to the research data the fish community of the reservoirs is represented by 43 species of 19 fish families.

  17. Design studies of lift fan engines suitable for use in civilian VTOL aircraft.

    Science.gov (United States)

    Roelke, R. J.; Zigan, S.

    1972-01-01

    Preliminary engine design studies have been made of two general types of low-pressure-ratio lift fan engines that are receiving increasing attention as a means to provide low-speed lift for large civilian VTOL transports. The two engine types are integral fans and remote powered fans. A portion of the results of these design studies is summarized, including the crucial engine requirements, and some of the characteristics of the emerging engine designs of each type.

  18. Women withdrawers in engineering studies : identity formation and learning culture as gendered barriers for persistence?

    OpenAIRE

    Wolffram, Andrea; Derboven, Wibke; Winker, Gabriele

    2009-01-01

    Scholarship on women in engineering education mainly focuses on the question of how to attract more women to this subject. The topic concerning women in engineering education is here guided by the question of why women leave engineering studies. The paper aims to examine the main conflicts women encounter in engineering education and to derive implications for interventions suited for strengthening institutional bonding forces.

  19. South Asia as a Reservoir for the Global Spread of Ciprofloxacin-Resistant Shigella sonnei: A Cross-Sectional Study

    Science.gov (United States)

    Pham Thanh, Duy; De Lappe, Niall; Cormican, Martin; Howden, Benjamin P.; Wangchuk, Sonam; Bodhidatta, Ladaporn; Nguyen Thi Nguyen, To; Thompson, Corinne N.; Phu Huong Lan, Nguyen; Voong Vinh, Phat; Ha Thanh, Tuyen; Turner, Paul; Sar, Poda; Thwaites, Guy; Thomson, Nicholas R.; Holt, Kathryn E.; Baker, Stephen

    2016-01-01

    Background Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR) lineage of Shigella sonnei (lineage III) is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei. Methods and Findings We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1) and two outside of Asia (Australia, n = 19; Ireland, n = 16). We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei. Conclusions This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing

  20. South Asia as a Reservoir for the Global Spread of Ciprofloxacin-Resistant Shigella sonnei: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Hao Chung The

    2016-08-01

    Full Text Available Antimicrobial resistance is a major issue in the Shigellae, particularly as a specific multidrug-resistant (MDR lineage of Shigella sonnei (lineage III is becoming globally dominant. Ciprofloxacin is a recommended treatment for Shigella infections. However, ciprofloxacin-resistant S. sonnei are being increasingly isolated in Asia and sporadically reported on other continents. We hypothesized that Asia is a primary hub for the recent international spread of ciprofloxacin-resistant S. sonnei.We performed whole-genome sequencing on a collection of 60 contemporaneous ciprofloxacin-resistant S. sonnei isolated in four countries within Asia (Vietnam, n = 11; Bhutan, n = 12; Thailand, n = 1; Cambodia, n = 1 and two outside of Asia (Australia, n = 19; Ireland, n = 16. We reconstructed the recent evolutionary history of these organisms and combined these data with their geographical location of isolation. Placing these sequences into a global phylogeny, we found that all ciprofloxacin-resistant S. sonnei formed a single clade within a Central Asian expansion of lineage III. Furthermore, our data show that resistance to ciprofloxacin within S. sonnei may be globally attributed to a single clonal emergence event, encompassing sequential gyrA-S83L, parC-S80I, and gyrA-D87G mutations. Geographical data predict that South Asia is the likely primary source of these organisms, which are being regularly exported across Asia and intercontinentally into Australia, the United States and Europe. Our analysis was limited by the number of S. sonnei sequences available from diverse geographical areas and time periods, and we cannot discount the potential existence of other unsampled reservoir populations of antimicrobial-resistant S. sonnei.This study suggests that a single clone, which is widespread in South Asia, is likely driving the current intercontinental surge of ciprofloxacin-resistant S. sonnei and is capable of establishing endemic transmission in new

  1. Studies on the Optimal behavior of Energy Storage in Reservoirs of a Hydroelectric system; Estudios sobre el comportamiento optimo del almacenamiento de energia en embalses de sistema hidroelectrico

    Energy Technology Data Exchange (ETDEWEB)

    Macedo Faria, Breno; Franco Barbosa, Paulo Sergio [Universidad Estatal de Campinas (Brazil)

