Convective descent simulations of drilling discharges on Georges and Sable Island banks

International Nuclear Information System (INIS)

Andrade, Y.; Loder, J.W.

1997-01-01

Factors affecting the fate of drilling mud discharges on Georges and Sable Island Banks were examined. The Koh and Chang jet discharge model was used to simulate the convective descent of a jet discharge of relatively dense materials at sites representing different hydrographic and depth regimes with a range of mud densities, and different discharge configurations, ocean currents and seasonal stratifications. The study revealed the dependence of the depth of descent and properties of the discharge plume on the discharge configuration and oceanographic conditions. The factors that affected the depth of descent were mud density, depth of release, initial downward volume flux of the discharge, current strength and ocean stratification. 22 refs., 3 tabs., 59 figs

The interpretation of geochemical logs from the oceanic basement: mineral modelling in Ocean Drilling Program (ODP) Hole 735B

International Nuclear Information System (INIS)

Harvey, P.K.; Lovell, M.A.; Bristow, J.F.

1991-01-01

Leg 118 of the Ocean Drilling Program was carried out in the vicinity of the Southwest Indian Ridge. Of the boreholes drilled, by far the most important and scientifically spectacular is Hole 735B which was located on a shallow platform adjacent to the Atlantis II Transform. This hole penetrates some 500 m of gabbroic rocks representing Layer 3 of the oceanic crust. The recovered gabbros show considerable variation both in mineralogy and in the degree of deformation. Core recovery averages 87% and there is excellent control and correlation between the core and the wide range of logs obtained. Mineralogy logs are derived and presented using both core sample data and downhole geochemical logs for Hole 735B. The problems of transforming these data for the particular mineralogy encountered are discussed. (Author)

Operational Review of the First Wireline In Situ Stress Test in Scientific Ocean Drilling

Directory of Open Access Journals (Sweden)

Casey Moore

2012-04-01

Full Text Available Scientific ocean drilling’s first in situ stress measurement was made at Site C0009A during Integrated Ocean Drilling Program (IODP Expedition 319 as part of Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE Stage 2. The Modular Formation Dynamics Tester (MDT, Schlumbergerwireline logging tool was deployed in riser Hole C0009A to measure in situ formation pore pressure, formation permeability (often reported as mobility=permeability/viscosity, and the least principal stress (S3 at several isolated depths (Saffer et al., 2009; Expedition 319 Scientists, 2010. The importance of in situ stress measurements is not only for scientific interests in active tectonic drilling, but also for geomechanical and well bore stability analyses. Certain in situ tools were not previously available for scientific ocean drilling due to the borehole diameter and open hole limits of riserless drilling. The riser-capable drillship, D/V Chikyu,now in service for IODP expeditions, allows all of the techniques available to estimate the magnitudes and orientations of 3-D stresses to be used. These techniques include downhole density logging for vertical stress, breakout and caliper log analyses for maximum horizontal stress, core-based anelastic strain recovery (ASR, used in the NanTroSEIZE expeditions in 2007–2008, and leak-off test (Lin et al., 2008 and minifrac/hydraulic fracturing (NanTroSEIZE Expedition319 in 2009. In this report, the whole operational planning process related to in situ measurements is reviewed, and lessons learned from Expedition 319 are summarized for efficient planning and testing in the future.

Mission Specific Platforms: Past achievements and future developments in European led ocean research drilling.

Science.gov (United States)

Cotterill, Carol; McInroy, David; Stevenson, Alan

2013-04-01

Mission Specific Platform (MSP) expeditions are operated by the European Consortium for Ocean Research Drilling (ECORD). Each MSP expedition is unique within the Integrated Ocean Drilling Program (IODP). In order to complement the abilities of the JOIDES Resolution and the Chikyu, the ECORD Science Operator (ESO) must source vessels and technology suitable for each MSP proposal on a case-by-case basis. The result is that ESO can meet scientific requirements in a flexible manner, whilst maintaining the measurements required for the IODP legacy programme. The process of tendering within EU journals for vessels and technology means that the planning process for each MSP Expedition starts many years in advance of the operational phase. Involvement of proposal proponents from this early stage often leads to the recognition for technological research and development to best meet the scientific aims and objectives. One example of this is the planning for the Atlantis Massif proposal, with collaborative development between the British Geological Survey (BGS) and MARUM, University of Bremen, on suitable instruments for seabed drills, with the European Petrophysics Consortium (EPC) driving the development of suitable wireline logging tools that can be used in association with such seabed systems. Other technological developments being undertaken within the European IODP community include in-situ pressure sampling for gas hydrate expeditions, deep biosphere and fluid sampling equipment and CORK technology. This multi-national collaborative approach is also employed by ESO in the operational phase. IODP Expedition 302 ACEX saw vessel and ice management support from Russia and Sweden to facilitate the first drilling undertaken in Arctic sea ice. A review of MSP expeditions past, present and future reveal the significant impact of European led operations and scientific research within the current IODP programme, and also looking forward to the start of the new International

Simulation of erosion in drilling tools for oil and gas industry

Energy Technology Data Exchange (ETDEWEB)

Arefi, B.; Settari, A. [Calgary Univ., AB (Canada); Angman, P. [Tesco Corp., Calgary, AB (Canada)

2004-07-01

Erosion in oil well drilling tools is a form of wear which occurs when fluid containing solid particles impacts a solid surface. The intensity of erosion is generally measured as the rate of material removal from the surface, and is expressed as E{sub r}, the weight of material removed by unit weight of impacting particles. Erosion can also be reduced by tool improvement and modification, thereby extending the life of drilling tools. To date, no attempt has been made to model the erosion phenomenon in drilling tools. This paper presents a newly developed erosion simulator which is the first design tool for the drilling industry. This work demonstrates that erosion can be simulated. A model was developed to calibrate the erosion coefficients for drilling tool conditions. The mechanism of erosion can be controlled by the impact velocity and angle. Algorithms were developed for transient simulation of the erosion of any surface in 2-dimensional geometry. The Erosion Simulator has been validated and calibrated against data provided by TESCO Corporation's casing drilling tools. The model has been shown to successfully predict and minimize erosion by modifying the tool geometry and metallurgy. 21 refs., 1 tab., 15 figs.

Scientific Ocean Drilling Behind the Assessment of Geo-Hazards from Submarine Slides

Directory of Open Access Journals (Sweden)

Gemma Ercilla

2007-03-01

Full Text Available The workshop ‘Scientific Ocean Drilling Behind the Assessment of Geo-hazards from Submarine Slides’ was held on 25–27 October 2006 in Barcelona (Spain. Fifty mainly European scientists and industry representatives attended from a wide spectrum of disciplines such as geophysics, stratigraphy, sedimentology, paleoceanography, marinegeotechnology, geotechnical engineering, and tsunami modeling.

Mud pressure simulation on large horizontal directional drilling

Energy Technology Data Exchange (ETDEWEB)

Placido, Rafael R.; Avesani Neto, Jose O.; Martins, Pedro R.R.; Rocha, Ronaldo [Instituto de Pesquisas Tecnologicas do Estado de Sao Paulo (IPT), Sao Paulo, SP (Brazil)

2009-07-01

Horizontal Directional Drilling (HDD) is being extensively used in Brazil for installation of oil and gas pipelines. This trenchless technology is currently used in crossings of water bodies, environmental sensitive areas, densely populated areas, areas prone to mass movement and anywhere the traditional technology is not suitable because of the risks. One of the unwanted effects of HDD is collapsing of the soil surrounding the bore-hole, leading to loss of fluid. This can result in problems such as reducing the drilling efficiency, ground heave, structures damage, fluid infiltration and other environmental problems. This paper presents four simulations of down-hole fluid pressures which represents two different geometrical characteristics of the drilling and two different soils. The results showed that greater depths are needed in longer drillings to avoid ground rupture. Thus the end section of the drilling often represents the critical stage. (author)

Seismic imaging for an ocean drilling site survey and its verification in the Izu rear arc

Science.gov (United States)

Yamashita, Mikiya; Takahashi, Narumi; Tamura, Yoshihiko; Miura, Seiichi; Kodaira, Shuichi

2018-01-01

To evaluate the crustal structure of a site proposed for International Ocean Discovery Program drilling, the Japan Agency for Marine-Earth Science and Technology carried out seismic surveys in the Izu rear arc between 2006 and 2008, using research vessels Kaiyo and Kairei. High-resolution dense grid surveys, consisting of three kinds of reflection surveys, generated clear seismic profiles, together with a seismic velocity image obtained from a seismic refraction survey. In this paper, we compare the seismic profiles with the geological column obtained from the drilling. Five volcaniclastic sedimentary units were identified in seismic reflection profiles above the 5 km/s and 6 km/s contours of P-wave velocity obtained from the velocity image from the seismic refraction survey. However, some of the unit boundaries interpreted from the seismic images were not recognised in the drilling core, highlighting the difficulties of geological target identification in volcanic regions from seismic images alone. The geological core derived from drilling consisted of seven lithological units (labelled I to VII). Units I to V were aged at 0-9 Ma, and units VI and VII, from 1320-1806.5 m below seafloor (mbsf) had ages from 9 to ~15 Ma. The strong heterogeneity of volcanic sediments beneath the drilling site U1437 was also identified from coherence, calculated using cross-spectral analysis between grid survey lines. Our results suggest that use of a dense grid configuration is important in site surveys for ocean drilling in volcanic rear-arc situations, in order to recognise heterogeneous crustal structure, such as sediments from different origins.

