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Sample records for well pressure

  1. Comparison of theoretical and observed pressure profiles in geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Marquez M, R.

    1981-01-01

    Two-phase water-steam flow conditions in geothermal wells are studied aimed at predicting pressure drops in these wells. Five prediction methods were selected to be analyzed and compared with each other and with actual pressure measurements. These five correlations were tested on five wells: three in New Zealand, one in Mexico, and one in the Philippines.

  2. 75 FR 23582 - Annular Casing Pressure Management for Offshore Wells

    Science.gov (United States)

    2010-05-04

    ... casing pressure. This rule will promote human safety and environmental protection, and require Outer... Minerals Management Service 30 CFR Part 250 RIN 1010-AD47 Annular Casing Pressure Management for Offshore... will establish regulations to address sustained casing pressure in oil and gas wells completed in the...

  3. Study of pressure in water wells using analytical methods

    Energy Technology Data Exchange (ETDEWEB)

    Lakatos, S.

    1979-01-01

    According to the data of studying wells, an examination is made of the possibility of determining the deep pressure. As applied to wells with gas influx, a method of correction is proposed which is based on laws regarding gas or laws of its solubility.

  4. Determination of permeability distribution from well-test pressure data

    Energy Technology Data Exchange (ETDEWEB)

    Feitosa, G.S.; Chu, L.; Thompson, L.G.; Reynolds, A.C. (Univ. of Tulsa, OK (United States))

    1994-07-01

    The emergence of reservoir characterization has stimulated efforts to obtain improved information on reservoir heterogeneities. This work considers single-phase flow to a well in a reservoir where permeability varies with distance from the well. The authors consider methods for estimating the permeability distribution from well-test pressure data. The methods considered were obtained by modifying and extending elegant seminal works of Oliver and Yeh and Agarwal. This work considers the analysis of pressure data, both drawdown and buildup, obtained at a well producing reservoir in which the absolute permeability varies with position. A new inverse-solution algorithm is presented that can be applied to estimate the reservoir permeability distribution as a function of distance from the well.

  5. Analysis of pressure data of vertically fractured injection wells

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C.O.; Reynolds, A.C. Jr.; Raghaven, R.

    1979-06-01

    This study investigates the flowing and shut-in pressure behavior of a fractured well located in a square drainage region with the outer boundary at a constant pressure. The fracture plane lies on one of the diagonals of the square. The results can be used to analyze pressure data for a five-spot pattern when the fracture orientation is most favorable (from the viewpoint of sweep efficiency). Comparisons with the results in the literature (which assume that the fracture orientation is unfavorable) are given. It is shown that the fracture orientation must be considered in the analysis of pressure data for the following conditions: (i) small values of fracture penetration ratio, (ii) large flowing times prior to shut-in, and (iii) large values of fracture flow capacity. New insights into the application of type curve analysis to estimate drainage volumes are presented. The drainage volume can be obtained from a pressure fall-off test only if the flowing times prior to shut-in are large. The estimate of the drainage volume obtained by type curve matching pressure build-up data can be erroneous even if producing times are long. Claims in the literature regarding the determination of the drainage volume by type curve matching appear to be based on unrealistic expectations. The flowing pressures were obtained by a Crank-Nicolson Galerkin procedure. Analytical expressions to evaluate the integrals of the basis functions used in this study are given.

  6. Horizontal high-pressure air injection well construction and operation

    Energy Technology Data Exchange (ETDEWEB)

    Hume, J. [Continental Resources Inc., ND (United States)

    2005-07-01

    This paper discussed the design and operational challenges of a horizontal high-pressure air injection well currently in use at the Cedar Hill Red River B field in North Dakota. The field was developed in 1994, using horizontal wells oriented from the northeast to the southwest corners of each section on 640 acre spacing. In March of 2001, the field was unitized resulting in a horizontal waterflood project and a 320 acre horizontal high pressure air injection project. Extreme temperatures and pressures occurring in the reservoir from the combustion processes associated with high pressure air injection have resulted in several challenges. Reservoir and fluid properties of the field were presented, as well as a type log. Details of the Buffalo and Cedar Hills field were also provided, with a comparison of horizontal and vertical patterns. A light oil displacement process was reviewed, with details of tubing leak corrosion, packer seal and detonation failures. Burn front exposure to casing was discussed, and a wellbore diagram was provided. Various horizontal conversions were discussed. A description of the Cedar Hills Compressor Station and compression trains was provided. It was concluded that knowledge gained from 25 years of vertical high pressure air injection experience has been successfully incorporated to create a safe and durable design. 1 tab., 16 figs.

  7. Synergistic Assessment of Sustained Casing Pressure on Oil Well

    Directory of Open Access Journals (Sweden)

    Darren Wong Vun Nyap

    2013-05-01

    Full Text Available The current research is based on modeling approach, where the objective is to develop a series of computer codes with the reference of existing pressure bleed-off time mathematical models. The results generated from the model are based on the three parameters: temperature, type of gases filled in annulus and depth of well. These three parameters can affect pressure bleed-off time in well’s annulus, with the fixed size of needle valve. Using this model generated from Wolfram Mathematical 8.0, it is enable to notify engineer to receive an early sign of warning if the well is suspected to leakage. Meanwhile, based on the matching process of field data and modeled data, field engineers will be able to aware and determine whether the occurrence of annular pressure is due to thermal induced annular pressure buildup or it is because of leakage in well components. The SCP well will eventually loss in production, caused severe failure in well’s integrity.

  8. TRANSMISSION BEHAVIOR OF MUD-PRESSURE PULSE ALONG WELL BORE

    Institute of Scientific and Technical Information of China (English)

    LIU Xiu-shan; LI Bo; YUE Yu-quan

    2007-01-01

    In oil and gas industry, mud-pulse telemetry has been widely used to obtain directional data, drilling parameters, formation evaluation data and safety data, etc. Generally, the drilling mud in most current models was considered to be a single-phase fluid through which the mud pulses travel, despite the fact that the drilling mud is composed of two or more phases. In this article, a multiphase flow formula was proposed to calculate the mud-pulse velocity as mud solids and free-gas content change, and a mathematical model was put forward to simulate the dynamic-transmission behavior of the mud-pressure pulse or waves. Compared to conventional methods, the present model provides more accurate mud-pulse attenuation, and the dynamic-transmission behavior of drilling-mud pulses along well bores can also be easily examined. The model is valuable in improving the existing mud-pulse systems and developing new drilling-mud pulse systems.

  9. Reducing uncertainty in geostatistical description with well testing pressure data

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, A.C.; He, Nanqun [Univ. of Tulsa, OK (United States); Oliver, D.S. [Chevron Petroleum Technology Company, La Habra, CA (United States)

    1997-08-01

    Geostatistics has proven to be an effective tool for generating realizations of reservoir properties conditioned to static data, e.g., core and log data and geologic knowledge. Due to the lack of closely spaced data in the lateral directions, there will be significant variability in reservoir descriptions generated by geostatistical simulation, i.e., significant uncertainty in the reservoir descriptions. In past work, we have presented procedures based on inverse problem theory for generating reservoir descriptions (rock property fields) conditioned to pressure data and geostatistical information represented as prior means for log-permeability and porosity and variograms. Although we have shown that the incorporation of pressure data reduces the uncertainty below the level contained in the geostatistical model based only on static information (the prior model), our previous results assumed did not explicitly account for uncertainties in the prior means and the parameters defining the variogram model. In this work, we investigate how pressure data can help detect errors in the prior means. If errors in the prior means are large and are not taken into account, realizations conditioned to pressure data represent incorrect samples of the a posteriori probability density function for the rock property fields, whereas, if the uncertainty in the prior mean is incorporated properly into the model, one obtains realistic realizations of the rock property fields.

  10. An Analytic Solution to Well-water Level Changes under Barometric Pressure

    Institute of Scientific and Technical Information of China (English)

    Liu Chunping; Deng Liang; Liao Xin; Wan Fei; Shi Yun

    2011-01-01

    Under barometric pressure, groundwater flow in well-aquifer systems is a kind of hydromechanical coupling problem. Applying the flux boundary conditions on borehole wall and water pressure equilibrium conditions inside and outside the borehole wall under

  11. Prediction of pressure between packers of staged fracturing pipe strings in high-pressure deep wells and its application

    Directory of Open Access Journals (Sweden)

    Fuxiang Zhang

    2015-03-01

    Full Text Available Addressing to the deteriorated load conditions of working string and packers caused by annular pressure drop between packers during the staged stimulation of high-pressure deep well, one 2D temperature field transient prediction model for borehole under injecting conditions which considers such influences as friction heat, convection heat exchange was set up, based on energy conservation principle and borehole heat transfer theory. By means of analyzing the influences of borehole temperature and pressure changes on the annular volume between packers, and in combination with borehole temperature transient prediction model, annular fluid PVT equations of state, radial deformation model of tubing and formation transient seepage equation, a typical high-pressure deep well inter-packer annular pressure prediction model was established. Taking a high-pressure gas well in Tarim Oilfield for example, the inter-packer annular pressure prediction was conducted, on which, the mechanical analysis on packers and working strings was carried out. The analysis results show that although the pipe string is safe in the viewpoint of conventional design methods, it is still susceptible to failure after the annular pressure drop between packers was taken into consideration. Such factor should be fully considered in the design of staged stimulation pipe strings, and this prediction model provides new thoughts for the optimal design of high-pressure deep well staged stimulation pipe strings.

  12. 40 CFR 147.3006 - Injection pressure for existing Class II wells authorized by rule.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Injection pressure for existing Class II wells authorized by rule. 147.3006 Section 147.3006 Protection of Environment ENVIRONMENTAL... Injection pressure for existing Class II wells authorized by rule. (a) Rule-authorized Class II saltwater...

  13. Numerical model for surge and swab pressures on wells with cross-section variation

    Energy Technology Data Exchange (ETDEWEB)

    Fedevjcyk, Joao Victor; Junqueira, Silvio Luiz de Mello; Negrao, Cezar Otaviano Ribeiro [UTFPR - Federal University of Technology - Parana - Curitiba, PR (Brazil)], e-mails: silvio@utfpr.edu.br, negrao@utfpr.edu.br

    2010-07-01

    Drilling is one of the most complex steps in petroleum exploration. The process is accomplished by rotating a drill bit to compress the rock formation. During drilling, a fluid is pumped into the well to lubricate and cool down the drill bit, to clean up the well, to avoid the formation fluid influx to the well and also to stabilize the borehole walls. Fluid circulation, however, can be interrupted for maintenance reasons and the drill pipe can be moved to remove the drill bit. The downward or upward movement of the drill pipe displaces the fluid within the well causing either under pressure (swab) or over pressure (surge), respectively. If the pressure at the well bore overcomes the formation fracture pressure, a loss of circulation can take place. On the other way round, the upward movement may reduce the pressure below the pore pressure and an inflow of fluid to the well (kick) can occur. An uncontrolled kick may cause a blowout with serious damages. The transient flow induced by the axial movement of the drill pipe is responsible for the pressure changes at the well bore. Nevertheless, the well bore cross section variation may modify the pressure change within the pipe. In this paper, the effects of diameter variation of the drilling well on the surge and swab pressures are investigated. The equations that represent the phenomenon (mass and momentum conservation) are discretized by the finite volume method. Despite its non-Newtonian properties, the fluid is considered Newtonian in this first work. The drill pipe is considered closed and the flow is assumed as single-phased, one-dimensional, isothermal, laminar, compressible and transient. A sensitivity analysis of the flow parameters is carried out. The cross-section changes cause the reflection of the pressure wave, and consequently pressure oscillations. (author)

  14. Temporal and spatial pore water pressure distribution surrounding a vertical landfill leachate recirculation well.

    Science.gov (United States)

    Kadambala, Ravi; Townsend, Timothy G; Jain, Pradeep; Singh, Karamjit

    2011-05-01

    Addition of liquids into landfilled waste can result in an increase in pore water pressure, and this in turn may increase concerns with respect to geotechnical stability of the landfilled waste mass. While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported. Pressure readings from vibrating wire piezometers placed in the waste surrounding a liquids addition well at a full-scale operating landfill in Florida were recorded over a 2-year period. Prior to the addition of liquids, measured pore pressures were found to increase with landfill depth, an indication of gas pressure increase and decreasing waste permeability with depth. When liquid addition commenced, piezometers located closer to either the leachate injection well or the landfill surface responded more rapidly to leachate addition relative to those far from the well and those at deeper locations. After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time. Despite the large pressures present at the bottom of the liquid addition well, much smaller pressures were measured in the surrounding waste. The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.

  15. Analysis of pressure-buildup data from a well in a multiwell system

    Energy Technology Data Exchange (ETDEWEB)

    Onur, M. (Istanbul Technical Univ. (TR)); Serra, K.V. (Petrobras, S.A. (BR)); Reynolds, A.C. (Tulsa Univ., OK (United States))

    1991-03-01

    This paper investigates the buildup response of a well located in a system of producing wells completed in a closed, bounded reservoir. Using an analysis method based on the pressure derivative, the authors show that the drainage area of the well (at the instant of shut-in) and the flow-capacity (permeability-thickness) product can be computed directly from the derivative of pressure-buildup data even in cases when conventional semilog straight lines are not well defined. The analysis methods assume that the buildup-surveyed well has established its own drainage area before shut-in. For a system of wells located in a closed, bounded reservoir, this means that pseudo-steady-state flow prevails at the instant of shut-in. The authors also present a second method for estimating a well's drainage area from pressure-buildup data. The second method relies on the fact that during buildup, the well's shut-in pressure increases to a maximum and then decreases as a result of interference from neighboring producing wells. It is shown that the maximum shut-in pressure, and the time at which it occurs, often can also be used to compute the well's drainage area st the instant of shut-in and the average pressure in this drainage area.

  16. Dynamical analysis of high-pressure supercritical carbon dioxide jet in well drilling

    Institute of Scientific and Technical Information of China (English)

    DU Yu-kun; WANG Rui-he; NI Hong-jian; HUANG Zhi-yuan; LI Mu-kun

    2013-01-01

    This paper presents the design of an experimental setup and mathematical and physical models to determine the dynamical characteristics of the high-pressure supercritical carbon dioxide (SC-CO2) jet with a highly potential applications in the well drilling.The effects of three major factors on the wellbore dynamical characteristics of the high-pressure SC-CO2 jet,i.e.,the nozzle diameter,the standoff distance and the jet pressure are determined.It is indicated that the pressure of CO2 reduces severely in the SC-CO2 jet impact process.It is also found that the bottom-hole pressure and the temperature increase as the nozzle diameter increases but decrease with the increase of the standoff distance.The higher the jet pressure at the wellbore inlet is,the higher the pressure and the lower the temperature at the bottom-hole will be.

  17. Pressure Buildup Analysis for Two-Phase Geothermal Wells: Application to the Baca Geothermal Field

    Science.gov (United States)

    Riney, T. D.; Garg, S. K.

    1985-03-01

    The recently published pressure transient analysis methods for two-phase geothermal wells are employed to analyze the pressure buildup data for several wells located in the Redondo Creek area of the Baca geothermal field in New Mexico. The downhole drilling information and pressure/temperature surveys are first interpreted to locate zones at which fluid enters the well bore from the formation and to estimate the initial reservoir temperature and pressure in these zones. All of the Baca wells considered here induced flashing in the formation upon production. Interpretation of the buildup data for each well considers well bore effects (e.g., phase change in the well bore fluid and location of the pressure sensor with respect to the permeable horizon) and the carbon dioxide content of the fluid and its effects on the phase behavior of the reservoir fluids and differentiates between the single- and two-phase portions of the pressure buildup data. Different straight-line approximations to the two portions (i.e., single- and two-phase) of the data on the Homer plot are used to obtain corresponding estimates for the single- and two-phase mobilities. Estimates for the formation permeability-thickness (kH) product are also given.

  18. Well-conditioning effects on bubblepoint pressure of fluid samples from solution-gas-drive reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, A.C. (Univ. of Tulsa, Tulsa, OK (US)); Peres, A.M.M.; Serra, K.V. (Petrobas (BR)); Macias-Chapa, L. (National Autonomous Univ. of Mexico (MX))

    1990-12-01

    This paper considers the determination of the initial or average reservoir bubblepoint pressure from a fluid sample obtained from a well producing a solution-gas-drive reservoir. It is shown that standard API recommended well-conditioning procedures (rate reductions) for obtaining a single-phase (liquid) bottomhole fluid sample do not always redissolve all free gas. Thus, it is not always possible to obtain a single-phase liquid (oil) bottomhole fluid sample that has a bubblepoint pressure equal to the initial or average reservoir bubblepoint pressure. Moreover, monitoring the producing GOR and bottomhole pressure does not always reliably indicate whether two-phase (oil and gas) or single-phase (oil) flow is prevalent in the near-wellbore region. Contrary to current opinion, it is shown that recombination of surface samples of oil and gas form the producing GOR usually yields reliable estimates of average reservoir bubblepoint pressure.

  19. Pressure- and temperature-driven phase transitions in HgTe quantum wells

    Science.gov (United States)

    Krishtopenko, S. S.; Yahniuk, I.; But, D. B.; Gavrilenko, V. I.; Knap, W.; Teppe, F.

    2016-12-01

    We present theoretical investigations of pressure- and temperature-driven phase transitions in HgTe quantum wells grown on a CdTe buffer. Using the eight-band k .p Hamiltonian we calculate evolution of energy-band structure at different quantum well widths with hydrostatic pressure up to 20 kbars and temperature ranging up to 300 K. In particular, we show that, in addition to temperature, tuning of hydrostatic pressure allows us to drive transitions between semimetal, band insulator, and topological insulator phases. Our realistic band-structure calculations reveal that the band inversion under hydrostatic pressure and temperature may be accompanied by nonlocal overlapping between conduction and valence bands. The pressure and temperature phase diagrams are presented.

  20. Adaptive identification and interpretation of pressure transient tests of horizontal wells: challenges and perspectives

    Science.gov (United States)

    Sergeev, V. L.; Van Hoang, Dong

    2016-09-01

    The paper deals with a topical issue of defining oil reservoir properties during transient tests of horizontal wells equipped with information-measuring systems and reducing well downtime. The aim is to consider challenges and perspectives of developing models and algorithms for adaptive identification and interpretation of transient tests in horizontal wells with pressure buildup curve analysis. The models and algorithms should allow analyzing flow behavior, defining oil reservoir properties and determining well test completion time, as well as reducing well downtime. The present paper is based on the previous theoretical and practical findings in the spheres of transient well testing, systems analysis, system identification, function optimization and linear algebra. Field data and results of transient well tests with pressure buildup curve analysis have also been considered. The suggested models and algorithms for adaptive interpretation of transient tests conducted in horizontal wells with resulting pressure buildup curve make it possible to analyze flow behavior, as well as define the reservoir properties and determine well test completion time. The algorithms for adaptive interpretation are based on the integrated system of radial flow PBC models with time- dependent variables, account of additional a priori information and estimates of radial flow permeability. Optimization problems are solved with the case study of PBC interpretation for five horizontal wells of the Verkhnechonsk field.

  1. Factors affecting shut-in pressure rise: kicks in offshore HPHT wells

    Energy Technology Data Exchange (ETDEWEB)

    Schilhab, L.C. [Sedco Forex, (Country unknown/Code not available); Rezmer-Cooper, I.M. [Anadril, (Country unknown/Code not available)

    1997-05-01

    Deep water and HPHT operations are two areas where the use of sophisticated simulators can enable difficult processes and procedures to be broken down into individual identifiable contributions. In the paper we discuss some of the factors that are likely to affect shut-in pressure rise in offshore drilling operations, and how a simulator can be used to answer other, less obvious questions concerning deep water well control operations. We examine the effect of gas solubility by considering a gas-kick in a deep HPHT well drilled with oil-base mud. In this case, most of the influx will be dissolved in the mud, thus removing one of the processes for increasing the wellbore pressure. In terms of s safe state to disconnect from a well in rough weather, provided that the mud yield stress negates migration of the gas-cut mud, leaving the influx in solution at the bottom of the well should not lead to increasing wellbore pressures. Significant wellbore pressure effects may also occur after closing the blowout preventers (BOP`s) on a well without an influx (or with an influx in solution), and allowing the mud to heat up. We show that in typical HPHT geometries the pressure can rise by up to 8 bar/deg C. Similar magnitudes of pressure can also increase whilst circulating trapped gas out of a BOP at the end of a well control operation. We note that these effects may also be attenuated by fluid loss and wellbore compliance for wells with significant open hole sections. Indeed, gas trapped in the BOP should be safety removed by established well control procedures. However, preliminary studies with the simulator (and confirmed by field tests in the literature) have shown that an accidental release of a small amount of gas into a deep water riser may disperse, and not cause the riser to unload. (authors) 5 refs.

  2. Analysis of pressure data from a restricted-entry well in a multilayer reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, N.; Reynolds, A.C.

    1989-03-01

    This work presents new semilog type curves for analyzing data obtained at a restricted-entry well completed in a multilayer reservoir where crossflow occurs between reservoir layers. Use of the new type curves along with standard semilog analysis of pseudoradial-flow pressure data makes possible a complete analysis of pressure data. Specifically, standard semilog analysis of pseudoradial-flow pressure data yields estimates of the total flow capacity and the total skin factor. The new type curves can then be used to estimate the real mechanical skin factor resulting from damage or stimulation, the flow capacity adjacent to the open (perforated) interval, and the effective average vertical permeability.

  3. Pressure Responses of a Vertically Hydraulic Fractured Well in a Reservoir with Fractal Structure

    CERN Document Server

    Razminia, Kambiz; Torres, Delfim F M

    2015-01-01

    We obtain an analytical solution for the pressure-transient behavior of a vertically hydraulic fractured well in a heterogeneous reservoir. The heterogeneity of the reservoir is modeled by using the concept of fractal geometry. Such reservoirs are called fractal reservoirs. According to the theory of fractional calculus, a temporal fractional derivative is applied to incorporate the memory properties of the fractal reservoir. The effect of different parameters on the computed wellbore pressure is fully investigated by various synthetic examples.

  4. Well test analysis results interpretation: Combined type curve and pressure derivative approach

    Energy Technology Data Exchange (ETDEWEB)

    Fabbri, P.; Matteotti, G. (Padua Univ. (Italy). Dip. di Geologia, Paleontologia e Geofisica Padua Univ. (Italy). Ist. di Idraulica)

    In reviewing theoretical concepts forming the basis for the interpretation of well test analyses, this paper focusses on the 'theoretical model' for the determination of the parameters and variables. It then applies this theory to the combined type curve and pressure derivative interpretation approaches. Finally, the paper illustrates an approach combining the combined type curve and pressure derivative methods for homogeneous and isotropic conditions in a thermal aquifer and in the presence of the skin effect and wellbore storage.

  5. Pressure falloff behavior in vertically fractured wells: Non-Newtonian power-law fluids

    Energy Technology Data Exchange (ETDEWEB)

    Vongvuthipornchai, S.; Raghauan, R.; Reynolds, A.C.

    1984-09-01

    This paper examines pressure falloff behavior in fractured wells following the injection of a non-Newtonian power-law fluid. Results are presented in a form suitable for field application. Responses at wells intercepting infinite-conductivity and uniformflux fractures are considered. Procedures to identify flow regimes are discussed. The solutions presented here are new and to our knowledge not available in the literature. The consequences of neglecting the non-Newtonian characteristics of the injected fluid are examined. The results of this work were obtained by a finite difference model. Procedures to compute the apparent viscosity of power-law fluids for twodimensional flow through porous media are discussed. The formulation given here avoids numerical problems (multiple solutions, cross over, etc.) reported in other studies. Although, the main objective of the work is to examine pressure falloff behavior at fractured wells, the authors also examine responses at unfractured wells. The main objective of this part of a study is to examine the validity of using the superposition principle to analyze pressure falloff data. (The pressure distribution for this problem is governed by a nonlinear partial differential equation.) If the solutions given in the literature are used, then correction factors are needed to analyze pressure falloff data. The results of this phase of the work can also be used to analyze data in fractured wells provided that pseudoradial flow conditions exist.

  6. Transient pressure analysis of fractured well in bi-zonal gas reservoirs

    Science.gov (United States)

    Zhao, Yu-Long; Zhang, Lie-Hui; Liu, Yong-hui; Hu, Shu-Yong; Liu, Qi-Guo

    2015-05-01

    For hydraulic fractured well, how to evaluate the properties of fracture and formation are always tough jobs and it is very complex to use the conventional method to do that, especially for partially penetrating fractured well. Although the source function is a very powerful tool to analyze the transient pressure for complex structure well, the corresponding reports on gas reservoir are rare. In this paper, the continuous point source functions in anisotropic reservoirs are derived on the basis of source function theory, Laplace transform method and Duhamel principle. Application of construction method, the continuous point source functions in bi-zonal gas reservoir with closed upper and lower boundaries are obtained. Sequentially, the physical models and transient pressure solutions are developed for fully and partially penetrating fractured vertical wells in this reservoir. Type curves of dimensionless pseudo-pressure and its derivative as function of dimensionless time are plotted as well by numerical inversion algorithm, and the flow periods and sensitive factors are also analyzed. The source functions and solutions of fractured well have both theoretical and practical application in well test interpretation for such gas reservoirs, especial for the well with stimulated reservoir volume around the well in unconventional gas reservoir by massive hydraulic fracturing which always can be described with the composite model.

  7. Methodology for Calculation of Pressure Impulse Distribution at Gas-Impulse Regeneration of Water Well Filters

    Directory of Open Access Journals (Sweden)

    V. V. Ivashechkin

    2010-01-01

    Full Text Available The paper considers a mathematical model for process of pressure impulse distribution in a water well which appear as a result of underwater gas explosions in cylindrical and spherical explosive chambers with elastic shells and in a rigid cylindrical chamber which is open from the bottom. The proposed calculation methodology developed on the basis of the mathematical model makes it possible to determine pressure in the impulse on a filter wall and at any point of a water well pre-filter zone. 

  8. Pore pressure prediction and well bore stability analysis in Lower Paleozoic shale formation, N Poland

    Science.gov (United States)

    Słota-Valim, Małgorzata

    2017-04-01

    Pore pressure and wellbore stability sometimes pose a serious challenge while drilling, especially through rock formations of reduced strength or through intervals where abnormally high pore pressure was formed. Lack of prediction of pore pressure and lack of wellbore stability analysis introduce an element of uncertainty in selection of drilling fluid density. Too low density of drilling fluid can lead to uncontrolled flow of the reservoir fluid to the wellbore (kicks), washouts and occurrence of cavern like structures called breakouts. On the other hand too high density can lead to formation fracturing and further fluid loss. Therefore wellbore stability loss frequently prolongs the operating time, rising the costs of the drilling and in severe cases may end up well abandons loss. The above mentioned complications can be avoided or greatly reduced by reliable analysis of drilling conditions with the aspects to geomechanical characteristics of drilled rock formations. This study presents the results of analysis of pore pressure performed with the use of commonly used in oil industry methods. The analysis of pore pressure was carried out in almost entire profile of four boreholes drilled through lower Paleozoic shales, deposited in the southern part of the Baltic Basin. In addition wellbore stability analysis was performed in the well with most complete geomechanical input data base. Obtained results helped identifying intervals with elevated pore pressure could pose a risk during drilling operation. Elaborated 1D geomechanical model provides safe mud weight window helping to reduce the instabilities risk and constitute a great tool for geomechanical model validation.

  9. Brownfield management opportunities to reduce the back pressure effects on the gas wells

    Directory of Open Access Journals (Sweden)

    Stefanescu Dan-Paul

    2017-01-01

    Full Text Available Gas mature fields are associated with challenges to optimize the hydrocarbon flow from reservoir to the sales point in a cost effective manner due to declining well productivity. Laslau Mare field is a mature gas field in Transylvanian basin (Mures County developed in 1970s and is producing∼99% methane with low water-gas ratio. As any brown field, the state of depleted reservoir will generate several constraints for gas flow from formation to surface facilities and further to delivery point. During the exploitation has been observed that the operation conditions are facing with unstable pressure in the system due to low demand. Therefore, the back pressure effect will affect the wells in terms of inability to unload the bottomhole accumulated liquids and the reservoir will suffer a higher pressure drawdown. The best fit-for-purpose solution to overcome the above challenges is represented by installation of group compressor. Laslau Mare field has 3 group compressors running and shows positive results, especially when external pressure fluctuates continuously. This paper explain the challenges seen in 2016 in Laslau Mare field with back pressure effects and how the compression overcome them, and also other solutions that should be considered to optimize the well production.

  10. Pressure Transient Behavior of Horizontal Well with Time-Dependent Fracture Conductivity in Tight Oil Reservoirs

    Directory of Open Access Journals (Sweden)

    Qihong Feng

    2017-01-01

    Full Text Available This work presents a discussion on the pressure transient response of multistage fractured horizontal well in tight oil reservoirs. Based on Green’s function, a semianalytical model is put forward to obtain the behavior. Our proposed model accounts for fluid flow in four contiguous regions of the tight formation by using pressure continuity and mass conservation. The time-dependent conductivity of hydraulic fractures, which is ignored in previous models but highlighted by recent experiments, is also taken into account in our proposed model. We also include the effect of pressure drop along a horizontal wellbore. We substantiate the validity of our model and analyze the different flow regimes, as well as the effects of initial conductivity, fracture distribution, and geometry on the pressure transient behavior. Our results suggest that the decrease of fracture conductivity has a tremendous effect on the well performance. Finally, we compare our model results with the field data from a multistage fractured horizontal well in Jimsar sag, Xinjiang oilfield, and a good agreement is obtained.

  11. Pressure Transient Analysis of Multi-Fractured Horizontal Well in Tight Gas Reservoirs

    Directory of Open Access Journals (Sweden)

    Zhao Ermeng

    2016-01-01

    Full Text Available Multi-fractured horizontal well is applied in tight gas reservoirs due to the low permeability. A new pressure transient model of multi-fractured horizontal well based on discrete-fracture model in which the hydraulic fractures are discretized as 2D entities is built in this paper, The model is divided into hydraulic fracture region and formation region. The model can be solved using the Galerkin finite element method, then the pressure transient type curves are plotted by computer programming. The results show that there are five different flow regimes observed in type curves including early linear flow, early radial flow, elliptical flow, later pseudo-radial flow and boundary response regime. A sensitivity analysis is conducted to study impacts of hydraulic fracture number, hydraulic fracture half-length, hydraulic fracture spacing, and hydraulic fracture conductivity on pressure transient type curves. The new model and obtained results in this paper not only enrich the well testing models, but also play a guiding role in analyzing pressure transient response of multi-fractured horizontal well in tight gas reservoirs.

  12. Analysis of gas well late-time pressure and rate data

    Energy Technology Data Exchange (ETDEWEB)

    Ding, W.; Onur, M.; Reynolds, A.C. (Tulsa Univ., OK (USA))

    1990-09-01

    New methods are presented for estimating average pressure, reservoir pore volume (initial gas in place) and drainage area from pressure and rate data obtained at a gas well during boundary-dominated flow. The methods, which utilize a combination of a material balance equation and approximations for the wellbore pseudopressure or flow rate obtained during boundary-dominated flow, represent an improvement over previous methods in that the new methods are direct procedures which do not require iteration. 9 figs., 23 refs., 5 tabs., 1 app.

  13. Analysis of pressure data from a restricted-entry well in a multilayer reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, N.S.; Reynolds, A.C.

    1986-01-01

    This work presents new semilog type curves for analyzing data obtained at a restricted-entry well completed in a multilayer reservoir where crossflow occurs between reservoir layers. Effective use of the type curve requires that wellbore storage effects become negligible prior to the time when pseudoradial flow begins, or, that the total sandface rate is measured so that wellbore storage effects can be removed by methods based on Duhamel's principle. By using the new type curve in conjunction with standard semilog analysis of pseudoradial flow pressure data, a complete analysis of pressure data is possible. Specifically, standard semilog analysis of pseudoradial flow pressure data yields estimates of the total flow capacity and the total skin factor. The new type curve can then be used to estimate the real skin factor due to damage or stimulation, the flow capacity adjacent to the open (perforated) interval and the effective average vertical permeability.

  14. New applications of the pressure derivative in well-test analysis

    Energy Technology Data Exchange (ETDEWEB)

    Onur, M.; Reynolds, A.C. (Tulsa Univ., OK (USA)); Yeh, N. (Amoco Production Co., Tulsa, OK (USA))

    1989-09-01

    This work represents and illustrates a new general procedure for constructing type curves on the basis of a new pressure-derivative group that involves the dimensionless pressure change divided by its logarithmic derivative. When type curves based on this group are constructed, the vertical scale of the dimensionless derivative group is automatically aligned with the vertical scale of the field-data derivative group. This automatic alignment of the vertical scales simplifies type-curve matching and is advantageous for determining whether field data actually represent the solution assumed by a given type curve. It is also shown that the basic idea used in constructing the type curves can be used to ensure that proper semilog straight lines are chosen when well-test pressure data are analyzed by semilog methods.

  15. Low parameter model to monitor bottom hole pressure in vertical multiphase flow in oil production wells

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Ahmadi

    2016-09-01

    Full Text Available The importance of the flow patterns through petroleum production wells proved for upstream experts to provide robust production schemes based on the knowledge about flow behavior. To provide accurate flow pattern distribution through production wells, accurate prediction/representation of bottom hole pressure (BHP for determining pressure drop from bottom to surface play important and vital role. Nevertheless enormous efforts have been made to develop mechanistic approach, most of the mechanistic and conventional models or correlations unable to estimate or represent the BHP with high accuracy and low uncertainty. To defeat the mentioned hurdle and monitor BHP in vertical multiphase flow through petroleum production wells, inventive intelligent based solution like as least square support vector machine (LSSVM method was utilized. The evolved first-break approach is examined by applying precise real field data illustrated in open previous surveys. Thanks to the statistical criteria gained from the outcomes obtained from LSSVM approach, the proposed least support vector machine (LSSVM model has high integrity and performance. Moreover, very low relative deviation between the model estimations and the relevant actual BHP data is figured out to be less than 6%. The output gained from LSSVM model are closed the BHP while other mechanistic models fails to predict BHP through petroleum production wells. Provided solutions of this study explicated that implies of LSSVM in monitoring bottom-hole pressure can indicate more accurate monitoring of the referred target which can lead to robust design with high level of reliability for oil and gas production operation facilities.

  16. SMART MONITORING AND DECISION MAKING FOR REGULATING ANNULUS BOTTOM HOLE PRESSURE WHILE DRILLING OIL WELLS

    Directory of Open Access Journals (Sweden)

    M. P. Vega

    Full Text Available Abstract Real time measurements and development of sensor technology are research issues associated with robustness and safety during oil well drilling operations, making feasible the diagnosis of problems and the development of a regulatory strategy. The major objective of this paper is to use an experimental plant and also field data, collected from a basin operation, offshore Brazil, for implementing smart monitoring and decision making, in order to assure drilling inside operational window, despite the commonly observed disturbances that produce fluctuations in the well annulus bottom hole pressure. Using real time measurements, the performance of a continuous automated drilling unit is analyzed under a scenario of varying levels of rate of penetration; aiming pressure set point tracking (inside the operational drilling window and also rejecting kick, a phenomenon that occurs when the annulus bottom hole pressure is inferior to the porous pressure, producing the migration of reservoir fluids into the annulus region. Finally, an empirical model was built, using real experimental data from offshore Brazil basins, enabling diagnosing and regulating a real drilling site by employing classic and advanced control strategies.

  17. CFD Method for Predicting Annular Pressure Losses and Cuttings Concentration in Eccentric Horizontal Wells

    Directory of Open Access Journals (Sweden)

    Titus N. Ofei

    2014-01-01

    Full Text Available In oil and gas drilling operations, predictions of pressure losses and cuttings concentration in the annulus are very complex due to the combination of interacting drilling parameters. Past studies have proposed many empirical correlations to estimate pressure losses and cuttings concentration. However, these developed correlations are limited to their experimental data range and setup, and hence, they cannot be applicable to all cases. CFD methods have the advantages of handling complex multiphase flow problems, as well as, an unlimited number of physical and operational conditions. The present study employs the inhomogeneous (Eulerian-Eulerian model to simulate a two-phase solid-fluid flow and predict pressure losses and cuttings concentration in eccentric horizontal annuli as a function of varying drilling parameters: fluid velocity, diameter ratio (ratio of inner pipe diameter to outer pipe diameter, inner pipe rotation speed, and fluid type. Experimental data for pressure losses and cuttings concentration from previous literature compared very well with simulation data, confirming the validity of the current model. The study shows how reliable CFD methods can replicate the actual, yet complex oil and gas drilling operations.

  18. Threaded connection qualification procedures utilized for an ultra-deep, high-pressure gas well

    Energy Technology Data Exchange (ETDEWEB)

    Minge, J.C.; Pejac, R.D.; Asbill, W.T.

    1986-01-01

    This paper describes the premium connection qualification program used to qualify three different connections for the production tubular strings used in an ultra-deep, high pressure gas well. A total of eight connection types were tested during the program. Four connections failed to meet the program's acceptance criteria. Full-scale test procedures and the data acquisition system used to collect, store, reduce, and plot strain gauge data while testing are discussed.

  19. Reservoir response to thermal and high-pressure well stimulation efforts at Raft River, Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Plummer, Mitchell [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bradford, Jacob [Energy & Geoscience Institute at the Univ. of Utah, Salt Lake City, UT (United States); Moore, Joseph [Energy & Geoscience Institute at the Univ. of Utah, Salt Lake City, UT (United States); Podgorney, Robert [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    An injection stimulation test begun at the Raft River geothermal reservoir in June, 2013 has produced a wealth of data describing well and reservoir response via high-resolution temperature logging and distributed temperature sensing, seismic monitoring, periodic borehole televiewer logging, periodic stepped flow rate tests and tracer injections before and after stimulation efforts. One of the primary measures of response to the stimulation is the relationship between fluid pressure and flow rate, short-term during forced flow rate changes and the long-term change in injectivity. In this paper we examine that hydraulic response using standard pumping test analysis methods, largely because pressure response to the stimulation was not detected, or measurable, in other wells. Analysis of stepped rate flow tests supports the inference from other data that a large fracture, with a radial extent of one to several meters, intersects the well in the target reservoir, suggests that the flow regime is radial to a distance of only several meters and demonstrates that the pressure build-up cone reaches an effective constant head at that distance. The well’s longer term hydraulic response demonstrated continually increasing injectivity but at a dramatically faster rate later from ~2 years out and continuing to the present. The net change in injectivity is significantly greater than observed in other longterm injectivity monitoring studies, with an approximately 150–fold increase occurring over ~2.5 years. While gradually increasing injectivity is a likely consequence of slow migration of a cooling front, and consequent dilation of fractures, the steady, ongoing, rate of increase is contrary to what would be expected in a radial or linear flow regime, where the cooling front would slow with time. As a result, occasional step-like changes in injectivity, immediately following high-flow rate tests suggest that hydro shearing during high-pressure testing altered the near-well

  20. An investigation of constant-pressure gas well testing influenced by high-velocity flow

    Energy Technology Data Exchange (ETDEWEB)

    Berumen, Sergio; Samaniego, Fernando; Cinco, Heber [PEMEX E and P and UNAM, Ciudad Universitaria, Coyoacan, Mexico (Mexico)

    1997-11-05

    This paper presents the results of a study of transient pressure analysis of gas flow under either constant bottom-hole pressure conditions or the constant wellhead pressure conditions. The effects of formation damage, wellbore storage and high-velocity flow are included in the model. The analysis of simulated well tests showed that the interpretation methods used for liquid flow are generally accurate when the m(p) is used. For these conditions, a graph of 1/q{sub D} vs. logt{sub D} presents gradually lower values of 1.1513 as the value of p{sub wf} decreases: for pressure buildup conditions, a graph of m{sub D}(1, {Delta}t{sub a{sub D}})/q{sub D}({Delta}t{sub a{sub D}}=0) vs. (t{sub a{sub D}}+{Delta}t{sub a{sub D}})/{Delta}t{sub a{sub D}} shows values of this slope within 1% of the 1.1513 value. However, when high-velocity flow influences constant pressure production tests, the slope can yield errors up to 13%. This upper limit occurs when the formation has a relatively `high` permeability (around 1 mD) and the rate performance test is affected by high-velocity flow. It was found that pressure buildup tests are superior to rate performance tests because high-velocity flow does not affect the slope of the straight line portion of the buildup curve. Derivative analysis of simulated buildup tests showed that the skin factor is considerably miscalculated when the high-velocity flow effect is significant. This problem could lead to errors in the calculation of the skin factor, s, up to 300%

  1. The Analysis of Fluid Pressure Impact on String Force and Deformation in Oil and Gas Wells

    Directory of Open Access Journals (Sweden)

    Gao Baokui

    2015-01-01

    Full Text Available Fluid pressure is a crucial factor to tubular string strength and deformation in oil and gas wells, and it is the most difficult factor to deal with. When the string constrained by downhole tools, such as packers, action pattern of fluid on string is changed. Calculation methods of string stress and deformation given by engineering handbooks doesn’t distinguish these issues in detail. So mistakes are often made when these methods are used. Tangled concepts lead to large calculation error. In this paper, the influence of fluid pressure on string axial force and deformation, buoyancy treatment in packed condition, are discussed roundly both in vertical wells and directional wells. Practical calculating method of string axial force through the hook load is presented, and element buoyancy in different borehole trajectory is given. It is found that the traditional simplified buoyancy coefficient method, which is used to calculate string axial force and axial extension, can only be used in vertical wells with tubular string suspended freely, because in this condition buoyancy acts on the bottom of string. If the string is constrained by downhole tools, such as packer or anchor, buoyancy could not be treated as usual. In directional well the buoyancy not only changes string axial force but induces shear stress in string cross section. When calculating the influence of fluid on string, operation sequence and constraints from borehole and downhole tools should be considered comprehensively.

  2. Improved Lifetime Pressure Drop Management for Subsurface Safety Valves in Oil and Gas Wells

    Directory of Open Access Journals (Sweden)

    Jamaliatul Munawwarah Mohd Alisjabana

    2013-01-01

    Full Text Available Pressure losses occur in restriction, especially in the Subsurface Safety Valve (SSSV might not be major but can be significant in some wells. As we could not always predict the behavior of the dynamic entity such as the reservoir and the flow of fluid, the production system could exceeds the expected performance, which then could affect the SSSV. Therefore, a proper management of SSSV could help overcome this problem. This project attempts to develop a numerical model which could predict the pressure drops in the SSSV in single and two-phase, subcritical flow as a part of the SSSV proper management program. The project also had done several sensitivities analysis on the parameters that could affect the pressure drops in SSSV which are presented in this paper. The knowledge on the parameters affecting the pressure drop can be used in designing an efficient and optimized SSSV. It is also hope that a proper and dynamic control over the SSSV could be achieved by using this model.

  3. Reparameterization techniques for generating reservoir descriptions conditioned to variograms and well-test pressure data

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, A.C.; He, N.; Chu, L. [Univ. of Tulsa, OK (United States)] [and others

    1995-12-31

    Recently, we have shown that reservoir descriptions conditioned to multiwell pressure data and univariate and bivariate statistics for permeability and porosity can be obtained by techniques developed from inverse problem theory. The techniques yield estimates of well skin factors and porosity and permeability fields which honor both the spatial statistics and the pressure data. Imbedded in the methodology is the application of the Gauss-Newton method to construct the maximum a posteriori estimate of the reservoir parameters. If one wishes to determine permeability and porosity values at thousands of grid-blocks for use in a reservoir simulator, then inversion of the Hessian matrix at each iteration of the Gauss-Newton procedure becomes computationally expensive. In this work, we present two methods to reparameterize the reservoir model to improve the computational efficiency. The first method uses spectral (eigenvalue/eigenvector) decomposition of the prior model. The second method uses a subspace method to reduce the size of the matrix problem that must be solved at each iteration of the Gauss-Newton method. It is shown that proper implementation of the reparameterization techniques significantly decreases the computational time required to generate realizations of the reservoir model, i.e., the porosity and permeability fields and well skin factors, conditioned to prior information on porosity and permeability and multiwell pressure data.

  4. Pressure effect on the electron mobility in AlAs/GaAs quantum wells

    Institute of Scientific and Technical Information of China (English)

    Hao Guo-Dong; Ban Shi-Liang; Jia Xiu-Min

    2007-01-01

    By taking the influence of optical phonon modes into account, this paper adopts the dielectric continuum phonon model and force balance equation to investigate the electronic mobility parallel to the interfaces for AlAs/GaAs semiconductor quantum wells (QWs) under hydrostatic pressure. The scattering from confined phonon modes, interface phonon modes and half-space phonon modes are analysed and the dominant scattering mechanisms in wide and narrow QWs are presented. The temperature dependence of the electronic mobility is also studied in the temperature range of optical phonon scattering being available. It is shown that the electronic mobility reduces obviously as pressure increases from 0 to 4GPa, the confined longitudinal optical (LO) phonon modes play an important role in wide QWs,whereas the interface optical phonon modes are dominant in narrow QWs, the half-space LO phonon modes hardlyinfluence the electronic mobility expect for very narrow QWs.

  5. Well production challenges and solutions in a mature, very low-pressure coalbed methane reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Okotie, V.U.; Moore, R.L. [BP, Houston, TX (United States)

    2010-07-01

    Coalbed methane (CBM) had been produced in the regions of southwestern Colorado and northwestern New Mexico for the past 30 years. Parts of the field are now at a mature stage of reservoir pressure depletion. Well production operations in the high permeability fairway are challenged by low reservoir pressure, heavy coal fines production, artificial lift challenges, and the presence of paraffin, inorganic scale, and corrosion. In this study, history matching reservoir simulations were used to determine the causes of production inefficiencies. Field observations and operating guidelines were discussed and successful well intervention histories were presented. An analysis of the simulations indicated that shift in permeability trends were primarily caused by changes in the mechanical properties of the coal. Excess volumes of coal fines have caused wells in the region to require more frequent cleanouts, and the presence of paraffin deposits has restricted fluid flow. Corrosion in the fairway was attributed to a high percentage of carbon dioxide (CO{sub 2}) in gas streams. Effective wellbore cleanout and pumping systems have been developed to address issues related to coal failure. 14 refs., 15 figs.

  6. Little pump that could : hydraulic submersible pump tackles low pressure, low fluid volume gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Ross, E.

    2008-03-15

    A new pump designed by Global Energy Services was described. The pump was designed to address problems associated with downhole pumps in coalbed methane (CBM) wells. The hydraulic submersible pump (HSP) was designed to address issues related to artificial lift gas lock and solids. The pump has been installed at 35 CBM wells in western Canada as well as at natural gas wells with low pressures and low rates of water. The HSP technology was designed for use with wells between 0.01 cubic metres and 24 cubic metres per day of water. A single joystick in the surface unit is used to determine the amount of hydraulic oil delivered to the bottomhole pump when then determines the amounts of fluid produced. A 10-slot self-flushing sand screen is used to filter out particles of sand, coal, and cement. The pump also includes a hydraulic flow control valve to control water volumes. The HSP's positive displacement design makes it suitable for use in horizontal and deviated wells. The pump technology is currently being re-designed to handle larger volumes at deeper depths. 2 figs.

  7. Error Propagation Dynamics of PIV-based Pressure Field Calculations: How well does the pressure Poisson solver perform inherently?

    Science.gov (United States)

    Pan, Zhao; Whitehead, Jared; Thomson, Scott; Truscott, Tadd

    2016-08-01

    Obtaining pressure field data from particle image velocimetry (PIV) is an attractive technique in fluid dynamics due to its noninvasive nature. The application of this technique generally involves integrating the pressure gradient or solving the pressure Poisson equation using a velocity field measured with PIV. However, very little research has been done to investigate the dynamics of error propagation from PIV-based velocity measurements to the pressure field calculation. Rather than measure the error through experiment, we investigate the dynamics of the error propagation by examining the Poisson equation directly. We analytically quantify the error bound in the pressure field, and are able to illustrate the mathematical roots of why and how the Poisson equation based pressure calculation propagates error from the PIV data. The results show that the error depends on the shape and type of boundary conditions, the dimensions of the flow domain, and the flow type.

  8. Error Propagation Dynamics of PIV-based Pressure Field Calculations: How well does the pressure Poisson solver perform inherently?

    CERN Document Server

    Pan, Zhao; Thomson, Scott; Truscott, Tadd

    2016-01-01

    Obtaining pressure field data from particle image velocimetry (PIV) is an attractive technique in fluid dynamics due to its noninvasive nature. The application of this technique generally involves integrating the pressure gradient or solving the pressure Poisson equation using a velocity field measured with PIV. However, very little research has been done to investigate the dynamics of error propagation from PIV-based velocity measurements to the pressure field calculation. Rather than measure the error through experiment, we investigate the dynamics of the error propagation by examining the Poisson equation directly. We analytically quantify the error bound in the pressure field, and are able to illustrate the mathematical roots of why and how the Poisson equation based pressure calculation propagates error from the PIV data. The results show that the error depends on the shape and type of boundary conditions, the dimensions of the flow domain, and the flow type.

  9. Error propagation dynamics of PIV-based pressure field calculations: How well does the pressure Poisson solver perform inherently?

    Science.gov (United States)

    Pan, Zhao; Whitehead, Jared; Thomson, Scott; Truscott, Tadd

    2016-08-01

    Obtaining pressure field data from particle image velocimetry (PIV) is an attractive technique in fluid dynamics due to its noninvasive nature. The application of this technique generally involves integrating the pressure gradient or solving the pressure Poisson equation using a velocity field measured with PIV. However, very little research has been done to investigate the dynamics of error propagation from PIV-based velocity measurements to the pressure field calculation. Rather than measure the error through experiment, we investigate the dynamics of the error propagation by examining the Poisson equation directly. We analytically quantify the error bound in the pressure field, and are able to illustrate the mathematical roots of why and how the Poisson equation based pressure calculation propagates error from the PIV data. The results show that the error depends on the shape and type of boundary conditions, the dimensions of the flow domain, and the flow type.

  10. COMPARISON OF VENTED AND ABSOLUTE PRESSURE TRANSDUCERS FOR WATER-LEVEL MONITORING IN HANFORD SITE CENTRAL PLATEAU WELLS

    Energy Technology Data Exchange (ETDEWEB)

    MCDONALD JP

    2011-09-08

    Automated water-level data collected using vented pressure transducers deployed in Hanford Site Central Plateau wells commonly display more variability than manual tape measurements in response to barometric pressure fluctuations. To explain this difference, it was hypothesized that vented pressure transducers installed in some wells are subject to barometric pressure effects that reduce water-level measurement accuracy. Vented pressure transducers use a vent tube, which is open to the atmosphere at land surface, to supply air pressure to the transducer housing for barometric compensation so the transducer measurements will represent only the water pressure. When using vented transducers, the assumption is made that the air pressure between land surface and the well bore is in equilibrium. By comparison, absolute pressure transducers directly measure the air pressure within the wellbore. Barometric compensation is achieved by subtracting the well bore air pressure measurement from the total pressure measured by a second transducer submerged in the water. Thus, no assumption of air pressure equilibrium is needed. In this study, water-level measurements were collected from the same Central Plateau wells using both vented and absolute pressure transducers to evaluate the different methods of barometric compensation. Manual tape measurements were also collected to evaluate the transducers. Measurements collected during this study demonstrated that the vented pressure transducers over-responded to barometric pressure fluctuations due to a pressure disequilibrium between the air within the wellbores and the atmosphere at land surface. The disequilibrium is thought to be caused by the relatively long time required for barometric pressure changes to equilibrate between land surface and the deep vadose zone and may be exacerbated by the restriction of air flow between the well bore and the atmosphere due to the presence of sample pump landing plates and well caps. The

  11. Use of inexpensive pressure transducers for measuring water levels in wells

    Science.gov (United States)

    Keeland, B.D.; Dowd, J.F.; Hardegree, W.S.

    1997-01-01

    Frequent measurement of below ground water levels at multiple locations is an important component of many wetland ecosystem studies. These measurements, however, are usually time consuming, labor intensive, and expensive. This paper describes a water-level sensor that is inexpensive and easy to construct. The sensor is placed below the expected low water level in a shallow well and, when connected to a datalogger, uses a pressure transducer to detect groundwater or surface water elevations. Details of pressure transducer theory, sensor construction, calibration, and examples of field installations are presented. Although the transducers must be individually calibrated, the sensors have a linear response to changing water levels (r2 ??? .999). Measurement errors resulting from temperature fluctuations are shown to be about 4 cm over a 35??C temperature range, but are minimal when the sensors are installed in groundwater wells where temperatures are less variable. Greater accuracy may be obtained by incorporating water temperature data into the initial calibration (0.14 cm error over a 35??C temperature range). Examples of the utility of these sensors in studies of groundwater/surface water interactions and the effects of water level fluctuations on tree growth are provided. ?? 1997 Kluwer Academic Publishers.

  12. ANALYSIS OF TWO-PHASE FLOW PRESSURE BUILDUP DATA FROM A WELL IN AN INFINITE MULTIWELL RESERVOIR

    Institute of Scientific and Technical Information of China (English)

    LIN Jia-en; YANG Hui-zhu

    2005-01-01

    A general method has been developed for analyzing two-phase flow pressure buildup data from a well located in a system of both production and injection wells completed in an infinite multiwell reservoir. The analysis technique assumes that the tested well has established its own drainage area before shut-in and a linear reservoir pressure trend dominates the well pressure behavior at the instant of shut-in. And for the two-phase flow problems the horizontal saturation gradients are assumed to be negligible. The entire pressure response, whether or not conventional semilog straight lines exist, can be analyzed and the Injection-Production Ratio (IPR), the total fluid (oil/water) mobility, the average drainage-area pressure, and also the skin factor can be calculated much easily. The validity and applicability of the method are demonstrated by a field example. The technique by using the type curves for analyzing the pressure-buildup data is also presented here.

  13. A model to determine the petroleum pressure in a well using fractional differential equations

    Science.gov (United States)

    Brito Martinez, Beatriz; Brambila Paz, Fernando; Fuentes Ruiz, Carlos

    2016-11-01

    A noninvasive method was used to determine the pressure of petroleum leaving a well. The mathematical model is based on nonlinear fractional differential equations. This model comes from the fractal dimension of the porous medium. The problem is solved in three stages. In the first stage the fractal dimension of the porous medium is determined. We show that microwaves reflected and transmitted through soil have a fractal dimension which is correlated with the fractal dimension of the porous medium. The fractal signature of microwave scattering correlates with certain physical and mechanical properties of soils (porosity, permeability, conductivity, etc.). In the second stage we use three partial fractional equations as a mathematical model to study the diffusion inside the porous medium. In this model sub-diffusive phenomenon occurs if fractal derivative is between zero and one and supra-diffusive occurs if the derivative is greater than 1 and less than 2. Finally in the third stage the mathematical model is used to determinate the petroleum pressure output in a Mexican oil field, which contains three partial fractional equations with triple porosity and permeability.

  14. Fluctuation pressure on a bio-membrane confined within a parabolic potential well

    Institute of Scientific and Technical Information of China (English)

    L. B. Freund

    2012-01-01

    A compliant bio-membrane with a nominally flat reference configuration is prone to random transverse deflections when placed in water,due primarily to the Brownian motion of the water molecules.On the average,these fluctuations result in a state of thermodynamic equilibrium between the entropic energy of the water and the total free energy of the membrane.When the membrane is in close proximity to a parallel surface,that surface restricts the fluctuations of the membrane which,in turn,results in an increase in its free energy.The amount of that increase depends on the degree of confinement,and the resulting gradient in free energy with degree of confinement implies the existence of a confining pressure.In the present study,we assume that the confinement is in the form of a continuous parabolic potential well resisting fluctuation.Analysis leads to a closed form expression for the mean pressure resulting from this confinement,and the results are discussed within the broader context of results in this area.In particular,the results provide insights into the roles of membrane stiffness,number of degrees of freedom in the model of the membrane and other system parameters.

  15. Note: High temperature pressure sensor for petroleum well based on silicon over insulator.

    Science.gov (United States)

    Tian, Bian; Liu, Hanyue; Yang, Ning; Zhao, Yulong

    2015-12-01

    In order to meet the requirements in petroleum well, a novel structure of high temperature pressure sensor based on the silicon over insulator (SOI) technology is proposed in this paper. The SOI sensor chip is bonded with a glass ring by electrostatic bonding. By controlling the inner diameter of the glass ring, the size of the circle membrane is obtained precisely. And the detailed parameters of the structure are established through analysis. Then, the sensor is fabricated. The test results show that this type sensor has high sensitivity and accuracy. It is able to measure at the temperature up to 180 °C and the measuring range is 60 MPa. Moreover, the results we got are closer to the actual situation.

  16. New mathematical model for bottom hole pressure control development in multiphase flowing wells while performing UBD operation

    Science.gov (United States)

    Kootiani, Reza Cheraghi; Chehrehgosha, Soroush; Mirali, Sasan; Samsuri, Ariffin Bin

    2014-10-01

    The analytical model for predicting the pressure at any point in a flow string is essential in determining optimum production string dimension and in the design of gas-lift installations. This information is also invaluable in predicting bottom-hole pressure in flowing wells. A variety of model on bottom-hole pressure in flowing wells have been reported in the literatures. Most of the early models on pressure drop in the flowing wells were based on single phase flowing wells, even the recent investigators treated the multiphase (liquid and gas phase) as a homogenous single phase flow without accounting for dissolved gas in oil. This paper present a modification of previous models for single phase flowing gas wells and the model was adapted to predict the pressure drop in multiphase flowing wells. In this paper, we can solve numerically to obtain the pressure upstream of the nozzle in two phase flow. The key operational and fluid/ pipe parameters which influence the degree of pressure drop in flowing wells are identified through the modification.