    2002-09-01

    This work aims at studying the results of an optimisation model applied to the Paranaiba river basin, Brazil. This system is made by the junction of three river branches located in a region with a well-defined seasonal hydrological behavior. The ratio between the total energy storage in the system and the active storage for every reservoir is evaluated from the optimal operational results. This relationship allows recognizing systematic patterns on the relative use for every reservoir, when compared to the entire system. The main parameters that define reservoir behavior are identified, with highlights on the position of the power station in the cascade, the relationship between the river flow and the active storage, and the installed capacity of the power station. In addition, the parameter hydrological scenario is also another factor that defines the relative use of the reservoirs. [Spanish] El modelo del presente trabajo tiene como objetivo estudiar los resultados de una optimizacion para el sistema hidroelectrico de la cuenca del rio Paranaiba, Brasil, la cual esta formada por la confluencia de tres rios en una region de distribucion de lluvias bien definidas en terminos hidrologicos. Se analiza la relacion entre la energia total almacenada en el sistema y el volumen util de cada embalse a partir de los resultados operativos optimos. Esta relacion permite identificar resultados sistematicos en lo que se refiere a la utilizacion de cada embalse, en comparacion con el uso del sistema como un todo. Se identifican los principales parametros responsables por el comportamiento de los embalses, destacando la influencia de la posicion de la central hidroelectrica en la cascada, de la relacion caudal/volumen util y de la potencia de central. Ademas, el parametro escenario hidrologico tambien es otro factor determinante en el uso relativo de los embalses.

  2. Mechanism study on a plague outbreak driven by the construction of a large reservoir in southwest china (surveillance from 2000-2015.

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2017-03-01

    Full Text Available Plague, a Yersinia pestis infection, is a fatal disease with tremendous transmission capacity. However, the mechanism of how the pathogen stays in a reservoir, circulates and then re-emerges is an enigma.We studied a plague outbreak caused by the construction of a large reservoir in southwest China followed 16-years' surveillance.The results show the prevalence of plague within the natural plague focus is closely related to the stability of local ecology. Before and during the decade of construction the reservoir on the Nanpan River, no confirmed plague has ever emerged. With the impoundment of reservoir and destruction of drowned farmland and vegetation, the infected rodent population previously dispersed was concentrated together in a flood-free area and turned a rest focus alive. Human plague broke out after the enzootic plague via the flea bite. With the construction completed and ecology gradually of human residential environment, animal population and type of vegetation settling down to a new balance, the natural plague foci returned to a rest period. With the rodent density decreased as some of them died, the flea density increased as the rodents lived near or in local farm houses where had more domestic animals, and human has a more concentrated population. In contrast, in the Himalayan marmot foci of the Qinghai-Tibet Plateau in the Qilian Mountains. There are few human inhabitants and the local ecology is relatively stable; plague is prevalence, showing no rest period. Thus the plague can be significantly affected by ecological shifts.

  3. Two-phase flow visualization under reservoir conditions for highly heterogeneous conglomerate rock: A core-scale study for geologic carbon storage.

    Science.gov (United States)

    Kim, Kue-Young; Oh, Junho; Han, Weon Shik; Park, Kwon Gyu; Shinn, Young Jae; Park, Eungyu

    2018-03-20

    Geologic storage of carbon dioxide (CO 2 ) is considered a viable strategy for significantly reducing anthropogenic CO 2 emissions into the atmosphere; however, understanding the flow mechanisms in various geological formations is essential for safe storage using this technique. This study presents, for the first time, a two-phase (CO 2 and brine) flow visualization under reservoir conditions (10 MPa, 50 °C) for a highly heterogeneous conglomerate core obtained from a real CO 2 storage site. Rock heterogeneity and the porosity variation characteristics were evaluated using X-ray computed tomography (CT). Multiphase flow tests with an in-situ imaging technology revealed three distinct CO 2 saturation distributions (from homogeneous to non-uniform) dependent on compositional complexity. Dense discontinuity networks within clasts provided well-connected pathways for CO 2 flow, potentially helping to reduce overpressure. Two flow tests, one under capillary-dominated conditions and the other in a transition regime between the capillary and viscous limits, indicated that greater injection rates (potential causes of reservoir overpressure) could be significantly reduced without substantially altering the total stored CO 2 mass. Finally, the capillary storage capacity of the reservoir was calculated. Capacity ranged between 0.5 and 4.5%, depending on the initial CO 2 saturation.