[Bone drilling simulation by three-dimensional imaging].

Science.gov (United States)

Suto, Y; Furuhata, K; Kojima, T; Kurokawa, T; Kobayashi, M

1989-06-01

The three-dimensional display technique has a wide range of medical applications. Pre-operative planning is one typical application: in orthopedic surgery, three-dimensional image processing has been used very successfully. We have employed this technique in pre-operative planning for orthopedic surgery, and have developed a simulation system for bone-drilling. Positive results were obtained by pre-operative rehearsal; when a region of interest is indicated by means of a mouse on the three-dimensional image displayed on the CRT, the corresponding region appears on the slice image which is displayed simultaneously. Consequently, the status of the bone-drilling is constantly monitored. In developing this system, we have placed emphasis on the quality of the reconstructed three-dimensional images, on fast processing, and on the easy operation of the surgical planning simulation.

Mathematical basis for the process of model simulation of drilling operations

Energy Technology Data Exchange (ETDEWEB)

Lipovetskiy, G M; Lebedinskiy, G L

1979-01-01

The authors describe the application of a method for the model simulation of drilling operations and for the solution of problems concerned with the planning and management of such operations. A description is offered for an approach to the simulator process when the drilling operations are part of a large system. An algorithm is provided for calculating complex events.

Land - Ocean Climate Linkages and the Human Evolution - New ICDP and IODP Drilling Initiatives in the East African Rift Valley and SW Indian Ocean

Science.gov (United States)

Zahn, R.; Feibel, C.; Co-Pis, Icdp/Iodp

2009-04-01

The past 5 Ma were marked by systematic shifts towards colder climates and concomitant reorganizations in ocean circulation and marine heat transports. Some of the changes involved plate-tectonic shifts such as the closure of the Panamanian Isthmus and restructuring of the Indonesian archipelago that affected inter-ocean communications and altered the world ocean circulation. These changes induced ocean-atmosphere feedbacks with consequences for climates globally and locally. Two new ICDP and IODP drilling initiatives target these developments from the perspectives of marine and terrestrial palaeoclimatology and the human evolution. The ICDP drilling initiative HSPDP ("Hominid Sites and Paleolakes Drilling Project"; ICDP ref. no. 10/07) targets lacustrine depocentres in Ethiopia (Hadar) and Kenya (West Turkana, Olorgesailie, Magadi) to retrieve sedimentary sequences close to the places and times where various species of hominins lived over currently available outcrop records. The records will provide a spatially resolved record of the East African environmental history in conjunction with climate variability at orbital (Milankovitch) and sub-orbital (ENSO decadal) time scales. HSPDP specifically aims at (1) compiling master chronologies for outcrops around each of the depocentres; (2) assessing which aspects of the paleoenvironmental records are a function of local origin (hydrology, hydrogeology) and which are linked with regional or larger-scale signals; (3) correlating broad-scale patterns of hominin phylogeny with the global beat of climate variability and (4) correlating regional shifts in the hominin fossil and archaeological record with more local patterns of paleoenvironmental change. Ultimately the aim is to test hypotheses that link physical and cultural adaptations in the course of the hominin evolution to local environmental change and variability. The IODP initiative SAFARI ("Southern African Climates, Agulhas Warm Water Transports and Retroflection

Oceanic crustal velocities from laboratory and logging measurements of Integrated Ocean Drilling Program Hole 1256D

Science.gov (United States)

Gilbert, Lisa A.; Salisbury, Matthew H.

2011-09-01

Drilling and logging of Integrated Ocean Drilling Program (IODP) Hole 1256D have provided a unique opportunity for systematically studying a fundamental problem in marine geophysics: What influences the seismic structure of oceanic crust, porosity or composition? Compressional wave velocities (Vp) logged in open hole or from regional refraction measurements integrate both the host rock and cracks in the crust. To determine the influence of cracks on Vp at several scales, we first need an accurate ground truth in the form of laboratory Vp on crack-free, or nearly crack-free samples. We measured Vp on 46 water-saturated samples at in situ pressures to determine the baseline velocities of the host rock. These new results match or exceed Vp logs throughout most of the hole, especially in the lower dikes and gabbros, where porosities are low. In contrast, samples measured at sea under ambient laboratory conditions, had consistently lower Vp than the Vp logs, even after correction to in situ pressures. Crack-free Vp calculated from simple models of logging and laboratory porosity data for different lithologies and facies suggest that crustal velocities in the lavas and upper dikes are controlled by porosity. In particular, the models demonstrate significant large-scale porosity in the lavas, especially in the sections identified as fractured flows and breccias. However, crustal velocities in the lower dikes and gabbros are increasingly controlled by petrology as the layer 2-3 boundary is approached.

New roles of LWD and wireline logging in scientific ocean drilling

Science.gov (United States)

Sanada, Y.; Kido, Y. N.; Moe, K.; Aoike, K.

2014-12-01

borehole. These in-situ measurement and stress experiment data are very important to understand physical properties and mechanism of fault zone (Exp319).Those new technologies and tools also expand the envelope of scientific ocean drilling.

A feasibility study of the disposal of radioactive waste in deep ocean sediments by drilled emplacement

International Nuclear Information System (INIS)

Bury, M.R.C.

1983-08-01

This report describes the second phase of a study of the feasibility of disposal and isolation of high level radioactive waste in holes drilled deep into the sediments of the ocean. In this phase, work has concentrated on establishing the state of the art of the various operations and developing the design, in particular the drilling operation, the loading of flasks containing waste canisters from supply vessels onto the platform, the handling of radioactive waste on board, and its emplacement into predrilled holes. In addition, an outline design of the offshore platform has been prepared. (author)

Automatic real time drilling support on Ekofisk utilizing eDrilling

Energy Technology Data Exchange (ETDEWEB)

Rommetveit, Rolv; Bjorkevoll, Knut S.; Halsey, George W.; Kluge, Roald; Molde, Dag Ove; Odegard, Sven Inge [SINTEF Petroleum Research, Trondheim (Norway); Herbert, Mike [HITEC Products Drilling, Stavanger (Norway); ConocoPhillips Norge, Stavanger (Norway)

2008-07-01

eDrilling is a new and innovative system for real time drilling simulation, 3D visualization and control from a remote drilling expert centre. The concept uses all available real time drilling data (surface and downhole) in combination with real time modelling to monitor and optimize the drilling process. This information is used to visualize the wellbore in 3D in real time. eDrilling has been implemented in an Onshore Drilling Center in Norway. The system is composed of the following elements, some of which are unique and ground-breaking: an advanced and fast Integrated Drilling Simulator which is capable to model the different drilling sub-processes dynamically, and also the interaction between these sub-processes in real time; automatic quality check and corrections of drilling data; making them suitable for processing by computer models; real time supervision methodology for the drilling process using time based drilling data as well as drilling models / the integrated drilling simulator; methodology for diagnosis of the drilling state and conditions. This is obtained from comparing model predictions with measured data. Advisory technology for more optimal drilling. A Virtual Wellbore, with advanced visualization of the downhole process. Dat low and computer infrastructure. e-Drilling has been implemented in an Onshore Drilling Center on Ekofisk in Norway. The system is being used on drilling operations, and experiences from its use are presented. The supervision and diagnosis functionalities have been useful in particular, as the system has given early warnings on ECD and friction related problems. This paper will present the eDrilling system as well as experiences from its use. (author)

Effects of drilling parameters in numerical simulation to the bone temperature elevation

Science.gov (United States)

Akhbar, Mohd Faizal Ali; Malik, Mukhtar; Yusoff, Ahmad Razlan

2018-04-01

Drilling into the bone can produce significant amount of heat which can cause bone necrosis. Understanding the drilling parameters influence to the heat generation is necessary to prevent thermal necrosis to the bone. The aim of this study is to investigate the influence of drilling parameters on bone temperature elevation. Drilling simulations of various combinations of drill bit diameter, rotational speed and feed rate were performed using finite element software DEFORM-3D. Full-factorial design of experiments (DOE) and two way analysis of variance (ANOVA) were utilised to examine the effect of drilling parameters and their interaction influence on the bone temperature. The maximum bone temperature elevation of 58% was demonstrated within the range in this study. Feed rate was found to be the main parameter to influence the bone temperature elevation during the drilling process followed by drill diameter and rotational speed. The interaction between drill bit diameter and feed rate was found to be significantly influence the bone temperature. It is discovered that the use of low rotational speed, small drill bit diameter and high feed rate are able to minimize the elevation of bone temperature for safer surgical operations.