  17. Analysis of variable-rate well-test pressure data using Duhamel's principle

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, L.G.; Reynolds, A.C.

    1986-10-01

    This work considers the use of Duhamel's principle to analyze pressure drawdown and buildup data when both bottomhole pressures (BHP's) and sandface flow rates are available. This analysis procedure uses Duhamel's principle to convert pressure data obtained when the sandface rate is variable to the equivalent pressure data that would be obtained for a constant sandface rate of production. The equivalent constant-rate pressure data then can be analyzed with standard procedures (semilog analysis of type-curve matching).

  18. InAsP-based quantum wells as infrared pressure gauges for use in a diamond anvil cell

    Science.gov (United States)

    Trushkin, S.; Kamińska, A.; Trzeciakowski, W.; Hopkinson, M.; Suchocki, A.

    2012-10-01

    The results of high-pressure, low-temperature luminescence measurements of three InAsP-based multiple quantum well structures are reported for application as pressure sensors for diamond anvil cells working in the near-infrared spectral range. The multiple quantum well structures exhibit a much higher pressure shift of the luminescence lines as compared with ruby, typically used as the pressure sensor for diamond anvil cell. However, the full width at half maximum of the quantum wells is much higher than that for ruby. This reduces the available sensitivity gain exhibited by the InAsP-based quantum wells, but the improvement is still 2-3 times higher than that of ruby. Three InAsP multiple quantum well samples were examined, which exhibited luminescence at various wavelengths. The wavelength shift of these samples could be calibrated using similar parameters.

  19. An investigation of constant pressure gas well testing influenced by high velocity flow

    Energy Technology Data Exchange (ETDEWEB)

    Berumen, S. [PEMEX Exploracion-Produccion, Mexico City (Mexico); Samaniego, F. [Universidad de Mexico, Mexico City (Mexico). Facultad de Ingeniera; Cinco-Ley, H. [Universidad de Mexico, Mexico City (Mexico). Facultad de Ingeniera; Bouhroum, A.

    1997-03-01

    This paper presents the results of a study of transient pressure analysis of gas flow under either constant bottom-hole conditions or the constant wellhead pressure conditions. The effect of formation damage, wellbore storage and high velocity flow are included in the model. The analysis of simulated well tests showed that the interpretation methods used for liquid flow are generally accurate when the p{sub p}(p) is used. For these conditions, a graph of 1/q{sub D} vs log t{sub D} presents gradually lower values of 1.1513 as the value of p{sub wf} decreases: For pressure buildup conditions a graph of p{sub pD}(1, {Delta}t{sub aD})/q{sub D}({Delta}t{sub aD}=0) vs (t{sub aD}+{Delta}t{sub aD})/{Delta}t{sub aD} shows values of this slope within 1% of the 1.1513 value. The maximum error was in the rate performance simulated cases that included high-velocity flows; being less than 13%. This upper limit occurs when the formation has a relatively `high` permeability (around 1 mD) and the rate performance test is affected by high-velocity flow. It was found that pressure buildup tests are superior to rate performance tests because high-velocity flow does not affect the slope of the straight line portion of the buildup curve. However, it was also found, through derivative analysis of simulated buildup tests, that the skin factor is sensibly miscalculated when the high-velocity flow effect is singificant. This problem could lead to errors in the calculation of the skin factor, s, up to 300%. (orig.) [Deutsch] Vorgestellt werden instationaere Testergebnisse an Gas-Sonden unter konstanten Bohrlochsohlenbedingungen bzw. konstantem Bohrlochkopfdruck. Folgende Stoereffekte: Sondennahe Tragerschaedigung, Speicherkapazitaet des Bohrloches und die bei der Gasstroemung eintretende hohe Fliessgeschwindigkeit werden beruecksichtigt. Die Auswertung von simulierten Testergebnissen zeigt, dass die zur Interpretation von Erdoelsonden bewaehrten Verfahren in der Darstellung p{sub p}(p) gute

  20. Finite element analysis of high-pressure hose for radial horizontal wells in coalbed methane extraction

    Institute of Scientific and Technical Information of China (English)

    Wei-Dong ZHOU; Wei SHI; Luo-Peng LI; Jing-Shuang WANG; Jun SUN

    2013-01-01

    Based on the serial-parallel model of single-layer board and the lamination theory,the forces exerted on different layers of the high-pressure hose and the resulting deformations were analyzed when the hose was radially stretched.An equation was proposed to calculate the anisotropic elastic constant of the composite layer with the wound steel wires.Furthermore,the finite element analysis (FEA) model of the high-pressure hose was established,followed by a simulation of the forces that act on different layers,and their deformations.The simulation results show that the stress imposed on the inner reinforced layer and external reinforced layer of the high-pressure hose are approximately 150 MPa and l 15 MPa,respectively,in the presence of inner pressure.The stress of the rubber coating and polyethylene coating is lower.The lowest stress occurs on the inner surface of the high-pressure hose and the rubber coating between the two composite layers.The deformation of the rubber layer in the inner surface of the high-pressure hose decreases gradually along the radial direction from the inner surface to the external surface.The deformation of the reinforced composite layer is less than that of the external surface of the rubber coating.The equivalent stress of the reinforced composite layer is higher than that caused by the inner pressure,due to the presence of both inner pressure and axial tension.

  1. Exploitation technology of pressure relief coalbed methane in vertical surface wells in the Huainan coal mining area

    Institute of Scientific and Technical Information of China (English)

    HAN Jia-zhang; SANG Shu-xun; CHENG Zhi-zhong; HUANG Hua-zhou

    2009-01-01

    Exploitation technology of pressure relief coalbed methane in vertical surface wells is a new method for exploration of gas and coalbed methane exploitation in mining areas with high concentrations of gas, where tectonic coal developed. Studies on vertical surface well technology in the Huainan Coal Mining area play a role in demonstration in the use of clean, new energy re-sources, preventing and reducing coal mine gas accidents and protecting the environment. Based on the practice of gas drainage engineering of pressure relief coalbed methane in vertical surface wells and combined with relative geological and exploration en-gineering theories, the design principles of design and structure of wells of pressure relief coaibed methane in vertical surface wells are studied. The effects of extraction and their causes are discussed and the impact of geological conditions on gas production of the vertical surface wells are analyzed. The results indicate that in mining areas with high concentrations of gas, where tectonic coal developed, a success rate of pressure relief coalbed methane in surface vertical well is high and single well production usually great. But deformation due to coal exploitation could damage boreholes and cause breaks in the connection between aquifers and bore-holes, which could induce a decrease, even a complete halt in gas production of a single well. The design of well site location and wellbore configuration are the key for technology. The development of the geological conditions for coalbed methane have a sig-nificant effect on gas production of coalbed methane wells.

  2. Pressure oscillations caused by momentum on shut in of a high rate well in a fractured formation

    Energy Technology Data Exchange (ETDEWEB)

    Bhatnagar, S.

    1989-06-01

    Pressure transient testing techniques are an important part of reservoir and production testing procedures. These techniques are frequently used to determine practical information about underground reservoirs such as the permeability, porosity, liquid content, reservoir and liquid discontinuities and other related data. This information is valuable in helping to analyze, improve and forecast reservoir performance. This report is concerned with developing models for pressure transient well testing in high permeability, high flow rate, naturally fractured reservoirs. In the present work, a study was made of the effects of liquid inertia in the fractures and the wellbore on the pressure response obtained during a well test. The effects of turbulent flow and multi-phase flow effects such as gravitational segregation or anisotropic porous media effects were not considered. The scope of the study was limited to studying inertial effects on the pressure response of a fractured reservoir.

  3. Better well control through safe drilling margin identification, influx analysis and direct bottom hole pressure control method for deep water

    Energy Technology Data Exchange (ETDEWEB)

    Veeningen, Daan [National Oilwell Varco IntelliServ (NOV), Houston, TX (United States)

    2012-07-01

    Currently, well control events are almost exclusively detected by using surface measurements. Measuring a volume increase in the 'closed loop' mud circulation system; a standpipe pressure decrease; or changes in a variety of drilling parameters provide indicators of a kick. Especially in deep water, where the riser comprises a substantial section of the well bore, early kick detection is paramount for limiting the severity of a well bore influx and improve the ability to regain well control. While downhole data is presently available from downhole tools nearby the bit, available data rates are sparse as mud pulse telemetry bandwidth is limited and well bore measurements compete with transmission of other subsurface data. Further, data transfer is one-directional, latency is significant and conditions along the string are unknown. High-bandwidth downhole data transmission system, via a wired or networked drill string system, has the unique capability to acquire real-time pressure and temperature measurement at a number of locations along the drill string. This system provides high-resolution downhole data available at very high speed, eliminating latency and restrictions that typically limit the availability of downhole data. The paper describes well control opportunities for deep water operations through the use of downhole data independent from surface measurements. First, the networked drill string provides efficient ways to identify pore pressure, fracture gradient, and true mud weight that comprise the safe drilling margin. Second, the independent measurement capability provides early kick detection and improved ability to analyze an influx even with a heterogeneous mud column through distributed along-string annular pressure measurements. Third, a methodology is proposed for a direct measurement method using downhole real-time pressure for maintaining constant bottom hole pressure during well kills in deep water. (author)

  4. Comparison of how well conscious cats tolerate blood pressure measurement from the radial and coccygeal arteries.

    Science.gov (United States)

    Cannon, Martha J; Brett, Jo

    2012-12-01

    Hypertension is a common condition of older cats and acquiring clinically relevant and repeatable blood pressure (BP) measurements in conscious cats is important in its diagnosis and management. The most common sites for indirect BP measurement in the cat are the radial artery (RA) and the coccygeal artery (CA) but, to date, there are no published data comparing how conscious cats tolerate BP measurements from these sites. A high-definition oscillometric BP monitor was used to measure BP in 30 cats admitted to a cat-only veterinary clinic for reasons other than hypertension. Systolic arterial pressure (SAP), mean arterial pressure (MAP) and diastolic arterial pressure (DAP) were measured using the RA and CA, alternating which site was used first. The number of failed attempts and total time to achieve six measurements was recorded. Measurement of BP using the CA was better tolerated than the RA, resulting in fewer failures and shorter total time required. SAP measurements were slightly higher from the CA compared with the RA, irrespective of which site was used first. There were no significant differences in MAP and DAP. The coccygeal artery appears to be the more appropriate site to use when measuring BP in conscious cats using this oscillometric machine. Further studies are required using alternative BP monitors, including Doppler machines, to establish whether this is a consistent finding. When measuring BP in cats the site used should be recorded and the same site used for all subsequent measurements from the same cat.

  5. Using pressure transient analysis to improve well performance and optimize field development in compartmentalized shelf margin deltaic reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Badgett, K.L.; Crawford, G.E.; Mills, W.H. [and others

    1996-12-31

    BP Exploration`s Gulf of Mexico group developed procedures to conduct effective well tests on conventional production wells and employed them during the development drilling phase of the Mississippi Canyon 109 (MC109) field. Bottomhole pressure data were recorded during the initial few weeks of production. Typically, a 48 hour pressure buildup survey (surface shut-in) was obtained near the end of data acquisition. Data from these tests were analyzed for completion efficiency, reservoir flow capacity, reservoir heterogeneities, and drainage area. Initially wells were gravel packed for sand control, until buildup interpretations indicated skins greater than 20. Frac packing technology was then employed, and an immediate improvement was observed with skins dropping into the teens. Over a period of time frac packs were optimized using the test derived skins as a metric. Analysis of pressure data also played an important role in identifying reservoir compartmentalization. The two major reservoir horizons at MC 109 are interpreted as shelf margin deltas. However, each of these has distinctly different compartmentalization issues. The continuous character of the G Sand made it easier to define the depositional system and investigate reservoir compartmentalization issues using a combination of well log, 3D seismic, static pressure trends, and fluid information. In the more distal deltaic reservoirs of the J Sand however, complications with seismic amplitudes and a less reliable tie between wireline and seismic data required the use of pressure transient analysis to efficiently exploit the reservoir.

  6. Surface Casing Pressure As an Indicator of Well Integrity Loss and Stray Gas Migration in the Wattenberg Field, Colorado.

    Science.gov (United States)

    Lackey, Greg; Rajaram, Harihar; Sherwood, Owen A; Burke, Troy L; Ryan, Joseph N

    2017-03-01

    The risk of environmental contamination by oil and gas wells depends strongly on the frequency with which they lose integrity. Wells with compromised integrity typically exhibit pressure in their outermost annulus (surface casing pressure, SfCP) due to gas accumulation. SfCP is an easily measured but poorly documented gauge of well integrity. Here, we analyze SfCP data from the Colorado Oil and Gas Conservation Commission database to evaluate the frequency of well integrity loss in the Wattenberg Test Zone (WTZ), within the Wattenberg Field, Colorado. Deviated and horizontal wells were found to exhibit SfCP more frequently than vertical wells. We propose a physically meaningful well-specific critical SfCP criterion, which indicates the potential for a well to induce stray gas migration. We show that 270 of 3923 wells tested for SfCP in the WTZ exceeded critical SfCP. Critical SfCP is strongly controlled by the depth of the surface casing. Newer horizontal wells, drilled during the unconventional drilling boom, exhibited critical SfCP less frequently than other wells because they were predominantly constructed with deeper surface casings. Thus, they pose a lower risk for inducing stray gas migration than legacy vertical or deviated wells with surface casings shorter than modern standards.

  7. Soft-sensing for multilateral wells with downhole pressure and temperature measurements

    NARCIS (Netherlands)

    Kruif, B.J. de; Leskens, M.; Linden, R. van der; Alberts, G.J.N.

    2008-01-01

    Real-time monitoring of downhole oil, gas and water flows in wells can significantly improve the production performance of these wells when this flow rate information is used to manipulate inflow control valves. An example of this is the allocation of a gas or water cone to its entrance point in a m

  8. Properties of high-density, well-ordered, and high-energy metallic glass phase designed by pressurized quenching

    Science.gov (United States)

    Miyazaki, Narumasa; Lo, Yu-Chieh; Wakeda, Masato; Ogata, Shigenobu

    2016-08-01

    We applied gigapascal-level compressive hydrostatic pressure to the melt-quenching process of metallic glass to obtain a unique high-pressure glass state with high density that is well-ordered yet has high energy. This state contradicts the common understanding that high-density, well-ordered metallic glass states have low energy. Through molecular dynamics simulations, we found that the high-pressure glass state of the metallic glass Zr50Cu40Al10 has a rich anti-free volume and that its relaxation is dominated by the annihilation of full icosahedra and the rich anti-free volume. The aging rate of the high-pressure metallic glass state (energy reduction rate) is almost the same as that of typical high-energy metallic glass, suggesting that it has a lifetime similar to that of a typical high-energy metallic glass that has been experimentally realized and reported previously [Wakeda et al., Sci. Rep. 5, 10545 (2015)]. Thus, the high-pressure phase can be realized even under the experimental cooling rate, suggesting its suitability for practical applications.

  9. The relation between photoluminescence properties and gas pressure with [0001] InGaN single quantum well systems

    Science.gov (United States)

    Tsutsumi, Toshiaki; Alfieri, Giovanni; Kawakami, Yoichi; Micheletto, Ruggero

    2017-01-01

    We show for the first time that photoluminescence of InGaN single quantum wells (SQW) devices is related to the gas pressure in which the sample is immersed, also we give a model of the phenomena to suggest a possible cause. Our model shows a direct relation between experimental behavior and molecular coverage dynamics. This strongly suggests that the driving force of photoluminescence decrease is oxygen covering the surface of the device with a time dynamics that depends on the gas pressure. This aims to contribute to the understanding of the physical mechanism of the so-called optical memory effect and blinking phenomenon observed in these devices.

  10. Results of the latest transient well pressure tests at Cerro Prieto

    Energy Technology Data Exchange (ETDEWEB)

    Abril G, A.; Vargas G, C.

    1981-01-01

    The equipment used in the interference and two-rate flow tests carried out at the Cerro Prieto geothermal field during 1980 are described. The results of two interference tests are presented, one between wells M-110 and M-104, and the other between wells M-7 and Q-757. The data was interpreted using type curve matching analysis. Results of two-rate flow tests carried out in wells M-102 and M-7 are also discussed. A technique for making two-rate flow tests is proposed. This approach, which attempts to avoid the uncertainty of present flow-rate measurements, makes use of devices for direct measurements of separated water and steam. Conclusions based on the above interpretations and recommendations for future tests are presented.

  11. A numerical approach for pressure transient analysis of a vertical well with complex fractures

    Institute of Scientific and Technical Information of China (English)

    Yizhao Wan; Yuewu Liu; Wenchao Liu; Guofeng Han; Congcong Niu

    2016-01-01

    A new well test model for a vertical fractured well is developed based on a discrete-fracture model in which the fractures are discretized as one dimensional (1-D) entities. The model overcomes the weakness of complex meshing, a large number of grids, and instability in conventional stripe-fracture models. Then, the discrete-fracture model is implemented using a hybrid element finite-element method. Triangular elements are used for matrix and line elements for the fractures. The finite element formulation is validated by comparing with the semi-analytical solution of a single ver-tical fractured well. The accuracy of the approach is shown through several examples with different fracture apertures, fracture conductivity, and fracture amount. Results from the discrete-fracture model agree reasonably well with the stripe-fracture model and the analytic solutions. The advantages of the discrete-fracture model are presented in mesh gen-eration, computational improvement, and abilities to handle complex fractures like wedge-shaped fractures and fractures with branches. Analytical results show that the number of grids in the discrete-fracture model is 10%less than stripe-fracture model, and computational efficiency increases by about 50%. The more fractures there are, the more the com-putational efficiency increases.

  12. Numerical Simulation of Geostress and Pore Pressure Evolution around Oil or Water Well under Different Injection-Production Ratio

    Directory of Open Access Journals (Sweden)

    Liu Jian-jun

    2013-01-01

    Full Text Available Geostress evolution in the process of oil field development can directly influence wellbore stability. Therefore, it is significant to strengthen the research of the evolution rule for well drilling and casing protection. Considering the interaction between reservoir seepage and stress fields, a mathematical model to characterize the stress evolution around wellbore was built. Using the FEM Software ABAQUS, through numerical simulation, the authors studied the evolution features of pore pressure and stress changes with time under different injection-production ratio, which disclosed the dynamic change regulation of pore pressure and stress of surrounding rock nearby the injection and production wells. These results may have implications in the treatment of wellbore stability and optimizing the injection and production processes during oil and gas production.

  13. Development and field application of a novel emulsion system O/W for well drilling of low pressure reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Arellano, J.; Ojeda, A.; Blanco, J.; Medina, N.; Gutierrez, X.; Carrasquero, M.; Briceno, H. [PDVSA (Venezuela)

    2011-07-01

    In Venezuela, there are important reserves of hydrocarbons in low pressure reservoirs but accessing to these reserves is a major challenge. This paper presents a new oil in water emulsion (O/W) system, using fatty acids and their salts as surfactant additives for use in such reservoirs, and the results obtained in field applications. Emulsions were prepared using two oil types and multiple salt (KCl) concentrations. Tests were then conducted to determine their thermal stability and return permeability percentage. Results showed good tolerance of high concentrations of KCl, as well as good stability under high temperatures and a good rheological behavior. The field test showed that the O/W emulsion system presents technological and cost advantages over other commercial technologies. This paper presented a new oil in water emulsion system which is a good alternative to water based fluids for well drilling in low pressure reservoirs.

  14. The Novel Method to Estimate Effect of Cement Slurry Consistency toward Friction Pressure in Oil/Gas Well Cementing

    Directory of Open Access Journals (Sweden)

    Adrian Pattinasarany

    2012-11-01

    Full Text Available The aim of this study is to investigate effect of cement slurry consistency toward friction pressure during oil/gas cementing operation. Completion of an oil/gas well has become more important because the reserve has become harder to find. The oil/gas company cannot afford to lose million dollars they spent when locating, drilling and recovering the oil from the Earth if they failed it. The safety, health and environment also have become more important issue, because any completion problem can lead to prolong operation and creating more hazard and risk. Cementing operation plays a very important role during completion because it creates a secure conduit to bring the precious oil/gas to the surface and a place to install completion jewelry. During cementing operation lost circulation can be one of the serious problems that arise. Circulation is said to be lost when the cement slurry pumped flows into one or more geological formations instead of returning up casing annulus. This is due to sum of hydrostatic pressure and friction pressure is exceeding fracture gradient. Method that commonly used to calculate friction from American Petroleum Institute (API assumed the cement slurry will exhibit time independent nature. Cement slurry consistency was found to have significant effect to friction pressure.

  15. Pressure Study of Photoluminescence in GaN/InGaN/ AlGaN Quantum Wells

    Science.gov (United States)

    Perlin, Piotr; Iota, V.; Weinstein, B. A.; Wisniewski, P.; Osinski, M.; Eliseev, P. G.

    1997-03-01

    We have studied the photoluminescence (PL) from two commercial high brightness single quantum well light emitting diodes (Nichia Chem. Industs.) with In_xGa_1-x N (x=0.45 and 0.2) as the active layers under hydrostatic pressures up to 7 GPa. These diodes are the best existing light emitters at short wavelengths, having the emission wavelengths of 430 nm and 530 nm depending on the content of indium in the 30 Åthick quantum wells. Although these devices show a remarkable quality and efficiency (luminosity as high as 12 cd), the mechanism of recombination remains obscure. We discovered that the pressure coefficient for each of the observed PL peaks is dramatically (2-3 times) lower than that of the energy gap of its InGaN active layer. These observations, in conjunction with the fact that the observed emission occurs below the energy gap of the quantum well material, and also considering the anomalous temperature behavior of the emission (peak energy increasing with temperature) suggest the involvement of localized states and exclude a simple band-to-band recombination picture. These localized states may be tentatively attributed to the presence of band tails in the gap which stem from composition fluctuations in the InGaN alloy. vih>(figures)

  16. Complete Fiber/Copper Cable Solution for Long-Term Temperature and Pressure Measurement in Supercritical Reservoirs and EGS Wells

    Energy Technology Data Exchange (ETDEWEB)

    Pastouret, Alan [Draka Cableteq USA, Inc., North Dighton, MA (United States); Gooijer, Frans [Draka Cableteq USA, Inc., North Dighton, MA (United States); Overton, Bob [Draka Cableteq USA, Inc., North Dighton, MA (United States); Jonker, Jan [Draka Cableteq USA, Inc., North Dighton, MA (United States); Curley, Jim [Draka Cableteq USA, Inc., North Dighton, MA (United States); Constantine, Walter [Draka Cableteq USA, Inc., North Dighton, MA (United States); Waterman, Kendall Miller [Draka Cableteq USA, Inc., North Dighton, MA (United States)

    2015-11-13

    High Temperature insulated wire and optical fiber cable is a key enabling technology for the Geothermal Technologies Program (GTP). Without insulated electrical wires and optical fiber, downhole temperature and pressure sensors, flow meters and gauges cannot communicate with the surface. Unfortunately, there are currently no insulated electrical wire or fiber cable constructions capable of surviving for extended periods of deployment in a geothermal well (240-325°C) or supercritical (374°C) reservoir. This has severely hindered engineered reservoir creation, management and utilization, as hot zones and cool water intrusions cannot be understood over time. The lack of a insulated electrical wire and fiber cable solution is a fundamental limitation to the viability of this energy source. The High Temperature Downhole Tools target specification is development of tools and sensors for logging and monitoring wellbore conditions at depths of up to 10,000 meters and temperatures up to 374oC. It well recognized in the industry that no current electronic or fiber cable can be successfully deployed in a well and function successfully for more a few days at temperatures over 240oC. The goal of this project was to raise this performance level significantly. Prysmian Group’s objective in this project was to develop a complete, multi-purpose cable solution for long-term deployment in geothermal wells/reservoirs that can be used with the widest variety of sensors. In particular, the overall project objective was to produce a manufacturable cable design that can perform without serious degradation: • At temperatures up to 374°C; • At pressures up to 220 bar; • In a hydrogen-rich environment; and • For the life of the well (> 5 years). This cable incorporates: • Specialty optical fibers, with specific glass chemistry and high temperature and pressure protective coatings for data communication and distributed temperature and pressure sensing, and • High

  17. A method for the flow diagnosis and interpretation of a well test through the use of the pressure derivative function

    Energy Technology Data Exchange (ETDEWEB)

    Fernando Ascencio Cendejas; Fernando Samaniego Verduzco; Jesus Rivera Rodriquez

    1994-01-20

    This paper presents an alternative technique for transient pressure analysis. The new method is based on the pressure derivative function and the impulse theory. This method uses a mathematical and graphical evaluation of an equation of the type [t{sub corr,f}] t{sup nf}{Delta}p'{sub 1} = m{sup 1}{sub f}, where n{sub f} is related to the specific flow pattern toward the well and the constant m{sup 1}{sub f} with the formation conductivity. This procedure simultaneously allows the diagnosis of the flow pattern through the presence of a horizontal line of a graph of [t{sub corr,f}]t{sup nf}{Delta}p'{sub 1} versus t, and an estimation of the formation conductivity through the value of the constant m{sup 1}{sub f}, given by the intersection of this line with the ordinate axis. In the ordinate graphing group, t{sub corr,f} is a correction factor for variable rate producing conditions, approximately equal to unity for long producing times. For constant rate drawdown tests this factor is equal to one. f in this graphing group stands for the type of flow prevailing during a specific period of the test, i.e., spherical, linear, or radial. Variable well flow rates are also considered in the theory of analysis presented in this study. This new method is successfully applied to three field cases published in the literature.

  18. Grandparent Caregiving and Psychological Well-Being Among Chinese American Older Adults-The Roles of Caregiving Burden and Pressure.

    Science.gov (United States)

    Xu, Ling; Tang, Fengyan; Li, Lydia W; Dong, Xin Qi

    2017-07-01

    Though ample research on grandparent caregiving and psychological well-being outcomes exist in Western literature, little attention has been focused on Chinese American grandparents. Based on role enhancement and role strain theories, this study examined grandparent caregiving and psychological well-being among Chinese American older adults and tested whether caregiving burden or pressure from adult children moderated such association. We used the data from the Population Study of ChINese Elderly in Chicago (PINE), a population-based survey of community-dwelling Chinese older adults in the Greater Chicago area. Grandparents with grandchildren younger than 16 years old were selected for present study (N = 2,775). Negative binominal regression and logistic regression models were used to test the relationships of grandparent caregiving time and psychological well-being measured by depressive symptoms and quality of life. Grandparents reported an average of 11.96 hours a week for caring for grandchildren. Caregiving time had a significantly negative association with depressive symptoms, but not with quality of life. The association between grandparent caregiving and depressive symptoms was moderated by the perception of caregiving burden. No moderating effect of caregiving pressure from adult children was found. More time spending on grandparent caregiving is generally beneficial to Chinese American grandparents' psychological well-being, thus supporting role enhancement theory. However, this association depends on whether this experience is a burden to the grandparents, therefore role strain theory is also supported. Policies and programs are discussed to address the grandparenting experience in the Chinese American older adults.

  19. The effects of aerobic and anaerobic training on fitness, blood pressure, and psychological stress and well-being.

    Science.gov (United States)

    Norris, R; Carroll, D; Cochrane, R

    1990-01-01

    To determine whether fitness alters psychological and physiological indices of well-being, male police officers were assigned to either an aerobic or anaerobic training condition or to a no treatment control group. The training groups met three times per week in 45 min sessions aimed at improving either cardiovascular endurance or muscle strength. Aerobic fitness level, heart rate, blood pressure and self-report of stress and well-being were measured prior to and following 10 weeks of training. Post-training fitness measures confirmed the effectiveness of training and between group differences for physiological and self-report measures were found. Subjects undergoing aerobic training evinced larger changes on the self-report measures of well-being and stress than the anaerobic trainers and both groups showed significant improvement when compared to controls. This experiment provides support for the hypothesis that exercise, and in particular aerobic exercise, has positive effects of well-being. It is suggested that future research might usefully explore the particular contribution of different aspects of the training situation to these effects.

  20. Computer program for predicting surface subsidence resulting from pressure depletion in geopressured wells: subsidence prediction for the DOW test well No. 1, Parcperdue, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, J.C.; Carver, D.R.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    The nucleus-of-strain concept is used to construct a computer program for predicting surface subsidence due to pressure reduction in geopressured reservoirs. Numerical integration allows one to compute the vertical displacement of the ground surface directly above and beyond the aquifer boundaries which results from the pressure reduction in each of the small finite volumes into which the aquifer is partitioned. The program treats depth (measured from the surface to the mean thickness of the aquifer) as a constant. Variation in aquifer thickness is accounted for by linear interpolation from one boundary to its opposite. In this simple model, subsidence is proportional to the pressure reduction (considered constant in this presentation) and to but one physical parameter, Cm(1-..nu..), in which Cm is its coefficient of uniaxial compaction, and ..nu.. is Poisson's ratio.

  1. Well-test analysis for solution-gas-drive reservoirs. Part 3; A unified treatment of the pressure-squared method

    Energy Technology Data Exchange (ETDEWEB)

    Serra, K.V.; Peres, A.M.M. (PETROBRAS, Rio de Janeiro, RJ (Brazil)); Reynolds, A.C. (Tulsa Univ., OK (USA))

    1990-06-01

    This work considers the analysis of radial-flow, well-test pressure data under multiphase flow conditions. The authors show that drawdown- and buildup-pressure data can be analyzed to obtain estimates of effective permeability and the skin factor with a semilog plot of pressure squared vs. time. It is shown that the liquid Matthews--Brons--Hazebroek (MBH) functions can be used to obtain an approximate estimate of average reservoir pressure. A theoretical explanation for semilog analysis method based on the pressure-squared method is presented.

  2. 40 CFR 147.1803 - Existing Class I and III wells authorized by rule-maximum injection pressure.

    Science.gov (United States)

    2010-07-01

    ... authorized by rule-maximum injection pressure. 147.1803 Section 147.1803 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) STATE, TRIBAL, AND EPA-ADMINISTERED...—maximum injection pressure. The owner or operator shall limit injection pressure to the lesser of: (a) A...

  3. Cement compositions for cementing wells, allowing pressure gas-channeling in the cemented annulus to be controlled

    Energy Technology Data Exchange (ETDEWEB)

    Parcevaux, P.A.; Piot, B.M.; Vercaemer, C.J.

    1987-01-27

    The invention relates to cement compositions for cementing oil and geothermal wells. These compositions allow pressure gas-channeling to be effectively controlled up to more than about 485/sup 0/F. The compositions according to the invention comprise four essential constituents: a cement, a styrene-butadiene latex, a latex stabilizer, and water. The cement is a hydraulic cement belonging to any class among those currently used for cementing oil wells. The useful stabilizers according to the invention are anionic polyelectrolytes such as lignosulfanates and their desulfonated and/or resulfonated derivatives; sulfonated lignin-Kraft products; melamine-formaldehyde resins modified by a sulfonic acid or sulfite; formaldehyde/sulfonated naphthalene resins; or the condensation products of bi-nuclear sulfonated phenols and of formaldehyde. Preferred are the sodium salts of the condensation product of mononaphthalenesulfonic acid and of formaldehyde. The patent also includes a description of tests of various cement compositions of the invention, plus scanning electron microscope observations. 10 figs., 7 tabs.

  4. Origins of and countermeasures for the abnormal pressures in well production of the Ojarly gas field in the Right Bank of the Amu-Darya River, Turkmenistan

    Directory of Open Access Journals (Sweden)

    Peijun Zhang

    2017-01-01

    Full Text Available The Ojarly gas field, the major supplier of the Project Phase Ⅱ of the Right Bank of the Amu Darya River, is just small but valuable like a golden bean, although it has good reservoir properties and a high gas production capacity, the occurrence of continuous sharp decline of pressure in the well production shows a great difference from the previous well test program. In view of this, an integrated analysis method was established for the whole gas well production process to discover the three main reasons causing the abnormal well pressure. First, the formation energy and pressure dropped so fast that the wellhead pressure also fell over the period. Second, there was abnormal fluids pressure drop in the wellbore tube and throttling effect might occur in the production tube, so the pressure drop became abnormally increased. Third, due to the abnormally-increasing gas-yield pressure drop and unusually-decreasing gas productivity, the wellhead oil pressure dropped significantly. Also, through dynamic monitoring and in-depth analysis, it is also considered that due to the high density of drilling fluids and well-developed pores and caverns in the reservoirs, more and more barites separated from the fluids would be settled down covering the pay zones, so both the gas-generating capacity and production pressure significantly decreased. On this basis, some technical countermeasures were taken such as re-stimulation of reservoirs, removal of gas-producing channels, increase of seepage capacity, etc. In addition, by use of sand-flushing and acidizing, both the comprehensive skin factor and the production pressure drop were reduced to improve the well gas production capacity and maintain high productivity effectively. This study provides a technical support for long-term sustainable development and production of this gas field.

  5. Pressure tuning of strains in Zn{sub 1-x}Cd{sub x}Se/ZnSe single quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Z.Z.; Liang, X.X.; Ban, S.L

    2002-12-30

    The pressure tuning of strains in ZnCdSe/ZnSe single quantum wells is studied theoretically. It is shown that the tuning can still occur before the structural phase transition for the quantum wells with small Cadmium content and thinner ZnSe/ZnCdSe layers. The effects of the Cadmium content change on the tuning pressure and the separation between the heavy hole and the light hole are also demonstrated.

  6. A Semi-Analytical Method for Rapid Estimation of Near-Well Saturation, Temperature, Pressure and Stress in Non-Isothermal CO2 Injection

    Science.gov (United States)

    LaForce, T.; Ennis-King, J.; Paterson, L.

    2015-12-01

    Reservoir cooling near the wellbore is expected when fluids are injected into a reservoir or aquifer in CO2 storage, enhanced oil or gas recovery, enhanced geothermal systems, and water injection for disposal. Ignoring thermal effects near the well can lead to under-prediction of changes in reservoir pressure and stress due to competition between increased pressure and contraction of the rock in the cooled near-well region. In this work a previously developed semi-analytical model for immiscible, nonisothermal fluid injection is generalised to include partitioning of components between two phases. Advection-dominated radial flow is assumed so that the coupled two-phase flow and thermal conservation laws can be solved analytically. The temperature and saturation profiles are used to find the increase in reservoir pressure, tangential, and radial stress near the wellbore in a semi-analytical, forward-coupled model. Saturation, temperature, pressure, and stress profiles are found for parameters representative of several CO2 storage demonstration projects around the world. General results on maximum injection rates vs depth for common reservoir parameters are also presented. Prior to drilling an injection well there is often little information about the properties that will determine the injection rate that can be achieved without exceeding fracture pressure, yet injection rate and pressure are key parameters in well design and placement decisions. Analytical solutions to simplified models such as these can quickly provide order of magnitude estimates for flow and stress near the well based on a range of likely parameters.

  7. Topological phase transition and evolution of edge states in In-rich InGaN/GaN quantum wells under hydrostatic pressure.

    Science.gov (United States)

    Łepkowski, S P; Bardyszewski, W

    2017-02-08

    Combining the k · p method with the third-order elasticity theory, we perform a theoretical study of the pressure-induced topological phase transition and the pressure evolution of topologically protected edge states in InN/GaN and In-rich InGaN/GaN quantum wells. We show that for a certain range of the quantum well parameters, thanks to a negative band gap pressure coefficient, it is possible to continuously drive the system from the normal insulator state through the topological insulator into the semimetal phase. The critical pressure for the topological phase transition depends not only on the quantum well thickness but also on the width of the Hall bar, which determines the coupling between the edge states localized at the opposite edges. We also find that in narrow Hall bar structures, near the topological phase transition, a significant Rashba-type spin splitting of the lower and upper branches of the edge state dispersion curve appears. This effect originates from the lack of the mirror symmetry of the quantum well potential caused by the built-in electric field, and can be suppressed by increasing the Hall bar width. When the pressure increases, the energy dispersion of the edge states becomes more parabolic-like and the spin splitting decreases. A further increase of pressure leads to the transition to a semimetal phase, which occurs due to the closure of the indirect 2D bulk band gap. The difference between the critical pressure at which the system becomes semimetallic, and the pressure for the topological phase transition, correlates with the variation of the pressure coefficient of the band gap in the normal insulator state.

  8. Topological phase transition and evolution of edge states in In-rich InGaN/GaN quantum wells under hydrostatic pressure

    Science.gov (United States)

    Łepkowski, S. P.; Bardyszewski, W.

    2017-02-01

    Combining the k · p method with the third-order elasticity theory, we perform a theoretical study of the pressure-induced topological phase transition and the pressure evolution of topologically protected edge states in InN/GaN and In-rich InGaN/GaN quantum wells. We show that for a certain range of the quantum well parameters, thanks to a negative band gap pressure coefficient, it is possible to continuously drive the system from the normal insulator state through the topological insulator into the semimetal phase. The critical pressure for the topological phase transition depends not only on the quantum well thickness but also on the width of the Hall bar, which determines the coupling between the edge states localized at the opposite edges. We also find that in narrow Hall bar structures, near the topological phase transition, a significant Rashba-type spin splitting of the lower and upper branches of the edge state dispersion curve appears. This effect originates from the lack of the mirror symmetry of the quantum well potential caused by the built-in electric field, and can be suppressed by increasing the Hall bar width. When the pressure increases, the energy dispersion of the edge states becomes more parabolic-like and the spin splitting decreases. A further increase of pressure leads to the transition to a semimetal phase, which occurs due to the closure of the indirect 2D bulk band gap. The difference between the critical pressure at which the system becomes semimetallic, and the pressure for the topological phase transition, correlates with the variation of the pressure coefficient of the band gap in the normal insulator state.

  9. Kinky vitrinite reflectance well profiles: evidence of paleopore pressure in low-permeability, gas-bearing sequences in Rocky Mountain foreland basins

    Science.gov (United States)

    Law, B.E.; Nuccio, V.F.; Barker, C.E.

    1989-01-01

    Vitrinite reflectance (Rm) profiles of wells drilled in abnormally pressured, low-permeability gas-bearing sequences in Rocky Mountain foreland basins are commonly non-linear with two or more nonparallel segments. These kinky profiles are most likely due to perturbations of the thermal gradient caused by contrasting heat transfer processes associated with the development of abnormally high pressures. We interpret the intersection of the shallow and intermediate Rm segments to mark the approximate original boundary between normal-pressured, water-bearing rocks and underlying overpressured gas- and water-bearing rocks. The intersection of the intermediate and deep Rm segments marks the approximate original boundary between overpressured gas- and water-bearing rocks and underlying overpressured gas-bearing rocks. However, because overpressuring is a transient condition that eventually evolves into normal pressuring or underpressuring, these intersections may not coincide with the present top of abnormal pressuring. -from Authors

  10. Casing selection and correlation technology for ultra-deep, ultra-high pressure, high H{sub 2}S gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Y. [CCDC Drilling and Production Technology Research Inst., Guanghan, Sichuan (China); Southwest Petroleum Univ., Beijing (China). State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation; Lin, Y.; Taihe, S. [Southwest Petroleum Univ., Beijing (China). State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation; Liao, P.; Shen, X. [Southwest Oil and Gas Co., Daxian (China). Northeast Sichuan Gas Field; Liu, H.; Zhao, H. [CCDC Drilling and Production Technology Research Inst., Guanghan, Sichuan (China)

    2010-07-01

    This poster highlighted some economical and suitable methods of choosing well casings for ultra-deep, ultra-high pressure, ultra-high temperature wells where acid gas injection is used for enhanced recovery. In China's northern Sichuan province, such wells tend to be sour. Casing failures have occurred at well temperatures below 90 degrees C due to the severity of the sour environment and sulphide stress cracking (SSC) of carbon and low-alloy steels. The plastic creep of rock salt, gypsum and clay shale may create high external collapse pressure on the outside surface of the casing. Sulphur resistant casings, such as C110 are required to meet ultra-high pressure criteria of more than 100 MPa, and also to meet high sulphur resistance criteria. This poster outlined an economical and suitable method of string design combined with sulphur resistance packer completion technology to address this current problem. tabs., figs.

  11. Digital archive of drilling mud weight pressures and wellbore temperatures from 49 regional cross sections of 967 well logs in Louisiana and Texas, onshore Gulf of Mexico basin

    Science.gov (United States)

    Burke, Lauri A.; Kinney, Scott A.; Kola-Kehinde, Temidayo B.

    2011-01-01

    This document provides the digital archive of in-situ temperature and drilling mud weight pressure data that were compiled from several historical sources. The data coverage includes the states of Texas and Louisiana in the Gulf of Mexico basin. Data are also provided graphically, for both Texas and Louisiana, as plots of temperature as a function of depth and pressure as a function of depth. The minimum, arithmetic average, and maximum values are tabulated for each 1,000-foot depth increment for temperature as well as pressure in the Texas and Louisiana data.

  12. Blood Pressure Associated with Arsenic Methylation and Arsenic Metabolism Caused by Chronic Exposure to Arsenic in Tube Well Water.

    Science.gov (United States)

    Wei, Bing Gan; Ye, Bi Xiong; Yu, Jiang Ping; Yang, Lin Sheng; Li, Hai Rong; Xia, Ya Juan; Wu, Ke Gong

    2017-05-01

    The effects of arsenic exposure from drinking water, arsenic metabolism, and arsenic methylation on blood pressure (BP) were observed in this study. The BP and arsenic species of 560 participants were determined. Logistic regression analysis was applied to estimate the odds ratios of BP associated with arsenic metabolites and arsenic methylation capability. BP was positively associated with cumulative arsenic exposure (CAE). Subjects with abnormal diastolic blood pressure (DBP), systolic blood pressure (SBP), and pulse pressure (PP) usually had higher urinary iAs (inorganic arsenic), MMA (monomethylated arsenic), DMA (dimethylated arsenic), and TAs (total arsenic) than subjects with normal DBP, SBP, and PP. The iAs%, MMA%, and DMA% differed slightly between subjects with abnormal BP and those with normal BP. The PMI and SMI were slightly higher in subjects with abnormal PP than in those with normal PP. Our findings suggest that higher CAE may elevate BP. Males may have a higher risk of abnormal DBP, whereas females have a higher risk of abnormal SBP and PP. Higher urinary iAs may increase the risk of abnormal BP. Lower PMI may elevate the BP. However, higher SMI may increase the DBP and SBP, and lower SMI may elevate the PP. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

  13. Linear and nonlinear optical absorption coefficients and refractive index changes in modulation-doped quantum wells: Effects of the magnetic field and hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Nazari, M.; Karimi, M.J., E-mail: karimi@sutech.ac.ir; Keshavarz, A.

    2013-11-01

    In this study, the linear, the third-order nonlinear and total optical absorption coefficients and refractive index changes of a modulation-doped GaAs/Al{sub x}Ga{sub 1−x}As quantum well are investigated numerically. In the effective-mass approximation, the electronic structure of modulation-doped quantum well is calculated by solving the Schrödinger and Poisson equations self-consistently. Optical properties are obtained using the compact density matrix approach. The effects of structure parameters, the applied magnetic field and the hydrostatic pressure on the optical properties of the modulation-doped quantum well are studied. Results show that the resonant peaks shift toward the higher (lower) energies with the increase in the magnetic field (pressure). The magnitude of the resonant peaks of the optical properties decreases with the increasing magnetic field or pressure.

  14. Experimental and numerical simulations of bottom hole temperature and pre-ssure distributions of supercritical CO2 jet for well-drilling

    Institute of Scientific and Technical Information of China (English)

    王瑞和; 霍洪俊; 黄志远; 宋慧芳; 倪红坚

    2014-01-01

    The supercritical carbon dioxide (SC-CO2) drilling is a novel drilling technique developed in recent years. A detailed study of temperature and pressure distributions of the SC-CO2 jet on the bottom of a well is essensial to the SC-CO2 drilling. In this paper, the distributions of pressure and temperature on the bottom of the hole during the SC-CO2 jet drilling are simulated experimentally and numerically, and the impacts of the nozzle diameter, the jet length, and the inlet pressure of the SC-CO2 jet are analyzed. It is shown that, the bottom hole temperature and pressure increase with the increase of the nozzle diameter, and the bottom hole temperature reduces and the pressure increases first and then decreases with the increase of the jet length, indicating that the jet length has an optimum value. The increase of the inlet pressure can increase the temperature and pressure on the bottom, which has a positive effect on the drilling rate.

  15. Photoluminescence energy transitions in GaAs-Ga{sub 1-x}Al{sub x}As double quantum wells: Electric and magnetic fields and hydrostatic pressure effects

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, S.Y. [Grupo de Educacion en Ciencias Experimentales y Matematicas-GECEM, Facultad de Educacion, Universidad de Antioquia, AA 1226 Medellin (Colombia); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Duque, C.A., E-mail: cduque@fisica.udea.edu.c [Instituto de Fisica, Universidad de Antioquia, AA 1226 Medellin (Colombia)

    2009-12-15

    The photoluminescence energy transitions in GaAs-Ga{sub 1-x}Al{sub x}As coupled double quantum wells are presented by considering the simultaneous effects of applied electric and magnetic fields and hydrostatic pressure. Calculations have been made in the framework of the effective mass and parabolic band approximations and using a variational procedure. The electric field is taken to be oriented along the growth direction of the heterostructure whereas for the magnetic field both in-plane and in-growth directions have been considered. The results show that the hydrostatic pressure and the applied electric field are two useful tools to tune the direct and indirect exciton transitions in such heterostructures. Our results are in good agreement with previous experimental findings in double quantum wells under applied electric field and hydrostatic pressure.

  16. High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis

    Science.gov (United States)

    Kaminska, A.; Jankowski, D.; Strak, P.; Korona, K. P.; Beeler, M.; Sakowski, K.; Grzanka, E.; Borysiuk, J.; Sobczak, K.; Monroy, E.; Krukowski, S.

    2016-09-01

    High-pressure and time-resolved studies of the optical emission from n-type doped GaN/AlN multi-quantum-wells (MQWs) with various well thicknesses are analysed in comparison with ab initio calculations of the electronic (band structure, density of states) and optical (emission energies and their pressure derivatives, oscillator strength) properties. The optical properties of GaN/AlN MQWs are strongly affected by quantum confinement and polarization-induced electric fields. Thus, the photoluminescence (PL) peak energy decreases by over 1 eV with quantum well (QW) thicknesses increasing from 1 to 6 nm. Furthermore, the respective PL decay times increased from about 1 ns up to 10 μs, due to the strong built-in electric field. It was also shown that the band gap pressure coefficients are significantly reduced in MQWs as compared to bulk AlN and GaN crystals. Such coefficients are strongly dependent on the geometric factors such as the thickness of the wells and barriers. The transition energies, their oscillator strength, and pressure dependence are modeled for tetragonally strained structures of the same geometry using a full tensorial representation of the strain in the MQWs under external pressure. These MQWs were simulated directly using density functional theory calculations, taking into account two different systems: the semi-insulating QWs and the n-doped QWs with the same charge density as in the experimental samples. Such an approach allowed an assessment of the impact of n-type doping on optical properties of GaN/AlN MQWs. We find a good agreement between these two approaches and between theory and experimental results. We can therefore confirm that the nonlinear effects induced by the tetragonal strain related to the lattice mismatch between the substrates and the polar MQWs are responsible for the drastic decrease of the pressure coefficients observed experimentally.

  17. Pressure Transient Analysis and Flux Distribution for Multistage Fractured Horizontal Wells in Triple-Porosity Reservoir Media with Consideration of Stress-Sensitivity Effect

    Directory of Open Access Journals (Sweden)

    Jingjing Guo

    2015-01-01

    Full Text Available Triple-porosity model is usually adopted to describe reservoirs with multiscaled pore spaces, including matrix pores, natural fractures, and vugs. Multiple fractures created by hydraulic fracturing can effectively improve the connectivity between existing natural fractures and thus increase well deliverability. However, little work has been done on pressure transient behavior of multistage fractured horizontal wells in triple-porosity reservoirs. Based on source/sink function method, this paper presents a triple-porosity model to investigate the transient pressure dynamics and flux distribution for multistage fractured horizontal wells in fractured-vuggy reservoirs with consideration of stress-dependent natural fracture permeability. The model is semianalytically solved by discretizing hydraulic fractures and Pedrosa’s transformation, perturbation theory, and integration transformation method. Type curves of transient pressure dynamics are generated, and flux distribution among hydraulic fractures for a fractured horizontal well with constant production rate is also discussed. Parametric study shows that major influential parameters on transient pressure responses are parameters pertinent to reservoir properties, interporosity mass transfer, and hydraulic fractures. Analysis of flux distribution indicates that flux density gradually increases from the horizontal wellbore to fracture tips, and the flux contribution of outermost fractures is higher than that of inner fractures. The model can also be extended to optimize hydraulic fracture parameters.

  18. Broadband hydroseismograms observed by closed borehole wells in the Kamioka mine, central Japan: Response of pore pressure to seismic waves from 0.05 to 2 Hz

    Science.gov (United States)

    Kano, Yasuyuki; Yanagidani, Takashi

    2006-03-01

    We obtained broadband hydroseismograms by monitoring the pore pressure changes of a rock mass in the Kamioka mine, using borehole wells. The wellhead was sealed to maintain an undrained condition, under which there is no flow of water through the interface between the well and the rock mass. This reduces the wellbore storage effect, which can cause a high-frequency cutoff response for systems of conventional open wells and rock mass. Using these closed borehole wells, 16 hydroseismograms were recorded for earthquakes in a range of magnitudes of 4.5-7.9 and epicentral distances of 1.0°-71.6°. Direct P waves, SV waves converted to P, and Rayleigh phases are clearly observed on the hydroseismograms. The similarity between hydroseismograms and seismograms reveals a clear relationship between radial ground velocity and pore pressure. The relationship is expressed as a zero-order system, which is characterized by no distortion or time lag between the input and output, and the pore pressure has no coupling with shear deformation. These results are consistent with an undrained constitutive relation of linear poroelastic theory and confirm that the relation is valid for the seismic frequency range. We determined in situ values of pore pressure sensitivity to volumetric change of the rock mass, which were then used to estimate in situ Skempton coefficients with values of 0.70-0.85.

  19. Assessment of Well Safety from Pressure and Temperature-Induced Damage during CO2 Injection in Deep Saline Aquifers

    Science.gov (United States)

    Singh, A. K.; Delfs, J.; Goerke, U.; Kolditz, O.

    2013-12-01

    Carbon dioxide Capture and Storage (CCS) technology is known for disposing a specific amount of CO2 from industrial release of flue gases into a suitable storage where it stays for a defined period of time in a safe way. Types of storage sites for CO2 are depleted hydrocarbon reservoirs, unmineable coal seams and saline aquifers. In this poster, we address the problem of CO2 sequestration into deep saline aquifers. The main advantage of this kind of site for the CO2 sequestration is its widespread geographic distribution. However, saline aquifers are very poorly characterized and typically located at one kilometer depth below the earth's surface. To demonstrate that supercritical CO2 injection into deep saline aquifers is technically and environmentally safe, it is required to perform thermo-hydro-mechanical analysis of failure moods with numerical models. In the poster, we present simple process-catching benchmark for testing the scenario of compressed CO2 injection into a multi- layered saline aquifer.The pores of the deformable matrix are initially filled with saline water at hydrostatic pressure and geothermal temperature conditions. This benchmark investigates (i) how the mechanical and thermal stresses enhance the permeability for CO2 migration; and (ii) subsequent failures mode, i.e., tensile, and shear failures. The tensile failure occurs when pore fluid pressure exceeds the principle stress whereas the Mohr-Coulomb failure criterion defines the shear failure mode. The thermo-hydro-mechanical (THM) model is based on a ';multi-componential flow' module . The coupled system of balance equations is solvedin the monolithic way. The Galerkin finite element approach is used for spatial discretization, whereas temporal discretization is performed with a generalized single step scheme. This numerical module has been implemented in the open-source scientific software OpenGeoSys.

  20. The nonlinear optical rectification and second harmonic generation in asymmetrical Gaussian potential quantum well: Effects of hydrostatic pressure, temperature and magnetic field

    Science.gov (United States)

    Liu, Xin; Zou, LiLi; Liu, Chenglin; Zhang, Zhi-Hai; Yuan, Jian-Hui

    2016-03-01

    In the present work, the effects of hydrostatic pressure, temperature, and magnetic field on the nonlinear optical rectification (OR) and second-harmonic generation (SHG) in asymmetrical Gaussian potential quantum well (QW) have been investigated theoretically. Here, the expressions for the optical properties are calculated by the compact-density-matrix approach and iterative method. Simultaneously, the energy eigenvalues and their corresponding eigenfunctions have been obtained by using the finite difference method. The energy eigenvalues and the shape of the confined potential are modulated by the hydrostatic pressure, temperature, and magnetic field. So the results of a number of numerical experiments indicate that the nonlinear OR and SHG strongly depends on the hydrostatic pressure, temperature, and magnetic field. This gives a new degree of freedom in various device applications based on the intersubband transitions of electrons.

  1. Effect of conduction band nonparabolicity on the optical properties in a single quantum well under hydrostatic pressure and electric field

    Indian Academy of Sciences (India)

    S Panda; B Panda

    2012-05-01

    The effect of conduction band nonparabolicity on the linear and nonlinear optical properties such as absorption coefficients, and changes in the refractive index are calculated in the Al0.3Ga0.7As/GaAs heterostructure-based symmetric rectangular quantum well under applied hydrostatic pressure and electric field. The electron envelope functions and energies are calculated in the effective mass equation including the conduction band nonparabolicity. The linear and nonlinear optical properties have been calculated in the density matrix formalism with two-level approximation. The conduction band nonparabolicity shifts the positions of the optical properties and decreases their strength compared to those without this correction. Both the optical properties are enhanced with the applied hydrostatic pressure. While the absorption coefficients are bleached under the combined effect of high pressure and electric field, the bleaching effect is reduced when nonparabolicity is included.

  2. Effects of an Intense Laser Field and Hydrostatic Pressure on the Intersubband Transitions and Binding Energy of Shallow Donor Impurities in a Quantum Well

    Institute of Scientific and Technical Information of China (English)

    U. Yesilgul; F. Ungan; E. Kasapoglu; H. Sari; I. S(o)kmen

    2011-01-01

    We have calculated the intersubband transitions and the ground-state binding energies of a hydrogenic donor impurity in a quantum well in the presence of a high-frequency laser field and hydrostatic pressure.The calculations are performed within the effective mass approximation,using a variational method. We conclude that the laser field amplitude and the hydrostatic pressure provide an important effect on the electronic and optical properties of the quantum wells.According to the results obtained from the present work,it is deduced that (i) the binding energies of donor impurity decrease as the laser field increase,(ii) the binding energies of donor impurity increase as the hydrostatic pressure increase,(iii) the intersubband absorption coefficients shift toward lower energies as the hydrostatic pressure increases,(iv) the magnitude of absorption coefficients decrease and also shift toward higher energies as the laser field increase.It is hopeful that the obtained results will provide important improvements in device applications.

  3. Surge and swab pressures in wells with cross-section changes; Pressoes de surge and swab em pocos com variacao de secao

    Energy Technology Data Exchange (ETDEWEB)

    Fedevjcyk, Joao Victor; Junqueira, Silvio Luiz de Mello; Negrao, Cezar Otaviano Ribeiro [Universidade Tecnologica Federal do Parana (UTFPR). Laboratorio de Ciencias Termicas (Lacit) (Brazil)], e-mails: silvio@utfpr.edu.br, negrao@utfpr.edu.br

    2009-12-15

    Well drilling is performed by rotating and applying a weighted drill bit to the geological formation. Well diameter variations and the use of drill pipe accessories might cause changes to the annular cross section space between the drill pipe and the borehole. It should be noted cross section changes influence pressure losses within the well. This study proposes a mathematical/ numerical model to simulate the surge and swab problem in wells with variable cross section areas. The fluid flow yielded by the drill pipe motion is considered to be one-dimensional, isothermal, compressible and transient. The proposed model features the mass and momentum conservation equations, along with a state equation and a constitutive equation for Bingham or Power Law fluids. The governing equations were discretized by the Finite Volume Method. The well is assumed to be impermeable and the drill pipe end to be closed. The results were compared to measured data obtained at the Taquipe experimental well with good agreement. Predictions can now be made as to how changes in cross section areas may significantly affect the transient surge and swab pressures. (author)

  4. Optimation Pressure Loss to Oil Production System with Electrical Submersible Pump (ESP) at the Well A SW Field Bojonegoro, East Java

    Science.gov (United States)

    Ilmah, A. M.; Hendrajaya, L.

    2017-07-01

    Study about oil and gas well A and SW fields have been conducted in Bojonegoro area, East Java Province. From the research, it is known that one of the constrain in oil and gas production process is a pressure drop, so that is necessary to set Electrical Submersible Pump (ESP) as an artificial lift pump at low pressure wells. It is needed to analyze the production well pressure as an effort to optimize the fluid production. It is in describe to relations between IPR (Inflow Performance Relationship ) curve with TPR (Tubing Performance Relationship), are getting down point cut TPR curve with IPR curve, fluid rate its optimal, so need tubing’s diameter variation and the number of stage pump ESP variation to can the most optimal fluid rate. Produced that to tubing variation are 2,441 ID is 876,729 bpd, 2,991 is 961,197 bpd, 3,476 id is 996, 26 Bpd, while on the number of stage pump esp variation The most high is stage 400 with fluid rate 961,197 by comparison stage 338 it has value fluid rate 921,165 bpd, stage 200 it has fluid rate 827,889 bpd, and stage 169 has fluid rate 774,646 bpd. Of some variation tubing and stage pumps that has the most influence to fluid rate optimalize is the change number of stage pump.