  4. Evaluation of Three Evaporation Estimation Techniques In A Semi-Arid Region (Omar El Mukhtar Reservoir Sluge, Libya- As a case Study

    Directory of Open Access Journals (Sweden)

    Lubna s. Ben Taher

    2017-02-01

    Full Text Available In many semi-arid countries in the world like Libya, drinking water supply is dependent on reservoirs water storage. Since the evaporation rate is very high in semi-arid countries, estimates and forecasts of reservoir evaporation rate can be useful in the management of major water source. Many researchers have been investigating the suitability of estimates evaporation rates methods in many climatic settings, infrequently of which were in an arid setting. This paper presents the modeling results of evaporation from Omar El Mukhtar Reservoir, Libya. Three techniques namely (artificial neural networks (ANN, Multiple linear regression (MLR and response surface methods (RSM were developed, to assess the estimation of monthly evaporation records from 2001 to 2009; their relative performance were compared using the coefficient of determination(E, mean absolute percentage error (MAPE%, and 95% confidence interval. The key variables used to develop and validate the models were: monthly (precipitation Rf., average temperature Temp., relative humidity Rh., sunshine hours Sh., atmospheric pressure Pa. and wind speed Ws.. The encouraging results approved that the models with more inputs generally had better accuracies and the ANN model performed superior to the other models in predicting monthly Evp with high E=0.86 and low MAPE%= 13.9 and the predicted mean within the range of observed 95CI%. In summary, it is revealed in this study that the ANN and RSM models are appropriate for predicting Evp using climatic inputs in semi-arid climate.

  5. Volume 4: Characterization of representative reservoirs -- Gulf of Mexico field, U-8 reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Koperna, G.J. Jr.; Johnson, H.R. [BDM Federal, Inc., McLean, VA (United States); Salamy, S.P.; Reeves, T.K. [BDM-Oklahoma, Inc., Bartlesville, OK (United States); Sawyer, W.K. [Mathematical and Computer Services, Inc., Danville, VA (United States); Kimbrell, W.C.; Schenewerk, P.A. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Petroleum Engineering

    1998-07-01

    A reservoir study was performed using a publicly available black oil simulator to history match and predict the performance of a Gulf of Mexico reservoir. The first objective of this simulation study was to validate the Black Oil Applied Simulation Tool version three for personal computers (BOAST3-PC) model to ensure the integrity of the simulation runs. Once validation was completed, a field history match for the Gulf of Mexico U-8 oil reservoir was attempted. A verbal agreement was reached with the operator of this reservoir to blindcode the name and location of the reservoir. In return, the operator supplied data and assistance in regards to the technical aspects of the research. On the basis of the best history match, different secondary recovery techniques were simulated as a predictive study for enhancing the reservoir productivity.

  6. Real cases study through computer applications for futures Agricultural Engineers

    Science.gov (United States)

    Moratiel, R.; Durán, J. M.; Tarquis, A. M.

    2010-05-01

    One of the huge concerns on the higher engineer education is the lag of real cases study that the future professionals need in the work and corporation market. This concern was reflected in Bologna higher education system including recommendations in this respect. The knowhow as why this or other methodology is one of the keys to resolve this problem. In the last courses given in Department of Crop Production, at the Agronomy Engineer School of Madrid (Escuela Técnica Superior de Ingenieros Agrónomos, UPM) we have developed more than one hundred applications in Microsoft Excel®. Our aim was to show different real scenarios which the future Agronomic Engineers can be found in their professional life and with items related to crop production field. In order to achieve our target, each application in Excel presents a file text in which is explained the theoretical concepts and the objectives, as well as some resources used from Excel syntax. In this way, the student can understand and use of such application, even they can modify and customize it for a real case presented in their context and/or master project. This electronic monograph gives an answer to the need to manage data in several real scenarios showed in lectures, calculus resolution, information analysis and manage worksheets in a professional and student level.