MONDO Project: real time ocean monitoring through Lagrangian drifters during offshore drilling operations

Energy Technology Data Exchange (ETDEWEB)

Mafra, Tatiana [Eni Oil do Brasil, Rio de Janeiro, RJ (Brazil); Fragoso, Mauricio da Rocha; Santos, Francisco Alves dos; Cruz, Leonardo M. Marques A.; Pellegrini, Julio A.C.; Cerrone, Bruna Nogueira [Prooceano, Rio de Janeiro, RJ (Brazil); Assireu, Arcilan Trevenzoli [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil)

2008-07-01

Monitoring the ocean conditions during offshore operations is essential for both operational and environmental aspects. Environmentally, not only to know better the environment where the activity is taking place, but also to be able to provide fast and accurate response in case of accidents. MONDO Project (Monitoring by Ocean Drifters) is a pioneer initiative from ENI Oil do Brasil and PROOCEANO that aimed to monitor currents as a part of a metoceanographic data monitoring project of drilling operations in Brazilian Waters, in Santos Basin throughout September to November 2007, 40 satellite tracked ocean drifters were deployed will be transmitting data up to November 2008. The results of this project can be used to study a wide range of subjects about ocean dynamics. Following the principles of social and environmental responsibility, MONDO Project aims to benefit the local ecosystem in increasing the scientific knowledge of the area to calibrate hydrodynamic models that will lead to more accurate modeling results and, as a consequence, to a better management of contingency plans. Based on these principles, the project will also provide unrestricted access to oceanographic data even after the end of operations. (author)

Ocean Wave Simulation Based on Wind Field.

Directory of Open Access Journals (Sweden)

Zhongyi Li

Full Text Available Ocean wave simulation has a wide range of applications in movies, video games and training systems. Wind force is the main energy resource for generating ocean waves, which are the result of the interaction between wind and the ocean surface. While numerous methods to handle simulating oceans and other fluid phenomena have undergone rapid development during the past years in the field of computer graphic, few of them consider to construct ocean surface height field from the perspective of wind force driving ocean waves. We introduce wind force to the construction of the ocean surface height field through applying wind field data and wind-driven wave particles. Continual and realistic ocean waves result from the overlap of wind-driven wave particles, and a strategy was proposed to control these discrete wave particles and simulate an endless ocean surface. The results showed that the new method is capable of obtaining a realistic ocean scene under the influence of wind fields at real time rates.

Sea surface temperature estimates for the mid-Piacenzian Indian Ocean—Ocean Drilling Program sites 709, 716, 722, 754, 757, 758, and 763

Science.gov (United States)

Robinson, Marci M.; Dowsett, Harry J.; Stoll, Danielle K.

2018-01-30

Despite the wealth of global paleoclimate data available for the warm period in the middle of the Piacenzian Stage of the Pliocene Epoch (about 3.3 to 3.0 million years ago [Ma]; Dowsett and others, 2013, and references therein), the Indian Ocean has remained a region of sparse geographic coverage in terms of microfossil analysis. In an effort to characterize the surface Indian Ocean during this interval, we examined the planktic foraminifera from Ocean Drilling Program (ODP) sites 709, 716, 722, 754, 757, 758, and 763, encompassing a wide range of oceanographic conditions. We quantitatively analyzed the data for sea surface temperature (SST) estimation using both the modern analog technique (MAT) and a factor analytic transfer function. The data will contribute to the U.S. Geological Survey (USGS) Pliocene Research, Interpretation and Synoptic Mapping (PRISM) Project’s global SST reconstruction and climate model SST boundary condition for the mid-Piacenzian and will become part of the PRISM verification dataset designed to ground-truth Pliocene climate model simulations (Dowsett and others, 2013).

Towards the design of new and improved drilling fluid additives using molecular dynamics simulations

International Nuclear Information System (INIS)

Anderson, Richard L.; Greenwel, H. Christopher; Suter, James L.; Coveney, Peter V.; Jarvis, Rebecca M.

2010-01-01

During exploration for oil and gas, a technical drilling fluid is used to lubricate the drill bit, maintain hydrostatic pressure, transmit sensor readings, remove rock cuttings and inhibit swelling of unstable clay based reactive shale formations. Increasing environmental awareness and resulting legislation has led to the search for new, improved biodegradable drilling fluid components. In the case of additives for clay swelling inhibition, an understanding of how existing effective additives interact with clays must be gained to allow the design of improved molecules. Owing to the disordered nature and nano scope dimension of the interlayer pores of clay minerals, computer simulations have become an increasingly useful tool for studying clay-swelling inhibitor interactions. In this work we briefly review the history of the development of technical drilling fluids, the environmental impact of drilling fluids and the use of computer simulations to study the interactions between clay minerals and swelling inhibitors. We report on results from some recent large-scale molecular dynamics simulation studies on low molecular weight water-soluble macromolecular inhibitor molecules. The structure and interactions of poly(propylene oxide)-diamine, poly(ethylene glycol) and poly(ethylene oxide)-diacrylate inhibitor molecules with montmorillonite clay are studied. (author)

Oman Drilling Project GT3 site survey: dynamics at the roof of an oceanic magma chamber

Science.gov (United States)

France, L.; Nicollet, C.; Debret, B.; Lombard, M.; Berthod, C.; Ildefonse, B.; Koepke, J.

2017-12-01

Oman Drilling Project (OmanDP) aims at bringing new constraints on oceanic crust accretion and evolution by drilling Holes in the whole ophiolite section (mantle and crust). Among those, operations at GT3 in the Sumail massif drilled 400 m to sample the dike - gabbro transition that corresponds to the top (gabbros) and roof (dikes) of the axial magma chamber, an interface where hydrothermal and magmatic system interacts. Previous studies based on oceanic crust formed at present day fast-spreading ridges and preserved in ophiolites have highlighted that this interface is a dynamic horizon where the axial melt lens that top the main magma chamber can intrude, reheat, and partially assimilate previously hydrothermally altered roof rocks. Here we present the preliminary results obtained in GT3 area that have allowed the community to choose the drilling site. We provide a geological and structural map of the area, together with new petrographic and chemical constraints on the dynamics of the dike - gabbro transition. Our new results allow us to quantify the dynamic processes, and to propose that 1/ the intrusive contact of the varitextured gabbro within the dikes highlights the intrusion of the melt lens top in the dike rooting zone, 2/ both dikes and previously crystallized gabbros are reheated, and recrystallized by underlying melt lens dynamics (up to 1050°C, largely above the hydrous solidus temperature of altered dikes and gabbros), 3/ the reheating range can be > 200°C, 4/ the melt lens depth variations for a given ridge position is > 200m, 5/ the reheating stage and associated recrystallization within the dikes occurred under hydrous conditions, 6/ the reheating stage is recorded at the root zone of the sheeted dike complex by one of the highest stable conductive thermal gradient ever recorded on Earth ( 3°C/m), 7/ local chemical variations in recrystallized dikes and gabbros are highlighted and used to quantify crystallization and anatectic processes, and the

Nd isotopic structure of the Pacific Ocean 70-30 Ma and numerical evidence for vigorous ocean circulation and ocean heat transport in a greenhouse world