  5. Enhancement of yield point at high pressure high temperature wells by using polymer nanocomposites based on ZnO & CaCO3 nanoparticles

    Directory of Open Access Journals (Sweden)

    A.Z. Noah

    2017-03-01

    Full Text Available Zinc oxide nanoparticles (ZnO-NPs and modified calcium carbonate (nano-CaCO3 nanoparticles were successfully prepared and added to polystyrene-butadiene rubber copolymer (PSBR matrix to prepare PSBR nanocomposites. The prepared nanomaterials (ZnO-NPs & nano-CaCO3 were characterized using scanning electron microscope (SEM, transmission electron microscope (TEM and X-ray diffraction (XRD. Furthermore, the prepared polymer nanocomposites and oil base mud were used for drilling in high pressure high temperature (HPHT wells. The consequence of using polymer nanocomposites based on different loading of ZnO-NPs and nano-CaCO3 on the rheological properties of oil base mud was evaluated and enhanced the yield point at high pressure high temperature wells (HPHT. The using of the polymer with different percentage from (0.5 in all percent the obtained results is very promising; this means that the increase of polymer is reasonable for the increase of apparent viscosity, plastic viscosity and yield point at high temperature. Correspondingly, polymer nanocomposites displayed rise of apparent viscosity, plastic viscosity, and yield point, decreased in fluid loss and increased in electrical stability at high pressure high temperature wells.

  6. The Forecast and Analysis of Pressure of Gas Well of Western Sichuan Gasfield%川西定向气井压力预测及分析

    Institute of Scientific and Technical Information of China (English)

    高升; 刘永辉; 章毅; 赖希; 李士国; 罗程程; 王武兵

    2012-01-01

    川西定向气井测压呈典型的两段分布,下部压降梯度大的原因是受到液相滑脱损失和倾斜段的影响。针对垂直段和倾斜段分别统计评价工程常用的气液两相管流压降模型:垂直段产气量低于1×104m3/d时采用无滑脱模型,否则采用Hagedorn&Brown模型;倾斜段采用DPI模型。组合建立适用于定向井的气液两相管流新模型。大牛地气田应用实践表明,新模型各项误差均小于5%,明显优于常规单一压降模型。%In western Sichuan gas field, measured pressure data in inclined gas well shows typical characteristics of two-stage. This paper analyzes the pressure gradient, and conclusion that it is influenced by gas-liquid slippage loss and inclined section. So we divided into vertical section and inclined section, and then statistically evaluate the common gas-liquid two phase pipe flow model. The conclusion is that the vertical gas production is less than 1 ~ 10~m3/d using no-slip model, otherwise we use Hagedorn and Brown model, and the DPI model is used in inclined section. Finally, forming a new model applies to inclined gas wells. Measured pressure data in Daniudi gasfield shows that the new model errors are less than 5%, and it is better than conventional model of pressure drop. Research results in deviated reservoir and condensate gas reservoir development have important application value and practical significance.

  7. Study of pressure decline on horizontal well after multiple-stage fracturing%水平井多段压裂后压力递减分析

    Institute of Scientific and Technical Information of China (English)

    李勇明; 翟锐; 高瑞民; 吴金桥; 申峰; 乔红军

    2012-01-01

    目前水平井多段压裂的应用越来越多,但是现有的压裂压力递减分析方法都是针对单条水力裂缝的.由于水平井多段裂缝闭合时,流体流动特征与直井单条裂缝具有明显不同,针对直井单条裂缝的压裂压力递减分析方法不适用于水平井多段压裂.考虑水平井多段裂缝闭合时的压力变化特点,对多段裂缝强制闭合与裂缝自然闭合进行了分析,建立了多段裂缝同时闭合的压力递减模型和裂缝参数解释方法,编制了水平井多段压裂后压力递减分析解释软件,并进行了实例分析.模拟结果表明,压力递减分析方法可以解释出水平井多段压裂的重要裂缝及储层参数,实例应用结果表明,由所建模型模拟出来的裂缝参数解释结果可靠,对水平井水力压裂理论的发展以及指导现场施工都有重要的意义和参考价值.%At present, the application of horizontal well multiple-stage fracturing becomes more and more popular. However, the existing model of pressure decline analysis aims primarily at single fracture. There are great differences in the flow performance of fluids between multiple-stage fractures and single fracture dunng the fracturing closure process. The model of pressure decline a-nalysis aiming at single fracture does not apply to the horizontal well multiple-stage fractures. Taking into account of the pressure change with the situation about the horizontal well multiple-stage fractures closure, this paper analyzes forced and natural closure of horizontal well after multiple-stage fracturing, and then establishes curve fitting method of related pressure decline model and fracturing parameters interpretation based on the pressure drop features while multiple-stage fractures are closing simultaneously, than we compiled the software about pressure decline analysis of horizontal well multiple-stage fracturing, and it has been used for the case analysis. The results show that this

  8. Intersubband optical absorption coefficients and refractive index changes in a graded quantum well under intense laser field: Effects of hydrostatic pressure, temperature and electric field

    Energy Technology Data Exchange (ETDEWEB)

    Ungan, F., E-mail: fungan@cumhuriyet.edu.tr [Department of Physics, Cumhuriyet University, 58140 Sivas (Turkey); Grupo de Materia Condensade-UdeA, Instituto de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Restrepo, R.L. [Grupo de Materia Condensade-UdeA, Instituto de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Escuela de Ingeniería de Antioquia AA 7516, Medellín (Colombia); Mora-Ramos, M.E. [Grupo de Materia Condensade-UdeA, Instituto de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Ave. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Morales, A.L.; Duque, C.A. [Grupo de Materia Condensade-UdeA, Instituto de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

    2014-02-01

    The effects of hydrostatic pressure, temperature, and electric field on the optical absorption coefficients and refractive index changes associated with intersubband transition in a typical GaAs/Ga{sub 0.7}Al{sub 0.3}As graded quantum well under intense laser field have been investigated theoretically. The electron energy eigenvalues and the corresponding eigenfunctions of the graded quantum well are calculated within the effective mass approximation and envelope wave function approach. The analytical expressions of the optical properties are obtained using the compact density-matrix approach and the iterative method. The numerical results show that the linear and nonlinear optical properties depend strongly on the intense laser field and electric field but weakly on the hydrostatic pressure and temperature. Additionally, it has been found that the electronic and optical properties in a GaAs/Ga{sub 0.7}Al{sub 0.3}As graded quantum well under the intense laser field can be tuned by changing these external inputs. Thus, these results give a new degree of freedom in the devices applications.

  9. Understanding the connection between spiritual well-being and physical health: an examination of ambulatory blood pressure, inflammation, blood lipids and fasting glucose.

    Science.gov (United States)

    Holt-Lunstad, Julianne; Steffen, Patrick R; Sandberg, Jonathan; Jensen, Bryan

    2011-12-01

    Growing research has demonstrated a link between spiritual well-being and better health; however, little is known about possible physiological mechanisms. In a sample of highly religious healthy male and female adults (n = 100) ages 19-59 (m = 28.28) we examined the influence of spiritual well-being, as measured by the Functional Assessment of Chronic Illness Therapy-Spiritual Well-Being (FACIT-Sp-Ex), on physiological risk factors for heart disease. Specifically we examined 24-h ambulatory blood pressure (BP), inflammation (hs-C-reactive protein), fasting glucose, and blood lipids. Regression analyses reveal that higher levels of spiritual-wellness (total FACIT-Sp-Ex score) was significantly related to lower systolic ambulatory BP (β = -.345; P < .001), diastolic ambulatory BP (β = -.24; P = .02), hs-C-reactive protein (β = -.23; P = .04), fasting glucose (β = -.28; P = .006), and marginally lower triglycerides (β = -.21; P = .09) and VLDL (β = -.21; P = .10) controlling for age, gender, and church attendance. Results remained generally consistent across the Meaning, Peace, Faith and Additional Spiritual Concerns subscales of the FACIT-Sp-Ex. Spiritual well-being may be cardio protective.

  10. Mittelplate A23. Completion of Germany's first pressure tight multi lateral well; Mittelplate A23. Komplettierung und Inproduktionsnahme von Deutschlands erster druckdichter Multilateralbohrung

    Energy Technology Data Exchange (ETDEWEB)

    Boor, C.; Seemann, G.; Kainer, T. [RWE Dea AG, Hamburg (Germany)

    2011-07-15

    Mittelplate Drilling and Production Island is located in the Southern part of the Wattenmeer National Park in the North German state of Schleswig-Holstein. The Wattenmeer tidal flatlands have been a National Park since 1985. Oil production from the island commenced in 1987, RWE Dea AG as the operator and Wintershall Holding GmbH as an equal partner, have already benefited from producing in excess of 25 million mt of crude oil. Mittelplate A23 is Germany's first pressure tight (TAML 5) multi lateral well. The advantage of using this technology was that 4000 m had to be drilled through only once in order to reach three different reservoir compartments. This significantly increased the commercial potential and will help to develop the field faster using fewer of the restricted number of slots. As the junction of Mittelplate A23 was placed in relative close proximity to a water injector, the junction had to be absolutely pressure-tight and withstand a minimum pressure differential of 450 bars to ensure that no water enters into the production stream. The motherbore has an overall length of ca. 5940 m (2865 mTVD) with a gross pay zone of 1800 m. A window was milled through the 9 5/8'' casing of the main bore at 4100 m, a 7.00'' and 5.00'' liner were installed to the lateral and added an additional 1200 m gross pay zone. To initiate the junction a Baker Hughes S-3 Hook Hanger System was installed. The Hook Hanger facilitated access to main bore and lateral providing selective re-entry capability to each branch. To provide pressure integrity at the junction a dual string completion was connected to the Hook Hanger to tie the two laterals together and seal off the junction. Two of the most important components of the junction completion are the Dual Seal Module (DSM) to connect the dual tubing strings with the Hook Hanger and the Selective Re-entry Tool (SRT) which acts as a transition point from dual to single string. After the two

  11. Building the model for pressure drop of choke in gas-well downhole%气井井下节流器压降模型的建立

    Institute of Scientific and Technical Information of China (English)

    蔡振华; 廖新维; 袁玉金

    2013-01-01

    Downhole choke plays an important role in natural gas production. It can reduce gas hydrate which will block production line. Other advantages include avoiding pressure surge and improving lifting water from downhole, etc. So this technology can Minimize the cost but bring some disadvantages as well. Such as pressure gauge can not be able reach middle depth of reservoir, so the pressure dada for production analysis and welltest is not real BHP. This paper is based on energy conservation, assuming process of gas flowing through choke is isentropic, applying PR state equation and other formula related to build the model of choke pressure drop. The program has been developed, and the result of model calculation was accurate with example.%井下节流器在天然气生产中有着重要作用,在气田尤其是苏里格气田有着大规模应用.节流器可以减少水合物生成,避免生产管线堵塞,降低井底压力激动,能有效提高气流携液能力并简化地面设备.与其他水合物预防方法相比,井下节流器成本较低,具有很好的经济效益.但同时也给生产带来一些不便,比如无法将压力计下到节流器以下,导致获得压力数据与实际井底流压相比存在节流压差,影响生产动态分析和试井解释的结果,导致解释结果有误差甚至错误,从而影响决策的正确性.以能量守恒为基础,假设气体通过节流器为等熵绝热过程,采用Peng-Robinson状态方程描述天然气节流的相平衡过程状态方程,结合其他经验公式建立井下节流器压降计算模型,并通过编程实现,化计算压差,经过实际案例验证,结果精确度较高.

  12. The well sorted fine sand community from the western Mediterranean Sea: A resistant and resilient marine habitat under diverse human pressures.

    Science.gov (United States)

    Dauvin, Jean-Claude; Bakalem, Ali; Baffreau, Alexandrine; Delecrin, Claire; Bellan, Gérard; Lardicci, Claudio; Balestri, Elena; Sardá, Rafael; Grimes, Samir

    2017-02-18

    The Biocoenosis of Well Sorted Fine Sands (WSFS) (SFBC, Sables Fins Bien Calibrés in French) is a Mediterranean community very well delimited by bathymetry (2-25 m) and sedimentology (>90% of fine sand) occurring in zones with relatively strong hydrodynamics. In this study focused on sites located along the Algerian, French, Italian and Spanish coasts of the Western Basin of the Mediterranean Sea (WBMS) we aim to compare the structure, ecological status and diversity of the macrofauna of the WSFS and examine the effects of recent human pressures on the state of this shallow macrobenthic community. We assess the ecological status and functioning of these WSFS using three categories of benthic indices: a) five indices based on classification of species into ecological groups, AMBI, BO2A, BPOFA, IQ and IP, b) the ITI index based on classification of species in trophic groups, and c) the Shannon H' index, and the Biological Traits Analysis (BTA), which is an alternative method to relative taxon composition analysis and integrative indices. Cluster analyses show that each zone show a particular taxonomic richness and dominant species. The seven benthic indices reveal that the macrobenthos of the WSFS of the four coastal zones show good or high Quality Status, except for one location on the Algerian coast (the Djendjen site) in 1997. BTA highlights the presence of three groups of species: 1) typical characteristic species; 2) indicator species of enrichment of fine particles and organic matter, and 3) coarse sand species which are accessorily found on fine sand. Finally, the WSFS which are naturally subject to regular natural physical perturbations show a high resilience after human pressures but are very sensitive to changes in the input of organic matter.

  13. Hydrostatic pressure effects on the {gamma}-X conduction band mixing and the binding energy of a donor impurity in GaAs-Ga{sub 1-x}Al{sub x}As quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Lopez, S.Y. [Facultad de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, C.P. 62210, Cuernavaca (Mexico)

    2007-06-15

    Mixing between {gamma} and X valleys of the conduction band in GaAs-Ga{sub 1-x}Al{sub x}As quantum wells is investigated taken into account the effect of applied hydrostatic pressure. This effect is introduced via the pressure-dependent values of the corresponding energy gaps and the main band parameters. The mixing is considered along the lines of a phenomenological model. Variation of the confined ground state in the well as a function of the pressure is reported. The dependencies of the variationally calculated binding energy of a donor impurity with the hydrostatic pressure and well width are also presented. It is shown that the inclusion of the {gamma}-X mixing explains the non-linear behavior in the photoluminescence peak of confined exciton states that has been observed for pressures above 20 kbar. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Fracturing Pressure Reducing Technique for Shale Gas Well in the Southeastern Sichuan%川东南页岩气井压裂降压技术

    Institute of Scientific and Technical Information of China (English)

    周成香; 周玉仓; 李双明; 胡圆圆

    2014-01-01

    In order to effectively stimulate the ultra-deep shale reservoirs in southeastern Sichuan and minimize the fracturing pressure ,some technical solutions were proposed ,such as optimization of perfora-tion parameters ,acid pretreatment before fracturing ,design of slick water system with high friction reduc-ing rate ,and application of lead silt slug techniques .Through analysis and calculation ,it was decided to use the φ89 mm perforating gun with type SDP40HMX28 8 charges for perforation at 18 shots/m and phase 60° .Based on core dissolution tests and characteristics of such ultra-deep shale reservoirs ,a formula of 15.0% HCl+1.5% HF+2.0% HT corrosion inhibitor+1.5% ferric ion stabilizer was determined .Ac-cording to the stratigraphic characteristics ,a laboratory experiment was performed and it revealed a slick water system consisting of 0.2% efficient friction reducer SRFR 1+0.3% compound anti-swelling agent+0.1% compound synergist + 0 .02% defoamer ,which is stable and easy to flowback ,with viscosity of a-bout 9 12 mPa · s ,friction reducing rate than 75% and formation damage less than 10% .Field application showed that the optimized perforation parameters could meet the requirement for perforation friction reduc-tion ;acid pretreatment before fracturing enabled the pressure reduced by 10 15 M Pa;the lead silt slug tech-nique could effectively reduce the friction due to fractures curvature ,thereby reducing the fracturing pres-sure .It showed that these technical solutions could help to reduce the fracturing pressure in ultra-deep shale gas wells in the southeastern Sichuan .%为实现川东南超深页岩储层有效改造,并最大限度地降低压裂施工压力,提出了优选射孔参数、进行压前酸液预处理、设计降阻率高的滑溜水体系及采用前置粉砂段塞技术等技术对策。通过分析和计算,采用φ89 mm射孔枪配合SDP40HMX288射孔弹,60°相位和18孔/m的孔密进行射孔。利用川东南超深页

  15. The hydrostatic pressure and temperature effects on hydrogenic impurity binding energies in lattice matched InP/In0.53Ga0.47As/InP square quantum well

    Science.gov (United States)

    Başer, P.; Elagoz, S.

    2017-02-01

    The on-center shallow-donor impurity binding energy in lattice matched InP/In0.53Ga0.47As square quantum well structure have been theoretically investigated using effective mass and variational techniques. The effects of hydrostatic pressure, temperature and well width has been calculated and the results are discussed.

  16. Simulation of surge and swab pressures in well drilling operations; Simulacao do problema de 'surge' e 'swab' em atividades de perfuracao de pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Fernando T.G.M.C. de; Kimura, Hudson Faglioni; Ramalho, Vanessa; Negrao, Cezar O. Ribeiro; Junqueira, Silvio L.M. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Martins, Andre Leibsohn [PETROBRAS, Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The movements of the well drilling pipe, known as trips, cause variations in the well inner pressure. When the pipe is moving downwards, in an operation called 'running', the pressure increases and is known as surge pressure and, when it is moving upwards, in an operation called 'pulling', the pressure decreases and it is so called a swab pressure. The study of this phenomenon is of great importance not only due to financial reasons but also for the determination of speeds and accelerations which should be used in running and pulling operations. Among the researchers have studied this problem, Fontenot and Clark are two of the most important. They formulated the problem solution through considerations about the friction factor. The present work's target is to develop a computational program which allows the calculus of those pressures, according to previous investigations and models found in the literature and for different types of fluids as well, such as Bingham fluid and Power Law fluid. (author)

  17. Effect of a pre-treatment of milk with high pressure homogenization on yield as well as on microbiological, lipolytic and proteolytic patterns of "Pecorino" cheese.

    Science.gov (United States)

    Vannini, Lucia; Patrignani, Francesca; Iucci, Luciana; Ndagijimana, Maurice; Vallicelli, Melania; Lanciotti, Rosalba; Guerzoni, Maria Elisabetta

    2008-12-10

    The principal aim of this work was to compare Pecorino cheeses obtained from ewes' milk previously subjected to high pressure homogenization (HPH) at 100 MPa with those produced from raw and heat treated ewes' milk. The HPH milk treatment induced a significant increase of the cheese yield and caused a reduction of enterococci, lactococci and yeasts in the curds. Enterococci cell loads remained at lower levels in cheeses obtained from HPH milk over the ripening period. Analyses of free fatty acids, Sodium Dodecil Sulphate (SDS)-PAGE profiles, Gas Chromatography-Mass Spectrometry-Solid Phase Microextraction (GC-MS-SPME) measurements of volatile compounds and sensory traits evidenced that the pressure treatment can be regarded also as a useful tool to differentiate products obtained from the same raw material. In fact such a milk treatment induced a marked lipolysis, an early proteolysis, a relevant modification of the volatile molecule profiles and sensory properties of Pecorino cheese.

  18. Comparative study of the hydrostatic pressure and temperature effects on the impurity-related optical properties in single and double GaAs-Ga{sub 1-x}Al{sub x}As quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Odhiambo Oyoko, H. [Department of Physics, Westville Campus, University of KwaZulu-Natal, Private Bag X 54001, Durban 4000 (South Africa); Porras-Montenegro, N. [Departamento de Fisica, Universidad del Valle, AA 25360, Cali (Colombia); Lopez, S.Y. [Facultad de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia)

    2007-07-01

    Using a variational technique within the effective mass approximation we have carried out a comparative study of the effect of hydrostatic pressure and temperature on the shallow-impurity related optical absorption spectra in GaAs-Ga{sub 1-x}Al{sub x}As single and double quantum wells. The results show a pressure dependent read-shift and a temperature dependent blue-shift in the optical absorption spectra. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. 存储式电子压力计在煤层气试井中的应用%Application of storage electronic pressure gauge in CBM well testing

    Institute of Scientific and Technical Information of China (English)

    杨新辉; 王盼; 王晨; 吕兆海

    2012-01-01

    The well testing is the main method to obtain the parameters of coal reservoir. The storage electronic pressure gauge has been widely used in the well testing. Field application shows that DDI storage electronic pressure gauge has good shock resistance and stability in well testing.%煤层气试井是获取煤储层参数的重要手段,而存储式电子压力计则是试井时广泛应用的仪器。通过对DDI型存储式电子压力计现场操作,以及试井实例应用,说明了其特点及其良好的抗震性和稳定性。

  20. RESEARCH ON CHARACTERISTICS AND DIFFERENCE OF BAROMETRIC PRESSURE EFFECT ON WELL WATER LEVEL%井水位气压效应特征差异研究

    Institute of Scientific and Technical Information of China (English)

    黄仲; 张卫华; 王慧; 张辉

    2012-01-01

    On the basis of geological structure background, the feature of barometer change and the structure of well hole in well network of the Three Gorges area, the characteristics and differences of barometer change in well water level are analyzed and the relation between it and the parameter of physical mechanics in water-bearing stratum is also studied. The results show that the characteristics and differences of inverted barometer effect in well water level have a certain relation with the lithology of water-bearing stratum and the depth of well hole.%基于三峡井网所在地的地质构造背景、气压变化特征和井孔结构,分析了整个井网井水位气压变化特征及其差异,以及与含水层物理力学参数之间的关系等.分析结果表明,承压井水位气压效应特征差异与含水层岩性、井孔深度有关.

  1. 超高压气井站场控制系统研究%Research on Control System of Super-high Pressure Gas Well

    Institute of Scientific and Technical Information of China (English)

    周晓; 四名; 邹凯

    2016-01-01

    This paper introduces the design of a RTU control system for super-high pressure gas wel based on the control wave redundant structure,integrated application of auto-control and touch screen terminal technology,with the function of output regulation,parameter monitoring and intel igent alarming,simulating manual operation steps,shut down the wel through pro-grammed language.The practical application shows that the system has the advantages of high stability and high intel igence.%介绍了一种基于CONTROL WAVE冗余架构的超高压气井RTU控制系统设计,集成运用自动化控制技术和触摸屏终端技术于一体,实现超高压气井的产量调节、参数监控和智能报警功能,模拟人工现场操作步骤,通过程序化的语言实现远程关井作业。实践应用表明该系统具有稳定性高、智能化程度高的优点。

  2. On Bottom-Hole Pressure Calculation of Ultra-Deep Natural Gas Wells%天然气超深井井底压力计算与应用

    Institute of Scientific and Technical Information of China (English)

    杨风杰; 胡晓芬; 鲁煜

    2015-01-01

    钻井液喷空后的井底压力可以精确计算,为正确地保证井底压力大于或等于地层压力提供了科学的数据.钻井液喷空后的深井超深井的天然气井 ,关井后的静气柱压力不是很小.井内有钻井液(或修井液)井底进入天然气时 ,井底压力在合理地处理井内天然气在井内的运移(体积法放压法)与二次循环法压井循环出进入井内的天然气是相同的 ,为钻井井控现场为避免压裂套管鞋处或地层压力低的地层提供了可靠的依据.%Bottom-hole pressure without drilling fluid can be accurately calculated to provide the scientific information for ensuring a bottom-hole pressure greater than or equal to formation pressure .Shut-in static gas pressure is not very small in deep or ultra-deep natural gas wells without drilling fluid .The bottom-hole pressure is the same while volumetric pressure release method or two-cycle method is used to deal with downhole natural gas ,providing a reliable basis for avoiding fracturing on casing shoe or on the formation with low pressure .

  3. Hierarchy Flow Measurement Technology for Water Injection Well Based on Differential Pressure Measurement%基于压差测量的注水井分层流量测量技术

    Institute of Scientific and Technical Information of China (English)

    刘均; 邹彦艳

    2015-01-01

    Based on differential pressure flow measurement technology,a downhole instrument for hierarchy flow measurement in water injection well was designed,which consist of the cone column,differential pressure transducer,signal processing circuit,ground control panel and the host computer;of it,the cone column pro-duces a flow-related pressure difference in the wellhole;and through measuring the small strain features,the capacitance differential pressure transducer transforms the pressure difference to the electric capacity to meas-ure the flow.This instrument can move along the well wall to measure hierarchy flow in the water injection well by calculating the differential flow.%基于压差流量测量技术,设计了用于测量注水井分层流量的分层测试流量计。该流量计由柱锥体、压差传感器、信号调理电路、地面控制板和上位机组成,柱锥体可在井筒内产生与流量直接相关的压力差,电容式压差传感器通过测量微小应变特性将电容差值转换为电压的变化,从而完成流量的测量。分层测试流量计能够沿井壁移动,通过计算不同位置流量差的方法测量出注水井各层的注入流量。

  4. Well cement aging in various H{sub 2}S-CO{sub 2} fluids at high pressure and high temperature : experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Jacquemet, N.; Pironon, J. [Nancy Univ. (France). CNRS-CREGU; BRGM, Orleans (France); Lagneau, V. [Mines Paris (France); Saint-Marc, J. [Total (France)

    2010-07-01

    The mitigation of residual gases from oil and gas wells was discussed with particular reference to the oil and gas industry's efforts to develop gas and oil reservoirs with high non-hydrocarbon content; reduce gas releases to the atmosphere; avoid expensive gas mineralization and storage; and re-inject gases into deep saline aquifers or depleted reservoir for enhanced oil recovery. The chemical reactions that occur between the well cement and the gas or brine within an acid gas geological storage site may alter the hydraulic properties of the material in terms of porosity, diffusivity and permeability. As a consequence, its mechanical strength may be affected. The well's sheath may provide a pathway for the hydrogen sulphide (H{sub 2}S) and carbon dioxide (CO{sub 2}) fluids to reach the surface. This study involved batch experiments at 500 bar and 120 degrees C to investigate the reactivity of a deep well cement analogue in contact with a brine with dissolved H{sub 2}S-CO{sub 2}; a dry H{sub 2}S-CO{sub 2} supercritical phase; and a two-phase fluid associating a brine with dissolved H{sub 2}S-CO{sub 2} and a H{sub 2}S-CO{sub 2} supercritical phase. The cement was carbonated by the CO{sub 2}. Different mineralogical alteration profiles were observed based on the various exposures. The study showed that H{sub 2}S reacts with the minor iron-bearing minerals of cement to form sulphate/sulphide mixtures. The maximum cement carbonation occurred within the dry supercritical phase without liquid water. The porosity decreased in all experiments from about 40 to 15 percent. A calcium carbonate coating precipitated on the surface cement because of the low W/R ratio in the reactor. This prevented further reactions when the cement was immersed in brine. tabs., figs.

  5. Application of Formation Testing While Drilling (GeoTap) for acquiring formation pressure data from the Azeri, Chirag and Guneshli wells which were drilled in the Khazarian-Caspian Sea of the Azerbaijan Republic

    Science.gov (United States)

    Amirov, Elnur

    2016-04-01

    A new technology to acquire wireline quality pressure tests using a Logging While Drilling approach has been successfully implemented few years ago in Azeri, Chirag and Guneshli wells which were drilled in the Khazarian-Caspian Sea of the Azerbaijan Republic. The Formation Tester While Drilling tool (GeoTap) uses a testing sequence similar to wireline tools. A single probe is extended to the borehole wall and a small pretest volume withdrawn from the formation. The resulting pressure transient is then analyzed for formation pressure, formation permeability and mobility information. Up-link and down-link capabilities have been added to achieve test control and quality feedback. An efficient downlink algorithm is used downhole to analyze the data. The parameters and pressure data are transmitted to the surface in real-time for continuous monitoring of the test. More detailed pressure data is recorded and retrieved after returning to surface. Use of a quartz gauge allows excellent accuracy. Azeri, Chirag and Guneshli fields consist of layered sand reservoirs alternation with shale sequences and detailed pressure data is acquired on a high percentage of wells in order to understand lateral and vertical continuity of different flow units. The formation tester can be utilized with the 'triple combo' Logging While Drilling string which eliminates the need to rig up wireline on many wells. Wireline formation tester runs are time consuming - particularly if high deviation or high overbalance conditions are encountered requiring pipe conveyed techniques. Non-Productive Time is high when the wireline tools are stuck and fishing operations are required. The Sperry Drilling GeoTap formation pressure tester service provides real-time formation pressure measurements. It bridges the critical gap between drilling safety and optimization, by providing early and reliable measurements of key reservoir properties, while improving reservoir understanding and completion design in real

  6. Mineralogical changes of a well cement in various H2S-CO2(-brine) fluids at high pressure and temperature.

    Science.gov (United States)

    Jacquemet, Nicolas; Pironon, Jacques; Saint-Marc, Jérémie

    2008-01-01

    The reactivity of a crushed well cement in contact with (1) a brine with dissolved H2S-CO2; (2) a dry H2S-CO2 supercritical phase; (3) a two-phase fluid associating a brine with dissolved H2S-CO2 and a H2S-CO2 supercritical phase was investigated in batch experiments at 500 bar and 120, 200 degrees C. All of the experiments showed that following 15-60 days cement carbonation occurred. The H2S reactivity with cement is limited since it only transformed the ferrites (minor phases) by sulfidation. It appeared that the primary parameter controlling the degree of carbonation (i.e., the rate of calcium carbonates precipitation and CSH (Calcium Silicate Hydrates) decalcification) is the physical state of the fluid phase contacting the minerals. The carbonation degree is complete when the minerals contact at least the dry H2S-CO2 supercritical phase and partial when they contactthe brine with dissolved H2S-CO2. Aragonite (calcium carbonate polymorph) precipitated specifically within the dry H2S-CO2 supercritical phase. CSH cristallinity is improved by partial carbonation while CSH are amorphized by complete carbonation. However, the features evidenced in this study cannot be directly related to effective features of cement as a monolith. Further studies involving cement as a monolith are necessary to ascertain textural, petrophysical, and mechanical evolution of cement.

  7. Simultaneous effects of hydrostatic pressure and applied electric field on the impurity-related self-polarization in GaAs/Ga{sub 1-x}Al{sub x}As multiple quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Restrepo, R.L.; Miranda, Guillermo L. [Fisica Teorica y Aplicada, Escuela de Ingenieria de Antioquia, A.A. 7516 Medellin (Colombia); Duque, C.A., E-mail: cduque_echeverri@yahoo.e [Instituto de Fisica, Universidad de Antioquia, A.A. 1226 Medellin (Colombia); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, CP 62209 Cuernavaca, Morelos (Mexico)

    2011-05-15

    A detailed theoretical study of the combined effects of hydrostatic pressure and in-growth direction applied electric field on the binding energy and self-polarization of a donor impurity in a system of GaAs-(Ga,Al)As coupled square quantum wells is presented. The study is performed in the framework of the effective mass and parabolic band approximations and using a variational procedure. The electron effective mass, the dielectric constant, the barrier height, the well sizes, all them varying with the hydrostatic pressure are taken into account within the study. The results obtained show that the impurity binding energy and its self-polarization bear strong dependencies with the hydrostatic pressure, the strength of the applied electric field, the width of the confining potential barriers, and the impurity position. - Research highlights: {yields} Impurity binding energy and self-polarization have a conjugate behavior in MQWs. {yields} Binding energy (self-polarization) is an increasing (decreasing) function of HP. {yields} For on-center impurity, the binding energy decreases with EF. {yields} For on-center impurity the self-polarization increases with EF.

  8. Acoustically-Controlled Oil Well Pressure Switch Development and Testing%油井声控压差平衡式开关控制器的研制与试验

    Institute of Scientific and Technical Information of China (English)

    陈江烨; 王一良; 侯庆春; 杨松

    2015-01-01

    为了克服传统油井找水工艺中施工复杂、生产周期长、费用高、准确性低等缺点,提高油井找水效率和准确性,研制了油井找堵水声控压差平衡式开关控制器。该开关控制器采用自适应动态压力平衡系统,其活塞阀开启和关闭时可承受20 M Pa压力差;采用油管传输声波信号的声波遥控技术,从地面遥控井下开关控制器开启、关闭,根据工艺要求进行分层开采或分段开采。室内静压试验表明,开关控制器在125℃、50 M Pa高温高压条件下,稳压30 min ,整体设备无渗漏无变形;耐压差试验表明,活塞在承受25 M Pa压差的情况下,压力平衡装置可以承受压差,电机驱动活塞做上下往复运动,动密封不渗不漏。现场试验表明,声波接收器接收地面指令后,可以控制电机驱动装置打开或关闭开关阀。试验结果表明,该开关控制器可为油井提高开采效率提供技术支持。%Conventional techniques for detecting in oil wells have been disadvantageous due to their complex process ,long production period ,high cost and low accuracy .In order to enhance the efficiency and accuracy of the techniques used for water detection and plugging ,an acoustic controlled pressure-bal-ance switch has been developed .With an adaptive dynamic pressure balance system ,piston valves in the switch can endure differential pressure up to 20 MPa during opening and closing processes .By means of re-mote acoustic controlled technique that transmits acoustic signals through tubing ,the down-hole switch can be controlled remotely on the ground to facilitate production in different layers (in vertical wells) or in different intervals (in horizontal wells) according to operational requirements .Laboratory static pressure testing shows that the switch can withstand high temperature up to 125 ℃ and high pressure up to 50 MPa for 30 min with no leak or deformation .Differential

  9. Relations between a novel, reliable, and rapid index of arterial compliance (PP-HDI) and well-established inidices of arterial blood pressure (ABP) in a sample of hypertensive elderly subjects.

    Science.gov (United States)

    Bergamini, L; Finelli, M E; Bendini, C; Ferrari, E; Veschi, M; Neviani, F; Manni, B; Pelosi, A; Rioli, G; Neri, M

    2009-01-01

    Hypertension is a risk factor for a long-lasting arterial wall-remodelling leading to stiffness. The rapid method measuring the pulse pressure (PP) by means of the tool of Hypertension Diagnostic Instruments (HDI) called PP-HDI, overcomes some of the problems arising with more-time consuming methods, like ambulatory blood pressure monitoring (ABPM), and give information about the elasticity of the arterial walls. We studied the relationship between the PP-HDI, the large artery compliance (LA-C) and small artery compliance (SA-C) and few well-established indices of arterial blood pressure (ABP) in a sample of 75 hypertensive subjects, aged 65 years and over. Significant correlations between LA-C and heart rate (HR), PP-ABPM and PP-HDI were found. SA-C relates with HR and systolic blood pressure (SBP) measured in lying and standing positions. Applying a stepwise regression analysis, we found that LA-C variance stems from PP-HDI and HR, while SA-C variance stems from SBP in lying position. Receiver operator characteristic (ROC) curves for thresholds of PP showed that PP-HDI reached levels of sensitivity/specificity similar to PP-ABPM. In conclusion, surveillance of ABP through hemo-dynamic indices, in particular of SBP, is essential, nevertheless the advantage of this control is not known in an elderly population where the organ damage is already evident. PP needs necessarily an instrumental measurement. The PP-HDI result is similar in reliability with respect to PPABPM, but is more rapid and well applicable in an elderly population.

  10. Hanford wells

    Energy Technology Data Exchange (ETDEWEB)

    McGhan, V.L.; Damschen, D.W.

    1977-06-01

    The Hanford Site contains about 2200 wells constructed from pre-Hanford Works days to the present. As of June 1977, about 1900 wells still exist, and about 850 of these existing wells were drilled to the ground-water table. About 700 of these wells (including about 24 farm wells) still contain water. The others have become dry through infiltration of sediments or a general lowering of the water table in their vicinity. This report, providing the most complete documentation of wells in and adjacent to the Hanford Site, supersedes all previous compilations of Hanford wells.

  11. 基于 LabVIEW 的高压气井环空带压管理系统应用%Research and Application of Management System of Sustained Casing Pressure for High-pressure Gas Well Based on LabVIEW

    Institute of Scientific and Technical Information of China (English)

    冯洁; 解秦保; 翟超; 王贝

    2016-01-01

    The sustained casing pressure (SCP)threatens the safety of gas production and environ-mental health.To effectively solve the problem in high-pressure gas wells,in this paper the causes of SCP was analyzed and then serious of management operation process for high-pressure gas wells was established.In connection with the production status in high pressure gas wells,the pressure transmitters were used and automatic pressure relief lines were added to the annulus connected valves in Christmas trees and then based on LabVIEW,with the DATAQ data acquisi-tion cards and PLC,a management system for SCP was developed to do the pressure relief/recov-ery monitoring and tests for gas leakage.The results show that the system is in high precision, stable and reliable,while also will save the labor costs and improve the management level of high pressure gas wells and risk-control techniques.%气井环空带压会严重威胁天然气的生产安全和环境健康。为有效管理高压气井环空带压问题,分析了高压气井环空带压原因,在此基础之上建立高压气井环空带压管理操作流程。针对高压气井生产动态,在采气树环空连通阀引入压力变送器与自动泄压管线,并基于 LabVIEW 平台,结合 DATAQ 数据采集卡、及 PLC 下位机,开发出高压气井环空压力管理系统。进而进行压力泄放/恢复监测与井口气体泄漏测试。结果表明,该系统测量精度高、运行稳定可靠,同时节省了人工成本,对提高高压气井动态管理水平与风险控制技术有重大意义。

  12. Well Spacing for Horizontal Wells

    Directory of Open Access Journals (Sweden)

    C.D.S. Keuengoua

    2011-06-01

    Full Text Available In the developing phase of a hydrocarbon reservoir and planning for drilling the production wells, it is necessary to drill the wells in an appropriate spacing to achieve maximum economic revenues during the reservoir life span. Well spacing which is the real location and interrelationship between producing oil or gas wells in an oil field is an important parameter. It is determined for the maximum ultimate production of a given reservoir and should be taken in consideration during well planning to avoid drilling of unnecessary wells. This study presents the concept of drainage area on horizontal well and horizontal productivity indices with different equations and their applications. A user friendly Excel Spreadsheet program was developed to calculate the productivity values of horizontal wells using three major available productivity equations. Also, the developed spreadsheet program was used to evaluate the effect of well spacing on the productivities of horizontal wells using productivity index approach and drainage area concept. It also helps to review the comparison between vertical and horizontal wells spacing based on drainage area concept. This program was validated, and then was used to study the effect of horizontal well length on the ratio of horizontal well productivity to vertical well productivity. The results show that higher ratio of horizontal well productivity to vertical well productivity values are obtained with increase length of the horizontal well. It is a very useful tool for making decision about the application of well spacing for horizontal wells.

  13. Impurity-related optical properties in rectangular-transverse section GaAs-Ga{sub 1-x}Al{sub x}As quantum well wires: Hydrostatic pressure and electric field effects

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, J.W.; Duque, C.A. [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Lopez, S.Y. [Facultad de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Rodriguez, A.H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico (UNAM), Apdo. Postal 20-364, San Angel 01000, Mexico DF (Mexico); Porras-Montenegro, N. [Departamento de Fisica, Universidad del Valle, AA 25360, Cali (Colombia)

    2007-01-15

    Using a variational procedure within the effective mass approximation, we have calculated the influence of an applied electric field and hydrostatic pressure on the shallow-impurity-related optical properties in a rectangular-transverse section GaAs-Ga{sub 1-x}Al{sub x}As quantum well wire. The electric field is applied in the plane of the transverse section of the wire and different angular directions have been considered. The results presented are for the impurity binding energy, its corresponding density of impurity states, and impurity-related transition energy and polarizability. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  14. Donor impurity-related optical absorption spectra in GaAs-Ga{sub 1-x}Al{sub x}As quantum wells: hydrostatic pressure and {gamma}-X conduction band mixing effects

    Energy Technology Data Exchange (ETDEWEB)

    Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, C.P. 62209, Cuernavaca, MOR (Mexico); Inst. de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain); Lopez, S.Y. [Fac. de Educacion, Universidad de Antioquia, AA 1226, Medellin (Colombia); Duque, C.A. [Inst. de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia); Velasco, V.R. [Inst. de Ciencia de Materiales de Madrid, CSIC, Sor Juana Ines de la Cruz 3, 28049 Madrid (Spain)

    2007-07-01

    Using a variational procedure within the effective mass approximation, the mixing between the {gamma} and X conduction band valleys in GaAs-Ga{sub 1-x}Al{sub x}As quantum wells is investigated by taking into account the effect of applied hydrostatic pressure. Some optical properties such as donor and/or acceptor binding energy and impurity-related transition energies are calculated and comparisons with available experimental data are presented. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Pressure Bearing and Contact Analysis of Ball Injection Sliding Sleeve in Horizontal Well Staged Fracturing%水平井分段压裂投球滑套承压接触分析

    Institute of Scientific and Technical Information of China (English)

    徐玉龙; 程智远; 刘志斌; 李世恒; 韩永亮; 周后俊

    2012-01-01

    Due to the fact that there is no jection sliding sleeve for horizontal well staged mature matching tool for open hole completion in China, the ball infracturing suitable for Sulige Gasfield was developed. In light of the problem that the sleeve is not noticeably in place in fracturing operation, the finite element analysis software was adopted to establish the contact model of the sleeve and analyze the effect of different pressures on low-density ball, ball seat deformation and stress distribution. The analysis shows that when the operation pressure changes from 10 MPa to 20 MPa, the contact pressure is approximate to a linear change. When the pressure increases from 20 MPa to 50 MPa, the plastic deformation occurs between ball and ball seat, the contact area increases and the contact pressure increase slows down. When the pressure is 50 MPa, the maximum stress value of the ball seat reaches 358 MPa, exceeding the yield strength of low-density ball and ball seat to cause plastic deformation. But it does not reach the yield limit, satisfying the field operation requirement.%鉴于国内还没有成熟的裸眼完井配套工具,研制了适合苏里格气田的水平井分段压裂投球滑套,并针对投球滑套在压裂施工中到位不明显的问题,利用有限元分析软件ANSYS建立了投球滑套的接触模型,分析了不同压力对低密度球和球座变形与应力分布的影响。分析结果表明,施工压力由10 MPa增至20 MPa时,接触压力近似线性变化,当压力从20 MPa增加到50 MPa时,球和球座之间开始产生塑性变形,接触面积增加,从而使接触压力增加变慢。当压力为50 MPa时,球座最大应力值达到358 MPa,超过了低密度球和球座的屈服强度而发生了塑性变形,但是没有达到材料的屈服极限,满足压裂施工的要求。

  16. Influence of working pressure and character traits of public security officers on subjective well-being%公安干警工作压力及性格特征对其主观幸福感的影响

    Institute of Scientific and Technical Information of China (English)

    吴喜强; 叶百维; 谢胜群; 徐娟; 刘永忠; 叶郁葱; 邬东红

    2015-01-01

    目的:调查公安干警工作压力及性格特征对公安干警主观幸福感的影响。方法采用整群随机抽样方法抽取2013年1~6月惠州市一县一区管辖内的公安分局、派出所的公安干警进行调查研究。公安干警压力源、A型行为类型评定量表、Campbell幸福感量表对公安干警进行工作压力及幸福感进行调查分析,并对公安干警工作压力及性格特征与主观幸福感的相关性进行分析。结果共发放550份问卷,可利用问卷为525份,可利用率为95.5%。不同性格特征(A型和B型)的公安干警工作压力评分结果显示,“工作任务本身”平均得分比较,差异无统计学意义(t=0.87,P>0.05),“组织和管理协调、人际和社会、自我能力和工作职业发展”比较,差异均有统计学意义(t=7.71、8.56、6.67、5.21,均P<0.05)。不同性格特征(A型和B型)的公安干警主观幸福感评分结果比较,“总体情感指数、生活满意、主观幸福感总分”比较差异均有统计学意义(t=8.77、9.81、6.96,均P<0.05)。公安干警工作压力、不同性格特征与主观幸福感均呈负相关(均P<0.05)。结论工作压力和不同的性格特征均影响着公安干警的主观幸福感。应采用合适的管理办法减轻公安干警的工作压力,进而减缓其心理压力,提高主观幸福感。%Objective To investigate the influence of working pressure and character traits of public security officers on subjective well-being.MethodsTo extract public security officers of public security subbureau and police station in one county one district of Huizhou city from January to June 2013 according to cluster random sampling, to make investigation and study. To make investigation and analysis of working pressure and subjective well-being of public security officers according to the pressure source, the rating scale of A behavior type, the well

  17. Hanford wells

    Energy Technology Data Exchange (ETDEWEB)

    McGhan, V.L.

    1989-06-01

    The Site Characterization and Assessment Section of the Geosciences Department at Pacific Northwest Laboratory (PNL) has compiled a list of wells located on or near the Hanford Site. Information has been updated on wells existing from the days before construction of the Hanford Works to the present. This work was funded by the US Department of Energy (DOE). The list of wells will be used by DOE contractors who need condensed, tabular information on well location, construction, and completion dates. This report does not include data on lithologic logs and ground-water contamination. Moreover, the completeness of this list is limited because of new well construction and existing well modifications, which are continually under way. Despite these limitations, this list represents the most complete description possible of data pertaining to wells on or adjacent to the Hanford Site. 7 refs., 1 fig., 2 tabs.

  18. 井下油套环空级联式光纤光栅压力传感器的研制%Fabrication of cascaded fiber grating pressure sensor for annulus of rod pumping wells

    Institute of Scientific and Technical Information of China (English)

    潘洪亮; 董惠娟; 何俊; 张广玉

    2012-01-01

    In order to realizethe pressure measurement with wide range in narrow sapce of annulus of rod pumping wells,a cascaded fiber grating pressure sensor has been developed.First,according to the actual working condition,a packaging structure of optical fiber grating pressure sensor is designed based on the combination of flat diaphragm and equal-strength beam.Using the method of cascading,the measuring range is expanded without changing the performance index of optical fiber grating,and the contradiction between pressure measurement range and sensitivity is solved.Then the rationality and feasibility of this structure are verified through mechanical analysis,and the temperature compensation method of cascaded pressure sensor is expounded.Finally,the experimental results show that the pressure measuring range is from 0 to 30 MPa,sensitivity is 329 pm/MPa,and linear degree is above 98%.The sensor is simple and small in structure,easy to realize,and the actual thickness is only 17 mm after assembling to the tube,which can satisfy requirements of pressure monitoring in annulus of rod pumping wells.%为了实现对油水井下油套环空中狭小空间大量程压力的监测,研制一种级联式的光纤光栅压力传感器。首先,根据实际工况,设计一种基于平膜片和等强度梁相结合的光纤光栅压力传感器封装结构;采用级联式的方法,在未改变原有光纤光栅性能指标的前提下,扩大传感器的测量范围,解决压力测量范围和灵敏度之间的矛盾;通过力学分析验证研制的传感器结构的合理性与可行性,同时阐明其温度补偿的方法。实验结果表明:本文传感器的测压范围为0~30MPa,灵敏度为329.5pm/MPa,线性度达到98%以上。并且传感器结构简单,尺寸小巧,易于实现,装配到油管后的实际厚度仅为17mm,能够满足油水井下油套环空中压力的监测要求。

  19. 缝洞型油藏钻遇溶洞油井的压力曲线特征%Pressure curve characteristics for wells drilled in cave of fracture-cavity carbonate reservoirs

    Institute of Scientific and Technical Information of China (English)

    刘洪; 任路; 胡治华

    2012-01-01

    Drilling stem emptying,massive mud leakage and acidification transformation appeared during the drilling process of fracture-cavity reservoirs,which increased difficulties for reservoir well test interpretation if using triple porosity well test method.It has great actual significance to establish well test interpretation model for wells drilled in cave and carry out well test interpretation of this reservoir.Based on the double porosity model,taking inner cave as an equipotential body whose internal pressure was equal everywhere,making outer fluid flow observe Darcy law,and according to cave mass conservation equation,a new well test interpretation model for wells drilled in cave was presented.Laplace transform and Stehfest reverse method were used to solve the model.The influences of cave storage ratio,size of cave,matrix interporosity flow coefficient and fracture storage ratio on the bottom pressure were analyzed.And the double log curve for wells drilled in cave of fracture-cavity carbonate reservoirs was used to interpret the measured pressure of some well in TZ area.Good results have been obtained,and this research can provide theory guidance for fracture-cavity reservoirs well test interpretation.%在缝洞型油藏实际钻井过程中经常出现钻杆放空、泥浆大量漏失等现象。这类油藏使用常规三重介质试井方法解释时困难较大,建立溶洞型储层试井解释模型并对这类油藏进行测试资料试井解释具有实际意义。在双重介质模型基础上,将溶洞简化为一个等势体,内部压力处处相等,溶洞外流体流动满足达西定律;基于溶洞质量守恒方程,建立了缝洞型油藏试井解释数学模型;采用Laplace变换和Stehfest数值反演算法得到了井底压力解析解;分析了溶洞储能比、溶洞大小、基质窜流系数、裂缝储能比等参数对井底压力及压力导数双对数曲线的影响。利用建立的钻遇溶洞模型双对数曲线图版对塔中地

  20. Well testing: interpretation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bourdarot, G. [Elf Aquitaine, 92 - Courbevoie (France)

    1998-12-31

    This book presents the different methods to use for interpreting well tests: conventional methods, type curves, derivative, according to the type of reservoir limits (faults, channels, secant faults, constant pressure limits, closed reservoir) and the well configuration (partial penetration, inclined, fractured, horizontal or injection well). It indicates the method to be used in the case of more complex reservoirs (fissured reservoirs, two-layered reservoirs), interference tests or pulse tests and when fluid produced is gas or polyphasic. (authors) 60 refs.

  1. Well testing: interpretation methods

    Energy Technology Data Exchange (ETDEWEB)

    Bourdarot, G. (Elf Aquitaine, 92 - Courbevoie (France))

    1998-01-01

    This book presents the different methods to use for interpreting well tests: conventional methods, type curves, derivative, according to the type of reservoir limits (faults, channels, secant faults, constant pressure limits, closed reservoir) and the well configuration (partial penetration, inclined, fractured, horizontal or injection well). It indicates the method to be used in the case of more complex reservoirs (fissured reservoirs, two-layered reservoirs), interference tests or pulse tests and when fluid produced is gas or polyphasic. (authors) 60 refs.

  2. Hanford wells

    Energy Technology Data Exchange (ETDEWEB)

    Chamness, M.A.; Merz, J.K.

    1993-08-01

    Records describing wells located on or near the Hanford Site have been maintained by Pacific Northwest Laboratory and the operating contractor, Westinghouse Hanford Company. In support of the Ground-Water Surveillance Project, portions of the data contained in these records have been compiled into the following report, which is intended to be used by those needing a condensed, tabular summary of well location and basic construction information. The wells listed in this report were constructed over a period of time spanning almost 70 years. Data included in this report were retrieved from the Hanford Envirorunental Information System (HEIS) database and supplemented with information not yet entered into HEIS. While considerable effort has been made to obtain the most accurate and complete tabulations possible of the Hanford Site wells, omissions and errors may exist. This document does not include data on lithologic logs, ground-water analyses, or specific well completion details.

  3. Cutting Under Pressure Technology for the Tubing String with Dual Packer in Gas Well%带压切割气井双封分压管柱工艺技术∗

    Institute of Scientific and Technical Information of China (English)

    谢涛; 杨红斌; 徐迎新

    2015-01-01

    复杂多个大直径工具管柱、腐蚀管柱和带喷砂器的管柱带压起钻工艺尚无有效方法,为此,研发了带压切割气井双封分压管柱工艺技术。该工艺技术采用专门的带压切割装置,利用切割刀具在装置内逐段切割,带压起出切割掉的油管,下带压密封捞矛打捞切割掉的油管鱼头,逐级起出复杂管柱。现场试验结果表明,气井带压切割工艺可以实现ø73�0 mm N80油管双封分压管柱的带压切割;对于腐蚀穿孔和双封分压以上复杂管柱可以采取装置内分段切割、密封打捞及分级起出的技术方案。%There is still no effective method of tripping out complex multiple large diameter tool string, corro⁃sion string and string with sandblast under pressure, to address the issue, a technology of cutting dual packer iso⁃lation string in gas well has been developed�A special device capable of cutting string under pressure is used to cut the string by cutter�After tripping out the cut tubing string section, run fishing spear for snubbing operation to fish the tubing string in well, thus, tripping out the complex string piece by piece�Field tests show that the cutting un⁃der pressure technology for gas well is fully capable of cutting the ø73�0 mm N80 tubing string with dual packer un⁃der pressure�For corrosion perforation and the complex string upper dual packer, cutting into piece, fishing with sealing and tripping out piece by piece could be a solution.

  4. Effects of germination and high hydrostatic pressure processing on mineral elements, amino acids and antioxidants in vitro bioaccessibility, as well as starch digestibility in brown rice (Oryza sativa L.).

    Science.gov (United States)

    Xia, Qiang; Wang, Liping; Xu, Congcong; Mei, Jun; Li, Yunfei

    2017-01-01

    The effects of germination and high hydrostatic pressure (HHP) processing on the in vitro bioaccessibility of mineral elements, amino acids (AAs), antioxidants and starch in brown rice (BR) were investigated. Germinated BR (GBR) was obtained by incubating at 37°C for 36h and then subjected to HHP treatments at 0.1, 100, 300 and 500MPa for 10min. The in vitro bioaccessibility of calcium and copper was increased by 12.59-52.17% and 2.87-23.06% after HHP, respectively, but bioaccessible iron was decreased. In addition, HHP significantly improved individual AAs, particularly indispensable AAs and gama-aminobutyric acid, as well as bioaccessible total antioxidant activities and starch resistance to enzymatic hydrolysis. However, germination greatly increased starch digestibility. Atomic force microscopy characterization suggested an obvious structural change in bran fraction at pressures above 300MPa. These results can help to understand the effects of germination and HHP technologies on nutrients bioaccessibility and develop appropriate processing conditions. Copyright © 2016. Published by Elsevier Ltd.

  5. Well production decline

    Energy Technology Data Exchange (ETDEWEB)

    Cvetkovic, Branimir

    2008-12-15

    Effective rate-time analysis during a declining production in an oil or gas wells is an important tool for establishing a successful management. The reasons behind the production decline include reservoir, fracture and well conditions. A well's decline rate is transient, signifying that the pressure wave propagates freely from the wellbore, leading to depletion when the outer boundary for the well is reached and to the wave propagation coming to a halt. This thesis studies the transient decline, with emphasis on a horizontal well with fracture wellbore responses. It also deals with the depletion decline, investigating the wellbore pressure responses for a vertical well producing under variable rate conditions of Arps decline. The well decline model solutions are analytical, and the modelling itself is carried out in two steps. The first step involves modelling the transient well responses of a multi fractured horizontal well. These responses originate from an infinitive reservoir and are considered as full-time rate-time responses. Multi-fractured horizontal well rate-time responses represent the solutions to a diffusion equation with varying boundary conditions and different fracture options (i.e., with or without fracture, a variety of fracture orientations, various fracture lengths, etc). The transient model calculates individual fracture rates, productivity indexes and an equivalent wellbore radius for the multi-fractured well. For the transient decline of a fractured-horizontal well model, well data is matched and the reservoir diagnosis and production prognosis are improved through the individual fracture production, with a model screening ability, and novel model features that can handle wellbore conditions changing from rate-to-pressure. Screening analyses can generate valuable information for fracture diagnosis in addition to a well and fracture production prognosis. Further model runs are carried out to match the real well data. The model solution is

  6. Effectiveness of tailored lifestyle interventions, using web-based and print-mail, for reducing blood pressure among rural women with prehypertension: main results of the Wellness for Women: DASHing towards Health clinical trial.

    Science.gov (United States)

    Hageman, Patricia A; Pullen, Carol H; Hertzog, Melody; Boeckner, Linda S

    2014-12-06

    Lifestyle modification is recommended for management of prehypertension, yet finding effective interventions to reach rural women is a public health challenge. This community-based clinical trial compared the effectiveness of standard advice to two multi-component theory-based tailored interventions, using web-based or print-mailed delivery, in reducing blood pressure among rural women, ages 40-69, with prehypertension. 289 women with prehypertension enrolled in the Wellness for Women: DASHing towards Health trial, a 12-month intervention with 12-month follow-up. Women were randomly assigned to groups using a 1:2:2 ratio, comparing standard advice (30-minute counseling session) to two interventions (two 2-hour counseling sessions, 5 phone goal-setting sessions, strength-training video, and 16 tailored newsletters, web-based or print-mailed). Linear mixed model methods were used to test planned pairwise comparisons of marginal mean change in blood pressure, healthy eating and activity, adjusted for age and baseline level. General estimating equations were used to examine the proportion of women achieving normotensive status and meeting health outcome criteria for eating and activity. Mean blood pressure reduction ranged from 3.8 (SD = 9.8) mm Hg to 8.1 (SD = 10.4) mm Hg. The 24-month estimated marginal proportions of women achieving normotensive status were 47% for web-based, and 39% for both print-mailed and standard advice groups, with no group differences (p = .11 and p = .09, respectively). Web-based and print-mailed groups improved more than standard advice group for waist circumference (p = .017 and p = .016, respectively); % daily calories from fat (p = .018 and p = .030) and saturated fat (p = .049 and p = .013); daily servings of fruit and vegetables (p = .008 and p theory-based lifestyle modifications can achieve a reduction of blood pressure and attainment of normotensive status. ClinicalTrials.gov NCT00580528.