  7. Pacifiers: a microbial reservoir.

    Science.gov (United States)

    Comina, Elodie; Marion, Karine; Renaud, François N R; Dore, Jeanne; Bergeron, Emmanuelle; Freney, Jean

    2006-12-01

    The permanent contact between the nipple part of pacifiers and the oral microflora offers ideal conditions for the development of biofilms. This study assessed the microbial contamination on the surface of 25 used pacifier nipples provided by day-care centers. Nine were made of silicone and 16 were made of latex. The biofilm was quantified using direct staining and microscopic observations followed by scraping and microorganism counting. The presence of a biofilm was confirmed on 80% of the pacifier nipples studied. This biofilm was mature for 36% of them. Latex pacifier nipples were more contaminated than silicone ones. The two main genera isolated were Staphylococcus and Candida. Our results confirm that nipples can be seen as potential reservoirs of infections. However, pacifiers do have some advantages; in particular, the potential protection they afford against sudden infant death syndrome. Strict rules of hygiene and an efficient antibiofilm cleaning protocol should be established to answer the worries of parents concerning the safety of pacifiers.

  8. Thin-bed reservoir characterization using integrated three-dimensional seismic and well log data: A case study of the central Boonsville Field, Fort Worth basin, north-central Texas

    Science.gov (United States)

    Xie, Deyi

    This dissertation is designed to resolve two problems using seismic attributes to: (1) delineate thin-bed reservoirs, and (2) distinguish thin-bed sandstone reservoirs from thin-bed non-reservoir carbonates where they appear similar at seismic scale. I evaluated some widely used techniques, developed new approaches for better imaging of thin-bed reservoirs, and found optimal attributes for thin-bed reservoir characterization. These techniques were then tested on the Pennsylvanian Caddo sequence of the Boonsville Field, Texas using public domain data. The main results found through this study are: (1) A new pattern recognition model has been developed to recognize the subtle geological and geophysical features of a thin-bed sequence based on cross-correlation of seismic traces with one or more traces believed to represent specific depositional environments. This algorithm has been proven, via the case study, to be robust and promising in defining seismic facies for subtle geological features and predicting thin-bed reservoirs. (2) Examination of the conventional thin-bed tuning model reveals that it works well only if one single thin-bed is developed or multiple thin beds are widely spaced in the sequence of interest. In other words, the model does not work for multiple closely-spaced thin-beds because of significant destructive interference. (3) A statistical inversion method was developed using the generalized regression neural network (GRNN). For a comparison study, two commercial packages were applied to the Boonsville Field data set. This study shows that all three models were able to identify the thicker reservoir sandstones and non-reservoir limestones. However, the resulting details for the thin beds vary. The GRNN method predicted the thin beds at 13 out of 20 wells with less noise and can be very useful in detecting thin-bed reservoirs in existing fields where a number of wells are available.

  9. Predicting interwell heterogeneity in fluvial-deltaic reservoirs: Outcrop observations and applications of progressive facies variation through a depositional cycle

    Energy Technology Data Exchange (ETDEWEB)

    Knox, P.R.; Barton, M.D. [Univ. of Texas, Austin, TX (United States)

    1997-08-01

    Nearly 11 billion barrels of mobile oil remain in known domestic fluvial-deltaic reservoirs despite their mature status. A large percentage of this strategic resource is in danger of permanent loss through premature abandonment. Detailed reservoir characterization studies that integrate advanced technologies in geology, geophysics, and engineering are needed to identify remaining resources that can be targeted by near-term recovery methods, resulting in increased production and the postponement of abandonment. The first and most critical step of advanced characterization studies is the identification of reservoir architecture. However, existing subsurface information, primarily well logs, provides insufficient lateral resolution to identify low-permeability boundaries that exist between wells and compartmentalize the reservoir. Methods to predict lateral variability in fluvial-deltaic reservoirs have been developed on the basis of outcrop studies and incorporate identification of depositional setting and position within a depositional cycle. The position of a reservoir within the framework of a depositional cycle is critical. Outcrop studies of the Cretaceous Ferron Sandstone of Utah have demonstrated that the architecture and internal heterogeneity of sandstones deposited within a given depositional setting (for example, delta front) vary greatly depending upon whether they were deposited in the early, progradational part of a cycle or the late, retrogradational part of a cycle. The application of techniques similar to those used by this study in other fluvial-deltaic reservoirs will help to estimate the amount and style of remaining potential in mature reservoirs through a quicklook evaluation, allowing operators to focus characterization efforts on reservoirs that have the greatest potential to yield additional resources.