Science.gov (United States)

Thomas, Deborah J.; Korty, Robert; Huber, Matthew; Schubert, Jessica A.; Haines, Brian

2014-05-01

The oceanic meridional overturning circulation (MOC) is a crucial component of the climate system, impacting heat and nutrient transport, and global carbon cycling. Past greenhouse climate intervals present a paradox because their weak equator-to-pole temperature gradients imply a weaker MOC, yet increased poleward oceanic heat transport appears to be required to maintain these weak gradients. To investigate the mode of MOC that operated during the early Cenozoic, we compare new Nd isotope data with Nd tracer-enabled numerical ocean circulation and coupled climate model simulations. Assimilation of new Nd isotope data from South Pacific Deep Sea Drilling Project and Ocean Drilling Program Sites 323, 463, 596, 865, and 869 with previously published data confirm the hypothesized MOC characterized by vigorous sinking in the South and North Pacific 70 to 30 Ma. Compilation of all Pacific Nd isotope data indicates vigorous, distinct, and separate overturning circulations in each basin until 40 Ma. Simulations consistently reproduce South Pacific and North Pacific deep convection over a broad range of conditions, but cases using strong deep ocean vertical mixing produced the best data-model match. Strong mixing, potentially resulting from enhanced abyssal tidal dissipation, greater interaction of wind-driven internal wave activity with submarine plateaus, or higher than modern values of the geothermal heat flux enable models to achieve enhanced MOC circulation rates with resulting Nd isotope distributions consistent with the proxy data. The consequent poleward heat transport may resolve the paradox of warmer worlds with reduced temperature gradients.

IODP Expedition 324: Ocean Drilling at Shatsky Rise Gives Clues about Oceanic Plateau Formation

Directory of Open Access Journals (Sweden)

Jörg Geldmacher

2011-09-01

Full Text Available Integrated Ocean Drilling Program (IODP Expedition 324 cored Shatsky Rise at five sites (U1346–U1350 to study processes of oceanic plateau formation and evolution. Site penetrations ranged from 191.8 m to 324.1 m with coring of 52.6 m to 172.7 m into igneous basement at four of the sites. Average recovery in basement was 38.7%–67.4%. Cored igneous sections consist mainly of variably evolved tholeiiticbasalts emplaced as pillows or massive flows. Massive flows are thickest and make up the largest percentage of section on the largest and oldest volcano, late Jurassic age Tamu Massif; thus, it may have formed at high effusion rates. Such massive flows are characteristic of flood basalts, and similar flows were cored at Ontong Java Plateau. Indeed, the similarity of igneous sections at Site U1347 with that cored on Ontong Java Plateau implies similar volcanic styles for these two plateaus. On younger, smaller Shatsky Rise volcanoes, pillow flows are common and massive flows thinner andfewer, which might mean volcanism waned with time. Cored sediments from summit sites contain fossils and structures implying shallow water depths or emergence at the time of eruption and normal subsidence since. Summit sites also show pervasive alteration that could be due to high fluid fluxes. A thick section of volcaniclastics cored on Tamu Massif suggests that shallow, explosive submarine volcanism played a significant role in the geologic development of the plateau summit. Expedition 324 results imply that Shatsky Risebegan with massive eruptions forming a huge volcano and that subsequent eruptions waned in intensity, forming volcanoes that are large, but which did not erupt with unusually high effusionrates. Similarities of cored sections on Tamu Massif with those ofOntong Java Plateau indicate that these oceanic plateaus formed insimilar fashion.

Simulator drills for the management of severe accidents

International Nuclear Information System (INIS)

Hoffmann, E.

1989-01-01

The present state of deliberations on the simulation of severe accidents is presented and applied to a training philosophy. The special characteristics of 'severe' accidents are addressed and, falling under this category, the 'psychological structure of the man-machine-situation' is examined. The valid rules for drilling 'post-RESA-conduct' (RESA = fast reactor shut down) and the monitoring of safety goals are introduced. 2 figs., 1 tab

Reconsidering Volcanic Ocean Island Hydrology: Recent Geophysical and Drilling Results

Science.gov (United States)

Thomas, D. M.; Pierce, H. A.; Lautze, N. C.

2017-12-01

Recent results of geophysical surveys and exploratory drilling in Hawaii have suggested that Hawaii's hydrogeology may be more complex than has been generally recognized. Instead of a more-or-less homogeneous pile of highly permeable eruptive basalts that are intermittently punctuated by volcanic dikes confined to calderas and rift zones, we are finding that dike compartmentalization is occurring outside of recognized rift zones, leading to significantly higher volumes of stored groundwater within the island. Analysis of recent geophysical surveys have shown local water table elevations that are substantially higher than can be accounted for by the high hydraulic conductivities of Hawaiian basalts. Recent diamond wireline drilling results have also shown that sub-horizontal variations in permeability, associated with significant changes in eruptive character (e.g. explosive vs effusive activity) are acting as significant perching and confining bodies over significant aerial extents and suggest that these features also contribute to increased storage of recharge. Not only is storage much higher than previously assumed, these features appear to impact subsurface groundwater flow in ways that are not accounted for in traditional methods of computing sustainable yields for near shore aquifers: where buried confining formations extend to depths well below sea level, higher elevation recharge is being intercepted and diverted to deep submarine groundwater discharge well below depths that are typically investigated or quantified. We will provide a summary of the recent geophysical survey results along with a revised conceptual model for groundwater circulation within volcanic ocean islands.

Tectonics and geology of spreading ridge subduction at the Chile Triple Junction: a synthesis of results from Leg 141 of the Ocean Drilling Program

Science.gov (United States)

Behrmann, J.H.; Lewis, S.D.; Cande, S.C.

1994-01-01

An active oceanic spreading ridge is being subducted beneath the South American continent at the Chile Triple Junction. This process has played a major part in the evolution of most of the continental margins that border the Pacific Ocean basin. A combination of high resolution swath bathymetric maps, seismic reflection profiles and drillhole and core data from five sites drilled during Ocean Drilling Program (ODP) Leg 141 provide important data that define the tectonic, structural and stratigraphic effects of this modern example of spreading ridge subduction. A change from subduction accretion to subduction erosion occurs along-strike of the South American forearc. This change is prominently expressed by normal faulting, forearc subsidence, oversteepening of topographic slopes and intensive sedimentary mass wasting, overprinted on older signatures of sediment accretion, overthrusting and uplift processes in the forearc. Data from drill sites north of the triple junction (Sites 859-861) show that after an important phase of forearc building in the early to late Pliocene, subduction accretion had ceased in the late Pliocene. Since that time sediment on the downgoing oceanic Nazca plate has been subducted. Site 863 was drilled into the forearc in the immediate vicinity of the triple junction above the subducted spreading ridge axis. Here, thick and intensely folded and faulted trench slope sediments of Pleistocene age are currently involved in the frontal deformation of the forearc. Early faults with thrust and reverse kinematics are overprinted by later normal faults. The Chile Triple Junction is also the site of apparent ophiolite emplacement into the South American forearc. Drilling at Site 862 on the Taitao Ridge revealed an offshore volcanic sequence of Plio-Pleistocene age associated with the Taitao Fracture Zone, adjacent to exposures of the Pliocene-aged Taitao ophiolite onshore. Despite the large-scale loss of material from the forearc at the triple junction

Numerical Simulations of Thermo-Mechanical Processes during Thermal Spallation Drilling for Geothermal Reservoirs

Science.gov (United States)

Vogler, D.; Walsh, S. D. C.; Rudolf von Rohr, P.; Saar, M. O.

2017-12-01

Drilling expenses constitute a significant share of the upfront capital costs and thereby the associated risks of geothermal energy production. This is especially true for deep boreholes, as drilling costs per meter increase significantly with depth. Thermal spallation drilling is a relatively new drilling technique, particularly suited to the hard crystalline (e.g., basement) rocks in which many deep geothermal resources are located. The method uses a hot jet-flame to rapidly heat the rock surface, which leads to large temperature gradients in the rock. These temperature gradients cause localized thermal stresses that, in combination with the in situ stress field, lead to the formation and ejection of spalls. These spalls are then transported out of the borehole with the drilling mud. Thermal spallation not only in principle enables much faster rates of penetration than traditional rotary drilling, but is also contact-less, which significantly reduces the long tripping times associated with conventional rotary head drilling. We present numerical simulations investigating the influence of rock heterogeneities on the thermal spallation process. Special emphasis is put on different mineral compositions, stress regimes, and heat sources.

Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts

Science.gov (United States)

2016-11-10

Hydrostatic Models Still Capable of Simulating Oceanic Fronts Yalin Fan Zhitao Yu Ocean Dynamics and Prediction Branch Oceanography Division FengYan Shi...OF PAGES 17. LIMITATION OF ABSTRACT Are Hydrostatic Models Still Capable of Simulating Oceanic Fronts? Yalin Fan, Zhitao Yu, and, Fengyan Shi1 Naval...mixed layer and thermocline simulations as well as large scale circulations. Numerical experiments are conducted using hydrostatic (HY) and

Dynamic Biological Functioning Important for Simulating and Stabilizing Ocean Biogeochemistry

Science.gov (United States)

Buchanan, P. J.; Matear, R. J.; Chase, Z.; Phipps, S. J.; Bindoff, N. L.

2018-04-01

The biogeochemistry of the ocean exerts a strong influence on the climate by modulating atmospheric greenhouse gases. In turn, ocean biogeochemistry depends on numerous physical and biological processes that change over space and time. Accurately simulating these processes is fundamental for accurately simulating the ocean's role within the climate. However, our simulation of these processes is often simplistic, despite a growing understanding of underlying biological dynamics. Here we explore how new parameterizations of biological processes affect simulated biogeochemical properties in a global ocean model. We combine 6 different physical realizations with 6 different biogeochemical parameterizations (36 unique ocean states). The biogeochemical parameterizations, all previously published, aim to more accurately represent the response of ocean biology to changing physical conditions. We make three major findings. First, oxygen, carbon, alkalinity, and phosphate fields are more sensitive to changes in the ocean's physical state. Only nitrate is more sensitive to changes in biological processes, and we suggest that assessment protocols for ocean biogeochemical models formally include the marine nitrogen cycle to assess their performance. Second, we show that dynamic variations in the production, remineralization, and stoichiometry of organic matter in response to changing environmental conditions benefit the simulation of ocean biogeochemistry. Third, dynamic biological functioning reduces the sensitivity of biogeochemical properties to physical change. Carbon and nitrogen inventories were 50% and 20% less sensitive to physical changes, respectively, in simulations that incorporated dynamic biological functioning. These results highlight the importance of a dynamic biology for ocean properties and climate.

Impact of ocean model resolution on CCSM climate simulations

Energy Technology Data Exchange (ETDEWEB)

Kirtman, Ben P.; Rousset, Clement; Siqueira, Leo [University of Miami, Rosenstiel School for Marine and Atmospheric Science, Coral Gables, FL (United States); Bitz, Cecilia [University of Washington, Department of Atmospheric Science, Seattle, WA (United States); Bryan, Frank; Dennis, John; Hearn, Nathan; Loft, Richard; Tomas, Robert; Vertenstein, Mariana [National Center for Atmospheric Research, Boulder, CO (United States); Collins, William [University of California, Berkeley, Berkeley, CA (United States); Kinter, James L.; Stan, Cristiana [Center for Ocean-Land-Atmosphere Studies, Calverton, MD (United States); George Mason University, Fairfax, VA (United States)

2012-09-15

The current literature provides compelling evidence suggesting that an eddy-resolving (as opposed to eddy-permitting or eddy-parameterized) ocean component model will significantly impact the simulation of the large-scale climate, although this has not been fully tested to date in multi-decadal global coupled climate simulations. The purpose of this paper is to examine how resolved ocean fronts and eddies impact the simulation of large-scale climate. The model used for this study is the NCAR Community Climate System Model version 3.5 (CCSM3.5) - the forerunner to CCSM4. Two experiments are reported here. The control experiment is a 155-year present-day climate simulation using a 0.5 atmosphere component (zonal resolution 0.625 meridional resolution 0.5 ; land surface component at the same resolution) coupled to ocean and sea-ice components with zonal resolution of 1.2 and meridional resolution varying from 0.27 at the equator to 0.54 in the mid-latitudes. The second simulation uses the same atmospheric and land-surface models coupled to eddy-resolving 0.1 ocean and sea-ice component models. The simulations are compared in terms of how the representation of smaller scale features in the time mean ocean circulation and ocean eddies impact the mean and variable climate. In terms of the global mean surface temperature, the enhanced ocean resolution leads to a ubiquitous surface warming with a global mean surface temperature increase of about 0.2 C relative to the control. The warming is largest in the Arctic and regions of strong ocean fronts and ocean eddy activity (i.e., Southern Ocean, western boundary currents). The Arctic warming is associated with significant losses of sea-ice in the high-resolution simulation. The sea surface temperature gradients in the North Atlantic, in particular, are better resolved in the high-resolution model leading to significantly sharper temperature gradients and associated large-scale shifts in the rainfall. In the extra-tropics, the

Cortical bone drilling: An experimental and numerical study.

Science.gov (United States)

Alam, Khurshid; Bahadur, Issam M; Ahmed, Naseer

2014-12-16

Bone drilling is a common surgical procedure in orthopedics, dental and neurosurgeries. In conventional bone drilling process, the surgeon exerts a considerable amount of pressure to penetrate the drill into the bone tissue. Controlled penetration of drill in the bone is necessary for safe and efficient drilling. Development of a validated Finite Element (FE) model of cortical bone drilling. Drilling experiments were conducted on bovine cortical bone. The FE model of the bone drilling was based on mechanical properties obtained from literature data and additionally conducted microindentation tests on the cortical bone. The magnitude of stress in bone was found to decrease exponentially away from the lips of the drill in simulations. Feed rate was found to be the main influential factor affecting the force and torque in the numerical simulations and experiments. The drilling thrust force and torque were found to be unaffected by the drilling speed in numerical simulations. Simulated forces and torques were compared with experimental results for similar drilling conditions and were found in good agreement.CONCLUSIONS: FE schemes may be successfully applied to model complex kinematics of bone drilling process.

Beyond 2013 - The Future of European Scientific Drilling Research - An introduction.

Science.gov (United States)

Camoin, G.; Stein, R.

2009-04-01

The Integrated Ocean Drilling Program (IODP) is funded for the period 2003-2013, and is now starting to plan the future of ocean drilling beyond 2013, including the development of new technologies, new emerging research fields as and the societal relevance of this programme. In this context an interdisciplinary and multinational (USA, Europe, Japan, Asian and Oceanian countries), key conference - INVEST IODP New Ventures in Exploring Scientific Targets - addressing all international IODP partners is therefore planned for September 23rd-25th 2009 in Bremen, Germany (more information at http://www.iodp.org and http://marum.de/iodp-invest.html) to discuss future directions of ocean drilling research and related aspects such as ventures with related programmes or with industry. The first critical step of INVEST is to define the scientific research goals of the second phase of the Integrated Ocean Drilling Program (IODP), which is expected to begin in late 2013. INVEST will be open to all interested scientists and students and will be the principal opportunity for the international science community to help shape the future of scientific ocean drilling. The outcome of the conference will be the base to draft a science plan in 2010 and to define new goals and strategies to effectively meet the challenges of society and future ocean drilling. The current EGU Session and the related two days workshop which will be held at the University of Vienna will specifically address the future of European scientific drilling research. The major objectives of those two events are to sharpen the European interests in the future IODP and to prepare the INVEST Conference and are therefore of prime importance to give weight to the European propositions in the program renewal processes, both on science, technology and management, and to provide the participants with information about the status/process of ongoing discussions and negotiations regarding program structure, and provide them

Mechanism-Based FE Simulation of Tool Wear in Diamond Drilling of SiCp/Al Composites.