  7. Optical and Electronic Properties of InGaN/GaN Multi-Quantum-Wells Near-Ultraviolet Lighting-Emitting-Diodes Grown by Low-Pressure Metalorganic Vapour Phase Epitaxy

    Institute of Scientific and Technical Information of China (English)

    李忠辉; 杨志坚; 秦志新; 童玉珍; 于彤军; 陆曙; 杨华; 张国义

    2003-01-01

    The near-ultraviolet lighting-emitting-diodes (UV-LEDs) with the InGaN/GaN multi-quantum-well (MQW)structure were grown by low-pressure metalorganic vapour phase epitaxy. The double crystal x-ray diffraction revealed a distinct second-order satellite peak. The near-ultraviolet InGaN/GaN MQW LEDs have been successfully fabricated to emit at 401.2nm with narrow FWHM of 14.3nm and the forward voltage of 3.6 V at 20mA injection current at room temperature. With increasing forward current from 10mA to 50mA, the redshift of the peak wavelength was observed due to the band-gap narrowing caused by heat generation.

  8. Militantly Well

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2015-01-01

    futures that transcend conflict engagement and wartime suffering for young militiamen. It clarifies the positive prospects that are expected to lie beyond the known horrors of war. Though conflict and warfare may provide strange points of departure for talking about well-being, imaginaries of happiness...... stand out from a background of hardship and are talked about in both a quite concrete way, as a lack of insecurity, as well as in an abstract way, as realization of social being. However, for most of the people I talk to, happiness remains elusive and evades their desperate attempts to grasp it....... It appears, as such, simultaneously to be what life is most profoundly about, as well as the dimension of it that constantly seems to avoid capture....

  9. Liver Wellness

    Science.gov (United States)

    ... can cause the liver to swell and not work well. Prevention: Hepatitis A vaccination is the best way to prevent HAV. Other ways to stop the spread of HAV are: • Always washing your hands with soap and warm water immediately after using the bathroom ...

  10. Wellness Matters

    Science.gov (United States)

    Arteaga, Brenda

    2011-01-01

    Creating a healthier school in today's world of budget cuts and seemingly endless to-do lists is not only possible, but it is also imperative. Beyond the health implications, one of the most compelling reasons for creating healthier schools is that wellness serves as a power booster for learning. Numerous studies have documented what educators…

  11. Wellness Matters

    Science.gov (United States)

    Arteaga, Brenda

    2011-01-01

    Creating a healthier school in today's world of budget cuts and seemingly endless to-do lists is not only possible, but it is also imperative. Beyond the health implications, one of the most compelling reasons for creating healthier schools is that wellness serves as a power booster for learning. Numerous studies have documented what educators…

  12. Werable wellness

    DEFF Research Database (Denmark)

    Rozycki, Bartosz

    2015-01-01

    We live in a world full of rush and a ‘relaxed state of being’ might increasingly play a role in today’s fast paced society to overcome contemporary stress and related illnesses such as burn-outs. The Sleephones concept is a wearable wellness device that aims to support relaxation by combing music...

  13. 莺歌海盆地高温低压定向井旋转尾管固井技术%Rotating Liner Cementing Technology for a Directional Well with High Temperature and Low Pressure in Yinggehai Basin

    Institute of Scientific and Technical Information of China (English)

    管申; 鹿传世; 方满宗; 张学佳; 林越青

    2012-01-01

    A deep directional Well A15 with typical high temperature and low pressure in Yinggehai Basin of South China Sea has small annular clearance in liner cementing. Using conventional liner cemen-ting method in the well could have such difficulties as poor displacement efficiency,gas channeling,lost cir-culation, such that good liner cementing quality would hardly be guaranteed. In order to improve the liner cementing quality, rotating liner cementing and high temperature anti-gas channeling cement slurry were used, together with oil based flushing fluid and spacer. By rotating torque and liner centering degree simula-tion,the Φ177. 8 mm liner cementing job in this high temperature and low pressure reservoir has been suc-cessfully completed. Sector Bond Tool (SBT) logging proved that Well A15 is highly improved in cement slurry displacement efficiency; with satisfactory cementing quality at gas-water interlayer and perforation intervals,qualified seal of high pressure water layers compared with offset wells cemented by conventional liner cementing method. The successful application of rotating liner cementing has offered a new solution for HTLP deep directional wells in gas field in Yinggehai Basin.%南海莺歌海盆地某气田A15井是一口典型的高温低压定向深井,井底温度高、地层压力低、尾管固井环空间隙小,若采用常规尾管固井技术固井顶替效率低,易发生气窜和漏失,高温低压气层井段的封固质量难以保证.为提高该井尾管固井的质量,该井采用了旋转尾管固井技术和高温胶乳防气窜水泥浆体系,与优选出的油基钻井液冲洗液和隔离液配合,通过预测旋转扭矩和尾管的居中度,完成了该井高温低压储层段(φ)177.8 mm尾管固井作业.高清扇区水泥胶结测井结果证实,该井尾管固井井段气水隔层和射孔井段封固质量达到良好,高压水层封固质量合格,与采用常规固井技术的邻井A9井相比,尾

  14. A comprehensive prediction model of wellbore temperature, pressure and accumulated liquid for gas wells%气井井筒温度、压力与积液综合预测模型

    Institute of Scientific and Technical Information of China (English)

    李波; 王军磊; 宁波; 苏海洋

    2014-01-01

    气井积液是产水气藏开发设计和气井生产管理面临的重要问题,但目前对气井流动机理与携液预测还存在争议。从气液两相流的基本流动机理出发,建立了考虑液滴变形和井斜影响下气井井筒的流型、温度、压力与携液综合预测模型,并用实际井数据对模型进行了验证。结果表明,所建模型可用于直井、斜井和水平井的产水气井井筒温度压力预测,预测误差小于5%;在环雾状流动情况下,井筒内液体以液滴和液膜的形式被完全带出井口,不会出现井筒积液;对常规垂直气井,利用井口数据便能判断气井积液情况,Turner 模型计算气井携液临界值较实际值偏大,李闽模型计算结果明显偏小,建议采用彭朝阳模型计算气井携液临界值;对斜井和水平井,则需要同时考虑液滴变形和井斜的影响,水平井近水平段携液临界流速和流量明显较垂直井段小,而造斜井段携液临界流速和临界流量随井斜角的增大先增大后减小,在井斜角为30°~60°之间达到最大值,因此造斜井段是气井积液判断的重点部位。%Accumulated fluid in gas well is a key issue confronted in development design of water-producing gas pools and pro-duction management of gas wells, but at present, there are controversies on flow mechanism and water carrying prediction in gas wells. From the basic flow mechanism of two-phase flow of gas and liquid, a comprehensive prediction model was built to predict the flow pattern, temperature, pressure and water-carrying in gas wells, and this model was verified using actual well data. The result shows that the model so built can be used to predict the wellbore temperature and pressure of water-producing vertical wells, deviated wells and horizontal wells, and the prediction error is less than 5%. Under condition of annular mist flow, the fluid in the wellbore is carried out of the wellhead

  15. 工作压力及性格特征对儿科护士主观幸福感的影响%Influence of working pressure and personality characteristics of pediatric nurses subjective well-being

    Institute of Scientific and Technical Information of China (English)

    何爱华; 邓春友; 吴辉霞; 许新连; 罗丽梅

    2014-01-01

    Objective To explore the impact of job stress and personality characteristics of pediatric nurses on the subjective well-being, and to provide basis for the optimization of human resource management in the hospital setting. Methods Two pediatric hospitals in Huizhou City as a sample, cluster random sampling method was used, 252 pedi-atric registered nurses from 15 general hospitals and 2 maternal and child health hospital were investigated and evalu-ated. All nurses were received by the working pressure Chinese nurse scale, Campbell well-being scale and type A be-havior questionnaire, data was recorded and analyzed. Results The pediatric nurses of three hospitals in total SWB score was (8.3±1.2) scores, which was higher than that of grade two hospitals [(7.1±1.1) scores], the difference was sta-tistically significant (P<0.05). Three level hospital work pressure scale was (87.0±7.3) scores, which was lower than the two hospital [(103.2±6.7) scores], the difference was statistically significant (P<0.05). A pediatric nurses subjective well-being scores was (7.9±1.4) scores, which was lower than that of B [(9.2±2.3) scores], the difference was statistical-ly significant (P<0.05). Working pressure of A nurses score was (109.2±9.7) scores, which was higher than that of B genotype [(99.2±8.4) scores], the difference was statistically significant (P<0.05). Department of pediatrics nurse work-ing pressure and the scores of subjective well-being was negatively correlated with total score (r = -0.19, P<0.05), which was positively related with hurry feeling, seek to prevail over others and hostile, A criminal behavior type score (r = 0.34, 0.30, 0.39, P< 0.05). Conclusion Three grade hospital pediatric nurses work pressure is lower than the two level of hospital, subjective well-being is higher than the two level of hospital, and type A behavior character easy will reduce the subjective well-being, hospital managers should be given such groups enough care and attention

  16. 高压气井完井管柱的流固耦合振动模型及其应用%A fluid-solid coupled oscillation model for completion string and its application in high pressure gas well

    Institute of Scientific and Technical Information of China (English)

    樊洪海; 王宇; 张丽萍; 杨行; 杨向同; 魏峰

    2011-01-01

    瞬态压力冲击诱发充液管道结构耦合振动,剧烈的振动将导致管道结构失效.笔者将进一步阐明天然气的瞬变流动诱发高压气井完井管柱的耦合振动过程.根据充液管道流固耦合振动模型,推导了适用于气井完井管柱的流固耦合振动四方程模型,采用特征线法及线性插值方法进行数值求解.以现场一口高压气井井口阀门开启过程中的瞬态响应为例,结合完井管柱系统的初边值条件,利用MATLAB语言编制了相应的计算机程序,计算分析了流体与管柱的耦合振动响应过程.计算结果表明:天然气的瞬变流动通过泊松耦合效应诱发完井管柱轴向往复运动,轴向往复运动将加剧完井管柱结构的疲劳破坏与磨损破坏.该结果对预防完井管柱先期失效有实际工程意义.%Transient pressure fluctuations in a liquid-filled pipe could induce coupled oscillations of pipe structures, even a structural failure if severe.The present paper elaborated the coupled oscillation process of completion string induced by transient flow of natural gas, and a fluid-solid coupled oscillation four-equation model applicable to completion string in gas wells was derived based on the fluid-solid coupled oscillation model for liquid-filled pipes.The model was numerically solved by the characteristic method and linear interpolation.Taking a transient flow caused instantaneously by opening the valve of a high-pressure gas well as an example, a corresponding software, combined with initial and boundary conditions, was programmed with the MATLAB code, which could calculate and analyze the process in response to coupled oscillations derived from fluid and pipe string.The calculation indicated that the transient flow of natural gas could induce an axial reciprocation of completion string by the Poisson coupling effect, which would aggravate the structural damage of completion string via stress fatigue and rubbing abrasion

  17. 基于压力恢复曲线的油井堵水决策技术%Decision-making technique of oil well water plugging based on pressure buildup curve

    Institute of Scientific and Technical Information of China (English)

    曲占庆; 张杰; 齐宁; 曲永林; 王荣

    2013-01-01

    从渗流力学基础理论出发,利用压力恢复曲线,建立数学模型并推导出计算油井堵水的决策指数fPBD的公式,在此基础上,结合影响堵水油井选择的含水上升率指数和剩余油饱和度两个因素,运用综合模糊评判方法求取油井堵水综合决策值,对需堵水的油井进行选择.对垦东521区块某小块7口油井进行堵水选井决策.结果表明:fPBD与水相渗透率相关,可以作为堵水油井决策的依据;该决策选井方法考虑因素完善、数据易取、决策准确,与成功的经验选井方法得出结果吻合程度较高.%The mathematical model and decision-making index (fPBD) of water shutoff can be established using the seepage mechanics theory and pressure buildup curve.The target wells were selected based on the fPBD value,water cut rising index,remaining oil saturation and water shutoff comprehensive decision value obtained by fuzzy evaluation method.Seven production wells in KD521 block were chosen.The results show thatfPBD is related to water permeability,which can be considered as the foundation of water shutoff decision-making.The decision method of selecting well is characterized by taking into account all the factors,data easy to be obtained,and precise decision.The results agree well with that of experienced well selection method.

  18. Calculation of leakage rate in casing annular of high pressure gas well containing acidic media%高压、含酸性介质气井油套环空泄漏速率计算

    Institute of Scientific and Technical Information of China (English)

    王云; 王晓冬; 佘治成

    2014-01-01

    The primary cause for failure of gas well integrity is pipe string leakage, which leads to anomalous annular pressure in gas wells and hence threatens safe production of gas wells. The leakage rate of annulus is the core parameter to judge whether the gas well integrity fails. At present, some companies abroad have instrument which can measure the annular leakage rate at ifeld;but there is no reliable domestic method to determine the annular leakage rate. This paper presents two ways to calculate the annular leakage rate:one is the safety valve method, which makes reference to the leakage rate of downhole safety valve; the other is differential method, which establishes the theoretical model for gas to be leaking in the annulus and determines the boundary conditions by the leakage model through small holes on gas lines. Due to the effect of ifeld pressure relief data, the downhole safety valve method is not applicable on site, so the differential method may be used to calculate the annular leakage rate. The differential method was used for example veriifcation in DN2 gas ifeld of Tarim Oilifeld, and the result agreed well with the real situation, showing that this method for annular leakage rate calculation is reliable and is of some reference signiifcance to the ifeld.%气井完整性失效最根本的原因就是管柱发生泄漏,从而导致气井环空异常带压,威胁气井安全生产。环空泄漏速率是判断气井完整性是否失效最核心的参数。目前,有国外石油公司通过设备现场测量环空泄漏速率,国内还未有可靠的方法确定环空泄漏速率。提出了两种环空泄漏速率的计算方法:一是安全阀法,借鉴井下安全阀泄漏速率的判别方法;二是微分法,建立气体在环空泄漏的理论模型,并通过输气管道小孔泄漏模型确定边界条件。由于现场泄压数据的影响,井下安全阀法不适用于现场,可采用微分法进行环空泄漏速率计

  19. Temperature stable low density slurry for low pressure loss deep wells%低压易漏深井大温差低密度水泥浆体系

    Institute of Scientific and Technical Information of China (English)

    黎泽寒; 李早元; 刘俊峰; 岳家平; 李怀仲; 郭小阳

    2012-01-01

    针对塔中低压深井长封固段大温差固井面临的低密度水泥浆高温稳定性差、易漏失、返出井口后长时间无强度等固井技术难题,开展了密度1.20~1.60 g/cm3大温差低密度水泥浆体系研究.从抗压、抗剪切性能、颗粒形态等方面对漂珠进行优选;基于颗粒级配原理,从提高水泥浆稳定性和抗压强度出发对减轻剂、填充剂、超细材料进行优选及合理组配,结合缓凝剂和降失水剂之间的协同作用,设计出一套长封固段大温差低密度水泥浆体系.实验结果表明:该低密度水泥浆体系流变性好,失水低,模拟工况条件下,水泥浆上下密度差小于0.02 g/cm3,稠化时间和强度发展满足施工要求,能满足温差70~120 ℃、一次性封固6 000m左右的固井需要.%To solve the cementing difficulty that the low density slurry has poor temperature stability and loss issues, and has no strength during a long period after the flowback, faced by the situation of low pressure deep well in Tazhong area cementing long vertical section with big temperature difference, it is studied that the temperature stable of low density slurry with density of 1.20~ 1.60 g/cm3. The floating potential is optimized from the aspects of pressure and shearing resistance and grain morphology. Based on grain composition principle, the light weight additive, filling agent, and superfine material are screened and matched, in view of improving slurry stability and pressure strength. Combining with the synergetic effect between retarder and filtrate reducer, a type of temperature stable low density slurry for long cementing sections is obtained. The results show that the slurry system has good rheology and low loss, and the density difference in the wellbore is lower than 0.02 g/cm3. The thickening time and strength increase satisfy with operation demand, especially the cementing need of temperature difference of 70~120℃ and cementing length of 6 000 m

  20. Well test analysis for Devonian-shale wells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Serra, K.; Chen, C.C.; Yeh, N.S.; Ohaeri, C.; Reynolds, A.C.; Raghavan, R.

    1981-09-30

    This work presents broad interpretive rules for analyzing Devonian Shale Wells based on simulated drawdown and buildup tests. The report consists of four parts: (1) New Pressure Transient Analysis Methods for Naturally Fractured Reservoirs, (2) Pressure Transient Analysis Methods for Bounded Naturally Fractured Reservoirs, (3) Pressure Response at Observation Wells in Fractured Reservoirs, and (4) Unsteady Flow to a Well Produced at a Constant Pressure in a Fractured Reservoir. Each of these sections is an independent unit; that is, knowledge of the other sections, even though desirable, is not necessary to understand the material in a given section. The principal contribution of this work is the identification of a new flow regime during the early transient period. The discovery of this flow regime represents a major advance in our ability to analyze pressure transient tests. The identification of the new flow regime also explains the response of wells in fractured reservoirs that until now have been considered anomalous. Systematic procedures to analyze single well (drawdown and buildup) tests and multiwell (interference) tests are discussed.

  1. Well test analysis for wells producing layered reservoirs with crossflow

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, R.; Prijambodo, R.; Reynolds, A.C.

    1985-06-01

    The pressure response of a well producing a two-layer reservoir with crossflow is examined. Virtually all studies on the response of a well in multilayered systems with crossflow claim that after a few hours of production these systems behave as if they are single-layer systems. In this study, the authors show that the flowing pressure response of a well at early times can be divided into three flow periods. The first period is one in which the reservoir behaves as if it were a stratified (no-crossflow) system. This period is followed by a transitional period. The response of the well during this period depends on the contrast in horizontal permeabilities and on the degree of communication between the layers. During the third period, the reservoir can be described by an equivalent single-layer system. An examination of the time ranges of the various flow periods indicates that, unless tests are designed properly, most of the interpretable pressure buildup data would be measured during the time the well response is influenced by the transitional period. The influence of the skin regions on the well response is examined. The significance of the estimate of the skin factor obtained from a pressure test is discussed. The authors show that the nature and the magnitude of the skin regions and the size of the reservoir determine the applicability of conventional semilog procedures to systems with interlayer communication.

  2. The world's deepest well

    Science.gov (United States)

    Kozlovskii, E. A.

    1984-12-01

    A 12,000-meter-deep research well at Kola in the Soviet Arctic is discussed. A major objective of the well was to penetrate into the basement rock of basaltic composition, presumably marked by an abrupt increase in the velocity of the seismic waves. At Kola the shift occurs at 9000 meters. However, instead of the basalt expected below that depth, an anomalous zone of disaggregated metamorphic rock was found. Further in that zone abundant flows of hot, highly mineralized 'water of crystallization' were found. Flows of gas, including helium, hydrogen, nitrogen, methane, and other hydrocarbons, and carbon dioxide were observed at all levels, thus indicating the existence of active gas-water processes, which raises the prospect of new ore deposits. The well utilizes a 400- to 500-ton aluminum alloy drill string. Unlike conventional drilling, the bit is powered by a turbine driven by the high-pressure flow of the drilling mud at 250 atm, which eliminates the disabling stresses at the surface caused by the rotation of the entire string. This technology opens the possibility of drilling to the depths of 15 to 17 km. The well is expected to help improve the interpretation of the seismic data.

  3. Studies on Impacts of Diluting Parameters on Wellhead Pressure of Heavy Oil Production Wells Assisted with Light Oil%稠油掺稀井掺稀参数对井口压力的影响研究

    Institute of Scientific and Technical Information of China (English)

    柳文莉; 韩国庆; 吴晓东; 朱明; 罗佳洁; 丁洪坤

    2011-01-01

    According to four diluting parameters affecting heavy oil production assisted with light oil-diluting amount. diluting relative density, diluting temperature and diluting depth, analysis on the impacts of diluting parameters of wellhead pressure using multi-element non-linear regression regression method is presented. The results show that the wellhead pressure increases as the increasement of diluting amount. diluting temperature and diluting depth and decreases as the increasement of the relative diluting density. Diluting amount makes the greatest impact on wellhead pressure, diluting temperature , diluting depth and relative diluting density' s impact is smaller.%针对影响稠油掺稀降黏的四种掺稀参数——掺稀量、掺稀相对密度、掺稀温度及掺稀深度,采用多元二次非线性回归方法研究了它们对稠油掺稀井井口压力的影响规律并进行了分析.结果表明:井口压力随着掺稀量、掺稀相对密度、掺稀温度及掺稀深度呈线性变化趋势,随着掺稀量、掺稀温度及掺稀深度的增加而增加,随着掺稀相对密度的增加而降低.掺稀量对井口压力的影响最大,而对掺稀相对密度、掺稀温度及掺稀深度的影响相对小些.

  4. Well test analysis for wells producing layered reservoirs with crossflow

    Energy Technology Data Exchange (ETDEWEB)

    Prijambodo, R.; Raghavan, R.; Reynolds, A.C.

    1981-01-01

    The pressure response of a well producing a two-layer reservoir with crossflow is examined. It is shown that the flowing pressure response of a well at early times can be divided into three flow periods. The first period is one in which the reservoir behaves as if it were a stratified system (no-crossflow). This period is followed by a transitional period. During the third period, the reservoir can be described by an equivalent single-layer system. The influence of the skin regions is presented. The significance of the estimate of the skin factor obtained from a pressure test is discussed. It is shown that the nature and magnitude of the skin regions and the size of the reservoir determine the applicability of procedures that are based on single-layer systems. 17 refs.

  5. Field project to obtain pressure core, wireline log, and production test data for evaluation of CO/sub 2/ flooding potential. Conoco MCA unit well No. 358, Maljamar Field, Lea County, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Swift, T.E.; Kumar, R.M.; Marlow, R.E.; Wilhelm, M.H.

    1982-08-01

    Field operations, which were conducted as a cooperative effort between Conoco and Gruy Federal, began on January 16, 1980 when the well was spudded. The well was drilled to 3692 feet, and 18 cores recovered in 18 core-barrel runs (144 feet). Upon completion of the coring phase, the hole was drilled to a total depth of 4150 feet and a complete suite of geophysical logs was run. Logging was then followed by completion and testing by Concoco. Core porosities agreed well with computed log porosities. Core water saturation and computed log porosities agree fairly well from 3692 to 3712 feet, poorly from 3712 to 3820 feet and in a general way from 4035 to 4107 feet. Computer log analysis techniques did not improve the agreement of log versus core derived water saturations. However, both core and log analysis indicated the ninth zone had the highest residual hydrocarbon saturations. Residual oil saturation were 259 STB/acre-ft for the 4035 - 4055 feet interval, and 150 STB/acre-ft for the 3692 - 3718 feet interval. Nine BOPD was produced from the 4035 - 4055 feet interval and no oil was produced from 3692 to 3718 feet interval, qualitatively confirming the relative oil saturations. The low oil production in the zone from 4022 to 4055 and the lack of production from 3692 to 3718 feet indicated the zone to be at or near residual waterflood conditions as determined by log analysis. 68 figures, 11 tables.

  6. Pressure ulcers

    National Research Council Canada - National Science Library

    Reddy, Madhuri

    2011-01-01

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to one third of people in hospitals or community care, and one fifth of nursing home residents...

  7. Pressure Sores

    Science.gov (United States)

    Pressure sores are areas of damaged skin caused by staying in one position for too long. They ... wheelchair, or are unable to change your position. Pressure sores can cause serious infections, some of which ...

  8. Pressure ulcers

    OpenAIRE

    Monfre, Jill M.

    2011-01-01

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers, which affect up to one third of people in hospitals or community care, and one fifth of nursing home residents. Pressure ulcers are more likely in people with reduced mobility and poor skin condition, such as older people or those with vascular disease.

  9. Pressure gradient of a two-region solid-liquid flow in horizontal wells; Gradiente de presion de un flujo bifasico solido-liquido de dos regiones en pozos horizontales

    Energy Technology Data Exchange (ETDEWEB)

    Salazar Mendoza, R.; Garcia Gutierrez, A. [Centro Nacional de Investigacion y Desarrollo Tecnologico (CENIDET), Cuernavaca, Morelos (Mexico); Espinosa Paredes, G. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D.F. (Mexico)

    2005-12-01

    A theoretical analysis is presented for the problem of cutting transport in a two-region, slurry-flow system in horizontal pipes, with a stationary bed of drill cuttings as a porous medium (w-region) below a two-phase dispersed flow (n-region). Volume averaging was applied to derive a rigorous mathematical model where each variable is precisely defined. The model includes volume-averaged transport equations for both the two-phase dispersed flow and the porous-medium regions, and terms from a macroscopic forces balance. The solution of the two-region model allowed evaluation of the behavior of the pressure gradient as a function of velocity, total volume fraction of cuttings, and the relationship between the height of the stationary bed and pipe diameter. It is based on a backward, finite-difference explicit scheme. The simulated physical system is a pipe diameter. It is based on a backward, finite-difference explicit scheme. The simulated physical system is a pipe of 4.135 m in horizontal length and 0.0508 m in diameter. A one dimensional, mesh-centered grid is used, consisting of 10 nodes. The numerical results were compared with experimental data on slurry flows and a good agreement was found. [Spanish] Se presenta un analisis teorico del problema de transporte de recortes de perforacion en pozos horizontales. Se estudia el flujo bifasico solido-liquido en dos regiones donde la region inferior es un lecho estacionario de recortes, considerado como medio poroso, mientras que la region superior es un flujo bifasico disperso solido-liquido. Se aplica el metodo de promediado en volumen para derivar de manera matematicamente rigurosa el modelo de dos regiones. El modelo incluye las ecuaciones de transporte promediadas en volumen para cada region y terminos que resultan de un balance de fuerzas macroscopico. La solucion del modelo permite evaluar el comportamiento del gradiente de presion como funcion de la velocidad, la fraccion de volumen de recortes total y la

  10. 某三级甲等中医院临床护士总体幸福感与工作压力的调查研究%Investigation on the general well being and working pressure among clinic nurses in a third grade class A tradi-tional Chinese medicine hospital

    Institute of Scientific and Technical Information of China (English)

    刘一弦; 蒋运兰; 李颖馨; 刘婉琳; 易银萍; 唐以薰; 刘芸峰

    2016-01-01

    Objective:To probe into the status and influencing factors of general well being and working pres-sure among clinic nurses in a third grade class A traditional Chinese medicine hospital.Methods:It used the General Information Questionnaire,General Well Being Schedule and the Chinese Nurse Work Pressure Source Scale to investigate 105 nurses in a third grade class A traditional Chinese medicine hospital in Chengdu.Re-sults:The general well being score of clinical nurses was 69.10 ± 12.62.There was no statistical significant difference(P>0.05)compared with Chinese female domestic norm.The working pressure source score of clini-cal nurses was 67.58±22.05.Pearson correlation analysis showed that there was a negative correlation between the general well being and the working pressure source(P0.05);护士工作压力源总分为67.58分±22.05分;Pearson相关性分析显示,总体幸福感与工作压力源呈负相关(P<0.01或P<0.05)。[结论]中医院临床护士总体幸福感较好,但工作压力较大,影响其总体幸福感,减轻护士工作压力可提高其总体幸福感。

  11. Peer Pressure

    Science.gov (United States)

    ... who are unsure of themselves, new to the group, or inexperienced with peer pressure may also be more likely to give in. ... stand that makes you look uncool to your group. But these situations can be ... up to peer pressure, but it does take courage — yours: Listen to ...

  12. WELL TESTING (YOUQIJING CESHI)%WELL TESTING (YOUQIJING CESHI)

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Research of Theory & Method;Research on Inclined Well Test Model for Orthographic Fault Slabby Double Porosity Reservoir;Research on Test Technology for Osmotic Pressure in Deep Drilling;Pressure Response in Polymer Flooding Reservoir Considering Inaccessible Pore Volume;Evaluation & ApplicationResearching on Diagnosis Method to Low Permeability Reservoir Pollution by Using Non-Stabilized Well Test.

  13. 护士压力、心理健康、社会支持、应对方式与主观幸福感关系的结构方程模型%Structural equation model of pressure, mental health, social support, coping style and subjective well-being of nurses

    Institute of Scientific and Technical Information of China (English)

    金卫华; 张玉千; 李勇; 邓惠芳; 高学农

    2015-01-01

    Objective To study the relationship between pressure, mental health, social support, coping style and subjective well-being of nurses. Methods A total of 261 nurses from 6 hospitals in Yichang were selected as re-search objects. General Well-Being Schedule, Symptom Checklist 90 (SCL-90), Chinese Nurse Job Stressors Ques-tionnaire, Simplified Coping Style Questionnaire, Perceived Social Support Scale (PSSS) were used for survey, and structural equation model (SEM) was constructed according to the survey results. Results Pressures and mental health had negative effect on subjective well-being (with effect coefficient of -0.31 and -0.54), while social sup-port had positive effect on subjective well-being (with effect coefficient of 0.43). Pressure affects subjective well-being negatively through mediation ways of social support and mental health, with the effect coefficient of-0.15 and-0.29. Conclusion Nurses' subjective well-being can be predicted from their pressure, mental health and social support. Pressure and subjective well-being are negatively correlated. A high level of mental health and social support will promote the level of subjective well-being of nurses.%目的 研究护士主观幸福感与压力、心理健康水平、社会支持、应对方式的关系.方法 选取本市6所医院的261名护理人员作为调查对象,使用总体幸福感量表、90项症状自评量表(SCL-90)、中国护士工作压力源量表、应对方式量表、领悟社会支持评定量表(PSSS)以问卷调查的方式调查,根据调查结果建构主观幸福感结构方程模型.结果 压力和心理健康对主观幸福感有负效应(效应系数分别为-0.31和-0.54),社会支持对主观幸福感有正效应(效应系数为0.43).压力通过社会支持和心理健康中介途径对主观幸福感的影响有负效应,效应系数分别为-0.15和-0.29.结论 由护士的压力、心理健康水平、社会支持水平能预测其主观幸福感.压力与主

  14. Pressure Sores

    Science.gov (United States)

    ... injury. Some chronic diseases, such as diabetes and hardening of the arteries, make it hard for pressure ... Use a mild soap and warm (not hot) water. Apply moisturizers so your skin doesn’t get ...

  15. Pressure sensor

    Science.gov (United States)

    Mee, David K.; Ripley, Edward B.; Nienstedt, Zachary C.; Nienstedt, Alex W.; Howell, Jr., Layton N.

    2015-09-29

    Disclosed is a passive, in-situ pressure sensor. The sensor includes a sensing element having a ferromagnetic metal and a tension inducing mechanism coupled to the ferromagnetic metal. The tension inducing mechanism is operable to change a tensile stress upon the ferromagnetic metal based on a change in pressure in the sensing element. Changes in pressure are detected based on changes in the magnetic switching characteristics of the ferromagnetic metal when subjected to an alternating magnetic field caused by the change in the tensile stress. The sensing element is embeddable in a closed system for detecting pressure changes without the need for any penetrations of the system for power or data acquisition by detecting changes in the magnetic switching characteristics of the ferromagnetic metal caused by the tensile stress.

  16. Riserless drilling (managed pressure drilling)

    OpenAIRE

    Khan, Ahsan

    2012-01-01

    There are several problems which an oil and gas industry is facing. These problems can be solved by riserless drilling method which comes under managed pressure drilling umbrella. The most important problem is increasing number of casing strings to complete a well and to control a well in limited pressure profile. A well model was developed and both conventional and riserless drilling approaches were applied to see how many casings will be needed to complete a same well with these approach...

  17. PRODUCTIVITY OF FRACTURED HORIZONTAL WELLS

    Directory of Open Access Journals (Sweden)

    Stjepan Antolović

    2009-12-01

    Full Text Available The interest and performance of horizontal drilling and completions has increased during the last two decades. Horizontal wells are advantageous compared to vertical wells in thin reservoirs, reservoirs with favorable vertical permeability and reservoirs with water and gas coning problems. In many reservoirs, the ratio of horizontal permeability to the vertical permeability is substantially larger than one and often is close to 10. Thus, these reservoirs are very good candidates for hydraulic fracturing. By hydraulic fracturing one or more fractures are created, which can be longitudinal or orthogonal. By that, flow is altered and it mostly conducts horizontally through reservoir toward horizontal wellbore. With this altered flow, fluid is produced faster, with less pressure loss by fluid unit of produced fluid. Some of the existing mathematical models to determine the productivity of multifractured horizontal wells are presented in this work (the paper is published in Croatian.

  18. Well testing of tight gas reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Jahanbani, A.; Aguilera, R. [Calgary Univ., AB (Canada)

    2008-07-01

    This paper discussed methods of evaluating tight gas sand reservoirs. Conventional well testing is not used in tight gas reservoirs due to their low permeability. Tight gas well testing techniques include pressure-dependent permeability testing; the estimation of pseudo--time at the average pressure of the region of influence; and supercharge effect testing. Pre-frac test analysis techniques were also discussed. Pressure-transient test designs were reviewed along with instantaneous source response methods for calculating influence functions. Impulse-fracture tests were discussed, as well as perforation inflow diagnostic testing. Perforation inflow tests provided reasonable estimates of reservoir parameters. Methods of determining pressure-dependent permeability data were discussed. After closure analysis (ACA) was used to analyze formation permeability. It was concluded that ACA can be coupled with pre-closure analysis to optimize fracture stimulation plans. The 22 refs., 17 figs.

  19. Well-being

    OpenAIRE

    Blatný, M. (Marek); Šolcová, I. (Iva)

    2015-01-01

    The chapter first discusses two essential theoretical concepts of well-being: subjective well-being and psychological well-being. Then the main findings on the links between well-being and socio-demographic variables are summarized. The main focus of the chapter is on the analysis of the links between personality and well-being. In agreement with the present views on personality domains, the relationships between well-being and personality traits, characteristic adaptations and personal narra...

  20. Effect of Measured Wellhead Parameters and Well Scaling on the Computed Downhole Conditions in Cerro Prieto Wells

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, K.P.; Miller, C.W.; Lippmann, M.J.

    1980-12-16

    This paper is devoted to the discussion of the wellbore model and its describing equations, comparison between the computed and measured pressures and the effect of measured wellhead parameters on the downhole pressures in the well. Finally a wellbore model with multiple inside diameters is discussed and the effect of well scaling on the bottom hole pressures is studied.

  1. 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 s

  2. A new method for treating wells in reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Gessel, G.M.; Hales, H.B.; Baxter, L.L. [Brigham Young Univ., Provo, UT (United States)

    2007-07-01

    A method of formulating finite difference equations for reservoir models and the singularities around wells was presented. The method incorporated approximate analytical expressions for pressure into a simulation tool's finite difference equations. The method was based on a Peaceman correction used to calculate well bore pressures. The method adopted finite difference equations based on the physics of the flow around the well, and used expressions for the pressure derivatives consistent with the theoretical pressure profiles around straight line wells in an infinite system. The finite difference equations included linear terms and quadratic terms but did not increase the number of pressure points and did not alter the complexity of the resulting linear algebra. Results showed that the pressure equation was accurate for bulk of the reservoir, and also accurately represented the near singularities around the wells. It was concluded that the method accurately represented near singularities in pressures that occur around wellbores. 10 refs., 4 figs.

  3. well-being perspective

    African Journals Online (AJOL)

    well-being, namely: self-acceptance, personal growth, purpose in life, positive relations with others .... Sternberg, 2004] identifies the concepts of exploration and commitment from the work of ..... Clinical applications of well-being therapy.

  4. Total well dominated trees

    DEFF Research Database (Denmark)

    Finbow, Arthur; Frendrup, Allan; Vestergaard, Preben D.

    cardinality then G is a total well dominated graph. In this paper we study composition and decomposition of total well dominated trees. By a reversible process we prove that any total well dominated tree can both be reduced to and constructed from a family of three small trees....

  5. Do professionals choke under pressure?

    OpenAIRE

    Dohmen, Thomas

    2005-01-01

    High rewards or the threat of severe punishment do not only provide incentives to exert high levels of effort but also create pressure. Such pressure can cause paradoxical performance effects, namely performance decrements despite strong incentives and high motivation. By analyzing the performance of professional football players on a well-defined task, namely to score on a penalty kick, the paper provides empirical evidence for the existence of such detrimental incentive effects. Two pressur...

  6. Pressure transducer

    Science.gov (United States)

    Anderson, Thomas T.; Roop, Conard J.; Schmidt, Kenneth J.; Gunchin, Elmer R.

    1989-01-01

    A pressure transducer suitable for use in high temperature environments includes two pairs of induction coils, each pair being bifilarly wound together, and each pair of coils connected as opposite arms of a four arm circuit; an electrically conductive target moveably positioned between the coil pairs and connected to a diaphragm such that deflection of the diaphragm causes axial movement of the target and an unbalance in the bridge output.

  7. [Measurement of arterial pressure].

    Science.gov (United States)

    Rorive, G

    1998-03-01

    The casual determination of blood pressure remains the basis of the diagnosis of arterial hypertension and the criteria for usefulness of drug therapy. The reference values usually in use concern determinations by the doctor in very well defined conditions, rest, size of the bladder, etc.... The poor reproductibility of the determinations made by the doctor in casual conditions has produced a large interest for new approaches: autodetermination by the patient at home, and ambulatory blood pressure determinations using automatic devices. These new approaches have their own reference values, specific indications and limitations.

  8. WELL TESTING (YOUQIJING CESHI)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Research of Theory & Method. Trilinear-Flow Well Test Model of Fractured Horizontal Well in Low Permeability Reservoir. 2011,20(5):1 ∽5 Yao Jun, Yin Xiuxing , Fan Dongyan, Sun Zhixue ( China Petroleum University (East China)) According to the characteristics of the threshold pressure gradient for low permeability reservoir, a mathematical model of tri-linear flow unsteady percolation for fractured horizontal well is established; then deduced from its analytical solution in Laplace space. Bottom hole pressure of fractured horizontal wells is got after considering wellbore storage and skin factor by Stehfest numerical inversion and Duhamel principle, finally discussing the influence factors of the bottom hole pressure of fractured horizontal wells . The study result showed that the threshold pressure gradient made the dimensionless pressure and its derivative curves go up in late time, the bigger the threshold pressure gradient , the higher the curve and the earlier the curve going up appears; the fractured conductivity mainly influence the appeared time of bilinear-flow; the fracture radial flow appears only when the fracture interspacing achieves some extent, and the larger the space is, the fracture radial flow lasts longer; storage capacity ratio co influences the hollow's width and depth of the pressure derivative curve , the smaller the co, the wider the deeper hollow; cross-flow coefficient ~, decides the position of hollow, the smaller the λ, the more right-hand the hollow; wellbore storage coefficient CD mainly affects the early freewheeling segment of the curve.

  9. Pressure Ulcer Prevention

    Science.gov (United States)

    2009-01-01

    Executive Summary In April 2008, the Medical Advisory Secretariat began an evidence-based review of the literature concerning pressure ulcers. Please visit the Medical Advisory Secretariat Web site, http://www.health.gov.on.ca/english/providers/program/mas/tech/tech_mn.html to review these titles that are currently available within the Pressure Ulcers series. Pressure ulcer prevention: an evidence based analysis The cost-effectiveness of prevention strategies for pressure ulcers in long-term care homes in Ontario: projections of the Ontario Pressure Ulcer Model (field evaluation) Management of chronic pressure ulcers: an evidence-based analysis (anticipated pubicstion date - mid-2009) Purpose A pressure ulcer, also known as a pressure sore, decubitus ulcer, or bedsore, is defined as a localized injury to the skin/and or underlying tissue occurring most often over a bony prominence and caused by pressure, shear, or friction, alone or in combination. (1) Those at risk for developing pressure ulcers include the elderly and critically ill as well as persons with neurological impairments and those who suffer conditions associated with immobility. Pressure ulcers are graded or staged with a 4-point classification system denoting severity. Stage I represents the beginnings of a pressure ulcer and stage IV, the severest grade, consists of full thickness tissue loss with exposed bone, tendon, and or muscle. (1) In a 2004 survey of Canadian health care settings, Woodbury and Houghton (2) estimated that the prevalence of pressure ulcers at a stage 1 or greater in Ontario ranged between 13.1% and 53% with nonacute health care settings having the highest prevalence rate (Table 1). Executive Summary Table 1: Prevalence of Pressure Ulcers* Setting Canadian Prevalence,% (95% CI) Ontario Prevalence,Range % (n) Acute care 25 (23.8–26.3) 23.9–29.7 (3418) Nonacute care† 30 (29.3–31.4) 30.0–53.3 (1165) Community care 15 (13.4–16.8) 13.2 (91) Mixed health care‡ 22 (20.9

  10. Blood pressure measurement

    Science.gov (United States)

    Diastolic blood pressure; Systolic blood pressure; Blood pressure reading; Measuring blood pressure ... or your health care provider will wrap the blood pressure cuff snugly around your upper arm. The lower ...

  11. Barotrauma: Tooth Under Pressure.

    Science.gov (United States)

    Kumar, Satheesh; Kumar, Preeti Satheesh; John, Jins; Patel, Ruchi

    2015-11-01

    With the growing number of air passengers, flight attendants, leisure pilots, as well as military and airline pilots, dentists may encounter physiological and pathological phenomena precipitated by high altitude. With the introduction of the self-contained breathing apparatus (SCUBA), many of these manifestations caused by changes in atmospheric pressure were reported in association with diving as well. Limited literature exists on this subject. Hence, this article aims to review literature concerning the classification, etiology and manifestations of barodontalgia, as well as important clinical considerations for its management.

  12. Wellness in Industry.

    Science.gov (United States)

    Hackleman, Karen T.; And Others

    1985-01-01

    Reports on efforts of three institutions in response to need for consumer health information: Health Education Center (promotes health in southwestern Pennsylvania), Tulsa City-County Library (Oklahoma), and Wellness Council of the Midlands (WELCOM) (promotes wellness at work site in Omaha, Nebraska, area). WELCOM's 62-item reference list is…

  13. Staying Well at Work.

    Science.gov (United States)

    Blai, Boris, Jr.

    Employee wellness directly affects business/industry operations and costs. When employees are helped and encouraged to stay well, this people-positive policy results in triple benefits: reduced worker absenteeism, increased employee productivity, and lower company expenditures for health costs. Health care programs at the worksite offer these…

  14. New challenges? Well, certainly!

    DEFF Research Database (Denmark)

    Lauridsen, Karen M.

    proficiency, but research as well as experience on the ground tells us that this is not enough. Everyone must learn to navigate in the multilingual and multicultural learning space because lecturers as well as students may come from different countries and cultures and therefore have different first languages...

  15. Water Treatment Technology - Wells.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on wells provides instructional materials for five competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: dug, driven, and chilled wells, aquifer types, deep well…

  16. Provider Health and Wellness.

    Science.gov (United States)

    Nanda, Anil; Wasan, Anita; Sussman, James

    2017-07-19

    Provider health and wellness is a significant issue and can impact patient care, including patient satisfaction, quality of care, medical errors, malpractice risk, as well as provider and office staff turnover and early retirement. Health and wellness encompasses various areas including burnout, depression, divorce, and suicide and affects providers of all specialties and at all levels of training. Providers deal with many everyday stresses, including electronic health records, office politics, insurance and billing issues, dissatisfied patients, and their own personal and family issues. Approximately half of all physicians suffer from burnout, and the rate of burnout among physicians of all specialties is increasing. An important first step in dealing with burnout is recognition and then seeking assistance. Strategies to prevent and treat burnout include increasing provider resiliency as well as implementing practical changes in the everyday practice of medicine. There is currently very little data regarding health and wellness specifically in the field of allergy and immunology, and studies are necessary to determine the prevalence of burnout and related issues in this field. Many medical specialties as well as state and national medical associations have health and wellness committees and other resources, which are essential for providers. Health and wellness programs should be introduced early in a provider's training and continued throughout a provider's career. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  17. Internal pressure and solubility parameter as a function of pressure

    DEFF Research Database (Denmark)

    Verdier, Sylvain Charles Roland; Andersen, Simon Ivar

    2005-01-01

    The main goal of this work was to measure the solubility parameter of a complex mixture, such as a crude oil, especially as a function of pressure. Thus, its definition is explained, as well as the main approximations generally used in literature. Then, the internal pressure is investigated, since...... it is presented as an alternative of the solubility parameter. In this work, the assumption that internal pressure is a measure of the physical solubility parameter was made, i.e. representing the dispersion and polar forces. As for the pressure influence, it was seen that internal pressure reaches a maximum...... contrary to solubility parameter. An indirect method was chosen to estimate internal pressure, using thermal expansivities (determined by microcalorimetry) and isothermal compressibilities (determined by density measurements). The uncertainty is within 2% for the expansivity and 0.1% for the density. Five...

  18. The WELL Detector

    CERN Document Server

    Bellazzini, R; Brez, A; Gariano, G; Latronico, L; Lumb, N; Papanestis, A; Spandre, G; Massai, M M; Raffo, R; Spezziga, M A

    1999-01-01

    We introduce the WELL detector, a new type of position-sensitive gas proportional counter produced using advanced printed circuit board (PCB) technology. The WELL is based on a thin kapton foil, copp erclad on both sides. Charge amplifying micro-wells are etched into the first metal and kapton layers. These end on a micro-strip pattern which is defined on the second metal plane. The array of micr o-strips is used for read-out to obtain 1-D positional information. First results from our systematic assessment of this device are reported.

  19. 高压高产气井试气求产过程中油管挤毁失效分析%Failure Analysis on the Collapsed Tubing of the High Pressure and High Production Gas Well in the Process of Testing and Production

    Institute of Scientific and Technical Information of China (English)

    薛继军; 赵滨; 赵赫

    2014-01-01

    One of the tubing used in the gas well under the high pressure and high production has occurred in the split,fall,collapse and severe diapirism of tube body in the trial extraction process.This paper have a test of tube so that certain the reason that split,fall,collapsed and se-vere diapirism of tube body by the analysis of the macroscopic,physical and chemical properties, microscopic metallographic.The result shows that gas,liquid pipe ram and solid multiphase flow in tube may be formatted the instantaneous negative pressure and increase the likelihood of the tubing were collapsed in the process of the gas testing and production.Then it has resulted in clogging,severe erosion,thinning wall and piercing in tube.Finally the tube has occurred in frac-ture because of the tensile strength.%某高压高产气井试气用油管在试提中发生管体断裂掉落,并有管体挤毁和严重刺穿现象。通过对油管进行宏观分析、理化性能分析、微观金相分析试验,以确定油管发生断裂掉落以及挤毁和刺穿的原因。结果表明:在放喷求产过程中油管内存在气、液、固等多相流,可能会形成瞬时负压,增加了油管被挤毁变形的可能性;随后造成流道堵塞,油管内冲蚀严重,壁厚变薄发生刺穿,最后因拉伸强度不足而发生断裂。

  20. Agricultural Drainage Well Intakes

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — Locations of surface intakes for registered agriculture drainage wells according to the database maintained by IDALS. Surface intakes were located from their...

  1. Optimizing well intervention routes

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Ronaldo O. [PETROBRAS S.A., Vitoria, ES (Brazil); Schiozer, Denis J.; Bordalo, Sergio N. [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Centro de Estudo do Petroleo (CEPETRO)]. E-mail: denis@dep.fem.unicamp.br; bordalo@dep.fem.unicamp.br

    2000-07-01

    This work presents a method for optimizing the itinerary of work over rigs, i.e., the search for the route of minimum total cost, and demonstrates the importance of the dynamics of reservoir behaviour. The total cost of a route includes the rig expenses (transport, assembly and operation), which are functions of time and distances, plus the losses of revenue in wells waiting for the rig, which are also dependent of time. A reservoir simulator is used to evaluate the monetary influence of the well shutdown on the present value of the production curve. Finally, search algorithms are employed to determine the route of minimal cost. The Simulated Annealing algorithm was also successful in optimizing the distribution of a list of wells among different work over rigs. The rational approach presented here is recommended for management teams as a standard procedure to define the priority of wells scheduled for work over. (author)

  2. Emotional Well-Being

    Science.gov (United States)

    ... Cancer Nutrition Information (AICR) Emotional Well-Being Patient Empowerment Support Get Answers To Your Questions Meet Patients ... with kidney cancer, you may wish to seek professional assistance. These services may be covered by your ...

  3. STIMULATION TECHNOLOGIES FOR DEEP WELL COMPLETIONS

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Wolhart

    2003-06-01

    The Department of Energy (DOE) is sponsoring a Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a project to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. Phase 1 was recently completed and consisted of assessing deep gas well drilling activity (1995-2007) and an industry survey on deep gas well stimulation practices by region. Of the 29,000 oil, gas and dry holes drilled in 2002, about 300 were drilled in the deep well; 25% were dry, 50% were high temperature/high pressure completions and 25% were simply deep completions. South Texas has about 30% of these wells, Oklahoma 20%, Gulf of Mexico Shelf 15% and the Gulf Coast about 15%. The Rockies represent only 2% of deep drilling. Of the 60 operators who drill deep and HTHP wells, the top 20 drill almost 80% of the wells. Six operators drill half the U.S. deep wells. Deep drilling peaked at 425 wells in 1998 and fell to 250 in 1999. Drilling is expected to rise through 2004 after which drilling should cycle down as overall drilling declines.

  4. VERTICAL WELL PRESSURE AND PRESSURE DERIVATIVE ANALYSIS FOR BINGHAM FLUIDS IN HOMOGENEOUS RESERVOIRS

    Directory of Open Access Journals (Sweden)

    JAVIER A. MARTINEZ

    2011-01-01

    Full Text Available Este trabajo presenta una técnica de interpretación del comportamiento de la presión y derivada de presión para un fl uido tipo Bingham en un yacimiento homogéneo drenado por un pozo vertical, aplicando la técnica TDS observando la infl uencia del gradiente mínimo de presión que caracteriza este comportamiento y puntos característicos con el propósito de calcular la permeabilidad, el área de drenaje y el factor de daño de la formación. Es la primera vez que se presenta en la literatura la derivada de presión para estos fl uidos. Entre mayor se hace el mínimo gradiente de presión la derivada se hace asimétricamente más cóncava hacia arriba. También se observó que en sistemas cerrados la pendiente unitaria tardía que se desarrolla en la derivada de presión coincide con la misma de fl uidos Newtonianos.

  5. Well Logging Symposium News

    Institute of Scientific and Technical Information of China (English)

    Yang Chunsheng

    1996-01-01

    @@ ‘96 International Symposium on Well Logging Techniques for Oilfield Development under Waterflood was held on 17-21 September, 1996 in Beijing. The symdrew than 160 experts and scholars in the well logging circle from Russia,The United States, France, Britain, Indonesia and China. About 80 papers were presented duringthe symposium. Mr. Zhang Yongyi,Vice President of CNPC delivered the opening remarks.

  6. Wellness as fairness.

    Science.gov (United States)

    Prilleltensky, Isaac

    2012-03-01

    I argue that distinct conditions of justice lead to diverse wellness outcomes through a series of psychosocial processes. Optimal conditions of justice, suboptimal conditions of justice, vulnerable conditions of injustice, and persisting conditions of injustice lead to thriving, coping, confronting, and suffering, respectively. The processes that mediate between optimal conditions of justice and thriving include the promotion of responsive conditions, the prevention of threats, individual pursuit, and avoidance of comparisons. The mechanisms that mediate between suboptimal conditions of justice and coping include resilience, adaptation, compensation, and downward comparisons. Critical experiences, critical consciousness, critical action, and righteous comparisons mediate between vulnerable conditions of injustice and confrontation with the system. Oppression, internalization, helplessness, and upward comparisons mediate between persisting conditions of injustice and suffering. These psychosocial processes operate within and across personal, interpersonal, organizational and community contexts. Different types of justice are hypothesized to influence well-being within each context. Intrapersonal injustice operates at the personal level, whereas distributive, procedural, relational, and developmental justice impact interpersonal well-being. At the organizational level, distributive, procedural, relational and informational justice influence well-being. Finally, at the community level, distributive, procedural, retributive, and cultural justice support community wellness. Data from a variety of sources support the suggested connections between justice and well-being.

  7. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  8. Change of guinea pig inner ear pressure by square wave middle ear cavity pressure variation

    NARCIS (Netherlands)

    Feijen, RA; Segenhout, JM; Albers, FWJ; Wit, HP

    2002-01-01

    The inner ear fluid pressure of guinea pigs was measured during square wave middle ear cavity pressure variation. Time constants were derived for the slopes of the inner ear pressure recovery curves after middle ear pressure change. A "single exponential" function did not fit well and therefore more

  9. 地层水侵入对超临界CO2钻井井筒温度和压力的影响%Influences of formation water invasion on the well bore temperature and pressure in supercritical CO2 drilling

    Institute of Scientific and Technical Information of China (English)

    王海柱; 沈忠厚; 李根生

    2011-01-01

    Aiming to study the influence of formation water invasion on the well bore temperature and pressure in SC-CO2 (supercritical CO2) drilling with coiled tubing, this paper builds up a weilbore flow model with formation water invasion in SC-CO2 drilling with coiled tubing, based on the comprehensive investigation of the influence of viscosity, density, thermal conductivity, isobaric heat capacity and Joule-Thompson coefficient of SC-CO2. The wellbore temperature and pressure distribution were calculated by the method of coupling among these parameters. The results show that the bigger the rate of invaded formation water and the bigger the density of mixed fluid,the bigger the convective heat transfer coefficient in the annulus. Because of the .Joule-Thompson cooling effect caused by nozzle throttling, the annulus mixture fluid density increased abruptly and the convective heat transfer coefficient decreased abruptly at the well depth of about 1 900 m (about 10 m to bottom hole). Meanwhile the wellbore fluid temperature increased with the invasion rate of formation water, and the same Joule-Thompson cooling effect caused the wellbore fluid temperature to decrease abruptly at the well depth of about 1 900 m. Moreover, the wellbore annulus pressure increased with the increasing of invaded formation water quantity, butthe amplitude is not obvious.%为了研究sC-CO(超临界CO)连续油管钻井过程中地层水侵入对井筒温度和压力的影响,在综合考虑CO流体的黏度、密度、导热系数、热容、焦耳-汤姆逊系数等参数影响的基础上,建立了SC-CO连续油管钻井地层水侵入井筒流动模型,并采用各参数相互耦合的方法对井筒温度和压力分布进行了计算.结果表明,地层水侵入速度越大其混合流体密度越高,环空混合流体对流换热系数越大,但由于喷嘴节流产生的焦耳-汤姆逊冷却效应,在井深约1 900 m处(离井底约10 m处)环空混合流体密度突然增大、对流

  10. Geothermal Well Stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D. A.; Morris, C. W.; Sinclair, A. R.; Hanold, R. J.; Vetter, O. J.

    1981-03-01

    The stimulation of geothermal wells presents some new and challenging problems. Formation temperatures in the 300-600 F range can be expected. The behavior of stimulation fluids, frac proppants, and equipment at these temperatures in a hostile brine environment must be carefully evaluated before performance expectations can be determined. In order to avoid possible damage to the producing horizon of the formation, high temperature chemical compatibility between the in situ materials and the stimulation materials must be verified. Perhaps most significant of all, in geothermal wells the required techniques must be capable of bringing about the production of very large amounts of fluid. This necessity for high flow rates represents a significant departure from conventional petroleum well stimulation and demands the creation of very high near-wellbore permeability and/or fractures with very high flow conductivity.

  11. Well Conductor Strain Monitoring

    Science.gov (United States)

    2014-05-06

    comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE JUL 2014 2. REPORT TYPE 3. DATES...849,429; filed on June 26, 2013 by the inventor, Dr. Anthony Ruffa and entitled “ SUBSEA WELL CONDUCTOR STRAIN MONITORING”. STATEMENT OF

  12. Rural Wellness and Prevention

    Science.gov (United States)

    ... governors of U.S. states have implemented wellness and prevention programs in their states in the last few years. The programs generally promote healthy habits, understanding of risks associated with lifestyles, disease management practices, and regular physical activity. Worksites provide ...

  13. Live Your Life Well

    Science.gov (United States)

    ... Workplace Wellness Work-Life Balance Mental Illness and Work Support an Employee Workplace Bullying & Violence Signs of a Healthy Workplace ... you can thrive even in the face of stress. We want you to know that you can ... you focus at work, overcome obstacles, get along with the people around ...

  14. Hantush Well Function Revisited

    NARCIS (Netherlands)

    Veling, E.J.M.; Maas, C.

    2010-01-01

    In this paper we comment on some recent numerical and analytical work to evaluate the Hantush Well Function. We correct an expression found in a Comment by Nadarajah (J. of Hydrology, vol. 338, p. 152-153 (2007)) to a paper by Prodanoff et al. (J. of Hydrology, vol. 318, p. 173-183 (2006)). We subse

  15. Child Wellness and Happiness

    Science.gov (United States)

    Rettew, David C.

    2009-01-01

    Wellness and happiness should be considered in the clinical treatment of child and adolescent psychiatry, in addition with thinking about illness. Meanwhile, various studies on child and adolescent psychiatry,which includes an article from the "Journal of Happiness Studies," are discussed.

  16. Why Does Well

    Science.gov (United States)

    Sartorius, Tara Cady

    2010-01-01

    There is something disappointing about life. It is messy and out of control. It seems the more one tries to put life in order, the more ordering there is to do. The more one seeks explanations, the more confusing things become. Life's an impossible task. Maybe one should just give up. Or, then again, one might as well keep trying. It's this…

  17. Child Wellness and Happiness

    Science.gov (United States)

    Rettew, David C.