  10. Integrated petrophysical and sedimentological study of the Middle Miocene Nullipore Formation (Ras Fanar Field, Gulf of Suez, Egypt): An approach to volumetric analysis of reservoirs

    Science.gov (United States)

    Afife, Mohamed M.; Sallam, Emad S.; Faris, Mohamed

    2017-10-01

    This study aims to integrate sedimentological, log and core analyses data of the Middle Miocene Nullipore Formation at the Ras Fanar Field (west central Gulf of Suez, Egypt) to evaluate and reconstruct a robust petrophysical model for this reservoir. The Nullipore Formation attains a thickness ranging from 400 to 980 ft and represents a syn-rift succession of the Middle Miocene marine facies. It consists of coralline-algal-reefal limestone, dolomitic limestone and dolostone facies, with few clay and anhydrite intercalations. Petrographically, seven microfacies types (MF1 to MF7) have been recognized and assembled genetically into three related facies associations (FA1 to FA3). These associations accumulated in three depositional environments: 1) peritidal flat, 2) restricted lagoon, and 3) back-shoal environments situated on a shallow inner ramp (homoclinal) setting. The studied rocks have been influenced by different diagenetic processes (dolomitization, cementation, compaction, authigenesis and dissolution), which led to diminishing and/or enhancing the reservoir quality. Three superimposed 3rd-order depositional sequences are included in the Nullipore succession displaying both retrogradational and aggradational packages of facies. Given the hydrocarbon potential of the Nullipore Formation, conventional well logs of six boreholes and core analyses data from one of these wells (RF-B12) are used to identify electrofacies zones of the Nullipore Formation. The Nullipore Formation has been subdivided into three electrofacies zones (the Nullipore-I, Nullipore-II, and Nullipore-III) that are well-correlated with the three depositional sequences. Results of petrographical studies and log analyses data have been employed in volumetric calculations to estimate the amount of hydrocarbon-in-place and then the ultimate recovery of the Nullipore reservoir. The volumetric calculations indicate that the total volume of oil-in-place is 371 MMSTB at 50% probability (P50), whereas

  11. Transport of reservoir fines

    DEFF Research Database (Denmark)

    Yuan, Hao; Shapiro, Alexander; Stenby, Erling Halfdan

    Modeling transport of reservoir fines is of great importance for evaluating the damage of production wells and infectivity decline. The conventional methodology accounts for neither the formation heterogeneity around the wells nor the reservoir fines’ heterogeneity. We have developed an integral...

  12. SILTATION IN RESERVOIRS

    African Journals Online (AJOL)

    Calls have been made to the government through various media to assist its populace in combating this nagging problem. It was concluded that sediment maximum accumulation is experienced in reservoir during the periods of maximum flow. Keywords: reservoir model, siltation, sediment, catchment, sediment transport. 1.

  13. Dynamic reservoir well interaction

    NARCIS (Netherlands)

    Sturm, W.L.; Belfroid, S.P.C.; Wolfswinkel, O. van; Peters, M.C.A.M.; Verhelst, F.J.P.C.M.

    2004-01-01

    In order to develop smart well control systems for unstable oil wells, realistic modeling of the dynamics of the well is essential. Most dynamic well models use a semi-steady state inflow model to describe the inflow of oil and gas from the reservoir. On the other hand, reservoir models use steady

  14. The freshwater reservoir effect in radiocarbon dating

    DEFF Research Database (Denmark)

    Philippsen, Bente

    2013-01-01

    effect on radiocarbon dating in an estuarine environment is examined. Here, freshwater influence causes reservoir ages to vary between 250 and 700 14C years during the period 5400 BC - AD 700. The examples in this study show clearly that the freshwater reservoir effect can seriously corrupt radiocarbon......The freshwater reservoir effect can result in anomalously old radiocarbon ages of samples from lakes and rivers. This includes the bones of people whose subsistence was based on freshwater fish, and pottery in which fish was cooked. Water rich in dissolved ancient calcium carbonates, commonly known...... as hard water, is the most common reason for the freshwater reservoir effect. It is therefore also called hardwater effect. Although it has been known for more than 60 years, it is still less well-recognized by archaeologists than the marine reservoir effect. The aim of this study is to examine the order...