Science.gov (United States)

Xiang, Junfeng; Pang, Siqin; Xie, Lijing; Gao, Feinong; Hu, Xin; Yi, Jie; Hu, Fang

2018-02-07

The aim of this work is to analyze the micro mechanisms underlying the wear of macroscale tools during diamond machining of SiC p /Al6063 composites and to develop the mechanism-based diamond wear model in relation to the dominant wear behaviors. During drilling, high volume fraction SiC p /Al6063 composites containing Cu, the dominant wear mechanisms of diamond tool involve thermodynamically activated physicochemical wear due to diamond-graphite transformation catalyzed by Cu in air atmosphere and mechanically driven abrasive wear due to high-frequency scrape of hard SiC reinforcement on tool surface. An analytical diamond wear model, coupling Usui abrasive wear model and Arrhenius extended graphitization wear model was proposed and implemented through a user-defined subroutine for tool wear estimates. Tool wear estimate in diamond drilling of SiC p /Al6063 composites was achieved by incorporating the combined abrasive-chemical tool wear subroutine into the coupled thermomechanical FE model of 3D drilling. The developed drilling FE model for reproducing diamond tool wear was validated for feasibility and reliability by comparing numerically simulated tool wear morphology and experimentally observed results after drilling a hole using brazed polycrystalline diamond (PCD) and chemical vapor deposition (CVD) diamond coated tools. A fairly good agreement of experimental and simulated results in cutting forces, chip and tool wear morphologies demonstrates that the developed 3D drilling FE model, combined with a subroutine for diamond tool wear estimate can provide a more accurate analysis not only in cutting forces and chip shape but also in tool wear behavior during drilling SiC p /Al6063 composites. Once validated and calibrated, the developed diamond tool wear model in conjunction with other machining FE models can be easily extended to the investigation of tool wear evolution with various diamond tool geometries and other machining processes in cutting different

High Temperature Logging and Monitoring Instruments to Explore and Drill Deep into Hot Oceanic Crust.

Science.gov (United States)

Denchik, N.; Pezard, P. A.; Ragnar, A.; Jean-Luc, D.; Jan, H.

2014-12-01

Drilling an entire section of the oceanic crust and through the Moho has been a goal of the scientific community for more than half of a century. On the basis of ODP and IODP experience and data, this will require instruments and strategies working at temperature far above 200°C (reached, for example, at the bottom of DSDP/ODP Hole 504B), and possibly beyond 300°C. Concerning logging and monitoring instruments, progress were made over the past ten years in the context of the HiTI ("High Temperature Instruments") project funded by the european community for deep drilling in hot Icelandic geothermal holes where supercritical conditions and a highly corrosive environment are expected at depth (with temperatures above 374 °C and pressures exceeding 22 MPa). For example, a slickline tool (memory tool) tolerating up to 400°C and wireline tools up to 300°C were developed and tested in Icelandic high-temperature geothermal fields. The temperature limitation of logging tools was defined to comply with the present limitation in wireline cables (320°C). As part of this new set of downhole tools, temperature, pressure, fluid flow and casing collar location might be measured up to 400°C from a single multisensor tool. Natural gamma radiation spectrum, borehole wall ultrasonic images signal, and fiber optic cables (using distributed temperature sensing methods) were also developed for wireline deployment up to 300°C and tested in the field. A wireline, dual laterolog electrical resistivity tool was also developed but could not be field tested as part of HiTI. This new set of tools constitutes a basis for the deep exploration of the oceanic crust in the future. In addition, new strategies including the real-time integration of drilling parameters with modeling of the thermo-mechanical status of the borehole could be developed, using time-lapse logging of temperature (for heat flow determination) and borehole wall images (for hole stability and in-situ stress determination

46 CFR 11.468 - Officer endorsements for mobile offshore drilling units.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Officer endorsements for mobile offshore drilling units... Officer endorsements for mobile offshore drilling units. Officer endorsements for service on mobile offshore drilling units (MODUs) authorize service on units of any gross tons upon ocean waters while on...

View-Dependent Tessellation and Simulation of Ocean Surfaces

Directory of Open Access Journals (Sweden)

Anna Puig-Centelles

2014-01-01

Full Text Available Modeling and rendering realistic ocean scenes have been thoroughly investigated for many years. Its appearance has been studied and it is possible to find very detailed simulations where a high degree of realism is achieved. Nevertheless, among the solutions to ocean rendering, real-time management of the huge heightmaps that are necessary for rendering an ocean scene is still not solved. We propose a new technique for simulating the ocean surface on GPU. This technique is capable of offering view-dependent approximations of the mesh while maintaining coherence among the extracted approximations. This feature is very important as most solutions previously presented must retessellate from the initial mesh. Our solution is able to use the latest extracted approximation when refining or coarsening the mesh.

A Reference Section through the Lower Fast-spreading Oceanic Crust in the Wadi Gideah (Sumail ophiolite, Sultanate Oman): Drill Sites GT1A and GT2A within the ICDP Oman Drilling Project

Science.gov (United States)

Mueller, S.; Koepke, J.; Garbe-Schoenberg, C. D.; Müller, T.; Mock, D.; Strauss, H.; Schuth, S.; Ildefonse, B.

2017-12-01

In the absence of a complete profile through fast-spreading oceanic crust in modern oceans, we established a reference profile through the whole paleocrust of the Sumail Ophiolite (Oman), which is regarded as the best analogue for fast-spreading oceanic crust on land. For establishing a coherent data set, we sampled the Wadi Gideah in the Wadi-Tayin massif from the mantle section up to the pillow basalts and performed different analytical and structural investigations on the same suite of samples (pool sample concept). The whole sample set contains about 400 samples focusing on both primary magmatic rocks and hydrothermal fault zones to characterize initial formation processes and cooling of the crust. The Wadi Gideah hosts the sites GT1A (lower crust) and GT2A (foliated / layered gabbro transition) where 400 m long cores have been drilled in the frame of the ICDP Oman Drilling Project (OmanDP). Thus, the Wadi Gideah crustal transect is well-suited for providing a reference frame for these two drill cores. Major and trace element data on minerals and rocks reveal in-situ crystallization in the deep crust, thus strongly supporting a hybrid accretion model that is characterized by sheeted sill intrusion in the lower part of the plutonic crust and gabbro glacier features in the upper section. This hybrid model is also supported by results on crystallographic preferred orientations (CPO) of the minerals within the gabbros, which call for distinct formation mechanisms in the upper and lower gabbro sections. A requirement for our hybrid model is significant hydrothermal cooling in the lower crust for the consumption of the latent heat of crystallization. This was facilitated by channelled hydrothermal flow zones, preserved today in faulted zones of extensively altered gabbro cutting both layered and foliated gabbros. These gabbros show higher Sr87/Sr86 ratios if compared to the background gabbro, the presence of late stage minerals (amphibole, oxides, orthopyroxene

Simulation of friction stir drilling process

Science.gov (United States)

Vijayabaskar, P.; Hynes, N. Rajesh Jesudoss

2018-05-01

The project is the study of the thermal drilling process. The process is a hole forming process in the sheet metals using the heat generated by means of friction. The main advantage of the process over the conventional drilling process is that the holes formed using this process does not need any backing arrangements such as weld nuts, rivet nuts etc. Because the extruded bush itself acts as a supporting structure for the fasteners. This eliminates the need for the access to the backside of the work material for fastening operations. The major factors contributing the thermal drilling operation are the spindle speed and the thrust force required for forming a hole. The process of finding out the suitable thrust force and the speed for drilling a particular material with particular thickness is a tedious process. The process can be simplified by forming a mathematical model by combining the empirical formulae from the literature. These formulae were derived in the literature from the experimental trials by following certain assumptions. In this paper a suitable mathematical model is formed by replicating the experiments and tried to be validated by the results from numerical analysis. The numerical analysis of the model is done using the ANSYS software.

The subsurface geology of Río Tinto: material examined during a simulated Mars drilling mission for the Mars Astrobiology Research and Technology Experiment (MARTE).

Science.gov (United States)

Prieto-Ballesteros, Olga; Martínez-Frías, Jesús; Schutt, John; Sutter, Brad; Heldmann, Jennifer L; Bell, Mary Sue; Battler, Melissa; Cannon, Howard; Gómez-Elvira, Javier; Stoker, Carol R

2008-10-01

The 2005 Mars Astrobiology Research and Technology Experiment (MARTE) project conducted a simulated 1-month Mars drilling mission in the Río Tinto district, Spain. Dry robotic drilling, core sampling, and biological and geological analytical technologies were collectively tested for the first time for potential use on Mars. Drilling and subsurface sampling and analytical technologies are being explored for Mars because the subsurface is the most likely place to find life on Mars. The objectives of this work are to describe drilling, sampling, and analytical procedures; present the geological analysis of core and borehole material; and examine lessons learned from the drilling simulation. Drilling occurred at an undisclosed location, causing the science team to rely only on mission data for geological and biological interpretations. Core and borehole imaging was used for micromorphological analysis of rock, targeting rock for biological analysis, and making decisions regarding the next day's drilling operations. Drilling reached 606 cm depth into poorly consolidated gossan that allowed only 35% of core recovery and contributed to borehole wall failure during drilling. Core material containing any indication of biology was sampled and analyzed in more detail for its confirmation. Despite the poorly consolidated nature of the subsurface gossan, dry drilling was able to retrieve useful core material for geological and biological analysis. Lessons learned from this drilling simulation can guide the development of dry drilling and subsurface geological and biological analytical technologies for future Mars drilling missions.