    2009-01-01

    Wellness and happiness should be considered in the clinical treatment of child and adolescent psychiatry, in addition with thinking about illness. Meanwhile, various studies on child and adolescent psychiatry,which includes an article from the "Journal of Happiness Studies," are discussed.

  18. Soft sensing for gas-lift wells

    NARCIS (Netherlands)

    Bloemen, H.H.J.; Belfroid, S.P.C.; Sturm, W.L.; Verhelst, F.J.P.C.M.G.

    2006-01-01

    This paper considers the use of extended Kalman filtering as a soft-sensing technique for gas lift wells. This technique is deployed for the estimation of dynamic variables that are not directly measured. Possible applications are the estimation of flow rates from surface and downhole pressure measu

  19. Stimulation Technologies for Deep Well Completions

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Wolhart

    2005-06-30

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies conducted a study to evaluate the stimulation of deep wells. The objective of the project was to review U.S. deep well drilling and stimulation activity, review rock mechanics and fracture growth in deep, high-pressure/temperature wells and evaluate stimulation technology in several key deep plays. This report documents results from this project.

  20. Method of treating wells

    Energy Technology Data Exchange (ETDEWEB)

    Knox, J.A.; Lasater, R.M.

    1966-11-22

    Chemical compositions and methods are provided for treating underground formations to render their surfaces water-repellent or preferentially oil-wettable. Previous methods have provided only temporary water-repellency because they do not actually act chemically with the reservoir rock. This improvement is obtained by using a treating agent which does not form a precipitate upon hydrolysis with water, such as a liquid organo-halogen- silane or its ester. A water-soluble anhydrous solvent which is nonreactive with the silane is used as a carrier. This method may be used for treating non-oil-bearing aquifers for increasing the flow rate of water, such as in water supply wells, or in water input rate, such as in water disposal wells. (10 claims)

  1. Low Blood Pressure

    Science.gov (United States)

    ... a problem. Sometimes blood pressure that is too low can also cause problems. Blood pressure is the ... reading is 90/60 or lower, you have low blood pressure. Some people have low blood pressure ...

  2. Normal Pressure Hydrocephalus (NPH)

    Science.gov (United States)

    ... your local chapter Join our online community Normal Pressure Hydrocephalus (NPH) Normal pressure hydrocephalus is a brain ... About Symptoms Diagnosis Causes & risks Treatments About Normal Pressure Hydrocephalus Normal pressure hydrocephalus occurs when excess cerebrospinal ...

  3. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Hypertension (High Blood Pressure) KidsHealth > For Teens > Hypertension (High Blood Pressure) Print ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

  4. [Pressure sore revision surgery].

    Science.gov (United States)

    Dorsche, Karin Marion

    2010-02-22

    Pressure sores are a major problem for patients as well as society in general. Immobilised patients are especially at risk. This group of patients with pressure sores should be hospitalised to perform surgical revision of the wound and reconstruction using a flap. Such surgery demands extensive postoperative relief of the flap. The University Centre for Wound Healing at Odense University Hospital has tested the effects of a reduction of the formerly recommended relief period from three to two weeks. In this article we report results covering all patients who have undergone surgery and reconstruction of pressure sores during the period from 1st October 2001 to 1st November 2008. The results are divided into two periods: the period before and the period after the introduction of the reduced relief period. A total of 80 patients were included; 34 in the first period and 46 in the second period. We achieved a considerable reduction in median length of stay from 38 to 27 days with no increase in surgical or complication frequency. Furthermore, the share of fully healed remained unchanged. We believe that there is no risk in shortening the immobile postoperative relief phase following reconstruction of pressure wounds in immobilised patients.

  5. Drilling and well technology

    Energy Technology Data Exchange (ETDEWEB)

    Milheim, K. [Mining University Leoben Institute for Drilling Technology, (Austria)

    1996-12-31

    Over a billion dollars a year is lost by exploration and production companies drilling wells because of the lack of learn curve management (LMC) practices. This paper presents the importance of the LMC concept, what it is, why LMC has not yet been recognized as a major initiative for improving drilling cost performance. The paper discusses the different types of planning, problems with implementation of plans, the use and misuse of drilling results and data bases, and the lack of post analysis practices. The major point of the paper is to show the massive savings that can be achieved by valuing LMC, learning LMC and successfully implementing LMC. . 2 refs., 5 figs.

  6. Quantum well lasers

    CERN Document Server

    Zory, Jr, Peter S; Kelley, Paul

    1993-01-01

    This book provides the information necessary for the reader to achieve a thorough understanding of all aspects of QW lasers - from the basic mechanism of optical gain, through the current technolgoical state of the art, to the future technologies of quantum wires and quantum dots. In view of the growing importance of QW lasers, this book should be read by all those with an active interest in laser science and technology, from the advanced student to the experienced laser scientist.* The first comprehensive book-length treatment of quantum well lasers* Provides a detailed treatment

  7. Phosphate based oil well cements

    Science.gov (United States)

    Natarajan, Ramkumar

    The main application of the cement in an oil well is to stabilize the steel casing in the borehole and protect it from corrosion. The cement is pumped through the borehole and is pushed upwards through the annulus between the casing and the formation. The cement will be exposed to temperature and pressure gradients of the borehole. Modified Portland cement that is being used presently has several shortcomings for borehole sealant. The setting of the Portland cement in permafrost regions is poor because the water in it will freeze even before the cement sets and because of high porosity and calcium oxide, a major ingredient it gets easily affected by the down hole gases such as carbon dioxide. The concept of phosphate bonded cements was born out of considerable work at Argonne National Laboratory (ANL) on their use in stabilization of radioactive and hazardous wastes. Novel cements were synthesized by an acid base reaction between a metal oxide and acid phosphate solution. The major objective of this research is to develop phosphate based oil well cements. We have used thermodynamics along with solution chemistry principles to select calcined magnesium oxide as candidate metal oxide for temperatures up to 200°F (93.3°C) and alumina for temperatures greater than 200°F (93.3°C). Solution chemistry helped us in selecting mono potassium phosphate as the acid component for temperatures less than 200°F (93.3°C) and phosphoric acid solution greater than 200°F (93.3°C). These phosphate cements have performance superior to common Portland well cements in providing suitable thickening time, better mechanical and physical properties.

  8. WellBe手环

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    来认识一下WellBe,一只能随时探测你精神压力状态,并立即提供解决建议的手环。WellBe判断佩戴者心理压力的依据是内藏的光学心率计所提供的实时测量值,在统计过最容易使佩戴者产生心理压力的场合后,为其提供量身定制的压力释放方式——包括冥思、深呼吸、引导想象,或是个性化过的学习课程或音乐播放列表。而它采用的软木腕带材质也在作出拥抱大自然,告别紧张快节奏的日常生活的暗示。

  9. Modeling Quantum Well Lasers

    Directory of Open Access Journals (Sweden)

    Dan Alexandru Anghel

    2012-01-01

    Full Text Available In semiconductor laser modeling, a good mathematical model gives near-reality results. Three methods of modeling solutions from the rate equations are presented and analyzed. A method based on the rate equations modeled in Simulink to describe quantum well lasers was presented. For different signal types like step function, saw tooth and sinus used as input, a good response of the used equations is obtained. Circuit model resulting from one of the rate equations models is presented and simulated in SPICE. Results show a good modeling behavior. Numerical simulation in MathCad gives satisfactory results for the study of the transitory and dynamic operation at small level of the injection current. The obtained numerical results show the specific limits of each model, according to theoretical analysis. Based on these results, software can be built that integrates circuit simulation and other modeling methods for quantum well lasers to have a tool that model and analysis these devices from all points of view.

  10. Quantum well nonlinear microcavities

    Science.gov (United States)

    Oudar, J. L.; Kuszelewicz, R.; Sfez, B.; Pellat, D.; Azoulay, R.

    We report on recent progress in reducing the power threshold of all-optical bistable quantum well vertical microcavities. Significant improvements are achieved through an increase of the cavity finesse, together with a reduction of the device active layer thickness. A critical intensity of 5 μW/μm 2 has been observed on a microcavity of finesse 250, with a nonlinear medium of only 18 GaAs quantum wells of 10 nm thickness. Further improvements of the Bragg mirror quality resulted in a finesse of 700 and a power-lifetime product of 15 fJ/μm 2. Microresonator pixellation allows to obtain 2-dimensional arrays. A thermally-induced alloy-mixing technique is described, which produced a 110 meV carrier confinement energy, together with a refractive index change of -.012, averaged over the 2.6 μm nonlinear medium thickness. The resulting electrical and optical confinement is shown to improve the nonlinear characteristics, by limiting lateral carrier diffusion and light diffraction.

  11. Well maintenance evaluation.

    Energy Technology Data Exchange (ETDEWEB)

    McGhan, V.L.

    1978-10-01

    The ground-water monitoring program is an integral part of the total environmental surveillance program for the Hanford Site. Extensive ground-water data have been collected and studied over the past several decades. All of this data is, of course, dependent upon the quality of the ground-water sampling structures. A program to upgrade the quality of ground-water sampling was initiated in early 1974. That program also included changes to avoid cross-contamination of ground-water samples by installing permanently mounted individual pumps in many of the sampling wells. These two programs have resulted in increased reliability of both the ground-water samples and the analytical data. This basic quality assurance effort has provided a high level of confidence in ground-water surveillance. The current program is providing data with reliabilities not previously attainable.

  12. High Pressure Biomass Gasification

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Pradeep K [Georgia Tech Research Corporation, Atlanta, GA (United States)

    2016-07-29

    According to the Billion Ton Report, the U.S. has a large supply of biomass available that can supplement fossil fuels for producing chemicals and transportation fuels. Agricultural waste, forest residue, and energy crops offer potential benefits: renewable feedstock, zero to low CO2 emissions depending on the specific source, and domestic supply availability. Biomass can be converted into chemicals and fuels using one of several approaches: (i) biological platform converts corn into ethanol by using depolymerization of cellulose to form sugars followed by fermentation, (ii) low-temperature pyrolysis to obtain bio-oils which must be treated to reduce oxygen content via HDO hydrodeoxygenation), and (iii) high temperature pyrolysis to produce syngas (CO + H2). This last approach consists of producing syngas using the thermal platform which can be used to produce a variety of chemicals and fuels. The goal of this project was to develop an improved understanding of the gasification of biomass at high pressure conditions and how various gasification parameters might affect the gasification behavior. Since most downstream applications of synags conversion (e.g., alcohol synthesis, Fischer-Tropsch synthesis etc) involve utilizing high pressure catalytic processes, there is an interest in carrying out the biomass gasification at high pressure which can potentially reduce the gasifier size and subsequent downstream cleaning processes. It is traditionally accepted that high pressure should increase the gasification rates (kinetic effect). There is also precedence from coal gasification literature from the 1970s that high pressure gasification would be a beneficial route to consider. Traditional approach of using thermogravimetric analyzer (TGA) or high-pressure themogravimetric analyzer (PTGA) worked well in understanding the gasification kinetics of coal gasification which was useful in designing high pressure coal gasification processes. However

  13. Pitting Behavior of HP2-13Cr in Simulated High Pressure and High Temperature Gas Well Environment%模拟高温高压气井环境中HP2-13Cr的点蚀行为研究

    Institute of Scientific and Technical Information of China (English)

    雷冰; 马元泰; 李瑛; 王福会; 常泽亮; 谢俊峰; 宋文文; 周理志

    2013-01-01

    The pitting behavior of HP2-13Cr in a simulated high pressure and high temperature gas well environment (including three periods: acidizing?returned residual acid? produced water) was investigated by OM/SEM observation. The results showed that the pitting was mainly occurred in the returned residual acid; the statistical analysis of the depth distribution of pits showed that the pitting rate in the period of returned residual acid was 7.56 mm/a, while 0.47 mm/a in the produced water. The depth distribution of pits followed Gumbel model and the shape of pits was shallow.%采用光学显微镜、扫描电子显微镜研究了HP2-13Cr油管钢在模拟高温高压气井环境中(酸化→返排残酸→采出水)点蚀行为的发展变化.结果表明:HP2-13Cr在服役过程中的点蚀主要在返排残酸阶段产生,残酸是引起HP2-13Cr点蚀的主要原因;统计了不同阶段点蚀坑深度的发展,得到返排残酸期间点蚀速率为7.56 mm/a,采出水期间点蚀发展速率为0.47 mm/a.点蚀坑深度的统计规律符合Gumbel分布,点蚀坑呈浅碟型.

  14. Blood pressure and contraceptive use

    OpenAIRE

    Khaw, Kay-Tee; Peart, W S

    1982-01-01

    In a survey of 461 women routinely attending family planning clinics those taking oral contraceptives had significantly higher mean systolic and diastolic blood pressures than those using non-hormonal contraception. There appeared to be a dose-response relation of blood pressure to the progestogen component of two oral contraceptives with an identical 30 μg ethinyloestradiol component. This supports the idea that the progestogen as well as the oestrogen component has an aetiological role in t...

  15. Stimulation Technologies for Deep Well Completions

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-09-30

    The Department of Energy (DOE) is sponsoring the Deep Trek Program targeted at improving the economics of drilling and completing deep gas wells. Under the DOE program, Pinnacle Technologies is conducting a study to evaluate the stimulation of deep wells. The objective of the project is to assess U.S. deep well drilling & stimulation activity, review rock mechanics & fracture growth in deep, high pressure/temperature wells and evaluate stimulation technology in several key deep plays. An assessment of historical deep gas well drilling activity and forecast of future trends was completed during the first six months of the project; this segment of the project was covered in Technical Project Report No. 1. The second progress report covers the next six months of the project during which efforts were primarily split between summarizing rock mechanics and fracture growth in deep reservoirs and contacting operators about case studies of deep gas well stimulation.

  16. Abandoning wells working group

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    The primary objective of this working group is to identify major technical, regulatory, and environmental issues that are relevant to the abandonment of offshore wellbores. Once the issues have been identified, the working group also has the objective of making recommendations or providing potential solutions for consideration. Areas for process improvement will be identified and {open_quotes}best practices{close_quotes} will be discussed and compared to {open_quotes}minimum standards.{close_quotes} The working group will primarily focus on wellbore abandonment in the Gulf of Mexico. However, workshop participants are encouraged to discuss international issues which may be relevant to wellbore abandonment practices in the Gulf of Mexico. The Abandoning Wells Group has identified several major areas for discussion that have concerns related to both operators and service companies performing wellbore abandonments in the Gulf of Mexico. The following broad topics were selected for the agenda: (1) MMS minimum requirements and state regulations. (2) Co-existence of best practices, new technology, and P & A economics. (3) Liability and environmental issues relating to wellbore abandonment.

  17. Nitrogen Monitoring of West Hackberry 117 Cavern Wells

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, Giorgia [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lord, David L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    U.S. Strategic Petroleum Reserve (SPR) oil storage cavern West Hackberry 117 was tested under extended nitrogen monitoring following a successful mechanical integrity test in order to validate a newly developed hydrostatic column model to be used to differentiate between normal "tight" well behavior and small-leak behavior under nitrogen. High resolution wireline pressure and temperature data were collected during the test period and used in conjunction with the hydrostatic column model to predict the nitrogen/oil interface and the pressure along the entire fluid column from the bradenhead flange nominally at ground surface to bottom of brine pool. Results here and for other SPR caverns have shown that wells under long term nitrogen monitoring do not necessarily pressurize with a relative rate (P N2 /P brine) of 1. The theoretical relative pressure rate depends on the well configuration, pressure and the location of the nitrogen-oil interface and varies from well to well. For the case of WH117 the predicted rates were 0.73 for well A and 0.92 for well B. The measured relative pressurization rate for well B was consistent with the model prediction, while well A rate was found to be between 0.58-0.68. A number of possible reasons for the discrepancy between the model and measured rates of well A are possible. These include modeling inaccuracy, measurement inaccuracy or the possibility of the presence of a very small leak (below the latest calculated minimum detectable leak rate).

  18. Nitrogen Monitoring of West Hackberry 117 Cavern Wells.

    Energy Technology Data Exchange (ETDEWEB)

    Bettin, Giorgia; Lord, David

    2015-02-01

    U.S. Strategic Petroleum Reserve (SPR) oil storage cavern West Hackberry 117 was tested under extended nitrogen monitoring following a successful mechanical integrity test in order to validate a newly developed hydrostatic column model to be used to differentiate between normal "tight" well behavior and small-leak behavior under nitrogen. High resolution wireline pressure and temperature data were collected during the test period and used in conjunction with the hydrostatic column model to predict the nitrogen/oil interface and the pressure along the entire fluid column from the bradenhead flange nominally at ground surface to bottom of brine pool. Results here and for other SPR caverns have shown that wells under long term nitrogen monitoring do not necessarily pressurize with a relative rate (P N2 /P brine) of 1. The theoretical relative pressure rate depends on the well configuration, pressure and the location of the nitrogen-oil interface and varies from well to well. For the case of WH117 the predicted rates were 0.73 for well A and 0.92 for well B. The measured relative pressurization rate for well B was consistent with the model prediction, while well A rate was found to be between 0.58-0.68. A number of possible reasons for the discrepancy between the model and measured rates of well A are possible. These include modeling inaccuracy, measurement inaccuracy or the possibility of the presence of a very small leak (below the latest calculated minimum detectable leak rate).

  19. Intracranial Pressure Monitoring

    DEFF Research Database (Denmark)

    Raboel, P H; Bartek, J; Andresen, M;

    2012-01-01

    Monitoring of intracranial pressure (ICP) has been used for decades in the fields of neurosurgery and neurology. There are multiple techniques: invasive as well as noninvasive. This paper aims to provide an overview of the advantages and disadvantages of the most common and well-known methods as ......-invasive techniques are without the invasive methods' risk of complication, but fail to measure ICP accurately enough to be used as routine alternatives to invasive measurement. We conclude that invasive measurement is currently the only option for accurate measurement of ICP....... as well as assess whether noninvasive techniques (transcranial Doppler, tympanic membrane displacement, optic nerve sheath diameter, CT scan/MRI and fundoscopy) can be used as reliable alternatives to the invasive techniques (ventriculostomy and microtransducers). Ventriculostomy is considered the gold...

  20. Method of hydrodynamic studies of wells in beds

    Energy Technology Data Exchange (ETDEWEB)

    Fedin, L.M.; Bondarenko, Ye.S.; Fedin, K.L.; Lisin, N.I.; Reytenbakh, V.G.

    1982-01-01

    A method is proposed for hydrodynamic studies of wells in beds including the termination of the coefficient of piezoconductance by spasmodic change in pressure in the well. It is distinguished by the fact that in order to reduce the time for idling of the well, above the studied bed an output meter is installed and the output of the bed fluid is measured during the time from spasmodic change in pressure to establishment of the stationary output.

  1. Pressure difference receiving ears

    DEFF Research Database (Denmark)

    Michelsen, Axel; Larsen, Ole Næsbye

    2007-01-01

    of such pressure difference receiving ears have been hampered by lack of suitable experimental methods. In this review, we review the methods for collecting reliable data on the binaural directional cues at the eardrums, on how the eardrum vibrations depend on the direction of sound incidence, and on how sound...... waves behave in the air spaces leading to the interior surfaces of eardrums. A linear mathematical model with well-defined inputs is used for exploring how the directionality varies with the binaural directional cues and the amplitude and phase gain of the sound pathway to the inner surface...

  2. INTRACRANIAL PRESSURE MONITORING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Ida Bagus Adi Kayana

    2013-03-01

    Full Text Available Head injury is the most significant cause of increased morbidity and mortality. An estimated 1.4 million head injuries occur each year, with and more than 1.1 million come to the Emergency Unit. On each patient head injury, an increase in intracranial pressure (ICP related to poor outcomes and aggressive therapy to increased ICP can improve the outcomes. ICP monitoring is the most widely used because of the prevention and control of ICP as well as maintain the pressure increase perfusion of cerebral (Cerebral Perfusion Pressure/CPP is the basic purpose of handling head injury. There are two methods of monitoring ICP that is an invasive methods (directly and non-invasive techniques (indirectly. The method commonly used, namely intraventricular and intraparenkimal (microtransducer sensor because it is more accurate but keep attention to the existence of the risk of bleeding and infection resulting from installation. Monitoring of ICT can determine the actions that avoid further brain injury, which can be lethal and irreversibel.

  3. Characteristic Value Method of Well Test Analysis for Horizontal Gas Well

    Directory of Open Access Journals (Sweden)

    Xiao-Ping Li

    2014-01-01

    Full Text Available This paper presents a study of characteristic value method of well test analysis for horizontal gas well. Owing to the complicated seepage flow mechanism in horizontal gas well and the difficulty in the analysis of transient pressure test data, this paper establishes the mathematical models of well test analysis for horizontal gas well with different inner and outer boundary conditions. On the basis of obtaining the solutions of the mathematical models, several type curves are plotted with Stehfest inversion algorithm. For gas reservoir with closed outer boundary in vertical direction and infinite outer boundary in horizontal direction, while considering the effect of wellbore storage and skin effect, the pseudopressure behavior of the horizontal gas well can manifest four characteristic periods: pure wellbore storage period, early vertical radial flow period, early linear flow period, and late horizontal pseudoradial flow period. For gas reservoir with closed outer boundary both in vertical and horizontal directions, the pseudopressure behavior of the horizontal gas well adds the pseudosteady state flow period which appears after the boundary response. For gas reservoir with closed outer boundary in vertical direction and constant pressure outer boundary in horizontal direction, the pseudopressure behavior of the horizontal gas well adds the steady state flow period which appears after the boundary response. According to the characteristic lines which are manifested by pseudopressure derivative curve of each flow period, formulas are developed to obtain horizontal permeability, vertical permeability, skin factor, reservoir pressure, and pore volume of the gas reservoir, and thus the characteristic value method of well test analysis for horizontal gas well is established. Finally, the example study verifies that the new method is reliable. Characteristic value method of well test analysis for horizontal gas well makes the well test analysis

  4. Blood Pressure Test

    Science.gov (United States)

    ... an online personal health record or blood pressure tracker, for example. This gives you the option of ... lower your blood pressure. Exercise regularly. Regular physical activity can help lower your blood pressure and keep ...

  5. Low Blood Pressure (Hypotension)

    Science.gov (United States)

    ... and rises sharply on waking. Blood pressure: How low can you go? What's considered low blood pressure ... even life-threatening disorders. Conditions that can cause low blood pressure Some medical conditions can cause low ...

  6. Preventing pressure ulcers

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/patientinstructions/000147.htm Preventing pressure ulcers To use the sharing features on this page, please enable JavaScript. Pressure ulcers are also called bedsores, or pressure sores. They ...

  7. Dealing with Peer Pressure

    Science.gov (United States)

    ... Lifesaver Kids Talk About: Coaches Dealing With Peer Pressure KidsHealth > For Kids > Dealing With Peer Pressure Print ... talk about how to handle it. Defining Peer Pressure Peers influence your life, even if you don' ...

  8. Intracranial pressure monitoring

    Science.gov (United States)

    ICP monitoring; CSF pressure monitoring ... There are 3 ways to monitor pressure in the skull (intracranial pressure). INTRAVENTRICULAR CATHETER The intraventricular catheter is the most accurate monitoring method. To insert an intraventricular catheter, a ...

  9. High Blood Pressure

    Science.gov (United States)

    ... normal blood pressure 140/90 or higher is high blood pressure Between 120 and 139 for the top number, ... prehypertension. Prehypertension means you may end up with high blood pressure, unless you take steps to prevent it. High ...

  10. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... Print Page Text Size: A A A Listen High Blood Pressure (Hypertension) Nearly 1 in 3 American adults has ... weight. How Will I Know if I Have High Blood Pressure? High blood pressure is a silent problem — you ...

  11. Low Blood Pressure (Hypotension)

    Science.gov (United States)

    Low blood pressure (hypotension) Overview By Mayo Clinic Staff Low blood pressure might seem desirable, and for some people, it causes no problems. However, for many people, abnormally low blood pressure (hypotension) can cause dizziness and fainting. In severe ...

  12. High blood pressure in women.

    Science.gov (United States)

    Calhoun, D A; Oparil, S

    1997-01-01

    There is a sexual dimorphism in blood pressure of humans and experimental animals: males tend to have higher blood pressure than females with functional ovaries, while ovariectomy or menopause tends to abolish the sexual dimorphism and cause females to develop a "male" pattern of blood pressure. Hypertensive male laboratory animals tend to have NaCl-sensitive blood pressure, while females are NaCl resistant unless their ovaries are removed, in which case NaCl sensitivity appears. The hormonal basis of NaCl sensitivity of blood pressure and of the sexual dimorphism of hypertension remains to be defined. Synthetic estrogens and progestins, as found in oral contraceptives, tend to elevate blood pressure, while naturally occurring estrogens lower it, or have no effect. Hypertension increases cardiovascular risk in women, as well as men, although the benefits of antihypertensive treatment have been more difficult to demonstrate in women. In the population of the United States, women are more aware of their hypertension, more likely to be treated medically, and more likely to have their blood pressure controlled.

  13. Revised National Pressure Ulcer Advisory Panel Pressure Injury Staging System

    Science.gov (United States)

    Black, Joyce M.; Goldberg, Margaret; McNichol, Laurie; Moore, Lynn; Sieggreen, Mary

    2016-01-01

    Our understanding of pressure injury etiology and development has grown in recent years through research, clinical expertise, and global interdisciplinary expert collaboration. Therefore, the National Pressure Ulcer Advisory Panel (NPUAP) has revised the definition and stages of pressure injury. The revision was undertaken to incorporate the current understanding of the etiology of pressure injuries, as well as to clarify the anatomical features present or absent in each stage of injury. An NPUAP-appointed Task Force reviewed the literature and created drafts of definitions, which were then reviewed by stakeholders and the public, including clinicians, educators, and researchers around the world. Using a consensus-building methodology, these revised definitions were the focus of a multidisciplinary consensus conference held in April 2016. As a result of stakeholder and public input, along with the consensus conference, important changes were made and incorporated into the new staging definitions. The revised staging system uses the term injury instead of ulcer and denotes stages using Arabic numerals rather than Roman numerals. The revised definition of a pressure injury now describes the injuries as usually occurring over a bony prominence or under a medical or other device. The revised definition of a Stage 2 pressure injury seeks to clarify the difference between moisture-associated skin damage and injury caused by pressure and/or shear. The term suspected has been removed from the Deep Tissue Pressure Injury diagnostic label. Each definition now describes the extent of tissue loss present and the anatomical features that may or may not be present in the stage of injury. These important revisions reflect the methodical and collaborative approach used to examine the available evidence and incorporate current interdisciplinary clinical expertise into better defining the important phenomenon of pressure injury etiology and development. PMID:27749790

  14. Negative-Pressure Pulmonary Edema.

    Science.gov (United States)

    Bhattacharya, Mallar; Kallet, Richard H; Ware, Lorraine B; Matthay, Michael A

    2016-10-01

    Negative-pressure pulmonary edema (NPPE) or postobstructive pulmonary edema is a well-described cause of acute respiratory failure that occurs after intense inspiratory effort against an obstructed airway, usually from upper airway infection, tumor, or laryngospasm. Patients with NPPE generate very negative airway pressures, which augment transvascular fluid filtration and precipitate interstitial and alveolar edema. Pulmonary edema fluid collected from most patients with NPPE has a low protein concentration, suggesting hydrostatic forces as the primary mechanism for the pathogenesis of NPPE. Supportive care should be directed at relieving the upper airway obstruction by endotracheal intubation or cricothyroidotomy, institution of lung-protective positive-pressure ventilation, and diuresis unless the patient is in shock. Resolution of the pulmonary edema is usually rapid, in part because alveolar fluid clearance mechanisms are intact. In this review, we discuss the clinical presentation, pathophysiology, and management of negative-pressure or postobstructive pulmonary edema.

  15. Impact of Hydraulic Well Restoration on Native Bacterial Communities in Drinking Water Wells

    OpenAIRE

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production ...

  16. Estimation of turgor pressure through comparison between single plant cell and pressurized shell mechanics

    Science.gov (United States)

    Durand-Smet, P.; Gauquelin, E.; Chastrette, N.; Boudaoud, A.; Asnacios, A.

    2017-10-01

    While plant growth is well known to rely on turgor pressure, it is challenging to quantify the contribution of turgor pressure to plant cell rheology. Here we used a custom-made micro-rheometer to quantify the viscoelastic behavior of isolated plant cells while varying their internal turgor pressure. To get insight into how plant cells adapt their internal pressure to the osmolarity of their medium, we compared the mechanical behavior of single plant cells to that of a simple, passive, pressurized shell: a soccer ball. While both systems exhibited the same qualitative behavior, a simple mechanical model allowed us to quantify turgor pressure regulation at the single cell scale.

  17. High-Pressure Vibrational Spectroscopy.

    Science.gov (United States)

    Pogson, Mark

    1987-09-01

    both low temperature as well as high pressure, and the other only at high pressure, the latter again associated with the stopping of methyl rotation. The iodide displays two high pressure transitions. A Raman -active soft-mode has been observed in all three analogues, at both high pressure and variable temperature. For the chloride and bromide analogues there is a discussion of the nature of the soft-mode along with the mechanism associated with the I/II transition. The results of the X-ray crystal structure determination of CH_3HgBr at ambient temperature and pressure are given.

  18. A simple deep monitoring well dilution technique.

    Science.gov (United States)

    Rogiers, Bart; Labat, Serge; Gedeon, Matej; Vandersteen, Katrijn

    2015-04-01

    Well dilution techniques are well known and studied as one of the basic techniques to quantify groundwater fluxes. A typical well dilution test consists of the injection of a tracer, a mixing mechanism (e.g. water circulation with a pump) to achieve a homogeneous concentration distribution within the well, and monitoring of the evolution of tracer concentration with time. An apparent specific discharge can be obtained from such a test, and when details on the well construction are known, it can be converted into a specific discharge representative of the undisturbed aquifer. For deep wells however, the injection of tracer becomes less practical and the use of pumps for circulating and mixing the water becomes problematic. This is due to the limited pressure that common pumps can endure at the outlet, as well as the large volume of water that makes it difficult to achieve a homogeneous concentration, and the impracticalities of getting a lot of equipment to large depths in very small monitoring wells. Injection and monitoring of tracer at a specific depth omits several of the problems with deep wells. We present a very simple device that can be used to perform a dilution test at a specific depth in deep wells. The injection device consists of a PVC tube with a detachable rubber seal at its bottom. To minimize disturbance of the water column in the well, we integrated an EC sensor in this injection device, which enables us to use demineralized water or dissolved salts as a tracer. Once at the target depth, the PVC tube is retracted and the EC sensor and tracer become subject to groundwater flow. The device was tested on a shallow well, on which different types of dilution tests were performed. The results of the other tests agree well with the injection tube results. Finally, the device was used to perform a dilution test in a deep well in order to demonstrate the feasibility of the approach.

  19. Gas Deliverability Model with Different Vertical Wells Properties

    Directory of Open Access Journals (Sweden)

    L. Mucharam

    2003-11-01

    Full Text Available We present here a gas deliverability computational model for single reservoir with multi wells. The questions of how long the gas delivery can be sustained and how to estimate the plateau time are discussed here. In order to answer such a question, in this case, a coupling method which consists of material balance method and gas flow equation method is developed by assuming no water influx in the reservoir. Given the rate and the minimum pressure of gas at the processing plant, the gas pressure at the wellhead and at the bottom hole can be obtained. From here, the estimation of the gas deliverability can be done. In this paper we obtain a computational method which gives direct computation for pressure drop from the processing plant to the wells, taking into account different well behavior. Here AOF technique is used for obtaining gas rate in each well. Further Tian & Adewumi correlation is applied for pressure drop model along vertical and horizontal pipes and Runge-Kutta method is chosen to compute the well head and bottom hole pressures in each well which then being used to estimate the plateau times. We obtain here direct computational scheme of gas deliverability from reservoir to processing plant for single reservoir with multi-wells properties. Computational results give different profiles (i.e. gas rate, plateau and production time, etc for each well. Further by selecting proper flow rate reduction, the flow distribution after plateau time to sustain the delivery is computed for each well.

  20. METHOD OF CALCULATING THE OPTIMAL HEAT EMISSION GEOTHERMAL WELLS

    Directory of Open Access Journals (Sweden)

    A. I. Akaev

    2015-01-01

    Full Text Available This paper presents a simplified method of calculating the optimal regimes of the fountain and the pumping exploitation of geothermal wells, reducing scaling and corrosion during operation. Comparative characteristics to quantify the heat of formation for these methods of operation under the same pressure at the wellhead. The problem is solved graphic-analytical method based on a balance of pressure in the well with the heat pump. 

  1. Hypertension (High Blood Pressure)

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Hypertension (High Blood Pressure) KidsHealth > For Teens > Hypertension (High Blood Pressure) A ... rest temperature diet emotions posture medicines Why Is High Blood Pressure Bad? High blood pressure means a person's heart ...

  2. High pressure technology 1994

    Energy Technology Data Exchange (ETDEWEB)

    Kapp, J.A.; Picqueuer, L.M. (eds.)

    1994-01-01

    This volume is divided into four sessions: fracture mechanics applications to high pressure vessels; high pressure code issues; high pressure design, analysis, and safety concerns; and military and other high pressure applications. Separate abstracts were prepared for eleven papers of this conference.

  3. High blood pressure - children

    Science.gov (United States)

    ... number is the diastolic pressure. This measures the pressure in the arteries when the heart is at rest. Blood pressure ... Medical Professional Call your child's provider if home monitoring shows that your child's blood pressure is still high. Prevention Your child's provider will ...

  4. Constant-pressure Blowers

    Science.gov (United States)

    Sorensen, E

    1940-01-01

    The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency.

  5. Common Questions About Pressure Ulcers.

    Science.gov (United States)

    Raetz, Jaqueline G M; Wick, Keren H

    2015-11-15

    Patients with limited mobility due to physical or cognitive impairment are at risk of pressure ulcers. Primary care physicians should examine at-risk patients because pressure ulcers are often missed in inpatient, outpatient, and long-term care settings. High-risk patients should use advanced static support surfaces to prevent pressure ulcers and air-fluidized beds to treat pressure ulcers. Physicians should document the size and clinical features of ulcers. Cleansing should be done with saline or tap water, while avoiding caustic agents, such as hydrogen peroxide. Dressings should promote a moist, but not wet, wound healing environment. The presence of infection is determined through clinical judgment; if uncertain, a tissue biopsy should be performed. New or worsening pain may indicate infection of a pressure ulcer. When treating patients with pressure ulcers, it is important to keep in mind the patient's psychological, behavioral, and cognitive status. The patient's social, financial, and caregiver resources, as well as goals and long-term prognosis, should also be considered in the treatment plan.

  6. Pressure fluctuations in gas fluidized beds

    OpenAIRE

    Leckner Bo.; Palchonok Genadij I.; Johnsson Filip

    2002-01-01

    The pressure fluctuations in a fluidized bed are a result of the actions of the bubbles. However, the bubbles may be influenced by the air supply system and by the pressure drop of the air distributor. These interactions are treated for low as well as for high velocity beds by means of a simple model of the principal frequency of the pressure fluctuations. The model includes the interaction with the air supply system and describes qualitatively two important bubbling regimes: the single bubbl...

  7. Estimation of production characteristic curves of geothermal wells and of the permeability of rocky formations through one single mass flow-pressure-enthalpy (W-P-h) measurement at the wellhead; Estimacion de curvas caracteristicas de produccion de pozos geotermicos y de permeabilidades de formaciones rocosas a partir de una sola medicion flujo masico-presion- entalpia (W-P-h) a boca de pozo

    Energy Technology Data Exchange (ETDEWEB)

    L Moya, Sara; Aragon, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1997-12-31

    The proposed methodology described ahead (Moya et al.,1996; Moya et al.,1997a, 1997b and 1997c) simplifies the construction of production characteristic curves of geothermal wells and of its associated thermal productivity, in requiring one single measurement of mass flow-pressure-enthalpy (W-P-h) at the wellhead. Therefore it is an ecological option, technically and economically more feasible. On the other hand, the methodology also allows to diagnose the rocky formation absolute permeability in the well feeding zone. This permeability is usually determined through well bottom pressure tests, than in some cases are difficult to interpret. The permeability inferred by means of the proposed technology represents a complementary tool for these field tests and for the laboratory measurements on drilling cores. [Espanol] La metodologia propuesta que se describe a continuacion [Moya et al., 1995d; Moya et al., 1996; Moya et al., 1997a, 1997b y 1997c] simplifica la construccion de curvas caracteristicas de produccion de pozos geotermicos y de su productividad termica asociada al requerir solo una medicion de flujo masico-presion-entalpia (W-P-h) a boca de pozo. Es por tanto una alternativa ecologica, tecnica y economicamente mas factible. Por otra parte, la metodologia tambien permite diagnosticar el valor de la permeabilidad absoluta de la formacion rocosa en la zona de alimentacion al pozo. Esta permeabilidad se determina usualmente a partir de pruebas de presion a fondo de pozo que en algunos casos son dificiles de interpretar. La permeabilidad inferida mediante la metodologia propuesta representa una herramienta complementaria a estas pruebas de campo y a las mediciones de laboratorio sobre nucleos de perforacion.

  8. Private Well Water and Fluoride

    Science.gov (United States)

    ... well. What do I need to know about fluoride and groundwater from a well? Fluoride is present ... well has less than the recommended level of fluoride for preventing tooth decay? The recommended fluoride level ...

  9. Pressure Dome for High-Pressure Electrolyzer

    Science.gov (United States)

    Norman, Timothy; Schmitt, Edwin

    2012-01-01

    A high-strength, low-weight pressure vessel dome was designed specifically to house a high-pressure [2,000 psi (approx. = 13.8 MPa)] electrolyzer. In operation, the dome is filled with an inert gas pressurized to roughly 100 psi (approx. = 690 kPa) above the high, balanced pressure product oxygen and hydrogen gas streams. The inert gas acts to reduce the clamping load on electrolyzer stack tie bolts since the dome pressure acting axially inward helps offset the outward axial forces from the stack gas pressure. Likewise, radial and circumferential stresses on electrolyzer frames are minimized. Because the dome is operated at a higher pressure than the electrolyzer product gas, any external electrolyzer leak prevents oxygen or hydrogen from leaking into the dome. Instead the affected stack gas stream pressure rises detectably, thereby enabling a system shutdown. All electrical and fluid connections to the stack are made inside the pressure dome and require special plumbing and electrical dome interfaces for this to be accomplished. Further benefits of the dome are that it can act as a containment shield in the unlikely event of a catastrophic failure. Studies indicate that, for a given active area (and hence, cell ID), frame outside diameter must become ever larger to support stresses at higher operating pressures. This can lead to a large footprint and increased costs associated with thicker and/or larger diameter end-plates, tie-rods, and the frames themselves. One solution is to employ rings that fit snugly around the frame. This complicates stack assembly and is sometimes difficult to achieve in practice, as its success is strongly dependent on frame and ring tolerances, gas pressure, and operating temperature. A pressure dome permits an otherwise low-pressure stack to operate at higher pressures without growing the electrolyzer hardware. The pressure dome consists of two machined segments. An O-ring is placed in an O-ring groove in the flange of the bottom

  10. Chronic blood pressure control.

    Science.gov (United States)

    Brands, Michael W

    2012-10-01

    Chronic blood pressure is maintained within very narrow limits around an average value. However, the multitude of physiologic processes that participate in blood pressure control present a bewildering array of possibilities to explain how such tight control of arterial pressure is achieved. Guyton and Coleman and colleagues addressed this challenge by creating a mathematical model that integrated the short- and long-term control systems for overall regulation of the circulation. The hub is the renal-body fluid feedback control system, which links cardiac function and vascular resistance and capacitance with fluid volume homeostasis as the foundation for chronic blood pressure control. The cornerstone of that system is renal sodium excretory capability, which is defined by the direct effect of blood pressure on urinary sodium excretion, that is, "pressure natriuresis." Steady-state blood pressure is the pressure at which pressure natriuresis balances sodium intake over time; therefore, renal sodium excretory capability is the set point for chronic blood pressure. However, this often is misinterpreted as dismissing, or minimizing, the importance of nonrenal mechanisms in chronic blood pressure control. This article explains the renal basis for the blood pressure set point by focusing on the absolute dependence of our survival on the maintenance of sodium balance. Two principal threats to sodium balance are discussed: (1) a change in sodium intake or renal excretory capability and (2) a change in blood pressure. In both instances, circulatory homeostasis is maintained because the sodium balance blood pressure set point is reached.

  11. [Prevention of pressure ulcer (bedsore)].

    Science.gov (United States)

    Sedmak, Dijana; Vrhovec, Marina; Huljev, Dubravko

    2013-10-01

    Although progress in many fields of science, medicine and technology is evident, we are still witnessing the appearance of bedsores and its consequences. However, in the last fifty years there has been considerable progress in the understanding of its causes, prevention and treatment. Prevention and treatment of pressure ulcers are complicated by the many misconceptions. However, with due knowledge of the process of healing of acute and chronic wounds and of the pathophysiological processes, in many cases chronic wounds, like pressure ulcers, can now be prevented and cured, and thus reduce the cost of treatment, as well as the mortality rate.

  12. Hanford well custodians. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    Schatz, A.L.; Underwood, D.J.

    1995-02-02

    The Hanford Site Groundwater Protection Management Program recognized the need to integrate monitoring well activities in a centralized manner. A key factor to Hanford Site well integration was the need to clearly identify a responsible party for each of the wells. WHC was asked to identify all wells on site, the program(s) using each well, and the program ultimately responsible for the well. This report lists the custodian and user(s) for each Hanford well and supplies a comprehensive list of all decommissioned and orphaned wells on the Hanford Site. This is the first update to the original report released in December 1993.

  13. Nonlinear flow model for well production in an underground formation

    Directory of Open Access Journals (Sweden)

    J. C. Guo

    2013-05-01

    Full Text Available Fluid flow in underground formations is a nonlinear process. In this article we modelled the nonlinear transient flow behaviour of well production in an underground formation. Based on Darcy's law and material balance equations, we used quadratic pressure gradients to deduce diffusion equations and discuss the origins of nonlinear flow issues. By introducing an effective-well-radius approach that considers skin factor, we established a nonlinear flow model for both gas and liquid (oil or water. The liquid flow model was solved using a semi-analytical method, while the gas flow model was solved using numerical simulations because the diffusion equation of gas flow is a stealth function of pressure. For liquid flow, a series of standard log-log type curves of pressure transients were plotted and nonlinear transient flow characteristics were analyzed. Qualitative and quantitative analyses were used to compare the solutions of the linear and nonlinear models. The effect of nonlinearity upon pressure transients should not be ignored. For gas flow, pressure transients were simulated and compared with oil flow under the same formation and well conditions, resulting in the conclusion that, under the same volume rate production, oil wells demand larger pressure drops than gas wells. Comparisons between theoretical data and field data show that nonlinear models will describe fluid flow in underground formations realistically and accurately.

  14. Transient productivity index for numerical well test simulations

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, G.; Ding, D.Y.; Ene, A. [Institut Francais du Petrole, Pau (France)] [and others

    1997-08-01

    The most difficult aspect of numerical simulation of well tests is the treatment of the Bottom Hole Flowing (BHF) Pressure. In full field simulations, this pressure is derived from the Well-block Pressure (WBP) using a numerical productivity index which accounts for the grid size and permeability, and for the well completion. This productivity index is calculated assuming a pseudo-steady state flow regime in the vicinity of the well and is therefore constant during the well production period. Such a pseudo-steady state assumption is no longer valid for the early time of a well test simulation as long as the pressure perturbation has not reached several grid-blocks around the well. This paper offers two different solutions to this problem: (1) The first one is based on the derivation of a Numerical Transient Productivity Index (NTPI) to be applied to Cartesian grids; (2) The second one is based on the use of a Corrected Transmissibility and Accumulation Term (CTAT) in the flow equation. The representation of the pressure behavior given by both solutions is far more accurate than the conventional one as shown by several validation examples which are presented in the following pages.

  15. Drawdown behavior of gravity drainage wells

    Energy Technology Data Exchange (ETDEWEB)

    Aasen, J.A.; Ramey, H.J. Jr.

    1993-10-01

    An analytical solution for drawdown in gravity drainage wells is developed. The free-surface flow is viewed as incompressible, and anisotropy effects are included. The well is a line source well, and the reservoir is infinitely large. The model is valid for small drawdowns. The uniform wellbore potential inner boundary condition is modelled using the proper Green`s function. The discontinuity at the wellbore is solved by introducing a finite skin radius, and the formulation produces a seepage face. The calculated wellbore flux distribution and wellbore pressures are in fair agreement with results obtained using a numerical gravity drainage simulator. Three distinct flow periods are observed. The wellbore storage period is caused by the moving liquid level, and the duration is short. During the long intermediate flow period, the wellbore pressure is nearly constant. In this period the free surface moves downwards, and the liquid is produced mainly by vertical drainage. At long times the semilog straight line appears. The confined liquid solutions by Theis (1935) and van Everdingen and Hurst (1949) may be used during the pseudoradial flow period if the flowrate is low. New type curves are presented that yield both vertical and horizontal permeabilities.

  16. Well data summary sheets. Vol. 30. North Sea wells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This thirtieth volume of the `Well Data Summary sheets` includes data from three recently released offshore wells from the North Sea. The two wells Amalie-1/1A and Skarv-1 are situated in the Danish Central Graben area. The Ida-1 well is one of a number of Danish North Sea wells situated outside the Central Graben (se also Volume 25). Minor corrections have been made since the first edition. The `Complete index of released wells` had been updated. Volume 27, 28 and 29 are regional volumes; volume 27 includes well data from Southern Jutland; volumes 28 and 29 cover well data from Northern Jutland. All data from released Danish North Sea wells are included in volumes 17-26 and 30. Data references are made to the revised volumes and not to the original published reference. (au)

  17. Well-test analysis for solution-gas-drive reservoirs. Part 2; Buildup analysis

    Energy Technology Data Exchange (ETDEWEB)

    Serra, K.V.; Peres, A.M.M. (PETROBRAS, Rio de Janeiro, RJ (Brazil)); Reynolds, A.C. (Tulsa Univ., OK (USA))

    1990-06-01

    This work presents new analysis methods for pressure-buildup data from a well completed in a solution-gas-drive reservoir. New procedures for estimating effective phase permeabilities as functions of pressure and saturation are presented.

  18. Hydraulic High Pressure Valve Controller Using the In-Situ Pressure Difference

    Science.gov (United States)

    Bao, Xiaoqi (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor); Hall, Jeffery L. (Inventor)

    2016-01-01

    A hydraulic valve controller that uses an existing pressure differential as some or all of the power source for valve operation. In a high pressure environment, such as downhole in an oil or gas well, the pressure differential between the inside of a pipe and the outside of the pipe may be adequately large to drive a linear slide valve. The valve is operated hydraulically by a piston in a bore. When a higher pressure is applied to one end of the bore and a lower pressure to the other end, the piston moves in response to the pressure differential and drives a valve attached to it. If the pressure differential is too small to drive the piston at a sufficiently high speed, a pump is provided to generate a larger pressure differential to be applied. The apparatus is conveniently constructed using multiport valves, which can be rotary valves.

  19. Reservoir pressure evolution model during exploration drilling

    Directory of Open Access Journals (Sweden)

    Korotaev B. A.

    2017-03-01

    Full Text Available Based on the analysis of laboratory studies and literature data the method for estimating reservoir pressure in exploratory drilling has been proposed, it allows identify zones of abnormal reservoir pressure in the presence of seismic data on reservoir location depths. This method of assessment is based on developed at the end of the XX century methods using d- and σ-exponentials taking into account the mechanical drilling speed, rotor speed, bit load and its diameter, lithological constant and degree of rocks' compaction, mud density and "regional density". It is known that in exploratory drilling pulsation of pressure at the wellhead is observed. Such pulsation is a consequence of transferring reservoir pressure through clay. In the paper the mechanism for transferring pressure to the bottomhole as well as the behaviour of the clay layer during transmission of excess pressure has been described. A laboratory installation has been built, it has been used for modelling pressure propagation to the bottomhole of the well through a layer of clay. The bulge of the clay layer is established for 215.9 mm bottomhole diameter. Functional correlation of pressure propagation through the layer of clay has been determined and a reaction of the top clay layer has been shown to have bulge with a height of 25 mm. A pressure distribution scheme (balance has been developed, which takes into account the distance from layers with abnormal pressure to the bottomhole. A balance equation for reservoir pressure evaluation has been derived including well depth, distance from bottomhole to the top of the formation with abnormal pressure and density of clay.

  20. Well data summary sheets. Vol. 33: North sea wells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    This 33rd volume of the `Well Data Summary sheets` includes data from seven recently released offshore wells from the North Sea. The wells Baron-2, S.E. Adda-1 and Skjold Flank-1 were presented in our `Well Data Summary Sheets, special volume`, published May 1, 1997. In volume 33, the wells Baron-2 and Skjold Flank-1 are updated with respect to information on sidewall cores. Information regarding all released well data, included in our well data summary sheets, are available on GEUS homepage: http://www.geus.dk/ or the departments homepage: http://www.geus.dk/departments/geol-info-data-centre/geoldata.htm/. A complete index of releases wells in volumes 17-33 is included. (au)

  1. Embedded programmable blood pressure monitoring system

    Science.gov (United States)

    Hasan, Md. Mahmud-Ul; Islam, Md. Kafiul; Shawon, Mehedi Azad; Nowrin, Tasnuva Faruk

    2010-02-01

    A more efficient newer algorithm of detecting systolic and diastolic pressure of human body along with a complete package of an effective user-friendly embedded programmable blood pressure monitoring system has been proposed in this paper to reduce the overall workload of medical personals as well as to monitor patient's condition more conveniently and accurately. Available devices for measuring blood pressure have some problems and limitations in case of both analog and digital devices. The sphygmomanometer, being analog device, is still being used widely because of its reliability and accuracy over digital ones. But it requires a skilled person to measure the blood pressure and obviously not being automated as well as time consuming. Our proposed system being a microcontroller based embedded system has the advantages of the available digital blood pressure machines along with a much improved form and has higher accuracy at the same time. This system can also be interfaced with computer through serial port/USB to publish the measured blood pressure data on the LAN or internet. The device can be programmed to determine the patient's blood pressure after each certain interval of time in a graphical form. To sense the pressure of human body, a pressure to voltage transducer is used along with a cuff in our system. During the blood pressure measurement cycle, the output voltage of the transducer is taken by the built-in ADC of microcontroller after an amplifier stage. The recorded data are then processed and analyzed using the effective software routine to determine the blood pressure of the person under test. Our proposed system is thus expected to certainly enhance the existing blood pressure monitoring system by providing accuracy, time efficiency, user-friendliness and at last but not the least the 'better way of monitoring patient's blood pressure under critical care' all together at the same time.

  2. Resonant Tunneling in Barrier-in-Well and Well-in-Well Structures

    Institute of Scientific and Technical Information of China (English)

    YAO Jiang-Hong; JIA Guo-Zhi; ZHANG Yan; LI Wei-Wu; SHU Yong-Chun; WANG Zhan-Guo; XU Jing-Jun

    2008-01-01

    @@ A Schr(o)dinger equation is solved numerically for a barrier in a quantum well and a quantum well in another well structure by the transfer matrix technique.Effect of structure parameters on the transmission probabilities is investigated in detail.The results suggest that symmetry plays an important role in the coupling effect between the quantum wells.The relationship between the width of the inner well and the resonant energy levels in well-in-well structures is also studied.It is found that the ground state energy and the second resonant energy decrease with increasing width of the inner well, while the first resonant energy remains constant.

  3. Pressure ulcers: treatment

    National Research Council Canada - National Science Library

    Reddy, Madhuri

    2015-01-01

    Unrelieved pressure or friction of the skin, particularly over bony prominences, can lead to pressure ulcers in up to one third of people in hospitals or community care, and one fifth of nursing home residents...

  4. Blood Pressure Medicines

    Science.gov (United States)

    High blood pressure, also called hypertension, usually has no symptoms. But it can cause serious problems such as stroke, ... kidney failure. If you cannot control your high blood pressure through lifestyle changes such as losing weight ...

  5. Pressure vessel design manual

    CERN Document Server

    Moss, Dennis R

    2013-01-01

    Pressure vessels are closed containers designed to hold gases or liquids at a pressure substantially different from the ambient pressure. They have a variety of applications in industry, including in oil refineries, nuclear reactors, vehicle airbrake reservoirs, and more. The pressure differential with such vessels is dangerous, and due to the risk of accident and fatality around their use, the design, manufacture, operation and inspection of pressure vessels is regulated by engineering authorities and guided by legal codes and standards. Pressure Vessel Design Manual is a solutions-focused guide to the many problems and technical challenges involved in the design of pressure vessels to match stringent standards and codes. It brings together otherwise scattered information and explanations into one easy-to-use resource to minimize research and take readers from problem to solution in the most direct manner possible. * Covers almost all problems that a working pressure vessel designer can expect to face, with ...

  6. High Blood Pressure

    Science.gov (United States)

    ... mmHg People read "118 over 76" millimeters of mercury. Normal Blood Pressure Normal blood pressure for adults ... health. Share your story with other women on Facebook . The Heart Truth campaign offers a variety of ...

  7. High blood pressure medications

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007484.htm High blood pressure medicines To use the sharing features on this page, please enable JavaScript. Treating high blood pressure will help prevent problems such as heart disease, ...

  8. The Root Pressure Phenomenon

    Science.gov (United States)

    Marsh, A. R.

    1972-01-01

    Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

  9. Atmospheric Pressure Indicator.

    Science.gov (United States)

    Salzsieder, John C.

    1995-01-01

    Discusses observable phenomena related to air pressure. Describes a simple, unobtrusive, semiquantitative device to monitor the changes in air pressure that are associated with altitude, using a soft-drink bottle and a balloon. (JRH)

  10. Doublets and other allied well patterns

    Energy Technology Data Exchange (ETDEWEB)

    Brigham, W.E.

    1997-06-01

    Whenever a liquid is injected into an infinite reservoir containing liquid with the same flow properties, the equations of flow are well known. The pressures in such a system vary over time and distance (radius) in ways that depend on the formation and liquid flow properties. Such equations are well known--they form the basis for the voluminous well-testing literature in petroleum engineering and ground water hydrology. Suppose there are two wells--one an injector and one a producer--with identical rates. The behavior of this system can be calculated using superposition; which merely means that the results can be added independently of each other. When this is done, the remarkable result is that after a period of time there is a region that approaches steady state flow. Thereafter, the pressures and flow velocities in this region stay constant. The size of this region increases with time. This ``steady state`` characteristic can be used to solve a number of interesting and useful problems, both in heat transfer and in fluid flow. The heat transfer problems can be addressed because the equations are identical in form. A number of such problems are solved herein for doublet systems. In addition, concepts are presented to help solve other cases that flow logically from the problems solved herein. It is not necessary that only two wells be involved. It turns out that any time the total injection and production are equal, the system approaches steady state. This idea is also addressed in these notes. A number of useful multiwell cases are addressed to present the flavor of such solutions.

  11. Raft River well stimulation experiments: geothermal reservoir well stimulation program

    Energy Technology Data Exchange (ETDEWEB)

    1980-08-01

    The Geothermal Reservoir Well Stimulation Program (GRWSP) performed two field experiments at the Raft River KGRA in 1979. Wells RRGP-4 and RRGP-5 were selected for the hydraulic fracture stimulation treatments. The well selection process, fracture treatment design, field execution, stimulation results, and pre- and post-job evaluations are presented.

  12. Reliability of plantar pressure platforms.

    Science.gov (United States)

    Hafer, Jocelyn F; Lenhoff, Mark W; Song, Jinsup; Jordan, Joanne M; Hannan, Marian T; Hillstrom, Howard J

    2013-07-01

    Plantar pressure measurement is common practice in many research and clinical protocols. While the accuracy of some plantar pressure measuring devices and methods for ensuring consistency in data collection on plantar pressure measuring devices have been reported, the reliability of different devices when testing the same individuals is not known. This study calculated intra-mat, intra-manufacturer, and inter-manufacturer reliability of plantar pressure parameters as well as the number of plantar pressure trials needed to reach a stable estimate of the mean for an individual. Twenty-two healthy adults completed ten walking trials across each of two Novel emed-x(®) and two Tekscan MatScan(®) plantar pressure measuring devices in a single visit. Intraclass correlation (ICC) was used to describe the agreement between values measured by different devices. All intra-platform reliability correlations were greater than 0.70. All inter-emed-x(®) reliability correlations were greater than 0.70. Inter-MatScan(®) reliability correlations were greater than 0.70 in 31 and 52 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. Inter-manufacturer reliability including all four devices was greater than 0.70 for 52 and 56 of 56 parameters when looking at a 10-trial average and a 5-trial average, respectively. All parameters reached a value within 90% of an unbiased estimate of the mean within five trials. Overall, reliability results are encouraging for investigators and clinicians who may have plantar pressure data sets that include data collected on different devices.

  13. Relative microvascular pressure sensing

    Science.gov (United States)

    Choi, Min; Zemp, Roger

    2016-03-01

    Microcirculation may be characterized by the vascular pressure as it is influenced by pressure-driven perfusion. Crosssections of blood vessels can be visualized by photoacoustic imaging and compressing on vessels causes deformation. The photoacoustic signals of blood, when compressed to the point of vessel collapse, may or may not vanish depending on the buckling process it undergoes. We form relative pressure images of microvessels by tracking vessel collapse as a function of externally applied pressure using photoacoustic imaging.