  15. Reduction of the HIV-1 reservoir in resting CD4+ T-lymphocytes by high dosage intravenous immunoglobulin treatment: a proof-of-concept study

    Directory of Open Access Journals (Sweden)

    Karlsson Annika C

    2009-07-01

    Full Text Available Abstract Background The latency of HIV-1 in resting CD4+ T-lymphocytes constitutes a major obstacle for the eradication of virus in patients on antiretroviral therapy (ART. As yet, no approach to reduce this viral reservoir has proven effective. Methods Nine subjects on effective ART were included in the study and treated with high dosage intravenous immunoglobulin (IVIG for five consecutive days. Seven of those had detectable levels of replication-competent virus in the latent reservoir and were thus possible to evaluate. Highly purified resting memory CD4+ T-cells were activated and cells containing replication-competent HIV-1 were quantified. HIV-1 from plasma and activated memory CD4+ T-cells were compared with single genome sequencing (SGS of the gag region. T-lymphocyte activation markers and serum interleukins were measured. Results The latent HIV-1 pool decreased with in median 68% after IVIG was added to effective ART. The reservoir decreased in five, whereas no decrease was found in two subjects with detectable virus. Plasma HIV-1 RNA ≥ 2 copies/mL was detected in five of seven subjects at baseline, but in only one at follow-up after 8–12 weeks. The decrease of the latent HIV-1 pool and the residual plasma viremia was preceded by a transitory low-level increase in plasma HIV-1 RNA and serum interleukin 7 (IL-7 levels, and followed by an expansion of T regulatory cells. The magnitude of the viral increase in plasma correlated to the size of the latent HIV-1 pool and SGS of the gag region showed that viral clones from plasma clustered together with virus from activated memory T-cells, pointing to the latent reservoir as the source of HIV-1 RNA in plasma. Conclusion The findings from this uncontrolled proof-of-concept study suggest that the reservoir became accessible by IVIG treatment through activation of HIV-1 gene expression in latently-infected resting CD4+ T-cells. We propose that IVIG should be further evaluated as an adjuvant

  16. Student employment and study effort for engineering students

    DEFF Research Database (Denmark)

    Clemmensen, Line Katrine Harder; Harder, D. E.

    2015-01-01

    to answer if the full-time student is under demise in these settings as opposed to settings without financial support [1, 2]. The research consisted of a web-based survey amongst all students at the Technical University of Denmark (DTU). The students in this survey had fewer employment hours and studied......The aim of this paper is to examine which factors effect student employment and study effort in a setting where engineering students are financially supported, such that their education is free of cost and that they receive financial support for living costs while studying. In addition, we wish...... more than those in studies from e.g. UK and US [3, 4, 5]. A similar trend was seen in a study from Norway [6]. Government financial support seems to limit the amount of hours spent on paid work but not the percentage of students who take on paid work. Thus, full-time studies with benefits of increased...

  17. FRACTURED PETROLEUM RESERVOIRS

    Energy Technology Data Exchange (ETDEWEB)

    Abbas Firoozabadi

    1999-06-11

    The four chapters that are described in this report cover a variety of subjects that not only give insight into the understanding of multiphase flow in fractured porous media, but they provide also major contribution towards the understanding of flow processes with in-situ phase formation. In the following, a summary of all the chapters will be provided. Chapter I addresses issues related to water injection in water-wet fractured porous media. There are two parts in this chapter. Part I covers extensive set of measurements for water injection in water-wet fractured porous media. Both single matrix block and multiple matrix blocks tests are covered. There are two major findings from these experiments: (1) co-current imbibition can be more efficient than counter-current imbibition due to lower residual oil saturation and higher oil mobility, and (2) tight fractured porous media can be more efficient than a permeable porous media when subjected to water injection. These findings are directly related to the type of tests one can perform in the laboratory and to decide on the fate of water injection in fractured reservoirs. Part II of Chapter I presents modeling of water injection in water-wet fractured media by modifying the Buckley-Leverett Theory. A major element of the new model is the multiplication of the transfer flux by the fractured saturation with a power of 1/2. This simple model can account for both co-current and counter-current imbibition and computationally it is very efficient. It can be orders of magnitude faster than a conventional dual-porosity model. Part II also presents the results of water injection tests in very tight rocks of some 0.01 md permeability. Oil recovery from water imbibition tests from such at tight rock can be as high as 25 percent. Chapter II discusses solution gas-drive for cold production from heavy-oil reservoirs. The impetus for this work is the study of new gas phase formation from in-situ process which can be significantly