Analysis and Testing of Load Characteristics for Rotary-Percussive Drilling of Lunar Rock Simulant with a Lunar Regolith Coring Bit

Directory of Open Access Journals (Sweden)

Peng Li

2017-01-01

Full Text Available Based on an optimized lunar regolith coring bit (LRCB configuration, the load characteristics of rotary-percussive drilling of lunar rock simulant in a laboratory environment are analyzed to determine the effects of the drilling parameters (the rotational velocity, the penetration rate, and the percussion frequency on the drilling load. The process of rotary drilling into lunar rock using an LRCB is modeled as an interaction between an elemental blade and the rock. The rock’s fracture mechanism during different stages of the percussive mechanism is analyzed to create a load forecasting model for the cutting and percussive fracturing of rock using an elemental blade. Finally, a model of the load on the LRCB is obtained from the analytic equation for the bit’s cutting blade distribution; experimental verification of the rotary-impact load characteristics for lunar rock simulant with different parameters is performed. The results show that the penetrations per revolution (PPR are the primary parameter influencing the drilling load. When the PPR are fixed, increasing the percussion frequency reduces the drilling load on the rock. Additionally, the variation pattern of the drilling load of the bit is in agreement with that predicted by the theoretical model. This provides a research basis for subsequent optimization of the drilling procedure and online recognition of the drilling process.

HYDRATE CORE DRILLING TESTS

Energy Technology Data Exchange (ETDEWEB)

John H. Cohen; Thomas E. Williams; Ali G. Kadaster; Bill V. Liddell

2002-11-01

The ''Methane Hydrate Production from Alaskan Permafrost'' project is a three-year endeavor being conducted by Maurer Technology Inc. (MTI), Noble, and Anadarko Petroleum, in partnership with the U.S. DOE National Energy Technology Laboratory (NETL). The project's goal is to build on previous and ongoing R&D in the area of onshore hydrate deposition. The project team plans to design and implement a program to safely and economically drill, core and produce gas from arctic hydrates. The current work scope includes drilling and coring one well on Anadarko leases in FY 2003 during the winter drilling season. A specially built on-site core analysis laboratory will be used to determine some of the physical characteristics of the hydrates and surrounding rock. Prior to going to the field, the project team designed and conducted a controlled series of coring tests for simulating coring of hydrate formations. A variety of equipment and procedures were tested and modified to develop a practical solution for this special application. This Topical Report summarizes these coring tests. A special facility was designed and installed at MTI's Drilling Research Center (DRC) in Houston and used to conduct coring tests. Equipment and procedures were tested by cutting cores from frozen mixtures of sand and water supported by casing and designed to simulate hydrate formations. Tests were conducted with chilled drilling fluids. Tests showed that frozen core can be washed out and reduced in size by the action of the drilling fluid. Washing of the core by the drilling fluid caused a reduction in core diameter, making core recovery very difficult (if not impossible). One successful solution was to drill the last 6 inches of core dry (without fluid circulation). These tests demonstrated that it will be difficult to capture core when drilling in permafrost or hydrates without implementing certain safeguards. Among the coring tests was a simulated hydrate

Drilling azimuth gamma embedded design

Directory of Open Access Journals (Sweden)

Zhou Yi Ren

2016-01-01

Full Text Available Embedded drilling azimuth gamma design, the use of radioactive measuring principle embedded gamma measurement while drilling a short section analysis. Monte Carlo method, in response to the density of horizontal well logging numerical simulation of 16 orientation, the orientation of horizontal well analysed, calliper, bed boundary location, space, different formation density, formation thickness, and other factors inclined strata dip the impact by simulating 137Cs sources under different formation conditions of the gamma distribution, to determine the orientation of drilling density tool can detect window size and space, draw depth of the logging methods. The data 360° azimuth imaging, image processing method to obtain graph, display density of the formation, dip and strata thickness and other parameters, the logging methods obtain real-time geo-steering. To establish a theoretical basis for the orientation density logging while drilling method implementation and application of numerical simulation in-depth study of the MWD azimuth and density log response factors of horizontal wells.

The ``Adopt A Microbe'' project: Web-based interactive education connected with scientific ocean drilling

Science.gov (United States)

Orcutt, B. N.; Bowman, D.; Turner, A.; Inderbitzen, K. E.; Fisher, A. T.; Peart, L. W.; Iodp Expedition 327 Shipboard Party

2010-12-01

We launched the "Adopt a Microbe" project as part of Integrated Ocean Drilling Program (IODP) Expedition 327 in Summer 2010. This eight-week-long education and outreach effort was run by shipboard scientists and educators from the research vessel JOIDES Resolution, using a web site (https://sites.google.com/site/adoptamicrobe) to engage students of all ages in an exploration of the deep biosphere inhabiting the upper ocean crust. Participants were initially introduced to a cast of microbes (residing within an ‘Adoption Center’ on the project website) that live in the dark ocean and asked to select and virtually ‘adopt’ a microbe. A new educational activity was offered each week to encourage learning about microbiology, using the adopted microbe as a focal point. Activities included reading information and asking questions about the adopted microbes (with subsequent responses from shipboard scientists), writing haiku about the adopted microbes, making balloon and fabric models of the adopted microbes, answering math questions related to the study of microbes in the ocean, growing cultures of microbes, and examining the gases produced by microbes. In addition, the website featured regular text, photo and video updates about the science of the expedition using a toy microbe as narrator, as well as stories written by shipboard scientists from the perspective of deep ocean microbes accompanied by watercolor illustrations prepared by a shipboard artist. Assessment methods for evaluating the effectiveness of the Adopt a Microbe project included participant feedback via email and online surveys, website traffic monitoring, and online video viewing rates. Quantitative metrics suggest that the “Adope A Microbe” project was successful in reaching target audiences and helping to encourage and maintain interest in topics related to IODP Expedition 327. The “Adopt A Microbe” project mdel can be adapted for future oceanographic expeditions to help connect the

Multi-state autonomous drilling for lunar exploration

Directory of Open Access Journals (Sweden)

Chen Chongbin

2016-10-01

Full Text Available Due to the lack of information of subsurface lunar regolith stratification which varies along depth, the drilling device may encounter lunar soil and lunar rock randomly in the drilling process. To meet the load safety requirements of unmanned sampling mission under limited orbital resources, the control strategy of autonomous drilling should adapt to the indeterminable lunar environments. Based on the analysis of two types of typical drilling media (i.e., lunar soil and lunar rock, this paper proposes a multi-state control strategy for autonomous lunar drilling. To represent the working circumstances in the lunar subsurface and reduce the complexity of the control algorithm, lunar drilling process was categorized into three drilling states: the interface detection, initiation of drilling parameters for recognition and drilling medium recognition. Support vector machine (SVM and continuous wavelet transform were employed for the online recognition of drilling media and interface, respectively. Finite state machine was utilized to control the transition among different drilling states. To verify the effectiveness of the multi-state control strategy, drilling experiments were implemented with multi-layered drilling media constructed by lunar soil simulant and lunar rock simulant. The results reveal that the multi-state control method is capable of detecting drilling state variation and adjusting drilling parameters timely under vibration interferences. The multi-state control method provides a feasible reference for the control of extraterrestrial autonomous drilling.

Effects of implant drilling parameters for pilot and twist drills on temperature rise in bone analog and alveolar bones.