  14. Osmosis at constant volume. Negative pressure

    CERN Document Server

    Zupanovic, Pasko; Brumen, Milan; Fajmut, Ales; Juretic, Davor

    2009-01-01

    A thermodynamic state of solvent and solution separated with an elastic semipermeable membrane, in the box with a fixed volume, is considered. It is shown that the minimum of the free energy is accompanied by the compression of the solution and tension of the solvent caused by the transfer of solvent molecules into compartment with solution. The tensile state of the solvent is described in terms of negative pressure. It is found that the negative pressure as well as compression pressure is of the order of osmotic pressure given by van't Hoff equation. It is proposed that this mechanism could be responsible for the water uptake in tall trees.

  15. Beam Loss Diagnostics Based on Pressure Measurements

    CERN Document Server

    Weinrich, U

    2003-01-01

    The GSI is operating a heavy ion synchrotron, which is currently undergoing an upgrade towards higher beam intensities. It was discovered that beam losses induce a significant pressure increase in the vacuum system. In order to detect the time constants of the pressure increase and decrease, fast total pressure measurements were put into operation. With the recently installed partial pressure diagnostics it is also possible to follow up which types of molecules are released. The presentation will focus on the different techniques applied as well as on some measurement results. The potential and difficulties of this diagnostic tool will also be discussed.

  16. Techniques in high pressure neutron scattering

    CERN Document Server

    Klotz, Stefan

    2013-01-01

    Drawing on the author's practical work from the last 20 years, Techniques in High Pressure Neutron Scattering is one of the first books to gather recent methods that allow neutron scattering well beyond 10 GPa. The author shows how neutron scattering has to be adapted to the pressure range and type of measurement.Suitable for both newcomers and experienced high pressure scientists and engineers, the book describes various solutions spanning two to three orders of magnitude in pressure that have emerged in the past three decades. Many engineering concepts are illustrated through examples of rea

  17. Treating High Blood Pressure

    Science.gov (United States)

    About High Blood Pressure Many people in the United States die from high blood pressure. This condition usually does not cause symptoms. Most ... until it is too late. A person has high blood pressure when the blood pushes against Visit your doctor ...

  18. High Blood Pressure Facts

    Science.gov (United States)

    ... More black women than men have high blood pressure. 2 Race of Ethnic Group Men (%) Women (%) African Americans 43.0 45.7 Mexican Americans 27.8 28.9 Whites 33.9 31.3 All 34.1 32.7 Top of Page Why Blood Pressure Matters View this graphic snapshot of blood pressure ...

  19. High-pressure apparatus

    NARCIS (Netherlands)

    Schepdael, van L.J.M.; Bartels, P.V.; Berg, van den R.W.

    1999-01-01

    The invention relates to a high-pressure device (1) having a cylindrical high-pressure vessel (3) and prestressing means in order to exert an axial pressure on the vessel. The vessel (3) can have been formed from a number of layers of composite material, such as glass, carbon or aramide fibers which

  20. Bedsores (Pressure Sores)

    Science.gov (United States)

    Bedsores (pressure ulcers) Overview By Mayo Clinic Staff Bedsores — also called pressure ulcers and decubitus ulcers — are injuries to skin and underlying tissue resulting from prolonged pressure on the skin. Bedsores most ... quickly. Most sores heal with treatment, but some never heal completely. ...

  1. Pressure effect on the sensitivity of quartz Bourdon tube gauges.

    Science.gov (United States)

    Szaniszlo, A. J.

    1972-01-01

    The sensitivity change for a commercial fused quartz Bourdon tube precision pressure gauge, due to a change in absolute pressure level, has been analytically computed and experimentally confirmed. The computed differential pressure error is 2.5% of full scale at a 100 atm absolute pressure level. The experimental method compared the fused quartz Bourdon tube gauge digital output to the results obtained from a nitrogen gas pressure system which had a high pressure, well-type mercury manometer as the differential pressure reference.

  2. Recent progress in high-pressure studies on organic conductors

    Directory of Open Access Journals (Sweden)

    Syuma Yasuzuka and Keizo Murata

    2009-01-01

    Full Text Available Recent high-pressure studies of organic conductors and superconductors are reviewed. The discovery of the highest Tc superconductivity among organics under high pressure has triggered the further progress of the high-pressure research. Owing to this finding, various organic conductors with the strong electron correlation were investigated under high pressures. This review includes the pressure techniques using the cubic anvil apparatus, as well as high-pressure studies of the organic conductors up to 10 GPa showing extraordinary temperature and pressure dependent transport phenomena.

  3. Pressure effect on dissimilatory sulfate reduction

    Science.gov (United States)

    Williamson, A. J.; Carlson, H. K.; Coates, J. D.

    2015-12-01

    Biosouring is the production of H2S by sulfate reducing microorganisms (SRM) in-situ or in the produced fluids of oil reservoirs. Sulfide is explosive, toxic and corrosive which can trigger equipment and transportation failure, leading to environmental catastrophe. As oil exploration and reservoir development continue, subsequent enhanced recovery is occurring in progressively deeper formations and typical oil reservoir pressures range from 10-50 MPa. Therefore, an understanding of souring control effects will require an accurate understanding of the influence of pressure on SRM metabolism and the efficacy of souring control treatments at high pressure. Considerable work to date has focussed on souring control at ambient pressure; however, the influence of pressure on biogeochemical processes and souring treatments in oil reservoirs is poorly understood. To explore the impact of pressure on SRM, wild type Desulfovibrio alaskensis G20 (isolated from a producing oil well in Ventura County, California) was grown under a range of pressures (0.1-14 MPa) at 30 °C. Complete sulfate reduction occurred in all pressures tested within 3 days, but microbial growth was inhibited with increasing pressure. Bar-seq identified several genes associated with flagella biosynthesis (including FlhB) and assembly as important for survival at elevated pressure and fitness was confirmed using individual transposon mutants. Flagellar genes have previously been implicated with biofilm formation and confocal microscopy on glass slides incubated with wild type D. alaskensis G20 showed more biomass associated with surfaces under pressure, highlighting the link between pressure, flagellar and biofilm formation. To determine the effect of pressure on the efficacy of SRM inhibitors, IC50 experiments were conducted and D. alaskensis G20 showed a greater resistance to nitrate and the antibiotic chloramphenicol, but a lower resistance to perchlorate. These results will be discussed in the context of

  4. Bottom-Fill Method for Stopping Leaking Oil Wells

    CERN Document Server

    Bloomfield, Louis A

    2010-01-01

    Hardware failure at the top of a deep underwater oil well can result in a catastrophic oil leak. The enormous pressure lifting the column of oil in that well makes it nearly impossible to stop from the top with seals or pressurization. We propose to fill the bottom of the well with dense and possibly streamlined objects that can descend through the rising oil. As they accumulate, those objects couple to the oil via viscous and drag forces and increase the oil's effective density. When its effective density exceeds that of the earth's crust, the oil will have essentially stopped flowing.

  5. New methodology for gas migration prediction before oil well cementing

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, G.H.V.P.; Martins, A.L.; Rocha, J.M.S. [Petroleo Brasileiro S.A. (PETROBRAS), Rio de Janeiro, RJ (Brazil)], E-mail: gustavo_cep@yahoo.com.br; Martinelli, A.E. [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2012-04-15

    Many challenges have been presented in oil well drilling including preventing gas migration after cementing operations. This phenomenon is potentially dangerous since the gas can migrate to the surface causing the annular pressurization or lead to a blowout with catastrophic results that may include the loss of the well. If the hydrostatic pressure in front of the gas zone becomes lower than the pressure in this zone, the gas will invade the well. This work presents a comprehensive methodology to evaluate gas migration after cementing operations taking into account the critical static gel strength concept associated with time dependent viscosity behavior. A mechanistic model based on a force balance acting on gas bubble was proposed to predict the bubble displacement through the cement slurry while it gels and evaluate if the hydraulic isolation will be affected allowing project operation changes to ensure well construction safely. (author)

  6. Active Feedback Control of Unstable Wells at the Brage Field

    Directory of Open Access Journals (Sweden)

    Morten Dalsmo

    2005-04-01

    Full Text Available In this paper we will present new results on stabilization of horizontal wells with gas lift. The stabilization is achieved by a novel dynamic feedback control solution using the production choke at the wellhead. The primary input to the dynamic feedback controller is a measurement of the downhole pressure. The field results to be presented are from the Brage field operated by Norsk Hydro in the North sea. Production at Brage began in 1993 and the field went off plateau in 1998. As the production has decreased, the problems related to unstable production from some of the wells have escalated steadily. The results from the extensive field tests on the Brage wells arc very promising. The tests have confirmed the stabilization feature of the control solution. The pressure and flow variations have been dramatically reduced, and it is possible to produce the wells at a lower downhole pressure leading to increased production.

  7. Prediction onset and dynamic behaviour of liquid loading gas wells

    NARCIS (Netherlands)

    Belfroid, S.P.C.; Schiferli, W.; Alberts, G.J.N.; Veeken, C.A.M.; Biezen, E.

    2008-01-01

    As reservoir pressures decrease in maturing gas wells, liquid drop-out forms an increasing restriction on gas production. Even though virtually all of the world's gas wells are either at risk of or suffering from liquid loading, the modeling of liquid loading behavior is still quite immature and the

  8. China's Wellness Revolution

    Institute of Scientific and Technical Information of China (English)

    MarkGodfrey

    2004-01-01

    SEVERAL years after its publication, the Wellness Revolution remains a cult best-selling book. Its writer, businessman and motivational speaker Paul Zane Pilzer, advised investors and ama-teur stock market players that "wellness" would be the next tril-

  9. Creating Wellness in Your Schools.

    Science.gov (United States)

    Tager, Mark J.

    1983-01-01

    Wellness programs emphasize positive motivation and usually include health awareness campaigns, behavior change programs, and cost containment strategies. Guides are offered for beginning wellness programs in school districts. (MLF)

  10. Laser techniques in high-pressure geophysics

    Science.gov (United States)

    Hemley, R. J.; Bell, P. M.; Mao, H. K.

    1987-01-01

    Laser techniques in conjunction with the diamond-anvil cell can be used to study high-pressure properties of materials important to a wide range of problems in earth and planetary science. Spontaneous Raman scattering of crystalline and amorphous solids at high pressure demonstrates that dramatic changes in structure and bonding occur on compression. High-pressure Brillouin scattering is sensitive to the pressure variations of single-crystal elastic moduli and acoustic velocities. Laser heating techniques with the diamond-anvil cell can be used to study phase transitions, including melting, under deep-earth conditions. Finally, laser-induced ruby fluorescence has been essential for the development of techniques for generating the maximum pressures now possible with the diamond-anvil cell, and currently provides a calibrated in situ measure of pressure well above 100 gigapascals.

  11. Negative Pressure Wound Therapy in Maxillofacial Applications

    Directory of Open Access Journals (Sweden)

    Adam J. Mellott

    2016-09-01

    Full Text Available Negative pressure wound therapy has greatly advanced the field of wound healing for nearly two decades, by providing a robust surgical adjunct technique for accelerating wound closure in acute and chronic wounds. However, the application of negative pressure wound therapy in maxillofacial applications has been relatively under utilized as a result of the physical articulations and contours of the head and neck that make it challenging to obtain an airtight seal for different negative pressure wound therapy systems. Adapting negative pressure wound therapies for maxillofacial applications could yield significant enhancement of wound closure in maxillofacial applications. The current review summarizes the basic science underlying negative pressure wound therapy, as well as specific maxillofacial procedures that could benefit from negative pressure wound therapy.

  12. Laser techniques in high-pressure geophysics

    Science.gov (United States)

    Hemley, R. J.; Bell, P. M.; Mao, H. K.

    1987-01-01

    Laser techniques in conjunction with the diamond-anvil cell can be used to study high-pressure properties of materials important to a wide range of problems in earth and planetary science. Spontaneous Raman scattering of crystalline and amorphous solids at high pressure demonstrates that dramatic changes in structure and bonding occur on compression. High-pressure Brillouin scattering is sensitive to the pressure variations of single-crystal elastic moduli and acoustic velocities. Laser heating techniques with the diamond-anvil cell can be used to study phase transitions, including melting, under deep-earth conditions. Finally, laser-induced ruby fluorescence has been essential for the development of techniques for generating the maximum pressures now possible with the diamond-anvil cell, and currently provides a calibrated in situ measure of pressure well above 100 gigapascals.

  13. Commonwealth Edison Company pressure locking test report

    Energy Technology Data Exchange (ETDEWEB)

    Bunte, B.D.; Kelly, J.F.

    1996-12-01

    Pressure Locking is a phenomena which can cause the unseating thrust for a gate valve to increase dramatically from its typical static unseating thrust. This can result in the valve actuator having insufficient capability to open the valve. In addition, this can result in valve damage in cases where the actuator capability exceeds the valve structural limits. For these reasons, a proper understanding of the conditions which may cause pressure locking and thermal binding, as well as a methodology for predicting the unseating thrust for a pressure locked or thermally bound valve, are necessary. This report discusses the primary mechanisms which cause pressure locking. These include sudden depressurization of piping adjacent to the valve and pressurization of fluid trapped in the valve bonnet due to heat transfer. This report provides a methodology for calculating the unseating thrust for a valve which is pressure locked. This report provides test data which demonstrates the accuracy of the calculation methodology.

  14. School wellness team best practices to promote wellness policy implementation.

    Science.gov (United States)

    Profili, Erika; Rubio, Diana S; Lane, Hannah G; Jaspers, Lea H; Lopes, Megan S; Black, Maureen M; Hager, Erin R

    2017-08-01

    Schools with wellness teams are more likely to implement federally mandated Local Wellness Policies (LWPs, Local Education Agency-level policies for healthy eating/physical activity). Best practices have been developed for wellness teams based on minimal empirical evidence. The purpose of this study is to determine, among schools with wellness teams, associations between LWP implementation and six wellness team best practices (individually and as a sum score). An online survey targeting Maryland school wellness leaders/administrators (52.4% response rate, 2012-2013 school year) was administered that included LWP implementation (17-item scale: categorized as no, low, and high implementation) and six wellness team best practices. Analyses included multi-level multinomial logistic regression. Wellness teams were present in 311/707 (44.0%) schools, with no (19.6%), low (36.0%), and high (44.4%) LWP implementation. A sum score representing active wellness teams (mean=2.6) included: setting healthy eating/physical activity goals (66.9%), informing the public of LWP activities (71.4%), meeting ≥4times/year (45.8%), and having school staff (46.9%), parent (25.4%), or student (14.8%) representation. In adjusted models, goal setting, meeting ≥4times/year, and student representation were associated with high LWP implementation. For every one-unit increase in active wellness team sum score, schools were 41% more likely to be in high versus no implementation (Likelihood Ratio=1.41, 95% C.I.=1.13, 1.76). In conclusion, wellness teams meeting best practices are more likely to implement LWPs. Interventions should focus on the formation of wellness teams with recommended composition/activities. Study findings provide support for wellness team recommendations stemming from the 2016 Healthy, Hunger-Free Kids Act final rule. Copyright © 2017. Published by Elsevier Inc.

  15. Wellbore pressure response in naturally fractured reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, A.C. Jr.; Chang, W.; Raghavan, R.

    1983-01-01

    Recently a new flow regime has been identified for pressure drawdown or buildup data obtained from a well producing a naturally fractured reservoir. During the time period corresponding to this new flow regime, a semilog plot of pressure vs. time exhibits a semilog straight line with slope equal to m/2, where m is the slope of both the early and late time semilog straight lines predicted by the Warren and Root model. The identification of this intermediate time semilog straight line means that pressure data may exhibit as many as 3 semilog straight lines. A virtually complete analysis of well test pressure data is possible when the data exhibits 2 or more of the 3 possible straight lines. This work presents type curves which can be used to obtain a virtually complete analysis of pressure data when only one of the 3 semilog straight lines is reflected by the data. 13 references.

  16. Insomnia and Well-Being

    Science.gov (United States)

    Hamilton, Nancy A.; Gallagher, Matthew W.; Preacher, Kristopher J.; Stevens, Natalie; Nelson, Christy A.; Karlson, Cynthia; McCurdy, Danyale

    2007-01-01

    Most Americans have occasional problems with insomnia. The relationship of insomnia to illness is well known. However, insomnia may also relate to lower levels of well-being. Although there are various definitions of well-being, one of the most clearly articulated and comprehensive models identifies 2 overarching constructs, psychological…

  17. A Laboratory Scale Aquifer-Well System for Analyzing Near-well Processes

    Science.gov (United States)

    Kalwa, Fritz; Bonilla, José; Händel, Falk; Binder, Martin; Stefan, Catalin

    2016-04-01

    Managed Aquifer Recharge (MAR) is constantly gaining popularity and one very promising technique in this context is infiltration by vertical wells. However, the near-well surrounding of these wells is still object of many open questions, related to - among others - clogging, screen design and the effects of underground heterogeneities. As a tool for a better understanding of these processes, a physical laboratory-scale aquifer-well model was designed. The physical model was assembled in a cylindrical tank with a height of 1.1 m and a diameter of 1 m. Water can be introduced via a small-diameter well screen (inner diameter: 2.54 cm) in the center of the tank and leaves the system via side outlets. These outlets were connected hydraulically to a single outflow system, allowing the adjustment of the same outflow head for all side outlets. Furthermore, a drainage system was attached to the tank's wall to assure circular flow from the well to the wall. The drainage system was chosen after preliminary tests of different drainage materials to determine the best performing setup. Remaining impoundment heights of up to 30 cm were observed in the tank, due to pressure losses at the outflow system. To include the resulting impoundment into a numerical model using Hydrus 2D/3D, a half-empirical formula was derived, plotting impoundment heights against infiltration rates and considering the pressure losses in the outflow system as well as in the drainage layer. Using the predicted impoundment heights for correction, the numerical model allowed satisfying simulation of the flow pattern in the tank for infiltration rates. The study shows how to develop an approach combining numerical and physical modeling as a base for future investigation of near-well processes under well-defined laboratory conditions.

  18. The changes of state-trait anxiety and blood plasma cortisol as well systolic pressure of armymen turned to sea training%部队转场海训后军人状态-特质焦虑与其收缩压和血皮质醇的变化

    Institute of Scientific and Technical Information of China (English)

    朱媛; 吴志颖; 付晓丽; 王丽杰

    2014-01-01

    Through investigating the state-trait anxiety of mental characteristics change of armymen in military activity,to provide the basis for early warning prevention. Methods Transition to sea training for the 15th day,state-trait anxiety based on a questionnaire of 420 people,and blood pressure,pulse rate and blood cortisol (08:00am-09:00am) were investigated and detected whose results were compared to the norm or the normal value. Results State anxiety was 2 values in 185 persons higher than the standard deviation of the norm, accounting for 44% of the total person-number. Trait anxiety values was 2 votes in 113 higher than the standard deviation of the norm (high trait anxiety), accounting for 26.9% of the total person-number, value of trait-anxiety was less than the standard deviation of the norm 2 votes(low trait anxiety) in 85 persons, accounting for 20.2% of the total number. Systolic blood pressure and cortisol changed significantly (P<0.01). State anxiety and serum cortisol and systolic blood pressure changed at the same time significantly in total person-number of 30.2%,but changes in diastolic blood pressure was not evident. Higher trait anxiety anxiety , blood cortisol and elevated systolic blood pressure in high trait anxiety persons were of 61.9%(70/113);state anxiety,elevated blood cortisol and systolic blood pressure were in 23.7% of the total number of non-higher trait anxiety persons (79/334),low trait anxiety of trait-anxiety were of 15% of total person-number(13/85). Conclusion Sea training is a stress event, trait anxiety refers to the relative stability,as personality trait anxiety tendency has individual differences. So coping anxiety active has military significance to physical and mental health and enhancing fighting capacity.%目的:通过调查状态-特质焦虑心理特质在军事活动中的变化,为预警预防提供依据。方法转场海训的第15天时,对420人进行状态-特质焦虑问卷、血

  19. Incisional Negative Pressure Wound Therapy

    DEFF Research Database (Denmark)

    Hyldig, Nana; Birke-Sorensen, Hanne; Kruse, Marie;

    Aim: Postoperative wound complications make many surgical procedures unnecessarily complex, particularly in high-risk patients. Negative Pressure Wound Therapy is well recognized in the management of open wounds. In recent years, it has been introduced as well in the management of closed surgical...... incisions to reduce postoperative wound complications, though the evidence base to support this intervention is limited. The aim of this study was to assess if Negative Pressure Wound Therapy (NPWT) reduces postoperative complications when applied on closed surgical incisions. Method: A systematic review...... formation (52%) compared to standard care. The reduction in wound dehiscence was not statistically significant. The numbers needed to treat were 3 (seroma), 17 (dehiscence), and 25 (infection). Methodical heterogeneity across studies led to downgrading quality of evidence to moderate for infection...

  20. Pressure locking test results

    Energy Technology Data Exchange (ETDEWEB)

    DeWall, K.G.; Watkins, J.C.; McKellar, M.G.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States)] [and others

    1996-12-01

    The U.S. Nuclear Regulatory Commission (NRC), Office of Nuclear Regulatory Research, is funding the Idaho National Engineering Laboratory (INEL) in performing research to provide technical input for their use in evaluating responses to Generic Letter 95-07, {open_quotes}Pressure Locking and Thermal Binding of Safety-Related Power-Operated Gate Valves.{close_quotes} Pressure locking and thermal binding are phenomena that make a closed gate valve difficult to open. This paper discusses only the pressure locking phenomenon in a flexible-wedge gate valve; the authors will publish the results of their thermal binding research at a later date. Pressure locking can occur when operating sequences or temperature changes cause the pressure of the fluid in the bonnet (and, in most valves, between the discs) to be higher than the pressure on the upstream and downstream sides of the disc assembly. This high fluid pressure presses the discs against both seats, making the disc assembly harder to unseat than anticipated by the typical design calculations, which generally consider friction at only one of the two disc/seat interfaces. The high pressure of the bonnet fluid also changes the pressure distribution around the disc in a way that can further contribute to the unseating load. If the combined loads associated with pressure locking are very high, the actuator might not have the capacity to open the valve. The results of the NRC/INEL research discussed in this paper show that the relationship between bonnet pressure and pressure locking stem loads appears linear. The results also show that for this valve, seat leakage affects the bonnet pressurization rate when the valve is subjected to thermally induced pressure locking conditions.

  1. Challenges in reservoir engineering from prospects for horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Fayers, F.J.; Arbabi, S.; Aziz, K. [Stanford Univ., CA (United States). Dept. of Petroleum Engineering

    1995-01-01

    In this review paper, a variety of reservoir applications are illustrated where horizontal wells can have advantages over the use of conventional vertical wells. It is stressed that one of the key advantages relates to the opportunities to optimize the orientation and position of horizontal wells with respect to the principal directions for the reservoir depositional environment, but this may interact with natural fracture or fault directions, and the principal stress direction if hydraulic fracturing is to be considered. Analytical methods for calculating critical coning rates in homogeneous reservoirs are reviewed, and shown to give a very large range of results for horizontal wells. The potential significance of two-phase pressure drop within the wellbore on GOR performance is discussed, and a range of uncertainty by a factor of six is indicated between the use of various correlations for calculating the well pressure drop. In the final section studies are summarized for a gas coning application using ECLIPSE, a commercial simulator. The simulation results indicated an apparently invariant behaviour on GOR history with respect to the effects of wellbore two-phase pressure drop when the horizontal well was produced at constant rate in a homogeneous reservoir. However, when the controlling conditions on the horizontal well were made more representative, and reservoir non-uniformity was introduced, it was then found that the two-phase pressure drop became very significant. Some areas for further research are indicated. (Author)

  2. Well Integrity and Sealing in CO2 Sequestration Wells

    Science.gov (United States)

    Sweatman, R.; Santra, A.; Kulakofsky, D.

    2009-12-01

    CO2 sequestration is a cost-effective and safe way to help mitigate climate change. Sustained well integrity and zonal isolation of CO2 by cement for the required 1000 year trapping period may be challenging. Some researchers report that cement fails when exposed to CO2 leading to potential leakage into the atmosphere or other underground zones. Others show cement samples from 30-50 year old CO2 wells that maintain the well’s sealing integrity, even though carbonization was found. This presentation provides reasons likely for this disparity between research lab test results and actual well performance data along with best practices to provide efficient cement-based systems for maintaining CO2 containment in storage and EOR (enhanced oil recovery) reservoirs. This discussion includes the geochemical conditions surrounding wells and the positive, long-term effects on cement durability, sealing integrity, and the protection of well casing from CO2 induced corrosion. Also discussed are recent laboratory results testing cement samples surrounded by formation material treated at two different downhole conditions. In one case the cement specimens were treated with a 40% humid CO2 at 140°F and 2000 psi whereas in the second case they were treated with saturated CO2 in water at 200°F and 2000 psi for various time intervals. Results show that samples of carefully designed cement systems had carbonization without any sign of loss of mechanical or sealing integrity which could lead to zonal isolation and well integrity failures. We also will report on a new lab method proposed to determine CO2 sealing performance by cement in a relatively short time period compared to previous methods. In summary, we will discuss a comprehensive approach that may be taken to help ensure longer term effective well integrity and CO2 containment in new CO2 wells and remedial solutions for old wells and for plugging and abandoning wells.

  3. The effect of atmospheric pressure on ventricular assist device output.

    Science.gov (United States)

    Goto, Takeshi; Sato, Masaharu; Yamazaki, Akio; Fukuda, Wakako; Watanabe, Ken-Ichi; Daitoku, Kazuyuki; Minakawa, Masahito; Fukui, Kozo; Suzuki, Yasuyuki; Fukuda, Ikuo

    2012-03-01

    The effect of cabin pressure change on the respiratory system during flight is well documented in the literature, but how the change in atmospheric pressure affects ventricular assist device (VAD) output flow has not been studied yet. The purpose of our study was to evaluate the change in VAD output using a mock circulatory system in a low-pressure chamber mimicking high altitude. Changes in output and driving pressure were measured during decompression from 1.0 to 0.7 atm and pressurization from 0.7 to 1.0 atm. Two driving systems were evaluated: the VCT system and the Mobart system. In the VCT system, output and driving pressure remained the same during decompression and pressurization. In the Mobart system, the output decreased as the atmospheric pressure dropped and recovered during pressurization. The lowest output was observed at 0.7 atm, which was 80% of the baseline driven by the Mobart system. Under a practical cabin pressure of 0.8 atm, the output driven by the Mobart system was 90% of the baseline. In the Mobart system, the output decreased as the atmospheric pressure dropped, and recovered during pressurization. However, the decrease in output was slight. In an environment where the atmospheric pressure changes, it is necessary to monitor the diaphragmatic motion of the blood pump and the driving air pressure, and to adjust the systolic:diastolic ratio as well as the positive and negative pressures in a VAD system.

  4. Influence of Stone Column’s Drainage Capacity and Well-resistance Effect on Pore-pressure Calculation of Composite Foundation%碎石桩排水能力和井阻效应对复合地基孔压计算的影响

    Institute of Scientific and Technical Information of China (English)

    冯艳辉; 王武刚

    2014-01-01

    Based on the assumption that the pile material’s drainage capacity is infinite ,many scholars at home and abroad have researched on the earthquake-resistance liquefaction characteristics of the stone column’s drainage capacity on saturated silt foundation .However ,in practical projects ,the drainage capacity of stone column is not infinite .Here , by using Barron consolidation theory ,and comprehensively considering that the dissipation velocity of the excess pore pressure induced by earthquake during the extremely short time is limited and the dispersed material has a certain resis -tance effect on verticle infiltration ,the drainage and pressure-reducing action of the stone column during earthquake was studied ,and the fitting formula for the development of the excess pore pressure was proposed including its generation , diffusion and dissipation .Meanwhile ,the action of the stone column for raising the earthquake-resistance liquefaction was evaluated through the comparison and analysis of engineering examples ,which would provide a certain reference for the design of saturated silt foundation .%国内外许多学者基于假定桩体材料排水能力为无限大基础上,研究了碎石桩复合地基排水减压作用在饱和粉土地基抗震液化方面的特性。在实际工程中,碎石桩的排水能力与地基土体相比是在一个可比的数量级上,并不是无限大的。利用巴隆固结理论,优化相应的边界条件和初始条件,综合考虑在地震作用时间极短的状况下,引起的超孔压消散速度是有限的,以及散体材料本身会对进入桩体中的水的垂直渗流有一定的阻力作用等条件下,研究了碎石桩在地震作用期间的排水减压作用,并提出了由地震引起的碎石桩复合地基中超孔压发展规律的拟合公式。经过工程实例的对比分析,对碎石桩排水减压作用在抗震液化能力提高方面进行评价,为饱和粉土地基抗

  5. Wellness as a worldwide phenomenon?

    Science.gov (United States)

    Elliott, Heather; Bernstein, Jennifer; Bowman, Diana M

    2014-10-01

    This article examines the concept of wellness through a comparative political economy and legal framework. It asks whether wellness, an increasingly defined term within US federal and state legislative instruments including, for example, the Patient Protection and Affordable Care Act, is primarily a US-centric phenomenon. Or is wellness, in its various different guises, a worldwide phenomenon? By focusing on three distinctly different jurisdictions - the United States, Germany, and Australia - this article examines wellness through the lens of employers, the health care system, employment and tort law, and the greater political economy. It notes that while improving employee health, well-being, and productivity is common across the three countries and their respective cultures, the focus on wellness as a distinct legal concept is unique to the United States. Copyright © 2014 by Duke University Press.

  6. Well sealing via thermite reactions

    Energy Technology Data Exchange (ETDEWEB)

    Lowry, William Edward; Dunn, Sandra Dalvit

    2016-11-15

    A platform is formed in a well below a target plug zone by lowering a thermite reaction charge into the well and igniting it, whereby the products of the reaction are allowed to cool and expand to form a platform or support in the well. A main thermite reaction charge is placed above the platform and ignited to form a main sealing plug for the well. In some embodiments an upper plug is formed by igniting an upper thermite reaction charge above the main thermite reaction charge. The upper plug confines the products of ignition of the main thermite reaction charge.

  7. The new frontier of wellness.

    Science.gov (United States)

    Clark, Ann D

    2008-01-01

    Businesses should focus on a proactive solution to rising health care costs, using integrated wellness programs that emphasize condition management and total health and well-being. If corporations wish to remain competitive, profitable and successful in attracting and retaining topnotch talent from all generations, they are going to have to start investing in and thinking creatively about wellness offerings. Not only do wellness programs have a proven track record of success in reducing health care costs, they also resonate loud and clear with modern-day employees who are determined to work for a company that understands their needs and is willing to make progress with the employee's best interests in mind.

  8. Approximate solutions for fractured wells producing layered reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C.O.; Reynolds, A.C.; Raghavan, R.

    1983-01-01

    New analytical solutions for the response at a well intercepting a layered reservoir are derived. The well is assumed to produce at a constant rate or at a constant pressure. Reservoir systems with and without interlayer communication were examined. The utility of these solutions is documented. An increased physical understanding of fractured wells in layered reservoirs was obtained from these solutions. The influence of vertical variations in fracture conductivity is considered also. 15 references.

  9. Approximate solutions for fractured wells producing layered reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, C.O.; Camacho-V., R; Raghavan, R.; Reynolds, A.C.

    1985-10-01

    New analytical solutions for the response at a well intercepting a layered reservoir are derived. The well is assumed to produce at a constant rate or a constant pressure. We examine reservoir systems without interlayer communication and document the usefulness of these solutions, which enable us to obtain increased physical understanding of the performance of fractured wells in layered reservoirs. The influence of vertical variations in fracture conductivity is also considered. Example applications of the approximations derived here are also presented.

  10. Impact of hydraulic well restoration on native bacterial communities in drinking water wells.

    Science.gov (United States)

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production system before, during, and after hydraulic purging. Variations were observed in bacterial communities between different wells of the same production system before maintenance, despite them having practically identical water chemistries. This may have reflected the distinct usage practices of the different wells, and also local aquifer heterogeneity. Hydraulic jetting of one well preferentially purged a subset of the dominating taxa, including lineages related to Diaphorobacter, Nitrospira, Sphingobium, Ralstonia, Alkanindiges, Janthinobacterium, and Pseudomonas spp, suggesting their tendency for growth in well-associated biofilms. Lineages of potential drinking water concern (i.e. Legionellaceae, Pseudomonadaceae, and Acinetobacter spp.) reacted distinctly to hydraulic jetting. Bacterial diversity was markedly reduced in drinking water 2 weeks after the cleaning procedure. The results of the present study provide a better understanding of drinking water wells as a microbial habitat, as well as their role in the microbiology of drinking water systems.

  11. 46 CFR 197.462 - Pressure vessels and pressure piping.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Pressure vessels and pressure piping. 197.462 Section... Diving Equipment § 197.462 Pressure vessels and pressure piping. (a) The diving supervisor shall ensure that each pressure vessel, including each volume tank, cylinder and PVHO, and each pressure...

  12. Water Well Locations - MO 2012 Certified Wells (SHP)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This data set provides information about wells that are certified by the State of Missouri. The parent data set is the Wellhead Information Management System (WIMS)...

  13. Community College Employee Wellness Programs

    Science.gov (United States)

    Thornton, L. Jay; Johnson, Sharon

    2010-01-01

    This paper describes the prevalence and characteristics of employee wellness programs in public community colleges accredited by the Southern Association of Colleges and Schools (SACS). A random sample of 250 public community colleges accredited by SACS was mailed a 46-item employee-wellness program survey. The survey solicited program information…

  14. Internationalization and migration pressure.

    Science.gov (United States)

    Kultalahti, O

    1994-01-01

    The author first develops the concept of migration pressure, which is defined as the growth in the number of people wishing to migrate and the barriers preventing them from so doing. Both macro- and micro-level factors affecting migration pressure are identified. Historical trends in migration pressure in Finland are then discussed. The author then applies this concept to the analysis of current Finnish migration trends. The primary focus is on international migration.

  15. Pressure cryocooling protein crystals

    Science.gov (United States)

    Kim, Chae Un; Gruner, Sol M.

    2011-10-04

    Preparation of cryocooled protein crystal is provided by use of helium pressurizing and cryocooling to obtain cryocooled protein crystal allowing collection of high resolution data and by heavier noble gas (krypton or xenon) binding followed by helium pressurizing and cryocooling to obtain cryocooled protein crystal for collection of high resolution data and SAD phasing simultaneously. The helium pressurizing is carried out on crystal coated to prevent dehydration or on crystal grown in aqueous solution in a capillary.

  16. Using Sealed Wells to Measure Water Levels Beneath Streams and Floodplains.

    Science.gov (United States)

    Noorduijn, Saskia L; Cook, Peter G; Wood, Cameron; White, Nick

    2015-01-01

    The design of wells beneath streams and floodplains has often employed with tall standpipes to prevent incursion of surface water into the well during flood events. Here, an approach has been presented to minimise the infrastructure demands in these environments by sealing the well top (e.g., prevent water entering the well) and monitor the total pressure in the water column using an absolute (non-vented) pressure transducer. The sealed well design was tested using a laboratory experiment where the total pressure responses were monitored in both an unsealed and sealed well, while the water level was varied. It is observed that, whether the well is sealed or not, the total pressure at a given depth in the aquifer will be equal to that within the well. This indicates that the sealed well design is a viable alternative to tall standpipes and also facilitates installation of wells beneath streams and floodplains.

  17. as well as, as well, might as well 之用法

    Institute of Scientific and Technical Information of China (English)

    盛艳明

    2009-01-01

    1. as well as =not only/just … but(also),但两者在意义上有不同之处:as well as 侧重前者,而not only /just…but (also)侧重后者,通常要理解为A as well as B=not only/just B but(also) A。如:

  18. Fiber bundle model under fluid pressure

    Science.gov (United States)

    Amitrano, David; Girard, Lucas

    2016-03-01

    Internal fluid pressure often plays an important role in the rupture of brittle materials. This is a major concern for many engineering applications and for natural hazards. More specifically, the mechanisms through which fluid pressure, applied at a microscale, can enhance the failure at a macroscale and accelerate damage dynamics leading to failure remains unclear. Here we revisit the fiber bundle model by accounting for the effect of fluid under pressure that contributes to the global load supported by the fiber bundle. Fluid pressure is applied on the broken fibers, following Biot's theory. The statistical properties of damage avalanches and their evolution toward macrofailure are analyzed for a wide range of fluid pressures. The macroscopic strength of the new model appears to be strongly controlled by the action of the fluid, particularly when the fluid pressure becomes comparable with the fiber strength. The behavior remains consistent with continuous transition, i.e., second order, including for large pressure. The main change concerns the damage acceleration toward the failure that is well modeled by the concept of sweeping of an instability. When pressure is increased, the exponent β characterizing the power-law distribution avalanche sizes significantly decreases and the exponent γ characterizing the cutoff divergence when failure is approached significantly increases. This proves that fluid pressure plays a key role in failure process acting as destabilization factor. This indicates that macrofailure occurs more readily under fluid pressure, with a behavior that becomes progressively unstable as fluid pressure increases. This may have considerable consequences on our ability to forecast failure when fluid pressure is acting.

  19. Modeling multiaquifer wells with MODFLOW.

    Science.gov (United States)

    Neville, Christopher J; Tonkin, Matthew J

    2004-01-01

    Multiaquifer wells, i.e., wells that are open across more than one aquifer, can have a profound effect on the hydraulics of a ground water system. These wells change the physical system by establishing direct hydraulic links between otherwise isolated strata. Several methods are available to simulate multiaquifer wells in the context of comprehensive ground water flow simulators. In this paper, we review four methods to represent multiaquifer wells with the widely used code MODFLOW. These methods include a specialized code developed, but never formally released, by the U.S. Geological Survey (USGS), the Multi-Aquifer Well (MAW1) Package. An expanded implementation of the techniques in the MAW1 Package has been incorporated in the Multi-Node Well Package released recently by the USGS (Halford and Hanson 2002). We examine the performance of the methods in the context of a benchmarking study against the analytical solutions of Papadopulos (1966) and Sokol (1963). Our results demonstrate that results obtained with the MAW1 Package closely match exact solutions for pumping and nonpumping conditions, using both coarse and refined grids.

  20. THE PRODUCTIVITY OF WELL PATTERN WITH HORIZONTAL WELLS AND VERTICAL WELLS

    Institute of Scientific and Technical Information of China (English)

    Zhao Chun-sen; Cui Hai-qing; Song Wen-ling; Zhang Zhen

    2003-01-01

    The calculation of productivity and the choice of well pattern of mixed horizontal and vertical wells were discussed in this paper. Because the naturall drainage areas of horizontal wells are oval rather than circular, rectangular drainage well patterns should be adopted. Using pseudo 3-dimensional method and conformal transformation, the potential function of a row of horizontal wells was deduced. Using this function and the superposition principle, an analytical solution of the productivity for the rectangular mixed well pattern was given. Quantitative means for defining the shapes of the optimum pattern were developed in this paper by introducing two dimensionless parameters, the shape factor and dimensionless length of horizontal well. The formula for productvity was used to optimize the mixed well patterns. The curves of the optimized shape factor against dimensionless length of horizontal well were drawn. The results show that the pattern area and formation thickness have no effect on the optimal shape factors and can be applied to the design of development for oil fields.

  1. Leg intravenous pressure during head-up tilt.

    NARCIS (Netherlands)

    Groothuis, J.T.; Poelkens, F.; Wouters, C.W.; Kooijman, M.; Hopman, M.T.E.

    2008-01-01

    Leg vascular resistance is calculated as the arterial-venous pressure gradient divided by blood flow. During orthostatic challenges it is assumed that the hydrostatic pressure contributes equally to leg arterial, as well as to leg venous pressure. Because of venous valves, one may question whether,

  2. Session: Long Valley Exploratory Well

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Finger, John T.; Eichelberger, John C.; Hickox, Charles E.

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of four presentations: ''Long Valley Exploratory Well - Summary'' by George P. Tennyson, Jr.; ''The Long Valley Well - Phase II Operations'' by John T. Finger; ''Geologic results from the Long Valley Exploratory Well'' by John C. Eichelberger; and ''A Model for Large-Scale Thermal Convection in the Long Valley Geothermal Region'' by Charles E. Hickox.

  3. Design of dual pressure regulator

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Soo; Kim, Kang Dae; Kim, Myoung Sub [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2008-07-01

    In this paper, we designed sandwich type pressure regulator for air pressure control system. As a result of research, we obtained several important conclusions. First, we decided theory of poppet valve and relief valve which are used in sandwich type pressure regulator, and then designed prototype of pressure regulator. Second, we organized circuit diagram of dual pressure regulator of air pressure control system.

  4. 7 Steps to Aging Well

    Science.gov (United States)

    ... Issue Past Issues Special Section 7 Steps to Aging Well Past Issues / Winter 2007 Table of Contents ... Exercise: A Guide from the National Institute on Aging is a publication from NIA that has strength, ...

  5. The well-being questionnaire

    DEFF Research Database (Denmark)

    Pouwer, F; Snoek, Frank J; Van Der Ploeg, Henk M

    2000-01-01

    analyses were conducted. Group B (N = 736) was split up into four subgroups of male or female patients with type 1 or type 2 diabetes. In these subgroups, confirmatory factor analyses were employed to test the model(s) developed in group A and the two models described in the literature (four-factor model......BACKGROUND: The Well-being Questionnaire (W-BQ) has been designed to measure psychological well-being in people with a chronic somatic illness and is recommended by the World Health Organization for widespread use. However, studies into the factor structure of this instrument are still limited....... This factor solution was stable across gender, type of diabetes and level of education. CONCLUSIONS: The best description of the factor structure of the Dutch translation of the W-BQ was given by a three-factor solution with 12 items (W-BQ12), measuring positive well-being (four items), negative well...

  6. Monitoring Animal Well-being

    DEFF Research Database (Denmark)

    Gronskyte, Ruta

    In recent years, animal well-being in industrial slaughterhouses has become a significant concern for consumers, farmers, and meat producers. Different groups have different interpretations of animal well-being. For the majority of consumers, animal well-being is highly influenced by their values......, it is common to mix pigs from different farmers in one area. Such mixing can cause fights between pigs, which can lead to additional stress or the animals being harmed. The unfamiliar environment also increases the animals’ stress levels. In some industrial slaughterhouses, up to 62,000 pigs per week...... are handled. Ensuring the well-being of such large numbers of pigs using only personnel is a complicated task. Video surveillance of humans has been widely used to ensure safety and order in multiple situations. Methods have been developed to detect individual actions or abnormal behavior in small groups...

  7. Wellness strategies for smaller businesses.

    Science.gov (United States)

    Neely, Marc

    2012-01-01

    While innovative smaller companies are implementing employee wellness programs, many smaller firms may point to a lack of resources, such as staffing and financial resources, to establish and sustain a wellness program. The uncertain economy and rising health care costs have caused many smaller businesses to focus on core business strategies to keep the doors open and the business going. However, innovative companies realize that building a culture of health is a long-term business strategy directly related to improving the bottom line. This article highlights one company's approach to wellness and the results of the company's programs. It also outlines the components of a successful wellness program and suggests practical implementation steps for smaller businesses.

  8. Properties of Sealing Materials in Groundwater Wells

    DEFF Research Database (Denmark)

    Köser, Claus

    on the maximum swelling pressure; i) the bulk density of the sample, and ii) whether the sample is sorted or unsorted. CT scans (Computed Tomography) have been used to evaluate certain properties of bentonite seals in a limited volume. In this context, a set of algorithms to convert CT numbers (HU unit......) into densities for clay/water systems has been developed. This method has successfully been used to evaluate e.g., macroporosity, homogenization of the bentonite seal during the hydration of water, hydraulic conductivity and the creation of channels in the bentonite seals. Based on the results obtained...... in this Ph.D. thesis, a number of recommendations has been offered; i) a change regarding the production of pellets and ii) how sealing material must be treated in the actual construction of groundwater wells....

  9. Entiat 4Mile WELLs Completion Report, 2006.

    Energy Technology Data Exchange (ETDEWEB)

    Malinowksi, Richard

    2007-01-01

    The Entiat 4-mile Wells (Entiat 4-mile) project is located in the Entiat subbasin and will benefit Upper Columbia steelhead, spring Chinook and bull trout. The goal of this project is to prevent juvenile fish from being diverted into an out-of-stream irrigation system and to eliminate impacts due to the annual maintenance of an instream pushup dam. The objectives include eliminating a surface irrigation diversion and replacing it with two wells, which will provide Bonneville Power Administration (BPA) and the Bureau of Reclamation (Reclamation) with a Federal Columbia River Power System (FCRPS) BiOp metric credit of one. Wells were chosen over a new fish screen based on biological benefits and costs. Long-term biological benefits are provided by completely eliminating the surface diversion and the potential for fish entrainment in a fish screen. Construction costs for a new fish screen were estimated at $150,000, which does not include other costs associated with implementing and maintaining a fish screening project. Construction costs for a well were estimated at $20,000 each. The diversion consisted of a pushup dam that diverted water into an off-channel pond. Water was then pumped into a pressurized system for irrigation. There are 3 different irrigators who used water from this surface diversion, and each has multiple water right claims totaling approximately 5 cfs. Current use was estimated at 300 gallons per minute (approximately 0.641 cfs). Some irrigated acreage was taken out of orchard production less than 5 years ago. Therefore, approximately 6.8 acre-feet will be put into the State of Washington Trust Water Right program. No water will be set aside for conservation savings. The construction of the two irrigation wells for three landowners was completed in September 2006. The Lower Well (Tippen/Wick) will produce up to 175 gpm while the Upper Well (Griffith) will produce up to 275 gpm during the irrigation season. The eight inch diameter wells were

  10. Electronic States in Thorium under Pressure

    DEFF Research Database (Denmark)

    Skriver, Hans Lomholt; Jan, J. P.

    1980-01-01

    ) the electronic band structure is formed by 7s and 6d states while the bottom of a relatively broad 5f band is positioned 0.07 Ry above EF. The calculated extremal areas of the Fermi surface and their calculated pressure dependence agree with earlier calculations and with de Haas-van Alphen measurements......We have used the local-density formalism and the atomic-sphere approximation to calculate self-consistently the electronic properties of thorium at pressures up to 400 kbar. The derived equation of state agrees very well with static pressure experiments and shock data. Below the Fermi level (EF...... supporting the validity of the itinerant description of the 5f electrons for the light actinides. The calculation shows that the gradual s to d transition taking place at pressures up to 200 kbar is the cause of the unusual pressure dependence of the Fermi surface seen experimentally....

  11. High Temperature and Pressure Alkaline Electrolysis

    DEFF Research Database (Denmark)

    Allebrod, Frank

    and oxygen with a new type of alkaline electrolysis cell at high temperatures and pressures. To perform measurements under high pressure and at elevated temperatures it was necessary to build a measurement system around an autoclave which could stand high temperatures up to 250 °C and pressures up to 200 bar...... as well as extremely caustic environments. Based on a literature study to identify resistant materials for these conditions, Inconel 600 was selected among the metals which are available for autoclave construction. An initial single atmosphere high temperature and pressure measurement setup was build...... comprising this autoclave. A second high temperature and pressure measurement setup was build based on experiences from the first setup in order to perform automatized measurements. The conductivity of aqueous KOH at elevated temperatures and high concentrations was investigated using the van der Pauw method...

  12. High blood pressure - infants

    Science.gov (United States)

    ... Certain tumors Inherited conditions (problems that run in families) Thyroid problems Blood pressure rises as the baby grows. The average blood ... vomiting constantly Prevention Some causes of high blood pressure run in families. Talk to your provider before you get pregnant ...

  13. Preventing High Blood Pressure

    Science.gov (United States)

    ... Web Sites Division for Heart Disease and Stroke Prevention Stroke Heart Disease Cholesterol Salt Million Hearts® WISEWOMAN Preventing High Blood Pressure: Healthy Living Habits Recommend on Facebook Tweet Share Compartir By living a healthy lifestyle, you can help keep your blood pressure in ...

  14. A life under pressure

    DEFF Research Database (Denmark)

    Jacobsen, Jens Christian Brings; von Holstein-Rathlou, Niels-Henrik

    2012-01-01

    Microvessels live 'a life under pressure' in several ways. In a literal sense, vessels of the microcirculation are exposed to high levels of stress caused primarily by the intravascular pressure head. In a figurative sense, the individual vessel and the microvascular network as a whole must...

  15. Neonatal Pressure Ulcer Prevention.

    Science.gov (United States)

    Scheans, Patricia

    2015-01-01

    The incidence of pressure ulcers in acutely ill infants and children ranges up to 27 percent in intensive care units, with a range of 16-19 percent in NICUs. Anatomic, physiologic, and developmental factors place ill and preterm newborns at risk for skin breakdown. Two case studies illustrate these factors, and best practices for pressure ulcer prevention are described.

  16. DIGITAL BLOOD PRESSURE MONITOR

    Directory of Open Access Journals (Sweden)

    R. Fuentes

    2004-12-01

    Full Text Available In this work we present a blood pressure monitor which measures both the high blood pressure (systolic pressure,and the low blood pressure (diastolic pressure. It is a semiautomatic meter because the inflation of the occlusivecuff is carried out in a manual way. The transducer used is a piezoresistive silicon pressure sensor integrated onchip which provides a proportional voltage to the input pressure, with a measurement range from 0 to 50 kPa (0–7.3 PSI. The oscillometric method is employed, which consists on detecting the oscillometric signal on brachialartery, being processed at each pressure step, when the cuff is gradually deflated. Signal sampling is carried out ata rate determined by the heart rate.In order to program the digital electronics of the circuit we used Altera tools, with the compiler MAX-PLUS II, andthe device selected to implement the design was an EPM7128SLC84-15 CPLD (Complex Programmable LogicDevice

  17. All's Well That Ends Well: Shakespeare's treatment of anal fistula.

    Science.gov (United States)

    Cosman, B C

    1998-07-01

    Textual and contextual evidence suggests that the French king's fistula, a central plot device in Shakespeare's play All's Well That Ends Well, is a fistula-in-ano. Anal fistula was known to the lay public in Shakespeare's time. In addition, Shakespeare may have known of the anal fistula treatise of John Arderne, an ancestor on Shakespeare's mother's side. Shakespeare's use of anal fistula differs from all previous versions of the story, which first appeared in Boccaccio's Decameron and from its possible historical antecedent, the fistula of Charles V of France. This difference makes sense given the conventions of Elizabethan comedy, which included anal humor. It is also understandable when one looks at what wounds in different locations mean in European legend. In this light, it is not surprising that subsequent expurgations treat Boccaccio's and Shakespeare's fistulas differently, censoring only Shakespeare's. This reading has implications for the staging of All's Well That Ends Well, and for our view of the place of anal fistulas in cultural history.

  18. Pseudophakia and intraocular pressure.

    Science.gov (United States)

    Radius, R L; Schultz, K; Sobocinski, K; Schultz, R O; Easom, H

    1984-06-01

    We studied the change in intraocular pressure in 373 consecutive eyes undergoing cataract extraction with intraocular lens implantation between Jan. 1, 1981, and May 31, 1982. There was a mean increase in intraocular pressure of 0.1 mm Hg following this surgery. This increase, however, was not statistically significant (P greater than .5). There was a mean rise in pressure of 0.8 mm Hg in the eyes undergoing intracapsular surgery and a mean fall in pressure of 0.6 mm Hg in the eyes undergoing extracapsular surgery (P less than .05). The change in pressure was unrelated to age, surgeon, or lens type. The results of a separate analysis of 16 eyes with a preoperative diagnosis of glaucoma and eight eyes with ocular hypertension were similar.

  19. Pressure mapping to prevent pressure ulcers in a hospital setting: A pragmatic randomised controlled trial.

    Science.gov (United States)

    Gunningberg, Lena; Sedin, Inga-Maj; Andersson, Sara; Pingel, Ronnie

    2017-07-01

    pressure mapping system on pressure ulcer prevalence and incidence. However, the study could have increased staff awareness and focus on pressure ulcer prevention, thus affecting the prevalence and incidence of pressure ulcers in a positive way in both study groups. It is important to further investigate the experience of the multidisciplinary team and the patients regarding their use of the pressure mapping system, as well as strengths and weaknesses of the system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Reduced pressure for fewer pressure ulcers: can real-time feedback of interface pressure optimise repositioning in bed?

    Science.gov (United States)

    Gunningberg, Lena; Carli, Cheryl

    2016-10-01

    The aim of this study was to (i) describe registered nurses' and assistant nurses' repositioning skills with regard to their existing attitudes to and theoretical knowledge of pressure ulcer (PU) prevention, and (ii) evaluate if the continuous bedside pressure mapping (CBPM) system provides staff with a pedagogic tool to optimise repositioning. A quantitative study was performed using a descriptive, comparative design. Registered nurses (n = 19) and assistant nurses (n = 33) worked in pairs, and were instructed to place two volunteers (aged over 70 years) in the best pressure-reducing position (lateral and supine), first without viewing the CBPM monitor and then again after feedback. In total, 240 positionings were conducted. The results show that for the same person with the same available pressure-reducing equipment, the peak pressure varied considerably between nursing pairs. Reducing pressure in the lateral position appeared to be the most challenging. Peak pressures were significantly reduced, based on visual feedback from the CBPM monitor. The number of preventive interventions also increased, as well as patients' comfort. For the nurses as a group, the knowledge score was 59·7% and the attitude score was 88·8%. Real-time visual feedback of pressure points appears to provide another dimension to complement decision making with respect to PU prevention. © 2014 The Authors. International Wound Journal © 2014 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  1. Cells under pressure - treatment of eukaryotic cells with high hydrostatic pressure, from physiologic aspects to pressure induced cell death.

    Science.gov (United States)

    Frey, Benjamin; Janko, Christina; Ebel, Nina; Meister, Silke; Schlücker, Eberhard; Meyer-Pittroff, Roland; Fietkau, Rainer; Herrmann, Martin; Gaipl, Udo S

    2008-01-01

    The research on high hydrostatic pressure in medicine and life sciences is multifaceted. According to the used pressure head the research has to be divided into two different parts. To study physiological aspects of pressure on eukaryotic cells physiological pressure (pHHP; highly reversible alterations and normally does not affect cellular viability. The treatment of eukaryotic cells with non-physiological pressure (HHP; > or = 100 MPa) reveals different outcomes. Treatment with HHP or = 200 MPa. Moreover, HHP treatment with > 300 MPa leads to necrosis. Therefore, HHP plays a role for the sterilisation of human transplants, of food stuff, and pharmaceuticals. Human tumour cells subjected to HHP > 300 MPa display a necrotic phenotype along with a gelificated cytoplasm, preserve their shape, and retain their immunogenicity. These observations favour the use of HHP to produce whole cell based tumour vaccines. Further experiments revealed that the increment of pressure as well as the pressure holding time influences the cell death of tumour cells. We conclude that high hydrostatic pressure offers both, an economic, easy to apply, clean, and fast technique for the generation of vaccines, and a promising tool to study physiological aspects.

  2. Responses of jawbone to pressure.

    Science.gov (United States)

    Carlsson, Gunnar E

    2004-06-01

    To provide a literature review of bone resorption of edentulous jaws focusing on responses to pressure. After the extraction of all teeth in a jaw there is a continuous reduction of the residual ridge. The individual variation of bone resorption is great, and the aetiology is complex and not yet well understood. A search of the literature published up to May 2003 on bone resorption and pressure was performed using PubMed/Medline. Animal studies have demonstrated that excessive and constant pressure induces bone resorption. Recent experimental research has indicated that bone resorption is a pressure-regulated phenomenon with a lower threshold for continuous than for intermittent pressure. Clinical studies have suggested that residual ridge resorption is due more to the effects of denture wearing than to disuse atrophy. However, the results of leaving out dentures at night are not conclusive. Nor does the literature offer any strong evidence for the so-called combination syndrome, which has been described as a result of unfavourable loading. Clinical studies using multivariate analyses indicate that female gender and systemic factors may be of greater importance than oral and denture factors. Implant-supported prostheses have a bone preserving effect rather than the continuing resorption under complete dentures. The best way to reduce bone resorption is to avoid total extraction, preserve a few teeth and fabricate overdentures. In edentulous jaws, placement of implant-supported prostheses will lead to less bone loss and may even promote bone growth. To increase our knowledge of residual ridge resorption extended experimental, clinical and statistical methods will be needed, preferably including collaboration between dental and medical researchers.

  3. Optimization of well field management

    DEFF Research Database (Denmark)

    Hansen, Annette Kirstine

    Groundwater is a limited but important resource for fresh water supply. Differ- ent conflicting objectives are important when operating a well field. This study investigates how the management of a well field can be improved with respect to different objectives simultaneously. A framework...... objectives. The sequential scheduling optimizes the management stepwise for daily time steps, and allows the final management to vary in time. The research shows that this method performs better than the constant scheduling when large variations in the hydrological conditions occur. This novel approach can...... multi-objective optimization framework has shown to be useful in optimizing the management of well fields, and it has successfully been applied to the two case studies, Hardhof and Søndersø waterworks. If the method is applied to all Danish waterworks it is estimated that 20-32 GWh/year could be saved...

  4. Quantum-Well Thermophotovoltaic Cells

    Science.gov (United States)

    Freudlich, Alex; Ignatiev, Alex

    2009-01-01

    Thermophotovoltaic cells containing multiple quantum wells have been invented as improved means of conversion of thermal to electrical energy. The semiconductor bandgaps of the quantum wells can be tailored to be narrower than those of prior thermophotovoltaic cells, thereby enabling the cells to convert energy from longer-wavelength photons that dominate the infrared-rich spectra of typical thermal sources with which these cells would be used. Moreover, in comparison with a conventional single-junction thermophotovoltaic cell, a cell containing multiple narrow-bandgap quantum wells according to the invention can convert energy from a wider range of wavelengths. Hence, the invention increases the achievable thermal-to-electrical energy-conversion efficiency. These thermophotovoltaic cells are expected to be especially useful for extracting electrical energy from combustion, waste-heat, and nuclear sources having temperatures in the approximate range from 1,000 to 1,500 C.

  5. Inhibiting scale in oil wells

    Energy Technology Data Exchange (ETDEWEB)

    D' Errico, M.J.; Adler, S.F.

    1972-09-27

    An oil well treatment is described to inhibit the formation of hard scale by precipitation from the oil well brine of scale-forming water insoluble sulfate, carbonate, and other salts. The process consists of incorporating into the oil well during a fracturing treatment, a fluid containing a solid polymeric material characterized by molecular weight in the range of 1,000 to 15,000 and a substantially linear structure, derived by the linear polymerization of at least one monoolefinically unsaturated compound through the olefinically unsaturated group. The linear structure has pendent groups, 50% of which are carboxy groups, the carboxy groups being neutralized with a sufficient proportion of at least one compound having a cation of a metal selected from alkaline earth metals, chromium, aluminum, iron, cobalt, zinc, nickel or copper to render the polymer soluble in water at 25$C to a concentration of not more than 50 ppm. (8 claims)

  6. Pressure compensated transducer system with constrained diaphragm

    Science.gov (United States)

    Percy, Joseph L.

    1992-08-01

    An acoustic source apparatus has an acoustic transducer that is enclosed in a substantially rigid and watertight enclosure to resist the pressure of water on the transducer and to seal the transducer from the water. The enclosure has an opening through which acoustic signals pass and over which is placed a resilient, expandable and substantially water-impermeable diaphragm. A net stiffens and strengthens the diaphragm as well as constrains the diaphragm from overexpansion or from migrating due to buoyancy forces. Pressurized gas, regulated at slightly above ambient pressure, is supplied to the enclosure and the diaphragm to compensate for underwater ambient pressures. Gas pressure regulated at above ambient pressure is used to selectively tune the pressure levels within the enclosure and diaphragm so that diaphragm resonance can be achieved. Controls are used to selectively fill, as well as vent the enclosure and diaphragm during system descent and ascent, respectively. A signal link is used to activate these controls and to provide the driving force for the acoustic transducer.

  7. 超级13Cr不锈钢在超深超高压高温油气井中的腐蚀行为研究%Corrosion Behavior of Super 13%Cr Martensitic Stainless Steel Under Ultra-deep, Ultra-high Pressure and High Temperature Oil and Gas Well Environment

    Institute of Scientific and Technical Information of China (English)

    刘艳朝; 常泽亮; 赵国仙; 薛艳; 牛坤

    2012-01-01

    通过模拟油田超深超高压高温油气井腐蚀环境,研究超级13Cr马氏体不锈钢管材抗均匀腐蚀、点蚀及电偶腐蚀性能.结果表明:随着Cl-浓度的增加,超级13Cr马氏体不锈钢的均匀腐蚀速率在气相腐蚀环境中逐渐增大,在液相中变化不大,且气相的均匀腐蚀速率要大于液相的腐蚀速率.但不论在液相还是在气相腐蚀条件下,均匀腐蚀速率均远小于0.1 mm/a,局部腐蚀严重.在温度为150℃的气相环境中,超级13Cr钢的最大局部腐蚀速率可达2.1379 mm/a:其7天实验的最大局部腐蚀坑深度可达41μm.存电偶腐蚀试验中,不论是小试样模拟试验还是实物试验,P110作为阳极,腐蚀加剧,腐蚀速率增大,在电偶处发生明显局部腐蚀.超级13Cr马氏体不锈钢作为阴极被保护,腐蚀减缓,腐蚀速率减小.%By simulating ultra-deep, ultra-high pressure and high temperature oil and gas corrosion environment, the performance of super 13%Cr martensite stainless tubular goods against uniform corrosion, pitting and galvanic corrosion was studied. The results indicate that the uniform corrosion rate of super 13%Cr martensite stainless steel increases as the C1-concentration increasing in gas phase, and changes little in the liquid phase. The uniform corrosion rate of gas phase is higher than one of the liquid phase. However, the uniform corrosion rate is far less than 0.1 mm/a, regardless of corrosion conditions of liquid phase and gas phase, and the localized corrosion is very severe. At 150 ℃ gas environment, the maximum local corrosion rate is up to 2.1379mm/a, the maximum local corrosion pit depth is up to 41 μm in the experiment of seven days. In the galvanic corrosion test, whether they are small sample simulation test or physical test, the corrosion rate of P110 increases, which is used as an anode, it has local corrosion dramatically in the contact point. The super 13%Cr martensite stainless steel used as the cathode is

  8. Hydrostatic limits of 11 pressure transmitting media

    Science.gov (United States)

    Klotz, S.; Chervin, J.-C.; Munsch, P.; LeMarchand, G.

    2009-04-01

    We present a systematic and comparative study of the pressure-induced solidification of 11 frequently used pressure transmitting fluids using the ruby fluorescence technique in a diamond anvil cell. These fluids are 1 : 1 and 5 : 1 iso-n pentane, 4 : 1 deuterated methanol-ethanol, 16 : 3 : 1 deuterated methanol-ethanol-water, 1 : 1 FC84-FC87 Fluorinert, Daphne 7474, silicone oil, as well as nitrogen, neon, argon and helium. The data provide practical guidelines for the use of these fluids in high pressure experiments up to 50 GPa.

  9. High-pressure oxidation of ethane

    DEFF Research Database (Denmark)

    Hashemi, Hamid; G. Jacobsen, Jon; Rasmussen, Christian T.

    2017-01-01

    Ethane oxidation at intermediate temperatures and high pressures has been investigated in both a laminar flow reactor and a rapid compression machine (RCM). The flow-reactor measurements at 600–900 K and 20–100 bar showed an onset temperature for oxidation of ethane between 700 and 825 K, depending...... as well as results at elevated pressure from literature. The experimental results and the modeling predictions do not support occurrence of NTC behavior in ethane oxidation. Even at the high-pressure conditions of the present work where the C2H5 + O2 reaction yields ethylperoxyl rather than C2H4 + HO2...

  10. Measuring Viscosities of Gases at Atmospheric Pressure

    Science.gov (United States)

    Singh, Jag J.; Mall, Gerald H.; Hoshang, Chegini

    1987-01-01

    Variant of general capillary method for measuring viscosities of unknown gases based on use of thermal mass-flowmeter section for direct measurement of pressure drops. In technique, flowmeter serves dual role, providing data for determining volume flow rates and serving as well-characterized capillary-tube section for measurement of differential pressures across it. New method simple, sensitive, and adaptable for absolute or relative viscosity measurements of low-pressure gases. Suited for very complex hydrocarbon mixtures where limitations of classical theory and compositional errors make theoretical calculations less reliable.

  11. Health and Wellness Policy Ethics

    Directory of Open Access Journals (Sweden)

    Frank J. Cavico

    2013-01-01

    Full Text Available This perspective is an ethical brief overview and examination of “wellness” policies in the modern workplace using practical examples and a general application of utilitarianism. Many employers are implementing policies that provide incentives to employees who lead a “healthy” lifestyle. The authors address how these policies could adversely affect “non-healthy” employees. There are a wide variety of ethical issues that impact wellness policies and practices in the workplace. The authors conclude that wellness programs can be ethical, while also providing a general reflective analysis of healthcare challenges in order to reflect on the externalities associated with such policies in the workplace.

  12. ADVANCED CEMENTS FOR GEOTHERMAL WELLS

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2007-01-01

    Using the conventional well cements consisting of the calcium silicate hydrates (CaO-SiO{sub 2}-H{sub 2}O system) and calcium aluminum silicate hydrates (CaO-Al{sub 2}O{sub 3}-SiO{sub 2}-H{sub 2}O system) for the integrity of geothermal wells, the serious concern confronting the cementing industries was their poor performance in mechanically supporting the metallic well casing pipes and in mitigating the pipe's corrosion in very harsh geothermal reservoirs. These difficulties are particularly acute in two geological regions: One is the deep hot downhole area ({approx} 1700 m depth at temperatures of {approx} 320 C) that contains hyper saline water with high concentrations of CO{sub 2} (> 40,000 ppm) in conjunction with {approx} 100 ppm H{sub 2}S at a mild acid of pH {approx} 5.0; the other is the upper well region between the well's surface and {approx} 1000 m depth at temperatures up to 200 C. The specific environment of the latter region is characterized by highly concentrated H{sub 2}SO{sub 4} (pH < 1.5) brine containing at least 5000 ppm CO{sub 2}. When these conventional cements are emplaced in these harsh environments, their major shortcoming is their susceptibility to reactions with hot CO{sub 2} and H{sub 2}SO4, thereby causing their deterioration brought about by CO{sub 2}-catalyzed carbonation and acid-initiated erosion. Such degradation not only reduced rapidly the strength of cements, lowering the mechanical support of casing pipes, but also increased the extent of permeability of the brine through the cement layer, promoting the rate of the pipe's corrosion. Severely carbonated and acid eroded cements often impaired the integrity of a well in less than one year; in the worst cases, casings have collapsed within three months, leading to the need for costly and time-consuming repairs or redrilling operations. These were the reasons why the geothermal well drilling and cementing industries were concerned about using conventional well

  13. Health and Wellness Policy Ethics

    Science.gov (United States)

    Cavico, Frank J.; Mujtaba, Bahaudin G.

    2013-01-01

    This perspective is an ethical brief overview and examination of “wellness” policies in the modern workplace using practical examples and a general application of utilitarianism. Many employers are implementing policies that provide incentives to employees who lead a “healthy” lifestyle. The authors address how these policies could adversely affect “non-healthy” employees. There are a wide variety of ethical issues that impact wellness policies and practices in the workplace. The authors conclude that wellness programs can be ethical, while also providing a general reflective analysis of healthcare challenges in order to reflect on the externalities associated with such policies in the workplace. PMID:24596847

  14. Computing Flow through Well Screens Using an Embedded Well Technique

    Science.gov (United States)

    2015-08-01

    the three- dimensional (3D) groundwater (GW) flow simulation using the finite element (FE) method. BACKGROUND: Accurate estimation of flow rates...equations of the coupled GW/well system that include the 3D Richards equation for subsurface flow and a one- dimensional (1D) steady-state equation...fluxes from multi- dimensional finite element flow simulations. ERDC TN-SWWRP-10-4. Vicksburg, MS: U.S. Army Engineer Research and Development Center

  15. Skin perfusion pressure on the legs measured as the external pressure required for skin reddening after blanching

    DEFF Research Database (Denmark)

    Holstein, P; Nielsen, P.E.; Lund, P

    1980-01-01

    Hg (SD 8.7). As compared to the intra-arterial blood pressure the BTEP was found to lie close to the mean blood pressure in normal subjects as well as in hypertensive subjects. The present data indicate that the skin perfusion pressure on the legs can be measured by the rapid photo-electric technique......The skin perfusion on the calf was measured photo-electrically and by isotope washout technique using external counter pressure by a blood pressure cuff. By the photocell the skin blanching threshold external pressure (BTEP) was recorded on histamine flared red skin. By isotope washout technique...... the skin blood flow cessation external pressure (FCEP) was recorded using intra-dermal [131I-]-antipyrine mixed with histamine in estimating the skin blood flow. The external pressure was measured with an airfilled plastic cushion connected to a mercury manometer. Over a wide range of pressures as obtained...

  16. Pore pressure migration during hydraulic stimulation due to permeability enhancement by low-pressure subcritical fracture slip

    Science.gov (United States)

    Mukuhira, Yusuke; Moriya, Hirokazu; Ito, Takatoshi; Asanuma, Hiroshi; Häring, Markus

    2017-04-01

    Understanding the details of pressure migration during hydraulic stimulation is important for the design of an energy extraction system and reservoir management, as well as for the mitigation of hazardous-induced seismicity. Based on microseismic and regional stress information, we estimated the pore pressure increase required to generate shear slip on an existing fracture during stimulation. Spatiotemporal analysis of pore pressure migration revealed that lower pore pressure migrates farther and faster and that higher pore pressure migrates more slowly. These phenomena can be explained by the relationship between fracture permeability and stress state criticality. Subcritical fractures experience shear slip following smaller increases of pore pressure and promote migration of pore pressure because of their enhanced permeability. The difference in migration rates between lower and higher pore pressures suggests that the optimum wellhead pressure is the one that can stimulate relatively permeable fractures, selectively. Its selection optimizes economic benefits and minimizes seismic risk.

  17. Design and Development of a Pressure Transducer for High Hydrostatic Pressure Measurements up to 200 MPa

    Science.gov (United States)

    Kumar, Anuj; Yadav, Sanjay; Agarwal, Ravinder

    2016-06-01

    A number of pressure transducers, based on strain gauge, capacitance/inductance type, frequency resonators, are commercially available and are being used for sensing and producing an electrical output proportional to applied pressure. These sensors have their own advantages and limitations due to operational ease, measurement uncertainty and the costs. Strain gauge type transducers are now well established devices for accurate and precise measurement of pressure within measurement uncertainty up to 0.1 % of full scale. In the present research work, an indigenous strain gauge pressure transducer has been designed, developed, tested and calibrated for pressure measurement up to 200 MPa. The measurement uncertainty estimated using the pressure transducer was found better than 0.1 % of full scale. This transducer was developed using four foil type strain gauges, bonded, two in axial direction while other two in radial direction, to the controlled stress zones of a tubular maraging steel active cylinder working also as diaphragm. The strain gages were then connected to a Wheatstone bridge arrangement to measure stress generated strains. The pressure was applied through matching connector designed in the same tubular transducer active element. The threaded unique design in a single piece through collar, ferule and tubing arrangement provides leak proof pressure connections with external devices without using additional seals. The calibration and performance checking of the pressure transducer was carried out using dead weight type national pressure standard using the internationally accepted calibration procedure.

  18. Design and Development of a Pressure Transducer for High Hydrostatic Pressure Measurements up to 200 MPa

    Science.gov (United States)

    Kumar, Anuj; Yadav, Sanjay; Agarwal, Ravinder

    2017-08-01

    A number of pressure transducers, based on strain gauge, capacitance/inductance type, frequency resonators, are commercially available and are being used for sensing and producing an electrical output proportional to applied pressure. These sensors have their own advantages and limitations due to operational ease, measurement uncertainty and the costs. Strain gauge type transducers are now well established devices for accurate and precise measurement of pressure within measurement uncertainty up to 0.1 % of full scale. In the present research work, an indigenous strain gauge pressure transducer has been designed, developed, tested and calibrated for pressure measurement up to 200 MPa. The measurement uncertainty estimated using the pressure transducer was found better than 0.1 % of full scale. This transducer was developed using four foil type strain gauges, bonded, two in axial direction while other two in radial direction, to the controlled stress zones of a tubular maraging steel active cylinder working also as diaphragm. The strain gages were then connected to a Wheatstone bridge arrangement to measure stress generated strains. The pressure was applied through matching connector designed in the same tubular transducer active element. The threaded unique design in a single piece through collar, ferule and tubing arrangement provides leak proof pressure connections with external devices without using additional seals. The calibration and performance checking of the pressure transducer was carried out using dead weight type national pressure standard using the internationally accepted calibration procedure.

  19. Pressure Ulcers Surveillance Report

    Directory of Open Access Journals (Sweden)

    Zehra Esin Gencer

    2015-04-01

    Full Text Available Objective: Pressure ulcer is a chronic wound. It reduces the quality of life of the elderly and individuals with restricted range of motion. It prolongs hospital stay and increases the risk of complications. The cost is quite high. Preventive actions for the prevention of pressure ulcers should be developed. Planning protocols and standards of care are among the main targets. Material and Method: Research was conducted in one-year period between 2012 May and 2013 May on patients who were followed up in Akdeniz University Hospital clinics and intensive care unit with pressure ulcers. The research population consisted of 569 patients. Patient data were recorded in SPSS 16 for Windows program. Statistical analyzes were performed with retrospective methods. The demographic characteristics of patients with pressure ulcers were analyzed as frequency and descriptive statistics. Prevalence and incidence of one year were calculated. Results: Of the patients, 58% were males, 42% were females. Of the patients, 36% were in the age range of 61-80 years, and their average length of stay was 42,9 days. Of the patients, 70% were at stage 2 and 3. In 15% of patients pressure ulcers occurred on the first day of hospitalization. Pressure ulcers were developed between days 2 and 10 in 59% of the patients. Prevalence rate was 2.5%, the incidence was 1.9%, the prevalence rate was 5.9% in the intensive care unit. Conclusion: It is easier to prevent pressure ulcers than treating.

  20. Design principles for high-pressure force fields: Aqueous TMAO solutions from ambient to kilobar pressures

    Science.gov (United States)

    Hölzl, Christoph; Kibies, Patrick; Imoto, Sho; Frach, Roland; Suladze, Saba; Winter, Roland; Marx, Dominik; Horinek, Dominik; Kast, Stefan M.

    2016-04-01

    Accurate force fields are one of the major pillars on which successful molecular dynamics simulations of complex biomolecular processes rest. They have been optimized for ambient conditions, whereas high-pressure simulations become increasingly important in pressure perturbation studies, using pressure as an independent thermodynamic variable. Here, we explore the design of non-polarizable force fields tailored to work well in the realm of kilobar pressures - while avoiding complete reparameterization. Our key is to first compute the pressure-induced electronic and structural response of a solute by combining an integral equation approach to include pressure effects on solvent structure with a quantum-chemical treatment of the solute within the embedded cluster reference interaction site model (EC-RISM) framework. Next, the solute's response to compression is taken into account by introducing pressure-dependence into selected parameters of a well-established force field. In our proof-of-principle study, the full machinery is applied to N,N,N-trimethylamine-N-oxide (TMAO) in water being a potent osmolyte that counteracts pressure denaturation. EC-RISM theory is shown to describe well the charge redistribution upon compression of TMAO(aq) to 10 kbar, which is then embodied in force field molecular dynamics by pressure-dependent partial charges. The performance of the high pressure force field is assessed by comparing to experimental and ab initio molecular dynamics data. Beyond its broad usefulness for designing non-polarizable force fields for extreme thermodynamic conditions, a good description of the pressure-response of solutions is highly recommended when constructing and validating polarizable force fields.

  1. Nozzle Bricks and Well Bricks

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2011-01-01

    1 Scope This standard specifies the classification,brand,technical requirements,test methods,inspection rules,marking,packing,transportation,storage,and quality certificate of nozzle bricks and well bricks.This standard is applicable to unfired and fired products.

  2. CCSD Well Logging Engineering Program

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper introduces briefly the tasks and characteristics of China Continent Science Drilling (CCSD) Well Logging Engineering, the logging methods measured with CCSD, the quality control of original logging information, the logging plan of CCSD, the logging engineering management of CCSD,the logging interpretation and the results and reports made with CCSD.

  3. Planets under pressure

    Science.gov (United States)

    Jeanloz, Raymond

    2009-04-01

    Deep inside the planet Jupiter, diamonds hail down from hydrocarbon clouds as intense atmospheric pressures break methane into its atomic components. Further in - but still only 15% of the way to the planet's centre - the pressure reaches a million times that of the Earth's atmosphere. This is enough to transform hydrogen from the transparent, insulating gas we know at our planet's surface into a metallic fluid that sustains Jupiter's huge magnetic field. Even diamond is not forever: at pressures of 8-10 million atmospheres it is transformed into an opaque, metallic form of carbon, rather than the familiar transparent crystal.

  4. Atmospheric Pressure During Landing

    Science.gov (United States)

    1997-01-01

    This figure shows the variation with time of pressure (dots) measured by the Pathfinder MET instrument during the landing period shown in image PIA00797. The two diamonds indicate the times of bridal cutting and 1st impact. The overall trend in the data is of pressure increasing with time. This is almost certainly due to the lander rolling downhill by roughly 10 m. The spacing of the horizontal dotted lines indicates the pressure change expected from 10 m changes in altitude. Bounces may also be visible in the data.

  5. Transient multiphase flow modeling of gas well liquid loading

    NARCIS (Netherlands)

    Veeken, K.; Hu, B.; Schiferli, W.

    2009-01-01

    Gas well liquid loading occurs when gas production becomes insufficient to lift the associated liquids to surface. When that happens gas production first turns intermittent and eventually stops. Hence in depleting gas reservoirs the technical abandonment pressure and ultimate recovery are typically

  6. 2013 strategic petroleum reserve big hill well integrity grading report.

    Energy Technology Data Exchange (ETDEWEB)

    Lord, David L.; Roberts, Barry L.; Lord, Anna C. Snider; Bettin, Giorgia; Sobolik, Steven Ronald; Park, Byoung Yoon; Rudeen, David Keith; Eldredge, Lisa; Wynn, Karen; Checkai, Dean; Perry, James Thomas

    2014-02-01

    This report summarizes the work performed in developing a framework for the prioritization of cavern access wells for remediation and monitoring at the Big Hill Strategic Petroleum Reserve site. This framework was then applied to all 28 wells at the Big Hill site with each well receiving a grade for remediation and monitoring. Numerous factors affecting well integrity were incorporated into the grading framework including casing survey results, cavern pressure history, results from geomechanical simulations, and site geologic factors. The framework was developed in a way as to be applicable to all four of the Strategic Petroleum Reserve sites.

  7. Well-leg compartment syndrome after gynecological laparoscopic surgery

    DEFF Research Database (Denmark)

    Boesgaard-Kjer, Diana H; Boesgaard-Kjer, Daniel; Kjer, Jens Jørgen

    2013-01-01

    Well-leg compartment syndrome in the lower extremities after surgery in the lithotomy position is a rare but severe complication requiring early diagnosis and intervention. Several circumstances predispose to this condition as a consequence of increased intra-compartmental pressure, such as posit....... Potential risk factors and preventive initiatives are listed to reduce the risk in future patients. We describe two patients who underwent gynecologic laparoscopic surgery and postoperatively developed well-leg compartment syndrome....

  8. Joint Cross Well and Single Well Seismic Studies at Lost Hills, California

    Energy Technology Data Exchange (ETDEWEB)

    Gritto, Roland; Daley, Thomas M.; Myer, Larry R.

    2002-06-25

    A series of time-lapse seismic cross well and single well experiments were conducted in a diatomite reservoir to monitor the injection of CO{sub 2} into a hydrofracture zone, based on P- and S-wave data. A high-frequency piezo-electric P-wave source and an orbital-vibrator S-wave source were used to generate waves that were recorded by hydrophones as well as three-component geophones. The injection well was located about 12 m from the source well. During the pre-injection phase water was injected into the hydrofrac-zone. The set of seismic experiments was repeated after a time interval of 7 months during which CO{sub 2} was injected into the hydrofractured zone. The questions to be answered ranged from the detectability of the geologic structure in the diatomic reservoir to the detectability of CO{sub 2} within the hydrofracture. Furthermore it was intended to determine which experiment (cross well or single well) is best suited to resolve these features. During the pre-injection experiment, the P-wave velocities exhibited relatively low values between 1700-1900 m/s, which decreased to 1600-1800 m/s during the post-injection phase (-5%). The analysis of the pre-injection S-wave data revealed slow S-wave velocities between 600-800 m/s, while the post-injection data revealed velocities between 500-700 m/s (-6%). These velocity estimates produced high Poisson ratios between 0.36 and 0.46 for this highly porous ({approx} 50%) material. Differencing post- and pre-injection data revealed an increase in Poisson ratio of up to 5%. Both, velocity and Poisson estimates indicate the dissolution of CO{sub 2} in the liquid phase of the reservoir accompanied by a pore-pressure increase. The single well data supported the findings of the cross well experiments. P- and S-wave velocities as well as Poisson ratios were comparable to the estimates of the cross well data. The cross well experiment did not detect the presence of the hydrofracture but appeared to be sensitive to overall

  9. Mud and cement for horizontal wells

    Energy Technology Data Exchange (ETDEWEB)

    Zurdo, C.; Georges, C.; Martin, M.

    1986-01-01

    High-angle and horizontal well bores raise many questions concerning the characteristics of mud and cement. This paper is a summary of the authors' knowledge and work on these two subjects. For all research carried out, large or full-scale laboratory test plants were used. Cutting transport is not only a problem in horizontal conditions but hole angles of 25 to 65/sup 0/ can be even more critical when parameters such as mud rheological properties and velocities are not optimized. Drilling a long horizontal drain creates a dynamic annulus pressure unbalance. This can lead to a loss and kick situation. Two test benches were thus used to obtain a good understanding of the inefficiency of conventional plugging methods and of the difficulties of gas migration control in subhorizontal well bores. High concentrations of LCM, high rheological properties of fluids and low flow rates increase the changes of solving the first problem. The results of the second bench demonstrate the difficulties of annulus gas evacution for angles varying from 90 to 100 degrees, or from over-gauged sections in horizontal holes.

  10. Design and Evaluation of a Pressure and Temperature Monitoring System for Pressure Ulcer Prevention

    Directory of Open Access Journals (Sweden)

    Farve Daneshvar Fard

    2014-08-01

    Full Text Available Introduction Pressure ulcers are tissue damages resulting from blood flow restriction, which occurs when the tissue is exposed to high pressure for a long period of time. These painful sores are common in patients and elderly, who spend extended periods of time in bed or wheelchair. In this study, a continuous pressure and temperature monitoring system was developed for pressure ulcer prevention. Materials and Methods The monitoring system consists of 64 pressure and 64 temperature sensors on a 40×50 cm2 sheet. Pressure and temperature data and the corresponding maps were displayed on a computer in real-time. Risk assessment could be performed by monitoring and recording absolute pressure and temperature values, as well as deviations over time. Furthermore, a posture detection procedure was proposed for sitting posture identification. Information about the patient’s movement history may help caregivers make informed decisions about the patient’s repositioning and ulcer prevention strategies. Results Steady temporal behaviour of the designed system and repeatability of the measurements were evaluated using several particular tests. The results illustrated that the system could be utilized for continuous monitoring of interface pressure and temperature for pressure ulcer prevention. Furthermore, the proposed method for detecting sitting posture was verified using a statistical analysis. Conclusion A continuous time pressure and temperature monitoring system was presented in this study. This system may be suited for pressure ulcer prevention given its feasibility for simultaneous monitoring of pressure and temperature and alarming options. Furthermore, a method for detecting different sitting postures was proposed and verified. Pressure ulcers in wheelchair-bound patients may be prevented using this sitting posture detection method.

  11. Pressure Safety Orientation Live #769

    Energy Technology Data Exchange (ETDEWEB)

    Glass, George [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-05-17

    Pressure Safety Orientation (course #769) introduces workers at Los Alamos National Laboratory (LANL) to the Laboratory Pressure Safety Program and to pressure-related hazards. This course also affords a hands-on exercise involving the assembly of a simple pressure system. This course is required for all LANL personnel who work on or near pressure systems and are exposed to pressure-related hazards. These personnel include pressure-system engineers, designers, fabricators, installers, operators, inspectors, maintainers, and others who work with pressurized fluids and may be exposed to pressure-related hazards.

  12. DRILL BITS FOR HORIZONTAL WELLS

    Directory of Open Access Journals (Sweden)

    Paolo Macini

    1996-12-01

    Full Text Available This paper underlines the importance of the correct drill bit application in horizontal wells. Afler the analysis of the peculiarities of horizontal wells and drainholes drilling techniques, advantages and disadvantages of the application of both roller cone and fixed cutters drill bits have been discussed. Also, a review of the potential specific featuries useful for a correct drill bit selection in horizontal small diameter holes has been highlighted. Drill bits for these special applications, whose importance is quickly increasing nowadays, should be characterised by a design capable to deliver a good penetration rate low WOB, and, at the same time, be able to withstand high RPM without premature cutting structure failure and undergauge. Formation properties will also determine the cutting structure type and the eventual specific features for additional gauge and shoulder protection.

  13. Implementing an effective wellness program

    Energy Technology Data Exchange (ETDEWEB)

    Dickson, N. [Bruce Power Inc., Toronto, ON (Canada)

    2004-07-01

    Bruce Power is one of the largest nuclear sites in the world, with more than 3,700 employees. The utility strives to be one of Canada's most dynamic and innovative teams. The values of Bruce Power include: safety first; profit through progress; openness; respect and recognition; and professional and personal integrity. With respect to health and safety, Bruce Power strives to have zero medically treated injuries. Details of the healthy workplace committee were presented as well as details of the health and wellness program. Charts of health and mental health screening strategies were presented. Other programs include: an excellent benefits package; flexible working hours; family care days; banked time; an electronic suggestion box; and station condition records. It was noted that there is a strong external focus on health and safety as well. Details of community involvement and sponsorship were presented, along with details of on-site fitness facilities and fitness membership subsidies. Details of the National Quality Institute certification were also provided, including physical environment; lifestyle behaviours; and psycho-social environment. The importance of strong leadership in encouraging feedback, team talk and continuous leadership development was emphasized. Strategies to strengthen leadership include new hiring criteria for managers; management days; first line manager academy; a mentoring program; and task observation and coaching. Communication strategies include articles in weekly newspapers; monthly safety meeting video segments; posters and electronic signs; and voice mail messages from the chief executive officer. Details of the Eat Smart and Weight Challenge certification were provided. The management at human resources faces the challenge of continual change, demographics, and the fact that wellness is difficult to measure. tabs., figs.

  14. Spacecraft Architecture and well being

    Science.gov (United States)

    Ören, Ayşe

    2016-07-01

    As we embark on a journey for new homes in the new worlds to lay solid foundations, we should consider not only the survival of frontiers but also well-being of those to live in zero gravity. As a versatile science, architecture encompasses abstract human needs as well. On our new different direction in the course of the Homo sapiens evolution, we can do this with designs addressing both our needs and senses. Well-being of humans can be achieved by creating environments supporting the cognitive and social stages in the evolution process. Space stations are going through their own evolution process. Any step taken can serve as a reference for further attempts. When studying the history of architecture, window designing is discussed in a later phase, which is the case for building a spaceship as well. We lean on the places we live both physically and metaphorically. The feeling of belonging is essential here, entailing trans-humanism, which is significant since the environment therein is like a dress comfortable enough to fit in, meeting needs without any burden. Utilizing the advent of technology, we can create moods and atmospheres to regulate night and day cycles, thus we can turn claustrophobic places into cozy or dream-like places. Senses provoke a psychological sensation going beyond cultural codes as they are rooted within consciousness, which allows designers to create a mood within a space that tells a story and evokes an emotional impact. Color, amount of light, sound and odor are not superficial. As much as intangible, they are real and powerful tools with a physical presence. Tapping into induction, we can solve a whole system based on a part thereof. Therefore, fractal designs may not yield good results unless used correctly in terms of design although they are functional, which makes geometric arrangement critical.

  15. Delay Pressure Detection Method to Eliminate Pump Pressure Interference on the Downhole Mud Pressure Signals

    OpenAIRE

    Yue Shen; Ling-Tan Zhang; Shi-Li Cui; Li-Min Sheng; Lin Li; Yi-Nao Su

    2013-01-01

    The feasibility of applying delay pressure detection method to eliminate mud pump pressure interference on the downhole mud pressure signals is studied. Two pressure sensors mounted on the mud pipe in some distance apart are provided to detect the downhole mud continuous pressure wave signals on the surface according to the delayed time produced by mud pressure wave transmitting between the two sensors. A mathematical model of delay pressure detection is built by analysis of transmission path...

  16. Metastable Systems under Pressure

    CERN Document Server

    Rzoska, Sylwester; Mazur, Victor

    2010-01-01

    The fundamental insight and the technological & environmental relevance of metastable systems have given a strong impetus from the last decade development of extreme pressures experimental techniques, from the GPa region to the challenging negative pressures domain. The ultimate verification of theoretical models and reliable equations for portraying basic properties for such systems seems to be possible only when including temperature and pressure paths. This volume presents a set of papers related to novel findings on the glass transition phenomenon, phase transitions in liquid crystals, critical mixtures, bioliquids, geophysical system which can reveal surprising "secret" features only when using extreme pressures. This can be illustrated by the link between colloidal and molecular glassformers, the universal onset of the non-trivial dynamics in glasses, demistification of the secondary relaxation or novel findings associated with liquid - liquid near critical transitions in critical mixture, liquid cr...

  17. Pressure Transducer Locations

    Data.gov (United States)

    National Aeronautics and Space Administration — Files are located here, defining the locations of the pressure transducers on the HIRENASD model. These locations also correspond to the locations that analysts...

  18. High Blood Pressure

    Science.gov (United States)

    ... giving Gift and estate planning Circle of Champions Corporate sponsorship Join us at an event The Hope ... blood pressure is the #2 cause of kidney failure. It accounts for about one-fourth of all ...

  19. Gasoline Reid Vapor Pressure

    Science.gov (United States)

    EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

  20. Normal pressure hydrocephalus

    Science.gov (United States)

    Hydrocephalus - occult; Hydrocephalus - idiopathic; Hydrocephalus - adult; Hydrocephalus - communicating; Dementia - hydrocephalus; NPH ... Ferri FF. Normal pressure hydrocephalus. In: Ferri FF, ed. ... Elsevier; 2016:chap 648. Rosenberg GA. Brain edema and disorders ...

  1. Internal pressure sensor

    Science.gov (United States)

    Dowalo, James A [Blackfoot, ID

    2010-03-16

    A pressure sensor for sensing changes in pressure in an enclosed vessel may include a first chamber having at least one expandable section therein that allows that first chamber to change in length. A reference member mounted within the first chamber moves as a result of changes in length of the first chamber. A second chamber having an expandable section therein allows the second chamber to change in length in response to changes in pressure in the enclosed vessel. The second chamber is operatively associated with the first chamber so that changes in length of the second chamber result in changes in length of the first chamber. A sensor operatively associated with the reference member detects changes in position of the reference member. Changes in position of the reference member are related to changes in pressure in the enclosed vessel.

  2. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... already been diagnosed with high blood pressure. Try yoga and meditation. Yoga and meditation not only can strengthen your body ... Accessed Sept. 21, 2015. Hu B, et al. Effects of psychological stress on hypertension in middle-aged ...

  3. More Pressure on Iran

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As the UN Security Council adopts a new resolution to pressure Iran over its nuclear activities, the country maintains a tough stance On March 24, the UN Security Council unanimously adopted a new resolution imposing tougher sanctions against Iran to

  4. High Blood Pressure (Hypertension)

    Science.gov (United States)

    ... possible. Practice healthy coping techniques, such as muscle relaxation, deep breathing or meditation. Getting regular physical activity ... you monitor your blood pressure at home. Practice relaxation or slow, deep breathing. Practice taking deep, slow ...

  5. Increased intracranial pressure

    Science.gov (United States)

    ... patient's bedside in an emergency room or hospital. Primary care doctors may sometimes spot early symptoms of increased intracranial pressure such as headache, seizures, or other nervous system problems. An MRI ...

  6. Llano puts pressure on drillers

    Energy Technology Data Exchange (ETDEWEB)

    Flatern, R. von

    1998-08-01

    An account of technological achievement in deepwater vertical drilling is given in the first of two articles. EEX`s used the Sedco Forex Omega platform to set a drilling depth record of 26,969 ft in 2600 ft of water in the Gulf of Mexico in June 1998. The second reports on technology to support measurements while drilling used to drill the world`s deepest horizontal well in Italy`s Villafortuna Trecate field. Technological innovations in the field of high-pressure composite drilling riser joints are also noted. (UK)

  7. Home monitoring of blood pressure

    OpenAIRE

    McGrath, Barry P.

    2015-01-01

    Home blood pressure monitoring is the self-measurement of blood pressure by patients. In the diagnosis and management of high blood pressure it is complementary to 24-hour ambulatory blood pressure monitoring and clinic blood pressure measurements. Home monitoring can also help to identify white-coat and masked hypertension.

  8. High Blood Pressure Fact Sheet

    Science.gov (United States)

    ... High Blood Pressure Salt Cholesterol Million Hearts® WISEWOMAN High Blood Pressure Fact Sheet Language: English Español (Spanish) Recommend on ... time. High blood pressure is also called hypertension. High Blood Pressure in the United States Having high blood pressure ...

  9. Idiopathic Normal Pressure Hydrocephalus

    OpenAIRE

    2016-01-01

    Idiopathic normal pressure hydrocephalus (iNPH) is a potentially reversible neurodegenerative disease commonly characterized by a triad of dementia, gait, and urinary disturbance. Advancements in diagnosis and treatment have aided in properly identifying and improving symptoms in patients. However, a large proportion of iNPH patients remain either undiagnosed or misdiagnosed. Using PubMed search engine of keywords “normal pressure hydrocephalus,” “diagnosis,” “shunt treatment,” “biomarkers,” ...

  10. Pressure ulcers: Back to the basics

    Science.gov (United States)

    Agrawal, Karoon; Chauhan, Neha

    2012-01-01

    Pressure ulcer in an otherwise sick patient is a matter of concern for the care givers as well as the medical personnel. A lot has been done to understand the disease process. So much so that USA and European countries have established advisory panels in their respective continents. Since the establishment of these organizations, the understanding of the pressure ulcer has improved significantly. The authors feel that the well documented and well publicized definition of pressure ulcer is somewhat lacking in the correct description of the disease process. Hence, a modified definition has been presented. This disease is here to stay. In the process of managing these ulcers the basic pathology needs to be understood well. Pressure ischemia is the main reason behind the occurrence of ulceration. Different extrinsic and intrinsic factors have been described in detail with review of literature. There are a large number of risk factors causing ulceration. The risk assessment scales have eluded the surgical literature and mostly remained in nursing books and websites. These scales have been reproduced for completion of the basics on decubitus ulcer. The classification of the pressure sores has been given in a comparative form to elucidate that most of the classifications are the same except for minor variations. The management of these ulcers is ever evolving but the age old saying of “prevention is better than cure” suits this condition the most. PMID:23162223

  11. Pressure ulcers: Back to the basics

    Directory of Open Access Journals (Sweden)

    Karoon Agrawal

    2012-01-01

    Full Text Available Pressure ulcer in an otherwise sick patient is a matter of concern for the care givers as well as the medical personnel. A lot has been done to understand the disease process. So much so that USA and European countries have established advisory panels in their respective continents. Since the establishment of these organizations, the understanding of the pressure ulcer has improved significantly. The authors feel that the well documented and well publicized definition of pressure ulcer is somewhat lacking in the correct description of the disease process. Hence, a modified definition has been presented. This disease is here to stay. In the process of managing these ulcers the basic pathology needs to be understood well. Pressure ischemia is the main reason behind the occurrence of ulceration. Different extrinsic and intrinsic factors have been described in detail with review of literature. There are a large number of risk factors causing ulceration. The risk assessment scales have eluded the surgical literature and mostly remained in nursing books and websites. These scales have been reproduced for completion of the basics on decubitus ulcer. The classification of the pressure sores has been given in a comparative form to elucidate that most of the classifications are the same except for minor variations. The management of these ulcers is ever evolving but the age old saying of "prevention is better than cure" suits this condition the most.

  12. Pressure Core Characterization

    Science.gov (United States)

    Santamarina, J. C.

    2014-12-01

    Natural gas hydrates form under high fluid pressure and low temperature, and are found in permafrost, deep lakes or ocean sediments. Hydrate dissociation by depressurization and/or heating is accompanied by a multifold hydrate volume expansion and host sediments with low permeability experience massive destructuration. Proper characterization requires coring, recovery, manipulation and testing under P-T conditions within the stability field. Pressure core technology allows for the reliable characterization of hydrate bearing sediments within the stability field in order to address scientific and engineering needs, including the measurement of parameters used in hydro-thermo-mechanical analyses, and the monitoring of hydrate dissociation under controlled pressure, temperature, effective stress and chemical conditions. Inherent sampling effects remain and need to be addressed in test protocols and data interpretation. Pressure core technology has been deployed to study hydrate bearing sediments at several locations around the world. In addition to pressure core testing, a comprehensive characterization program should include sediment analysis, testing of reconstituted specimens (with and without synthetic hydrate), and in situ testing. Pressure core characterization technology can be used to study other gas-charged formations such as deep sea sediments, coal bed methane and gas shales.

  13. Influence of Casing Shoe Depth on Sustained Casing Pressure

    OpenAIRE

    2012-01-01

    In 2006 the Petroleum Safety Authority Norway (PSA) performed a well integrity survey. The survey indicated that about 20 % of wells on the Norwegian Continental shelf (NCS) may suffer from well integrity issues. Most of the problems were related to deficiency in annulus safety valve, tubing, cement and casing. Pressure build-up in annulus, i.e. sustained casing pressure, is one of the main indicators of a significant well integrity problem. Increased understanding on the field may help engin...

  14. Pressure ratio effects on self-similar scalar mixing of high-pressure turbulent jets in a pressurized volume

    Science.gov (United States)

    Ruggles, Adam; Pickett, Lyle; Frank, Jonathan

    2014-11-01

    Many real world combustion devices model fuel scalar mixing by assuming the self-similar argument established in atmospheric free jets. This allows simple prediction of the mean and rms fuel scalar fields to describe the mixing. This approach has been adopted in super critical liquid injections found in diesel engines where the liquid behaves as a dense fluid. The effect of pressure ratio (injection to ambient) when the ambient is greater than atmospheric pressure, upon the self-similar collapse has not been well characterized, particularly the effect upon mixing constants, jet spreading rates, and virtual origins. Changes in these self-similar parameters control the reproduction of the scalar mixing statistics. This experiment investigates the steady state mixing of high pressure ethylene jets in a pressurized pure nitrogen environment for various pressure ratios and jet orifice diameters. Quantitative laser Rayleigh scattering imaging was performed utilizing a calibration procedure to account for the pressure effects upon scattering interference within the high-pressure vessel.

  15. Physiological hydrostatic pressure protects endothelial monolayer integrity.

    Science.gov (United States)

    Müller-Marschhausen, K; Waschke, J; Drenckhahn, D

    2008-01-01

    Endothelial monolayer integrity is required to maintain endothelial barrier functions and has found to be impaired in several disorders like inflammatory edema, allergic shock, or artherosclerosis. Under physiologic conditions in vivo, endothelial cells are exposed to mechanical forces such as hydrostatic pressure, shear stress, and cyclic stretch. However, insight into the effects of hydrostatic pressure on endothelial cell biology is very limited at present. Therefore, in this study, we tested the hypothesis that physiological hydrostatic pressure protects endothelial monolayer integrity in vitro. We investigated the protective efficacy of hydrostatic pressure in microvascular myocardial endothelial (MyEnd) cells and macrovascular pulmonary artery endothelial cells (PAECs) by the application of selected pharmacological agents known to alter monolayer integrity in the absence or presence of hydrostatic pressure. In both endothelial cell lines, extracellular Ca(2+) depletion by EGTA was followed by a loss of vascular-endothelial cadherin (VE-caherin) immunostaining at cell junctions. However, hydrostatic pressure (15 cmH(2)O) blocked this effect of EGTA. Similarly, cytochalasin D-induced actin depolymerization and intercellular gap formation and cell detachment in response to the Ca(2+)/calmodulin antagonist trifluperazine (TFP) as well as thrombin-induced cell dissociation were also reduced by hydrostatic pressure. Moreover, hydrostatic pressure significantly reduced the loss of VE-cadherin-mediated adhesion in response to EGTA, cytochalasin D, and TFP in MyEnd cells as determined by laser tweezer trapping using VE-cadherin-coated microbeads. In caveolin-1-deficient MyEnd cells, which lack caveolae, hydrostatic pressure did not protect monolayer integrity compromised by EGTA, indicating that caveolae-dependent mechanisms are involved in hydrostatic pressure sensing and signaling.

  16. How can horizontal wells help in naturally fractured reservoir characterization?

    Energy Technology Data Exchange (ETDEWEB)

    Mazouzi, A.; Deghmoum, A.; Azzouguen, A. [Sonatrach Inc., Hydra (Algeria); Oudjida, A. [Anadarko Inc., (Algeria)

    2000-11-01

    Two successfully drilled horizontal gas wells in the Tin Fouye Tabankort (TFT) fractured reservoir in Algeria were described. The productivity index of horizontal wells compared to vertical wells depends on the pay zone height, vertical anisotropy, lateral anisotropy, the length of the horizontal drain and the amplitude of the damaged zone. Transient tests in horizontal wells can solve the problem of quantifying the vertical and lateral anisotropies. Horizontal wells also minimize the turbulence effects in the vicinity of the wellbore, particularly in gas wells. The two horizontal wells in the TFT reservoir provide an important gas flow rate. The productivity index for each well is triple that of a vertical well. The permeability tensor on the TFT reservoir is established on the basis of transient test reconstitution using numerical simulation. The vertical permeability yields the best match for pressure response. It can be shown as a translation effect in time at the beginning of the linear flow regime. The horizontal anisotropy reacts to the translation of pressure and its derivative in the vertical direction. The configuration of the reservoir shows a high lateral anisotropy with regards to permeability. The vertical permeability can be considered as the composite permeability of both the matrix and fractures. Numerical and laboratory studies show that low permeability is due to fracture opening. Therefore, fracture doesn't necessarily enhance permeability. 8 refs., 3 tabs., 13 figs.

  17. Mathematical Modelling of Silica Scaling Deposition in Geothermal Wells

    Science.gov (United States)

    Nizami, M.; Sutopo

    2016-09-01

    Silica scaling is widely encountered in geothermal wells in which produce two-phase geothermal fluid. Silica scaling could be formed due to chemical reacting by mixing a geothermal fluid with other geothermal fluid in different compositions, or also can be caused by changes in fluid properties due to changes pressure and temperature. One of method to overcome silica scaling which is occurred around geothermal well is by workover operation. Modelling of silica deposition in porous medium has been modeled in previously. However, the growth of silica scaling deposition in geothermal wells has never been modeled. Modelling of silica deposition through geothermal is important aspects to determine depth of silica scaling growth and best placing for workover device to clean silica scaling. This study is attempted to develop mathematical models for predicting silica scaling through geothermal wells. The mathematical model is developed by integrating the solubility-temperature correlation and two-phase pressure drop coupled wellbore fluid temperature correlation in a production well. The coupled model of two-phase pressure drop and wellbore fluid temperature correlation which is used in this paper is Hasan-Kabir correlation. This modelling is divided into two categories: single and two phase fluid model. Modelling of silica deposition is constrained in temperature distribution effect through geothermal wells by solubility correlation for silica. The results of this study are visualizing the growth of silica scaling thickness through geothermal wells in each segment of depth. Sensitivity analysis is applied in several parameters, such as: bottom-hole pressure, temperature, and silica concentrations. Temperature is most impact factor for silica scaling through geothermal wellbore and depth of flash point. In flash point, silica scaling thickness has reached maximum because reducing of mole in liquid portion.

  18. A graphene-based resistive pressure sensor with record-high sensitivity in a wide pressure range.

    Science.gov (United States)

    Tian, He; Shu, Yi; Wang, Xue-Feng; Mohammad, Mohammad Ali; Bie, Zhi; Xie, Qian-Yi; Li, Cheng; Mi, Wen-Tian; Yang, Yi; Ren, Tian-Ling

    2015-02-27

    Pressure sensors are a key component in electronic skin (e-skin) sensing systems. Most reported resistive pressure sensors have a high sensitivity at low pressures (pressures (>5 kPa), which is inadequate for practical applications. For example, actions like a gentle touch and object manipulation have pressures below 10 kPa, and 10-100 kPa, respectively. Maintaining a high sensitivity in a wide pressure range is in great demand. Here, a flexible, wide range and ultra-sensitive resistive pressure sensor with a foam-like structure based on laser-scribed graphene (LSG) is demonstrated. Benefitting from the large spacing between graphene layers and the unique v-shaped microstructure of the LSG, the sensitivity of the pressure sensor is as high as 0.96 kPa(-1) in a wide pressure range (0 ~ 50 kPa). Considering both sensitivity and pressure sensing range, the pressure sensor developed in this work is the best among all reported pressure sensors to date. A model of the LSG pressure sensor is also established, which agrees well with the experimental results. This work indicates that laser scribed flexible graphene pressure sensors could be widely used for artificial e-skin, medical-sensing, bio-sensing and many other areas.

  19. Pressurized Lunar Rover (PLR)

    Science.gov (United States)

    Creel, Kenneth; Frampton, Jeffrey; Honaker, David; McClure, Kerry; Zeinali, Mazyar; Bhardwaj, Manoj; Bulsara, Vatsal; Kokan, David; Shariff, Shaun; Svarverud, Eric

    The objective of this project was to design a manned pressurized lunar rover (PLR) for long-range transportation and for exploration of the lunar surface. The vehicle must be capable of operating on a 14-day mission, traveling within a radius of 500 km during a lunar day or within a 50-km radius during a lunar night. The vehicle must accommodate a nominal crew of four, support two 28-hour EVA's, and in case of emergency, support a crew of six when near the lunar base. A nominal speed of ten km/hr and capability of towing a trailer with a mass of two mt are required. Two preliminary designs have been developed by two independent student teams. The PLR 1 design proposes a seven meter long cylindrical main vehicle and a trailer which houses the power and heat rejection systems. The main vehicle carries the astronauts, life support systems, navigation and communication systems, lighting, robotic arms, tools, and equipment for exploratory experiments. The rover uses a simple mobility system with six wheels on the main vehicle and two on the trailer. The nonpressurized trailer contains a modular radioisotope thermoelectric generator (RTG) supplying 6.5 kW continuous power. A secondary energy storage for short-term peak power needs is provided by a bank of lithium-sulfur dioxide batteries. The life support system is partly a regenerative system with air and hygiene water being recycled. A layer of water inside the composite shell surrounds the command center allowing the center to be used as a safe haven during solar flares. The PLR 1 has a total mass of 6197 kg. It has a top speed of 18 km/hr and is capable of towing three metric tons, in addition to the RTG trailer. The PLR 2 configuration consists of two four-meter diameter, cylindrical hulls which are passively connected by a flexible passageway, resulting in the overall vehicle length of 11 m. The vehicle is driven by eight independently suspended wheels. The dual-cylinder concept allows articulated as well as double

  20. Why Mathematics Works So Well

    CERN Document Server

    Yanofsky, Noson S

    2015-01-01

    A major question in philosophy of science involves the unreasonable effectiveness of mathematics in physics. Why should mathematics, created or discovered, with nothing empirical in mind be so perfectly suited to describe the laws of the physical universe? We review the well-known fact that the symmetries of the laws of physics are their defining properties. We show that there are similar symmetries of mathematical facts and that these symmetries are the defining properties of mathematics. By examining the symmetries of physics and mathematics, we show that the effectiveness is actually quite reasonable. In essence, we show that the regularities of physics are a subset of the regularities of mathematics.

  1. Quantum Wells in Photovoltaic Cells

    CERN Document Server

    Rohr, C; Ballard, I M; Bushnell, D B; Connolly, J P; Daukes, N J Ekins-; Barnham, K W J

    2016-01-01

    The fundamental efficiency limit of a single bandgap solar cell is about 31% at one sun with a bandgap of about Eg = 1.35 eV (1), determined by the trade-off of maximising current with a smaller bandgap and voltage with a larger bandgap. Multiple bandgaps can be introduced to absorb the broad solar spectrum more efficiently. This can be realised in multi- junction cells, for example, where two or more cells are stacked on top of each other either mechanically or monolithically connected by a tunnel junction. An alternative or complementary (see section 1.4) approach is the quantum well cell (QWC).

  2. Recommended reference materials for realization of physicochemical properties pressure-volume-temperature relationships

    CERN Document Server

    Herington, E F G

    1977-01-01

    Recommended Reference Materials for Realization of Physicochemical Properties presents recommendations of reference materials for use in measurements involving physicochemical properties, namely, vapor pressure; liquid-vapor critical temperature and critical pressure; orthobaric volumes of liquid and vapor; pressure-volume-temperature properties of the unsaturated vapor or gas; and pressure-volume-temperature properties of the compressed liquid. This monograph focuses on reference materials for vapor pressures at temperatures up to 770 K, as well as critical temperatures and critical pressures

  3. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... the NHLBI on Twitter. Diagnosis of High Blood Pressure For most patients, health care providers diagnose high ... 140/90 mmHg or above. Confirming High Blood Pressure A blood pressure test is easy and painless ...

  4. Helping Teens Resist Sexual Pressure

    Science.gov (United States)

    ... Size Email Print Share Helping Teens Resist Sexual Pressure Page Content Article Body Teens are more likely ... time they had intercourse. Helping Teens Resist Sexual Pressure “The pressure on teenagers to have sex is ...

  5. Prevention of High Blood Pressure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Prevention of High Blood Pressure Healthy lifestyle habits, proper use of medicines, and ... prevent high blood pressure or its complications. Preventing High Blood Pressure Onset Healthy lifestyle habits can help prevent high ...

  6. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... providers diagnose high blood pressure when blood pressure readings are consistently 140/90 mmHg or above. Confirming ... minutes before the test. To track blood pressure readings over a period of time, the health care ...

  7. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... Blood Pressure » Diagnosis of High Blood Pressure Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living With Clinical ...

  8. Excitons in asymmetric quantum wells

    Science.gov (United States)

    Grigoryev, P. S.; Kurdyubov, A. S.; Kuznetsova, M. S.; Ignatiev, I. V.; Efimov, Yu. P.; Eliseev, S. A.; Petrov, V. V.; Lovtcius, V. A.; Shapochkin, P. Yu.

    2016-09-01

    Resonance dielectric response of excitons is studied for the high-quality InGaAs/GaAs heterostructures with wide asymmetric quantum wells (QWs). To highlight effects of the QW asymmetry, we have grown and studied several heterostructures with nominally square QWs as well as with triangle-like QWs. Several quantum confined exciton states are experimentally observed as narrow exciton resonances. A standard approach for the phenomenological analysis of the profiles is generalized by introducing different phase shifts for the light waves reflected from the QWs at different exciton resonances. Good agreement of the phenomenological fit to the experimentally observed exciton spectra for high-quality structures allowed us to reliably obtain parameters of the exciton resonances: the exciton transition energies, the radiative broadenings, and the phase shifts. A direct numerical solution of the Schrödinger equation for the heavy-hole excitons in asymmetric QWs is used for microscopic modeling of the exciton resonances. Remarkable agreement with the experiment is achieved when the effect of indium segregation is taken into account. The segregation results in a modification of the potential profile, in particular, in an asymmetry of the nominally square QWs.

  9. Computer Security: Well fought, FP!

    CERN Multimedia

    Stefan Lueders, Computer Security Team

    2015-01-01

    We are used to spam and phishing emails. But at the end of last year, a very special email struck one of our colleagues in the FP Department.   An accountant was gently asked in an email from “Rolf.Heuer@cern.ch” to prepare a financial transaction - in the strictest confidence. A phone call from the beneficiary to the accountant was made in an attempt to support this request. Despite being instructed not to talk to anyone, the e-mail, the phone conversation and the circumstances were all so suspicious that our colleague consulted his hierarchy, the internal audit service and us. Well done, FP Department! This is a rare case of an attempt at “social engineering”, i.e. luring someone into doing something detrimental to the Organization. The e-mail was fake. While it appeared to come from “Rolf.Heuer@cern.ch”, it actually came from an alleged fraudster outside CERN. The e-mail and the phone call showed that he was well prepared and dire...

  10. Pure component vapor pressures of organic isomers

    Science.gov (United States)

    Dang, Caroline; Bannan, Thomas; Topping, David

    2017-04-01

    Atmospheric aerosols affect the Earth's climate directly through light scattering and absorption as well as indirectly by affecting cloud formation. There are many unanswered questions about how material properties of organic aerosols affect the climate. Predicting the formation of secondary organic aerosol (SOA), arising from gas to particle partitioning of potentially millions of compounds, remains one of the most challenging aspects in this regards. Of particular importance on predicting SOA formation is the saturation vapor pressure of each component. This property is typically obtained from group contribution methods (GCMs). However, it is currently unclear as to what level of accuracy is required or attainable from such techniques. Researchers have recently been able to measure low vapor pressures (lower limit of 10-8 Pa) experimentally using various techniques, and the University of Manchester Knudsen Effusion Mass Spectrometer (KEMS) has previously been used to measure vapor pressure of low volatility organics. Our recent KEMS work shows that functional group positioning has an effect on vapor pressure that is not accurately captured with estimation methods, and that experimental vapor pressures are 1-4 orders of magnitudes lower than predictive techniques. This has atmospheric impact through the variable amount of organic aerosol that is predicted to condense. In this study we present new measurements from the KEMS that can then be used to refine different experimental vapor pressure techniques as well as to provide data sets for building regression models to improve current predictive techniques.

  11. Pressure Effect on Entrance Flow

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Couch, Mark

    1997-01-01

    The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts.......The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts....

  12. Pressure Effect on Entrance Flow

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Couch, Mark

    1997-01-01

    The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts.......The paper reports on experimentally determined pressure drops associated with orifice and capillary dies, where the exit pressure is elevated. The effect of hydrostatic pressure up to 70 MPa is reported for PS, LDPE and PP melts....

  13. Response of wells producing layered reservoirs: Unequal fracture length

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, R.G.; Raghavan, R.; Reynolds, A.C.

    1987-03-01

    The response of fractured wells producing noncommunicating layered reservoirs is the focus of this work. The conductivity of the fracture is assumed to be finite. The fracture length is assumed to vary from layer to layer. Two modes of production - constant wellbore pressure and constant rate - are considered. In the first part, the fractures are assumed to communicate only at the wellbore. The results given in this section are intended to provide engineers with analytical capabilities to examine responses in wells where the layers that have been stimulated are separated by considerable distances. Procedures to interpret the results of pressure buildup and/or production tests (drawdown responses) in terms of layer properties are presented. Criteria to ensure maximum productivity are specified. The second part examines well responses when the fractures are in communication at points other than the wellbore. All other things being identical, we show that communication between fractures increases productivity.

  14. Response of wells producing layered reservoirs: Unequal fracture length

    Energy Technology Data Exchange (ETDEWEB)

    Camacho-V., R.G.; Raghavan, R.; Reynolds, A.C.

    1984-05-01

    The response of fractured wells producing noncommunicating layered reservoirs is the focus of this work. The conductivity of the fracture is assumed to be finite. The fracture length is assumed to vary from layer to layer. Two modes of production--constant wellbore pressure and constant rate--are considered. In the first part of this work the fractures are assumed to communicate only at the wellbore. The results given in this section are intended to provide engineers with analytical capabilities to examine responses in wells where the layers that have been stimulated are separated by considerable distances. Procedures to interpret the results of pressure buildup and/or production tests (drawdown responses) in terms of layer properties are presented. Criteria to ensure maximum productivity are specified. The second part of this work examines well responses when the fractures are in communication at points other than the wellbore. All other things being identical, the authors show that communication between fractures increases productivity.

  15. Effect of ground stress on hydraulic fracturing of methane well

    Institute of Scientific and Technical Information of China (English)

    DU Chun-zhi; MAO Xian-biao; MIAO Xie-xing; WANG Peng

    2008-01-01

    Most of the coal reservoirs in China are of low-permeability, so hydraulic fracturing is widely used to improve the permeability in the extraction of gas by ground drilling. The ground stress around the well was analyzed by using theory of elasticity. The pressure when the well fractured is formulated and the effect of ground stress on pressure is discussed. The effect of ground-stress-differences on hydraulic fracturing was analyzed by using the numerical software RFPA2D-Flow in reference to the tectonic stress in Jincheng coal area. The results show that: 1) the position where initial fracture appears is random and fracture branches emerge when the fractures expand if ground stresses in any two directions within a horizontal plane are equal; 2) otherwise, the fractures expand in general along the direction of maximum ground stress and the critical pressure decreases with increasing ground-stress-differences and 3) the preferred well-disposition pattern is diamond shaped. The preferred well spacing is 250 m×300 m. This study can provide a reference for the design of wells.

  16. Ultra Thin Quantum Well Materials

    Energy Technology Data Exchange (ETDEWEB)

    Dr Saeid Ghamaty

    2012-08-16

    This project has enabled Hi-Z technology Inc. (Hi-Z) to understand how to improve the thermoelectric properties of Si/SiGe Quantum Well Thermoelectric Materials. The research that was completed under this project has enabled Hi-Z Technology, Inc. (Hi-Z) to satisfy the project goal to understand how to improve thermoelectric conversion efficiency and reduce costs by fabricating ultra thin Si/SiGe quantum well (QW) materials and measuring their properties. In addition, Hi-Z gained critical new understanding on how thin film fabrication increases the silicon substrate's electrical conductivity, which is important new knowledge to develop critical material fabrication parameters. QW materials are constructed with alternate layers of an electrical conductor, SiGe and an electrical insulator, Si. Film thicknesses were varied, ranging from 2nm to 10nm where 10 nm was the original film thickness prior to this work. The optimum performance was determined at a Si and SiGe thickness of 4nm for an electrical current and heat flow parallel to the films, which was an important conclusion of this work. Essential new information was obtained on how the Si substrate electrical conductivity increases by up to an order of magnitude upon deposition of QW films. Test measurements and calculations are accurate and include both the quantum well and the substrate. The large increase in substrate electrical conductivity means that a larger portion of the electrical current passes through the substrate. The silicon substrate's increased electrical conductivity is due to inherent impurities and thermal donors which are activated during both molecular beam epitaxy and sputtering deposition of QW materials. Hi-Z's forward looking cost estimations based on future high performance QW modules, in which the best Seebeck coefficient and electrical resistivity are taken from separate samples predict that the electricity cost produced with a QW module could be achieved at <$0.35/W

  17. Well Monitoring System For EGS

    Energy Technology Data Exchange (ETDEWEB)

    Normann, Randy [Perma Works LLC, Pattonville, TX (United States); Glowka, Dave [Perma Works LLC, Pattonville, TX (United States); Normann, Charles [Perma Works LLC, Pattonville, TX (United States); Parker, James [Electrochemical Systems Inc, Knoxville, TN (United States); Caja, Josip [Electrochemical Systems Inc, Knoxville, TN (United States); Dustan, Don [Electrochemical Systems Inc, Knoxville, TN (United States); Caja, Mario [Electrochemical Systems Inc, Knoxville, TN (United States); Sariri, Kouros [Frequency Management Int. Inc., Huntington Beach, CA (United States); Beal, Craig [MajiQ Technologies Inc., Somerville, MA (United States)

    2017-02-26

    This grant is a collection of projects designed to move aircraft high temperature electronics technology into the geothermal industry. Randy Normann is the lead. He licensed the HT83SNL00 chip from Sandia National Labs. This chip enables aircraft developed electronics for work within a geothermal well logging tool. However, additional elements are needed to achieve commercially successful logging tools. These elements are offered by a strong list of industrial partners on this grant as: Electrochemical Systems Inc. for HT Rechargeable Batteries, Frequency Management Systems for 300C digital clock, Sandia National Labs for experts in high temperature solder, Honeywell Solid-State Electronics Center for reprogrammable high temperature memory. During the course of this project MagiQ Technologies for high temperature fiber optics.

  18. Biomedical wellness challenges and opportunities

    Science.gov (United States)

    Tangney, John F.

    2012-06-01

    The mission of ONR's Human and Bioengineered Systems Division is to direct, plan, foster, and encourage Science and Technology in cognitive science, computational neuroscience, bioscience and bio-mimetic technology, social/organizational science, training, human factors, and decision making as related to future Naval needs. This paper highlights current programs that contribute to future biomedical wellness needs in context of humanitarian assistance and disaster relief. ONR supports fundamental research and related technology demonstrations in several related areas, including biometrics and human activity recognition; cognitive sciences; computational neurosciences and bio-robotics; human factors, organizational design and decision research; social, cultural and behavioral modeling; and training, education and human performance. In context of a possible future with automated casualty evacuation, elements of current science and technology programs are illustrated.

  19. Dietary fiber and blood pressure control.

    Science.gov (United States)

    Aleixandre, A; Miguel, M

    2016-04-01

    In the past few years, new strategies to control blood pressure levels are emerging by developing new bioactive components of foods. Fiber has been linked to the prevention of a number of cardiovascular diseases and disorders. β-Glucan, the main soluble fiber component in oat grains, was initially linked to a reduction in plasma cholesterol. Several studies have shown afterward that dietary fiber may also improve glycaemia, insulin resistance and weight loss. The effect of dietary fiber on arterial blood pressure has been the subject of far fewer studies than its effect on the above-mentioned variables, but research has already shown that fiber intake can decrease arterial blood pressure in hypertensive rats. Moreover, certain fibers can improve arterial blood pressure when administered to hypertensive and pre-hypertensive subjects. The present review summarizes all those studies which attempt to establish the antihypertensive effects of dietary fiber, as well as its effect on other cardiovascular risk factors.

  20. Micromachined pressure sensors: Review and recent developments

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, W.P.; Smith, J.H. [Sandia National Labs., Albuquerque, NM (United States). Intelligent Micromachines Dept.

    1997-03-01

    Since the discovery of piezoresistivity in silicon in the mid 1950s, silicon-based pressure sensors have been widely produced. Micromachining technology has greatly benefited from the success of the integrated circuits industry, burrowing materials, processes, and toolsets. Because of this, microelectromechanical systems (MEMS) are now poised to capture large segments of existing sensor markets and to catalyze the development of new markets. Given the emerging importance of MEMS, it is instructive to review the history of micromachined pressure sensors, and to examine new developments in the field. Pressure sensors will be the focus of this paper, starting from metal diaphragm sensors with bonded silicon strain gauges, and moving to present developments of surface-micromachined, optical, resonant, and smart pressure sensors. Considerations for diaphragm design will be discussed in detail, as well as additional considerations for capacitive and piezoresistive devices.

  1. Cold pressure welding - the mechanisms governing bonding

    DEFF Research Database (Denmark)

    Bay, Niels

    1979-01-01

    Investigations of the bonding surface in scanning electron microscope after fracture confirm the mechanisms of bond formation in cold pressure welding to be: fracture of work-hardened surface layer, surface expansion increasing the area of virgin surface, extrusion of virgin material through cracks...... of the original surface layer, and establishment of real contact and bonding between virgin material. This implies that normal pressure as well as surface expansion are basic parameters governing the bond strength. Experimental investigations of pressure welding Al-Al under plane strain compression in a specially...... developed equipment allowing independent variation of normal pressure and surface expansion confirm this. Based upon a slip-line analysis of the extrusion through cracks of the surface layer and upon the establishment of real contact between virgin material, a theory for the bond strength as a function...

  2. Effects of pressure-shift freezing and pressure-assisted thawing on sea bass (Dicentrarchus labrax) quality.

    Science.gov (United States)

    Tironi, V; LeBail, A; de Lamballerie, M

    2007-09-01

    Effects of pressure-shift freezing and/or pressure-assisted thawing on the quality of sea bass muscle were evaluated and compared with conventional (air-blast) frozen and thawed samples. Microstructural analysis showed a marked decrease of muscle cell damage for pressure-assisted frozen samples. According to differential scanning calorimetry (DSC), protein extractability, and SDS-PAGE results, high-pressure treatment (200 MPa) produced a partial denaturation with aggregation and insolubilization of the myosin, as well as alterations of the sarcoplasmic proteins. Only small differences between high-pressure processes (freezing or/and thawing) were registered. High-pressure-treated systems led to a decrease of water holding capacity but differences between high-pressure and conventional methods disappeared after cooking. Muscle color showed important alterations due to high-pressure treatments (increasing L* and b*).

  3. Preconditioning the pressure operator for the time dependent Stokes problem

    Energy Technology Data Exchange (ETDEWEB)

    Bramble, J.H.; Pasciak, J.E.

    1994-12-31

    In implicit time stepping procedures for the linearized Navier Stokes equations, a linear perturbed Stokes problem must be solved at each time step. Many methods for doing this require a good preconditioner for the resulting pressure operator (Schur complement). In contrast to the time independent Stokes equations where the pressure operator is well conditioned, the pressure operator for the perturbed system becomes more illconditioned as the time step is reduced (and/or the Reynolds number is increased). The authors describe the method for solving the coupled velocity/pressure systems and, in particular, show how to construct good preconditioners for the poorly conditioned pressure operator.

  4. Harmonics tracking of intracranial and arterial blood pressure waves.

    Science.gov (United States)

    Shahsavari, Sima; McKelvey, Tomas

    2008-01-01

    Considering cardiorespiratory interaction and heart rate variability, a new approach is proposed to decompose intracranial pressure and arterial blood pressure to their different harmonics. The method is based on tracking the amplitudes of the harmonics by a Kalman filter based tracking algorithm. The algorithm takes benefit of combined frequency estimation technique which uses both Fast Fourier Transform and RR-interval detection. The result would be of use in intracranial pressure and arterial blood pressure waveform analysis as well as other investigations which need to estimate contribution of specific harmonic in above mentioned signals such as Pressure-Volume Compensatory Reserve assessment.

  5. Functional Sub-states by High-pressure Macromolecular Crystallography.

    Science.gov (United States)

    Dhaussy, Anne-Claire; Girard, Eric

    2015-01-01

    At the molecular level, high-pressure perturbation is of particular interest for biological studies as it allows trapping conformational substates. Moreover, within the context of high-pressure adaptation of deep-sea organisms, it allows to decipher the molecular determinants of piezophily. To provide an accurate description of structural changes produced by pressure in a macromolecular system, developments have been made to adapt macromolecular crystallography to high-pressure studies. The present chapter is an overview of results obtained so far using high-pressure macromolecular techniques, from nucleic acids to virus capsid through monomeric as well as multimeric proteins.

  6. Compaction measurements on cores from the Pleasant Bayou wells

    Energy Technology Data Exchange (ETDEWEB)

    Jogi, P.N.; Gray, K.E.; Ashman, T.R.; Thompson, T.W.; Bebout, D.G.; Bachman, A.L. (eds.)

    1981-01-01

    Additional measurements of compressibility, compaction coefficients, porosities, permeabilities, and resistivities have been conducted on cores from Pleasant Bayou wells No. 1 and No. 2. All rock parameters show non-linear behavior with changing reservoir or pore pressure, which is of interest in modelling reservoir performance and subsidence. Compressibilities and uniaxial compaction coefficients decline by a factor of 2 to 3 as reservoir pressure declines from geopressured to normal hydrostatic conditions. Porosity reductions are 6 to 8% while permeability reductions are on the order of 10 to 30% over that reservoir pressure range. Measured formation factors were 2 to 4 times log derived values for F. Matrix compressibilities were not insignificant relative to bulk compressibilities.

  7. Magnetostrictive Pressure Regulating System

    Science.gov (United States)

    Richard, James A. (Inventor); Pickens, Herman L. (Inventor)

    2013-01-01

    A magnetostrictive pressure regulating system includes a magnetostrictive valve that incorporates a magnetostrictive actuator with at least one current-carrying coil disposed thereabout. A pressure force sensor, in fluid communication with the fluid exiting the valve, includes (i) a magnetostrictive material, (ii) a magnetic field generator in proximity to the magnetostrictive material for inducing a magnetic field in and surrounding the magnetostrictive material wherein lines of magnetic flux passing through the magnetostrictive material are defined, and (iii) a sensor positioned adjacent to the magnetostrictive material and in the magnetic field for measuring changes in at least one of flux angle and flux density when the magnetostrictive material experiences an applied force that is aligned with the lines of magnetic flux. The pressure of the fluid exiting the valve causes the applied force. A controller coupled to the sensor and to the current-carrying coil adjusts a current supplied to the current-carrying coil based on the changes so-measured.

  8. [Myth of optimal pressure].

    Science.gov (United States)

    van Leeuwen, E J; Maltha, J C

    2000-04-01

    Orthodontic tooth movement always follows the same pattern. Four phases can be distinguished. During the last phase, the linear phase, the tooth moves through the alveolar bone. One could assume that the rate of tooth displacement is related to the magnitude of the force or to the pressure in the periodontal ligament. No consensus exists on the optimal pressure for orthodontic tooth movement. In literature pressures are advocated, ranging from 2 to 30 KPa. Animal experiments show that a large range of force magnitudes results in an equal rate of tooth movement. A dose-response relation is only feasible when forces are used which are far below those used in an everyday practice.

  9. Decay of weak pressure waves in a low-pressure tube

    Energy Technology Data Exchange (ETDEWEB)

    Takiya, Toshio; Terada, Yukihiro; Komura, Akio [Hitachi Zosen Corp., Osaka (Japan); Higashino, Fumio; Abe, Hideaki; Ando, Masami

    1997-05-01

    In this study, the characteristics of pressure wave propagation in a vacuum tube have been investigated experimentally from the viewpoint of vacuum protection in the beamlines of a synchrotron radiation facility. Baffle plates having a single orifice of 5, 10 or 15 mm in diameter were installed in shock tubes 5 m in length and 36.6 or 68.8 mm in diameter, in order to slow the pressure wave or shock wave propagation, as a model for the beamline. To evaluate the decay of pressure waves, pressure changes with time at several locations along the side wall as well as at the end wall of the tube were measured. The results showed that the effect of the orifices on pressure wave propagation and its decay was significant. The present investigation may contribute to the design and construction of high-energy synchrotron radiation facilities with long beamlines. (author)

  10. Bridging the pressure gap: Can we get local quantitative structural information at 'near-ambient' pressures?

    Science.gov (United States)

    Woodruff, D. P.

    2016-10-01

    In recent years there have been an increasing number of investigations aimed at 'bridging the pressure gap' between UHV surface science experiments on well-characterised single crystal surfaces and the much higher (ambient and above) pressures relevant to practical catalyst applications. By applying existing photon-in/photon-out methods and developing instrumentation to allow photoelectron emission to be measured in higher-pressure sample environments, it has proved possible to obtain surface compositions and spectroscopic fingerprinting of chemical and molecular states of adsorbed species at pressures up to a few millibars. None of these methods, however, provide quantitative structural information on the local adsorption sites of isolated atomic and molecular adsorbate species under these higher-pressure reaction conditions. Methods for gaining this information are reviewed and evaluated.

  11. Spin photocurrents in quantum wells

    CERN Document Server

    Ganichev, S D

    2003-01-01

    Spin photocurrents generated by homogeneous optical excitation with circularly polarized radiation in quantum wells (QWs) are reviewed. The absorption of circularly polarized light results in optical spin orientation due to the transfer of the angular momentum of photons to electrons of a two-dimensional electron gas. It is shown that in QWs belonging to one of the gyrotropic crystal classes a non-equilibrium spin polarization of uniformly distributed electrons causes a directed motion of electrons in the plane of the QW. A characteristic feature of this electric current, which occurs in unbiased samples, is that it reverses its direction upon changing the radiation helicity from left-handed to right-handed and vice versa. Two microscopic mechanisms are responsible for the occurrence of an electric current linked to a uniform spin polarization in a QW: the spin polarization-induced circular photogalvanic effect and the spin-galvanic effect. In both effects the current flow is driven by an asymmetric distribut...

  12. Linking individual and organizational wellness.

    Science.gov (United States)

    Canosa, J F; Lewandowski, L M

    1993-09-01

    In addition to intervening when workers have substance abuse or stress problems, many hospital employee assistance programs (EAPs) now include a wellness component that emphasizes prevention and organizational wholeness. The EAP at St. Joseph's Hospital & Medical Center, Paterson, NJ, has taken a number of steps to improve its responsiveness to employees' needs and promote constructive organizational changes. To meet increasing requests for mental health services, St. Joseph's EAP implemented a short-term (up to 12 sessions) counseling program that focuses on problem-solving techniques. The EAP has also used feedback from clients to address organizational issues. For example, a survey that revealed differences between managers' and employees' perceptions of managers' leadership skills has led St. Joseph's to consider development of further workshops to train managers on how to be more effective leaders. And in response to complaints from nurses about a lack of communication with physicians, St. Joseph's invested $8,000 to implement nursing support groups and seminars to enhance nurse-physician collaboration. Additional EAP activities include consulting services for other corporations and help for employees in overcoming financial barriers to access to healthcare and social services. As budgets tighten, effective marketing of EAPs will be essential to their continued growth. In particular, EAP administrators must learn how to document the strategic and financial benefits of their programs.

  13. The Misunderstanding and New Nursing Progress of Pressure Ulcers

    Institute of Scientific and Technical Information of China (English)

    Zhaoxia XIE; Zhaohua LIU

    2015-01-01

    In recent years, many foreign and domestic scholars have made a further study on the risk factors, high-risk groups, prevention and nursing of pressure ulcers. For all reasons such as clinical nursing workers and managers, new progresses can' t be well applied, and simultaneously pressure ulcers are misunderstood to some extent. These conditions are not conducive to the prevention and nursing of pressure ulcers and the improvement of patients' life quality and nursing service quality. Therefore, it is necessary to keep away from the misunderstanding, know well new progresses and reduce the incidence of pressure ulcers.

  14. Wellbore pressure transducer

    Science.gov (United States)

    Shuck, Lowell Z.

    1979-01-01

    Subterranean earth formations containing energy values are subjected to hydraulic fracturing procedures to enhance the recovery of the energy values. These fractures are induced in the earth formation by pumping liquid into the wellbore penetrating the earth formation until the pressure of the liquid is sufficient to fracture the earth formation adjacent to the wellbore. The present invention is directed to a transducer which is positionable within the wellbore to generate a signal indicative of the fracture initiation useful for providing a timing signal to equipment for seismic mapping of the fracture as it occurs and for providing a measurement of the pressure at which the fracture is initiated.

  15. Transient pressure analysis in porous and fractured fractal reservoirs

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Fluid flow in porous and fractured fractal reservoirs is studied in the paper. The basic formulae of seepage velocity,permeability and porosity in both porous and fractured fractal media are developed. The pressure diffusion equation of slightly compressible fluid in fractal reservoirs is derived. The analytical solutions of the transient pressure are given for the line-source well and the well with well-bore storage and skin factor. The typical curves of pressure and the derivative of pressure are established,along with the interpretation of the well-testing method via type-curve matching. In addition,3-D pressure diffusion equations for anisotropic fractal media are given in both Cartesian coordinates and Cy-lindrical coordinates.

  16. Major influencing factors of water flooding in abnormally high-pressure carbonate reservoir

    Science.gov (United States)

    Qingying, Hou; Kaiyuan, Chen; Zifei, Fan; Libing, Fu; Yefei, Chen

    2017-01-01

    The higher pressure coefficient is the major characteristics of the abnormal high pressure carbonate reservoirs, which the pressure coefficient generally exceeds 1.2 and the initial formation pressure is higher than normal sandstone reservoirs. Due to the large pressure difference between initial formation and saturated pressure, oil wells are capable to production with high flow rate by the natural energy at early production stage. When the formation pressure drops to the saturation pressure, the water or gas is usually injected to stabilize the well productivity and sustain the formation pressure. Based on the characteristics of Kenkiak oilfield, a typical abnormal high pressure carbonate reservoir, a well group model is designed to simulate and analyze the influence factors on water flooding. The conclusion is that permeability, interlayer difference and reserve abundance are the main three factors on the water flooding development in these reservoirs.

  17. Straight-Line Conventional Transient Pressure Analysis for Horizontal Wells with Isolated Zones

    Directory of Open Access Journals (Sweden)

    Freddy Humberto Escobar

    2014-01-01

    Full Text Available Es común en la industria petrolera completar los pozos en forma selectiva. Incluso, dicha selección se efectúa de forma natural ya que la heterogeneidad del yacimiento podría causar comportamiento segmentado del pozo. La segmentación podría estar parcialmente abierto al flujo en virtud a la alto factor de daño bajas vetas de permeabilidad. Ellas pueden tratarse como una distribución no uniforme del factor de daño. Algunos pocos modelos se han introducido para capturar estos detalles especiales. Las metodologías de interpretación existentes usan análisis de regresión no lineal y la técnica TDS; pero, se adolece de ecuaciones para el método convencional. En este estudio se desarrolla la metodología convencional para la interpretación de pruebas de presión en pozos horizontales con zonas aisladas de modo que se puedan estimar las permeabilidades y los factores de daño. Las expresiones desarrolladas se probaron satisfactoriamente con varios problemas encontrados en la literatura y se compararon con los resultados procedentes de otras fuentes.

  18. How well can centenarians hear?

    Science.gov (United States)

    Mao, Zhongping; Zhao, Lijun; Pu, Lichun; Wang, Mingxiao; Zhang, Qian; He, David Z Z

    2013-01-01

    With advancements in modern medicine and significant improvements in life conditions in the past four decades, the elderly population is rapidly expanding. There is a growing number of those aged 100 years and older. While many changes in the human body occur with physiological aging, as many as 35% to 50% of the population aged 65 to 75 years have presbycusis. Presbycusis is a progressive sensorineural hearing loss that occurs as people get older. There are many studies of the prevalence of age-related hearing loss in the United States, Europe, and Asia. However, no audiological assessment of the population aged 100 years and older has been done. Therefore, it is not clear how well centenarians can hear. We measured middle ear impedance, pure-tone behavioral thresholds, and distortion-product otoacoustic emission from 74 centenarians living in the city of Shaoxing, China, to evaluate their middle and inner ear functions. We show that most centenarian listeners had an "As" type tympanogram, suggesting reduced static compliance of the tympanic membrane. Hearing threshold tests using pure-tone audiometry show that all centenarian subjects had varying degrees of hearing loss. More than 90% suffered from moderate to severe (41 to 80 dB) hearing loss below 2,000 Hz, and profound (>81 dB) hearing loss at 4,000 and 8,000 Hz. Otoacoustic emission, which is generated by the active process of cochlear outer hair cells, was undetectable in the majority of listeners. Our study shows the extent and severity of hearing loss in the centenarian population and represents the first audiological assessment of their middle and inner ear functions.

  19. How well can centenarians hear?

    Directory of Open Access Journals (Sweden)

    Zhongping Mao

    Full Text Available With advancements in modern medicine and significant improvements in life conditions in the past four decades, the elderly population is rapidly expanding. There is a growing number of those aged 100 years and older. While many changes in the human body occur with physiological aging, as many as 35% to 50% of the population aged 65 to 75 years have presbycusis. Presbycusis is a progressive sensorineural hearing loss that occurs as people get older. There are many studies of the prevalence of age-related hearing loss in the United States, Europe, and Asia. However, no audiological assessment of the population aged 100 years and older has been done. Therefore, it is not clear how well centenarians can hear. We measured middle ear impedance, pure-tone behavioral thresholds, and distortion-product otoacoustic emission from 74 centenarians living in the city of Shaoxing, China, to evaluate their middle and inner ear functions. We show that most centenarian listeners had an "As" type tympanogram, suggesting reduced static compliance of the tympanic membrane. Hearing threshold tests using pure-tone audiometry show that all centenarian subjects had varying degrees of hearing loss. More than 90% suffered from moderate to severe (41 to 80 dB hearing loss below 2,000 Hz, and profound (>81 dB hearing loss at 4,000 and 8,000 Hz. Otoacoustic emission, which is generated by the active process of cochlear outer hair cells, was undetectable in the majority of listeners. Our study shows the extent and severity of hearing loss in the centenarian population and represents the first audiological assessment of their middle and inner ear functions.

  20. Diagnostics of pressure ulcer risk and pressure ulcers

    OpenAIRE

    Kottner, Jan

    2011-01-01

    Pressure ulcers are serious health problems and they develop in every healthcare setting. Pressure ulcer risk scales aim to support practitioners in determining individual pressure ulcer risk and in starting preventive activities. Study results indicate validity problems inherent in pressure ulcer risk scale scores. Since risk scores are too imprecise for individual clinical decision making, it is questionable whether the standardized pressure ulcer risk assessments improve resident and patie...

  1. Diagnostics of pressure ulcer risk and pressure ulcers

    OpenAIRE

    Kottner, Jan

    2011-01-01

    Pressure ulcers are serious health problems and they develop in every healthcare setting. Pressure ulcer risk scales aim to support practitioners in determining individual pressure ulcer risk and in starting preventive activities. Study results indicate validity problems inherent in pressure ulcer risk scale scores. Since risk scores are too imprecise for individual clinical decision making, it is questionable whether the standardized pressure ulcer risk assessments improve resident and patie...

  2. Long and short term pump testing for landfill gas wells

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, D.W.; Fleming, I.R. [Saskatchewan Univ., Saskatoon, SK (Canada). Dept. of Civil and Geological Engineering

    2009-07-01

    A study was conducted to evaluate vertical well designs drilled into existing landfills as part of a landfill gas collection retrofitting project. Well designs and construction techniques were compared in relation to pneumatic efficiency and the capacity of each well. The aim of the study was to devise a method of evaluating well efficiency and long-term performance. Short-term, single well step-drawdown tests were conducted. Long-term pumping from the entire well field was conducted using different flow rate control approaches. Flow rates were measured at several different system pressures. Data were then compared with drawdown flow rate data from the short-term tests. The study proved that the single well short-term tests accurately predicted the long-term performance of the well field. The study also demonstrated that there was no apparent relationship between well productivity and the length of the screened zone, the diameter of the well, or the diameter of the borehole. No relationship was observed between well performance and the capital costs of individual wells.

  3. Effect of Interfacial Turbulence and Accommodation Coefficient on CFD Predictions of Pressurization and Pressure Control in Cryogenic Storage Tank

    Science.gov (United States)

    Kassemi, Mohammad; Kartuzova, Olga; Hylton, Sonya

    2015-01-01

    Laminar models agree closely with the pressure evolution and vapor phase temperature stratification but under-predict liquid temperatures. Turbulent SST k-w and k-e models under-predict the pressurization rate and extent of stratification in the vapor but represent liquid temperature distributions fairly well. These conclusions seem to equally apply to large cryogenic tank simulations as well as small scale simulant fluid pressurization cases. Appropriate turbulent models that represent both interfacial and bulk vapor phase turbulence with greater fidelity are needed. Application of LES models to the tank pressurization problem can serve as a starting point.

  4. Diagnosis of High Blood Pressure

    Medline Plus

    Full Text Available ... High Blood Pressure Explore High Blood Pressure What Is... Other Names Causes Who Is at Risk Signs & Symptoms Diagnosis Treatments Prevention Living ... Confirming High Blood Pressure A blood pressure test is easy and painless and can be done in ...

  5. Living with High Blood Pressure

    Science.gov (United States)

    ... page from the NHLBI on Twitter. Living With High Blood Pressure If you have high blood pressure, the best thing to do is to talk ... help you track your blood pressure. Pregnancy Planning High blood pressure can cause problems for mother and baby. High ...

  6. Pressurized Vessel Slurry Pumping

    Energy Technology Data Exchange (ETDEWEB)

    Pound, C.R.

    2001-09-17

    This report summarizes testing of an alternate ''pressurized vessel slurry pumping'' apparatus. The principle is similar to rural domestic water systems and ''acid eggs'' used in chemical laboratories in that material is extruded by displacement with compressed air.

  7. Pressure pain sensitivity

    DEFF Research Database (Denmark)

    Bergmann, Natasha; Ballegaard, Søren; Holmager, Pernille

    2013-01-01

    to induce hyperalgesia.The aim of the present study was to evaluate hyperalgesia by pressure pain sensitivity (PPS) in patients with IHD, and compare PPS to questionnaires measuring depressive symptoms, reduced psychological wellbeing, and QOL as markers of stress. Design. A cross-sectional study of 361...

  8. Pressure to perform

    National Research Council Canada - National Science Library

    Kirk, Peter A

    2011-01-01

    .... To further understand the dynamics of air pressure within your suit, take time to examine your suit's exhaust valves. Whether you are looking to purchase a new hazmat suit or donning an old favorite, understanding the dynamics of your suit should provide peace of mind, which is something every first responder deserves.

  9. Pressure simulation program

    NARCIS (Netherlands)

    Knoll, B.; Phaff, J.C.; Gids, W.F. de

    1995-01-01

    A computer program has been developed to predict the wind pressure coefficients Cp on facades and roofs of block shaped buildings. The program is based on fits of measured data, including wind shielding by obstacles and terrain roughness. Main advantages of the program are: it needs no expertise of

  10. Farmers Under Pressure

    DEFF Research Database (Denmark)

    Andrade, Stefan Bastholm; Anneberg, Inger

    2014-01-01

    of them face severe financial difficulties, divorce and psychiatric problems, which are connected to an increased risk of being convicted for the neglect of farm animals. The narratives bring forward themes of pressure related to financial trouble, technological break down, family problems, stress...

  11. GOLD PRESSURE VESSEL SEAL

    Science.gov (United States)

    Smith, A.E.

    1963-11-26

    An improved seal between the piston and die member of a piston-cylinder type pressure vessel is presented. A layer of gold, of sufficient thickness to provide an interference fit between the piston and die member, is plated on the contacting surface of at least one of the members. (AEC)

  12. Renal denervation: under pressure?

    NARCIS (Netherlands)

    de Jager, R.L.

    2017-01-01

    Worldwide, 871 million people suffers from hypertension (an office systolic blood pressure (BP) of ≥140 and/or diastolic BP ≥90 mmHg). Only 35% of the patients known with hypertension reaches guideline targets. The remaining 65% percent is defined as having resistant hypertension, in other words,

  13. PRESSURE-RESISTANT VESSEL

    NARCIS (Netherlands)

    Beukers, A.; De Jong, T.

    1997-01-01

    Abstract of WO 9717570 (A1) The invention is directed to a wheel-shaped pressure-resistant vessel for gaseous, liquid or liquefied material having a substantially rigid shape, said vessel comprising a substantially continuous shell of a fiber-reinforced resin having a central opening, an inner l

  14. Low Blood Pressure

    Science.gov (United States)

    ... Blood Pressure • Know Your Numbers • Understand Symptoms and Risks • Learn How HBP Can Harm Your Health • Make Changes That Matter • Find Tools & Resources Watch, Learn and Live Our Interactive Cardiovascular Library has detailed animations and illustrations to help you ...

  15. Blood pressure and atherosclerosis

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    2010319 Effects of combined application of Xuezhikang capsule with hypotensive drugs on arterial compliance and smoothness of the dynamic blood pressure. ZHU Zongtao(朱宗涛),et al. Dept Cardiol, Centr People’s Hosp, Tengzhou 277500.Chin J Integr Tradit & West Med 2010;30

  16. Conservative Pressures on Curriculum.

    Science.gov (United States)

    Bryson, Joseph E.

    Pressure on the public schools is coming from conservative New Right religious-political groups. Their concerns focus on: (1) secular humanism--a Godless form of religion that the public schools are alleged to be teaching; (2) scientific evolution versus creationism--the balanced treatment statute; (3) Bible clubs and prayer in the classroom; and…

  17. Peer Pressure--Beyond Rhetoric to Reality

    Science.gov (United States)

    Maxwell, Claire; Chase, Elaine

    2008-01-01

    Internationally, as well as here in the UK, the concept of "peer pressure" is widely used in analysing the factors influencing young people's experiences of sex and pregnancy--illustrated, for instance, by the following strapline from a recent English government-funded teenage pregnancy national media campaign: "Should I let my…

  18. Peer Pressure--Beyond Rhetoric to Reality

    Science.gov (United States)

    Maxwell, Claire; Chase, Elaine

    2008-01-01

    Internationally, as well as here in the UK, the concept of "peer pressure" is widely used in analysing the factors influencing young people's experiences of sex and pregnancy--illustrated, for instance, by the following strapline from a recent English government-funded teenage pregnancy national media campaign: "Should I let my…

  19. Abnormal pressures as hydrodynamic phenomena

    Science.gov (United States)

    Neuzil, C.E.

    1995-01-01

    So-called abnormal pressures, subsurface fluid pressures significantly higher or lower than hydrostatic, have excited speculation about their origin since subsurface exploration first encountered them. Two distinct conceptual models for abnormal pressures have gained currency among earth scientists. The static model sees abnormal pressures generally as relict features preserved by a virtual absence of fluid flow over geologic time. The hydrodynamic model instead envisions abnormal pressures as phenomena in which flow usually plays an important role. This paper develops the theoretical framework for abnormal pressures as hydrodynamic phenomena, shows that it explains the manifold occurrences of abnormal pressures, and examines the implications of this approach. -from Author

  20. Electrical heating of well bore area in wells of Uzbekistan oil region

    Energy Technology Data Exchange (ETDEWEB)

    Alidzhanov, G.A.; Osmanov, M.T.; Simkin, E.M.; Sheinman, A.B.

    1966-11-01

    The productivity of many wells in the Fergan area, Uzbekistan, decreased to 1/6 of initial value in the first year of production. Stimulation with hot gasoline or acid was only moderately successful. Best results were obtained by installing an electrical heater opposite the pay zone. In a typical case, well No. 464 (562 m deep) was completed in 1962 with an initial production of 10 tons/day. After 4 acid treatments, production was 2.5 tons/day in 1964, bottomhole temperature was 33$C, and pressure was 20 kg/cmU2D. A 10.5-kw electric heater was used for 3 days to raise bottomhole temperature to 52$C. Production increased to 3.5 tons/day and remained at that level for a month. In a second treatment a 21-kw heater increased bottomhole temperature to 120$C, whereupon production increased to 4.3 tons/day, and remained at that level for 3.5 months. Similar results were obtained in many other wells. Electrical method of stimulation is more economical than other methods in this area.

  1. Crystal structures at high pressures and temperatures

    Science.gov (United States)

    Caldwell, Wendel Alexander

    2000-10-01

    The diamond anvil cell (DAC) is a unique instrument that can generate pressures equivalent to those inside planetary interiors (pressures on the order of 1 million atmospheres) under sustained conditions. When combined with a bright source of collimated x-rays, the DAC can be used to probe the structure of materials in-situ at ultra-high pressures. An understanding of the high-pressure structure of materials is important in determining what types of processes may take place in the Earth at great depths. Motivated by previous studies showing that xenon becomes metallic at pressures above ˜1 megabar (100 GPa), we examined the stable structures and reactivity of xenon at pressures approaching that of the core-mantle boundary in the Earth. Our findings indicate the transformation of xenon from face-centered cubic (fcc) to hexagonal close-packed (hcp) structures is kinetically hindered at room temperature, with the equilibrium fcc--hcp phase boundary at 21 (+/-3) gigapascals, a pressure lower than was previously thought. Additionally, we find no tendency on the part of xenon to form a metal alloy with iron or platinum to at least 100 to 150 gigapascals, making it unlikely that the Earth's core serves as a reservoir for primordial xenon. Measurements of the compressibility of natural (Mg.75,Fe .25)2SiO4 gamma-spinel at pressures of the Earth's transition zone yield a pressure derivative of the bulk modulus K0 ' = 6.3 (+/-0.3). As gamma-spinel is considered to be a dominant mineral phase of the transition-zone of the Earth's mantle (400--670 km depth), the relatively high value of K0' for gamma-spinel may help explain the rapid increase with depth of seismic velocities through the transition zone. The thermodynamics, mechanisms and kinetics of pressure-induced amorphization are not well understood. We report here new studies indicating little or no entropy difference between the crystalline and glassy states of Ca(OH) 2 (portlandite). Additional work on the pressure

  2. Enhanced Expectancies Improve Performance Under Pressure

    OpenAIRE

    McKay, Brad; Lewthwaite, Rebecca; Wulf,Gabriele

    2012-01-01

    Beyond skill, beliefs in requisite abilities and expectations can affect performance. This experiment examined effects of induced perceptions of ability to perform well under generic situations of challenge. Participants (N = 31) first completed one block of 20 trials on a throwing accuracy task. They then completed questionnaires ostensibly measuring individual differences in the ability to perform under pressure. Enhanced-expectancy group participants were told that they were well-suited to...

  3. Pressurized burner test facility

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, D.J.; Norton, T.S.; Hadley, M.A.

    1993-09-01

    The US Department of Energy`s METC has recently completed construction and commissioning of a new high-pressure combustion research facility. Utilities servicing the facility enable combustion tests at scales up to 3 MW (10 MM Btu/h) and pressures in excess of 3000 kPa (30 atm). These include a preheated, high-pressure air supply that can deliver up to 1.7 kg/s (3.7 lbs/s) of combustion air, and a high-pressure, natural gas compressor that can deliver 0.8 kg/s (.19 lbs/s). In the summer of 1994 METC`s syngas generator is scheduled to come on line, at which time combustion tests on a range of fuel gases from low to medium to high heating values will be possible. The syngas generator will simulate a range of fuel gas compositions characteristic of coal gasification product streams. As part of the combustion facility, a high-pressure burner test facility is currently being constructed to support the development of gas turbine combustion systems fired on natural gas and coal-derived gaseous fuels containing fuel-bound nitrogen. The facility, illustrated in Figure 1, is a 61-centimeter (24-inch) diameter, refractory-lined vessel of modular construction, offering the flexibility to test a variety of NO{sub x} control concepts. Burner test modules are sandwiched between gas inlet and sampling plenums with a maximum combustion test zone of 2.2 m (90 inches) in length. Modules are custom designed for specific burners.

  4. Effects of interface pressure distribution on human sleep quality.

    Directory of Open Access Journals (Sweden)

    Zongyong Chen

    Full Text Available High sleep quality promotes efficient performance in the following day. Sleep quality is influenced by environmental factors, such as temperature, light, sound and smell. Here, we investigated whether differences in the interface pressure distribution on healthy individuals during sleep influenced sleep quality. We defined four types of pressure models by differences in the area distribution and the subjective feelings that occurred when participants slept on the mattresses. One type of model was showed "over-concentrated" distribution of pressure; one was displayed "over-evenly" distributed interface pressure while the other two models were displayed intermediate distribution of pressure. A polysomnography analysis demonstrated an increase in duration and proportion of non-rapid-eye-movement sleep stages 3 and 4, as well as decreased number of micro-arousals, in subjects sleeping on models with pressure intermediately distributed compared to models with over-concentrated or over-even distribution of pressure. Similarly, higher scores of self-reported sleep quality were obtained in subjects sleeping on the two models with intermediate pressure distribution. Thus, pressure distribution, at least to some degree, influences sleep quality and self-reported feelings of sleep-related events, though the underlying mechanisms remain unknown. The regulation of pressure models imposed by external sleep environment may be a new direction for improving sleep quality. Only an appropriate interface pressure distribution is beneficial for improving sleep quality, over-concentrated or -even distribution of pressure do not help for good sleep.

  5. Fuzzy control applied to nuclear power plant pressurizer system

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Mauro V.; Almeida, Jose C.S., E-mail: mvitor@ien.gov.b, E-mail: jcsa@ien.gov.b [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2011-07-01

    In a pressurized water reactor (PWR) nuclear power plants (NPPs) the pressure control in the primary loop is very important for keeping the reactor in a safety condition and improve the generation process efficiency. The main component responsible for this task is the pressurizer. The pressurizer pressure control system (PPCS) utilizes heaters and spray valves to maintain the pressure within an operating band during steady state conditions, and limits the pressure changes, during transient conditions. Relief and safety valves provide overpressure protection for the reactor coolant system (RCS) to ensure system integrity. Various protective reactor trips are generated if the system parameters exceed safe bounds. Historically, a proportional-integral derivative (PID) controller is used in PWRs to keep the pressure in the set point, during those operation conditions. The purpose of this study has two main goals: first is to develop a pressurizer model based on artificial neural networks (ANNs); second is to develop a fuzzy controller for the PWR pressurizer pressure, and compare its performance with the P controller. Data from a simulator PWR plant was used to test the ANN and the controllers as well. The reference simulator is a Westinghouse 3-loop PWR plant with a total thermal output of 2785 MWth. The simulation results show that the pressurizer ANN model response are in reasonable agreement with the simulated power plant, and the fuzzy controller built in this study has better performance compared to the P controller. (author)

  6. Semilog analysis of gas well drawdown and buildup data

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, A.C.; Bratvold, R.G.; Ding, W.

    1985-03-01

    The pseudo-pressure function is well understood and widely used for analyzing gas well drawdown and buildup data. The utility of the pseudo-time function for analyzing buildup data using drawdown type curves also has been established. Unfortunately, the pseudotime concept is often incorrectly applied when analyzing drawdown data by semilog methods. This work provides information on appropriate definitions of time which yield accurate analysis of data obtained under radial flow conditions. From the pratical viewpoint, the most important result is that there exist two Horner time ratios, one based on a normalized shut-in time and one based on shut-in pseudo-time which yield an accurate analysis of buildup data including the correct determination of average pressure using the liquid Matthews-Brons-Hazebroek functions.

  7. The helical screw expander evaluation project. [for geothermal wells

    Science.gov (United States)

    Mckay, R. A.

    1977-01-01

    A positive-displacement helical-screw expander of the Lysholm type has been adapted for geothermal service and successfully demonstrated in a 50 kW prototype power system. Evaluation of the expander by tests of a new model in a 1 MW power system under wellhead conditions in selected liquid-dominated geothermal fields is proposed. The objectives are to determine the performance characteristics of the expander and power system over a broad range of operating conditions and also to examine the concept of wellhead power plants. Throttling and fractionation of the fluids from the test wells is planned to simulate a wide range of wellhead pressures and steam fractions. Variation in the expander exhaust pressure is also planned. The investigation will include expander efficiency, corrosion, erosion, scale formation and control, and endurance testing. Interaction studies with the wells and an electric grid are also proposed.

  8. Barotrauma with extreme pressures in sport: from scuba to skydiving.

    Science.gov (United States)

    Lynch, James H; Deaton, Travis G

    2014-01-01

    The human body is well adapted to dealing with small variations in atmospheric pressure. However when our pursuit of sport and recreation takes us to extreme altitudes or ocean depths, the change in surrounding pressure has the potential to cause significant morbidity. Sports with more extreme changes in atmospheric pressure such as skydiving and scuba diving commonly place the athlete at risk for barotrauma injuries, especially in the middle ear and sinuses. Middle ear barotrauma occurs when a pressure differential develops between the middle ear and the pressure outside of the tympanic membrane. Early symptoms include ear pain, dizziness, and muffled hearing. When extreme pressure gradients are not relieved, middle ear effusions and rupture of the tympanic membrane can occur. A similar mechanism and injury pattern occurs in the sinuses as well. With proper training and prevention strategies, athletes in these sports can protect themselves from most barotrauma injuries.

  9. Propagation of Weak Pressure Waves against Two Parallel Subsonic Streams

    Institute of Scientific and Technical Information of China (English)

    Makiko YONAMINE; Takanori USHIJIMA; Yoshiaki MIYAZATO; Mitsuharu MASUDA; Hiroshi KATANODA; Kazuyasu MATSUO

    2006-01-01

    In this paper, the characteristics of a pressure wave propagating against two parallel subsonic streams in a constant-area straight duct are investigated by one-dimensional analysis, two-dimensional numerical simulation,and experiments. Computations have been carried out by the two-dimensional Euler Equations using the Chakravarthy-Osher-type TVD scheme. Optical observations by the schlieren method as well as wall pressure measurements have been performed to clarify both the structure and the propagation velocity of pressure waves.The results show that the pressure wave propagating against the streams changes into a bifurcated pressure wave and the bifurcation occurs in the low speed streams. It is also found that the propagation velocity of the pressure wave obtained by the analysis and computation agrees well with the present experimental data.

  10. Stability of pressurized long inelastic cylinders under radial transverse loads

    Science.gov (United States)

    Karamanos, S. A.

    1996-10-01

    In the present paper, the structural capacity of relatively thick inelastic steel cylindrical tubes under external or internal pressure and concentrated radial loads is investigated, through a rigorous finite element analysis, as well as using a simplified analytical model. For zero pressure, the tubes exhibit inelastic cross-sectional deformation and are capable of dissipating a significant amount of plastic energy. The energy absorption capacity, as well as the ultimate transverse load, are reduced in the presence of external pressure. The effects of internal pressure are also examined. Results are reported in the form of load-deflection curves for different pressure levels. In addition, collapse envelops showing the interaction of pressure versus radial transverse loads are presented. The conclusions of this study are important for the structural integrity of cylindrical steel tubulars for pipeline and other offshore applications.

  11. Methodological problems in pressure profile calculations for lipid bilayers

    DEFF Research Database (Denmark)

    Sonne, Jacob; Hansen, Flemming Yssing; Peters, Günther H.J.

    2005-01-01

    From molecular dynamics simulations of a dipalmitoyl-phosphatidyl-choline (DPPC) lipid bilayer in the liquid crystalline phase, pressure profiles through the bilayer are calculated by different methods. These profiles allow us to address two central and unresolved problems in pressure profile...... calculations: The first problem is that the pressure profile is not uniquely defined since the expression for the local pressure involves an arbitrary choice of an integration contour. We have investigated two different choices leading to the Irving-Kirkwood (IK) and Harasima (H) expressions for the local...... pressure tensor. For these choices we find that the pressure profile is almost independent of the contour used, which indicates that the local pressure is well defined for a DPPC bilayer in the liquid crystalline phase. This may not be the case for other systems and we therefore suggest that both the IK...

  12. Pressure Relations and Vertical Equilibrium in the Turbulent, Multiphase ISM

    CERN Document Server

    Koyama, H

    2008-01-01

    We use numerical simulations of turbulent, multiphase, self-gravitating gas orbiting in model disk galaxies to study the relationships among pressure, the vertical gas distribution, and the ratio of dense to diffuse gas. We show that the disk height and mean midplane pressure are consistent with effective hydrostatic equilibrium, provided that the turbulent vertical velocity dispersion and gas self-gravity are included. Mass-weighted pressures are an order of magnitude higher than the midplane pressure because self-gravity concentrates gas and increases the pressure in clouds. We also investigate the ratio Rmol=M(H2)/M(HI) for our simulations. Blitz and Rosolowsky (2006) showed that Rmol is proportional to the estimated midplane pressure. For model series in which the epicyclic frequency, kappa, and gas surface density, Sigma, are proportional, we recover the empirical relation. For other model series in which kappa and Sigma are independent, the midplane pressure and Rmol are not well correlated. We conclude...

  13. A system for incubations at high gas partial pressure

    DEFF Research Database (Denmark)

    Sauer, Patrick; Glombitza, Clemens; Kallmeyer, Jens

    2012-01-01

    High-pressure is a key feature of deep subsurface environments. High partial pressure of dissolved gasses plays an important role in microbial metabolism, because thermodynamic feasibility of many reactions depends on the concentration of reactants. For gases, this is controlled by their partial...... pressure, which can exceed 1 MPa at in situ conditions. Therefore, high hydrostatic pressure alone is not sufficient to recreate true deep subsurface in situ conditions, but the partial pressure of dissolved gasses has to be controlled as well. We developed an incubation system that allows for incubations...... and inert PVDF (polyvinylidene fluoride) incubator sleeve, which is almost impermeable for gases, holds the sample and separates it from the pressure fluid. The flexibility of the incubator sleeve allows for sub-sampling of the medium without loss of pressure. Experiments can be run in both static and flow...

  14. Determination of inflow performance relationship (IRR) by well testing

    Energy Technology Data Exchange (ETDEWEB)

    Jahanbani, A. [Petroleum Univ. of Technology, Tehran (Iran, Islamic Republic of); Calgary Univ., AB (Canada); Shadizadeh, S.R. [Petroleum Univ. of Technology, Tehran (Iran, Islamic Republic of)

    2009-07-01

    The knowledge of inflow performance relationship (IPR) is an important piece of information for well performance evaluation and optimization. For single phase oil flow, production rate is proportional to pressure drawdown and therefore the IPR curve is a straight line. Although limited in their application, several empirical relations have been proposed in the literature to predict the performance of oil wells producing with two phase flow conditions. This paper presented a general approach for determination of IPR curves of oil wells below the bubble point pressure. This approach uses the results of well test analysis along with relative permeability and PVT data in the proper fluid flow equations for generation of IPR curves. The proposed method was also capable of predicting future IPR curves. The proposed approach was applied to an example oil well in a naturally fractured reservoir in order to demonstrate that it was applicable to a wide variety of cases. The paper also provided a comparison of the new method proposed for fractured reservoirs with some of the empirical methods. It was demonstrated that the new method could predict well deliverability more accurately than other methods. 17 refs., 5 tabs., 11 figs., 1 appendix.

  15. Beat-to-Beat Blood Pressure Monitor

    Science.gov (United States)

    Lee, Yong Jin

    2012-01-01

    This device provides non-invasive beat-to-beat blood pressure measurements and can be worn over the upper arm for prolonged durations. Phase and waveform analyses are performed on filtered proximal and distal photoplethysmographic (PPG) waveforms obtained from the brachial artery. The phase analysis is used primarily for the computation of the mean arterial pressure, while the waveform analysis is used primarily to obtain the pulse pressure. Real-time compliance estimate is used to refine both the mean arterial and pulse pressures to provide the beat-to-beat blood pressure measurement. This wearable physiological monitor can be used to continuously observe the beat-to-beat blood pressure (B3P). It can be used to monitor the effect of prolonged exposures to reduced gravitational environments and the effectiveness of various countermeasures. A number of researchers have used pulse wave velocity (PWV) of blood in the arteries to infer the beat-to-beat blood pressure. There has been documentation of relative success, but a device that is able to provide the required accuracy and repeatability has not yet been developed. It has been demonstrated that an accurate and repeatable blood pressure measurement can be obtained by measuring the phase change (e.g., phase velocity), amplitude change, and distortion of the PPG waveforms along the brachial artery. The approach is based on comparing the full PPG waveform between two points along the artery rather than measuring the time-of-flight. Minimizing the measurement separation and confining the measurement area to a single, well-defined artery allows the waveform to retain the general shape between the two measurement points. This allows signal processing of waveforms to determine the phase and amplitude changes.

  16. Negative pressure device for intra-abdominal pressure reduction

    Energy Technology Data Exchange (ETDEWEB)

    David, M; Geido, D; Pracca, F; Sanchez, G; Simini, F; Zoppolo, C [Nucleo de Ingenierfa Biomedica, Universidad de la Republica O. del Uruguay, Hospital de ClInicas, Av. Italia S/N, 11600, Montevideo (Uruguay)

    2007-11-15

    A device that generates negative extra-abdominal pressure (ABDOPRE) for treatment of patients with high intra-abdominal pressure was developed. It includes pressure sensors for transducing intra-abdominal pressure through an intra-vesical catheter and negative pressure in the vacuum bell which is placed over the abdomen. By means of a control system, a pattern for reducing IAP is set, according to a clinical protocol. The external negative pressure is generated using a vacuum pump connected to the bell. The system registers the values of interest for the medical history. The system is being tested over ICU patients, registering a satisfactory IAP reduction.

  17. Experimental evaluation on well pattern adaptability of ultra-low permeability reservoir using sandstone flat model

    Institute of Scientific and Technical Information of China (English)

    肖前华; 魏国齐; 杨正明; 徐轩; 田文博; 张亚蒲

    2014-01-01

    As for ultra-low permeability reservoir, the adaptability of common nine-spot well pattern is studied through large-scale flat models made by micro-fractured natural sandstone outcrops. Combined with non-linear porous flow characteristics, the concept of dimensionless pressure sweep efficiency and deliverability index are put forward to evaluate the physical models’ well pattern adaptability. Through experiments, the models’ pressure distribution is measured and on which basis, the pressure gradient fields are drawn and the porous flow regions of these models are divided into dead oil region, non-linear porous flow region, and quasi-linear porous flow region with the help of twin-core non-linear porous flow curve. The results indicate that rectangular well pattern in fracture reservoirs has the best adaptability, while the worst is inverted nine-spot equilateral well pattern. With the increase of drawdown pressure, dead oil region decreases, pressure sweep efficiency and deliverability index increase; meantime, the deliverability index of rectangular well pattern has much more rational increase. Under the same drawdown pressure, the rectangular well pattern has the largest pressure sweep efficiency.

  18. Effect of pressure on nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Uma D. [Department of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar-263145 (India); Kumar, M., E-mail: munish_dixit@yahoo.co [Department of Physics, G.B. Pant University of Agriculture and Technology, Pantnagar-263145 (India)

    2010-07-01

    A simple theory is proposed to predict the effect of pressure on nanomaterials, which gets support from the Mie-Gruneisen theory of thermal expansivity as formulated by Born and Huang. We considered LiAlSi{sub 2}O{sub 6} to study the effect of pressure in the light of other formulations, viz. Murnaghan, Birch-Murnaghan, Vinet and Kumar. The results obtained are found to present a good agreement with the experimental data as well as other formulations. To confirm the validity of the formulation, we applied the method to study the compression behaviour of a number of nanomaterials, viz. CdSe, Rb{sub 3}C{sub 60}, Ni(20 nm), carbon nanotube, {gamma}-Fe{sub 2}O{sub 3}, {epsilon}-Fe (Hexagonal iron), MgO, CuO, {gamma}-Al{sub 2}O{sub 3} (67 nm), {alpha}-Fe{sub 2}O{sub 3}, {alpha}-Fe (filled nanotube), TiO{sub 2} (anatase), 3C-SiC (30 nm), TiO{sub 2} (rutile phase), Zr{sub 0.1}Ti{sub 0.9}O{sub 2}, AlN (hexagonal), {gamma}-Si{sub 3}N{sub 4}, Ni-filled MWCNT and Fe-filled MWCNT. The results obtained are compared with the experimental data. A good agreement between theory and experiment demonstrates the validity of the present approach.

  19. General Pressurization Model in Simscape

    Science.gov (United States)

    Servin, Mario; Garcia, Vicky

    2010-01-01

    System integration is an essential part of the engineering design process. The Ares I Upper Stage (US) is a complex system which is made up of thousands of components assembled into subsystems including a J2-X engine, liquid hydrogen (LH2) and liquid oxygen (LO2) tanks, avionics, thrust vector control, motors, etc. System integration is the task of connecting together all of the subsystems into one large system. To ensure that all the components will "fit together" as well as safety and, quality, integration analysis is required. Integration analysis verifies that, as an integrated system, the system will behave as designed. Models that represent the actual subsystems are built for more comprehensive analysis. Matlab has been an instrument widely use by engineers to construct mathematical models of systems. Simulink, one of the tools offered by Matlab, provides multi-domain graphical environment to simulate and design time-varying systems. Simulink is a powerful tool to analyze the dynamic behavior of systems over time. Furthermore, Simscape, a tool provided by Simulink, allows users to model physical (such as mechanical, thermal and hydraulic) systems using physical networks. Using Simscape, a model representing an inflow of gas to a pressurized tank was created where the temperature and pressure of the tank are measured over time to show the behavior of the gas. By further incorporation of Simscape into model building, the full potential of this software can be discovered and it hopefully can become a more utilized tool.

  20. Raman spectroscopy on carbon nanotubes at high pressure

    OpenAIRE

    Loa, I.

    2003-01-01

    Raman spectroscopy has been the most extensively employed method to study carbon nanotubes at high pressures. This review covers reversible pressure-induced changes of the lattice dynamics and structure of single- and multi-wall carbon nanotubes as well as irreversible transformations induced by high pressures. The interplay of covalent and van-der-Waals bonding in single-wall nanotube bundles and a structural distortion near 2 GPa are discussed in detail. Attempts of transforming carbon nano...