Science.gov (United States)

Chen, Yung-Chuan; Hsiao, Chih-Kun; Ciou, Ji-Sih; Tsai, Yi-Jung; Tu, Yuan-Kun

2016-11-01

This study concerns the effects of different drilling parameters of pilot drills and twist drills on the temperature rise of alveolar bones during dental implant procedures. The drilling parameters studied here include the feed rate and rotation speed of the drill. The bone temperature distribution was analyzed through experiments and numerical simulations of the drilling process. In this study, a three dimensional (3D) elasto-plastic dynamic finite element model (DFEM) was proposed to investigate the effects of drilling parameters on the bone temperature rise. In addition, the FE model is validated with drilling experiments on artificial human bones and porcine alveolar bones. The results indicate that 3D DFEM can effectively simulate the bone temperature rise during the drilling process. During the drilling process with pilot drills or twist drills, the maximum bone temperature occurred in the region of the cancellous bones close to the cortical bones. The feed rate was one of the important factors affecting the time when the maximum bone temperature occurred. Our results also demonstrate that the elevation of bone temperature was reduced as the feed rate increased and the drill speed decreased, which also effectively reduced the risk region of osteonecrosis. These findings can serve as a reference for dentists in choosing drilling parameters for dental implant surgeries. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Environmental Measurement-While-Drilling System and Horizontal Directional Drilling Technology Demonstration, Hanford Site

International Nuclear Information System (INIS)

Williams, C.V.; Lockwood, G.J.; Normann, R.A.; Myers, D.A.; Gardner, M.G.; Williamson, T.; Huffman, J.

1999-01-01

The Environmental Measurement-While-Drilling (EMWD) system and Horizontal Directional Drilling (HDD) were successfully demonstrated at the Mock Tank Leak Simulation Site and the Drilling Technology Test Site, Hanford, Washington. The use of directional drilling offers an alternative to vertical drilling site characterization. Directional drilling can develop a borehole under a structure, such as a waste tank, from an angled entry and leveling off to horizontal at the desired depth. The EMWD system represents an innovative blend of new and existing technology that provides the capability of producing real-time environmental and drill bit data during drilling operations. The technology demonstration consisted of the development of one borehole under a mock waste tank at a depth of approximately minus8 m (minus27 ft.), following a predetermined drill path, tracking the drill path to within a radius of approximately1.5 m (5 ft.), and monitoring for zones of radiological activity using the EMWD system. The purpose of the second borehole was to demonstrate the capability of drilling to a depth of ∼ -21 m (-70 ft.), the depth needed to obtain access under the Hanford waste tanks, and continue drilling horizontally. This report presents information on the HDD and EMWD technologies, demonstration design, results of the demonstrations, and lessons learned

Building Comprehensive Strategies for Obstetric Safety: Simulation Drills and Communication.

Science.gov (United States)

Austin, Naola; Goldhaber-Fiebert, Sara; Daniels, Kay; Arafeh, Julie; Grenon, Veronique; Welle, Dana; Lipman, Steven

2016-11-01

As pioneers in the field of patient safety, anesthesiologists are uniquely suited to help develop and implement safety strategies to minimize preventable harm on the labor and delivery unit. Most existing obstetric safety strategies are not comprehensive, lack input from anesthesiologists, are designed with a relatively narrow focus, or lack implementation details to allow customization for different units. This article attempts to address these gaps and build more comprehensive strategies by discussing the available evidence and multidisciplinary authors' local experience with obstetric simulation drills and optimization of team communication.

Biogeochemical Reactions Under Simulated Europa Ocean Conditions

Science.gov (United States)

Amashukeli, X.; Connon, S. A.; Gleeson, D. F.; Kowalczyk, R. S.; Pappalardo, R. T.

2007-12-01

Galileo data have demonstrated the probable presence of a liquid water ocean on Europa, and existence of salts and carbon dioxide in the satellite's surface ice (e.g., Carr et al., 1998; McCord et al., 1999, Pappalardo et al., 1999; Kivelson et al., 2000). Subsequently, the discovery of chemical signatures of extinct or extant life in Europa's ocean and on its surface became a distinct possibility. Moreover, understanding of Europa's potential habitability is now one of the major goals of the Europa Orbiter Flagship mission. It is likely, that in the early stages of Europa's ocean formation, moderately alkaline oceanic sulfate-carbonate species and a magnetite-silicate mantel could have participated in low-temperature biogeochemical sulfur, iron and carbon cycles facilitated by primitive organisms (Zolotov and Shock, 2004). If periodic supplies of fresh rock and sulfate-carbonate ions are available in Europa's ocean, then an exciting prospect exists that life may be present in Europa's ocean today. In our laboratory, we began the study of the plausible biogeochemical reactions under conditions appropriate to Europa's ocean using barophilic psychrophilic organisms that thrive under anaerobic conditions. In the near absence of abiotic synthetic pathways due to low Europa's temperatures, the biotic synthesis may present a viable opportunity for the formation of the organic and inorganic compounds under these extreme conditions. This work is independent of assumptions regarding hydrothermal vents at Europa's ocean floor or surface-derived oxidant sources. For our studies, we have fabricated a high-pressure (5,000 psi) reaction vessel that simulates aqueous conditions on Europa. We were also successful at reviving barophilic psychrophilic strains of Shewanella bacterium, which serve as test organisms in this investigation. Currently, facultative barophilic psychrophilic stains of Shewanella are grown in the presence of ferric food source; the strains exhibiting iron

Contamination tracer testing with seabed drills: IODP Expedition 357

Science.gov (United States)

Orcutt, Beth N.; Bergenthal, Markus; Freudenthal, Tim; Smith, David; Lilley, Marvin D.; Schnieders, Luzie; Green, Sophie; Früh-Green, Gretchen L.

2017-11-01

IODP Expedition 357 utilized seabed drills for the first time in the history of the ocean drilling program, with the aim of collecting intact sequences of shallow mantle core from the Atlantis Massif to examine serpentinization processes and the deep biosphere. This novel drilling approach required the development of a new remote seafloor system for delivering synthetic tracers during drilling to assess for possible sample contamination. Here, we describe this new tracer delivery system, assess the performance of the system during the expedition, provide an overview of the quality of the core samples collected for deep biosphere investigations based on tracer concentrations, and make recommendations for future applications of the system.

Information on commercial disposal facilities that may have received offshore drilling wastes.

Energy Technology Data Exchange (ETDEWEB)

Gasper, J. R.; Veil, J. A.; Ayers, R. C., Jr.

2000-08-25

The U.S. Environmental Protection Agency (EPA) is developing regulations that would establish requirements for discharging synthetic-based drill cuttings from offshore wells into the ocean. Justification for allowing discharges of these cuttings is that the environmental impacts from discharging drilling wastes into the ocean may be less harmful than the impacts from hauling them to shore for disposal. In the past, some onshore commercial facilities that disposed of these cuttings were improperly managed and operated and left behind environmental problems. This report provides background information on commercial waste disposal facilities in Texas, Louisiana, California, and Alaska that received or may have received offshore drilling wastes in the past and are now undergoing cleanup.

Integrated Approach to Drilling Project in Unconventional Reservoir Using Reservoir Simulation

Science.gov (United States)

Stopa, Jerzy; Wiśniowski, Rafał; Wojnarowski, Paweł; Janiga, Damian; Skrzypaszek, Krzysztof

2018-03-01

Accumulation and flow mechanisms in unconventional reservoir are different compared to conventional. This requires a special approach of field management with drilling and stimulation treatments as major factor for further production. Integrated approach of unconventional reservoir production optimization assumes coupling drilling project with full scale reservoir simulation for determine best well placement, well length, fracturing treatment design and mid-length distance between wells. Full scale reservoir simulation model emulate a part of polish shale - gas field. The aim of this paper is to establish influence of technical factor for gas production from shale gas field. Due to low reservoir permeability, stimulation treatment should be direct towards maximizing the hydraulic contact. On the basis of production scenarios, 15 stages hydraulic fracturing allows boost gas production over 1.5 times compared to 8 stages. Due to the possible interference of the wells, it is necessary to determine the distance between the horizontal parts of the wells trajectories. In order to determine the distance between the wells allowing to maximize recovery factor of resources in the stimulated zone, a numerical algorithm based on a dynamic model was developed and implemented. Numerical testing and comparative study show that the most favourable arrangement assumes a minimum allowable distance between the wells. This is related to the volume ratio of the drainage zone to the total volume of the stimulated zone.

COBBOOM: The Continental Breakup and Birth of Oceans Mission

Directory of Open Access Journals (Sweden)

Joann M. Stock

2007-09-01

Full Text Available The rupture of continents and creation of new oceans is a　fundamental yet primitively understood aspect of the plate　tectonic cycle. Building upon past achievements by ocean　drilling and geophysical and geologic studies, we propose　“The Continental Breakup and Birth of Oceans Mission　(COBBOOM” as the next major phase of discovery, for　which sampling by drilling will be essential.In September 2006, fifty-one scientists from six continents　gathered in Pontresina, Switzerland to discuss current　knowledge of continental breakup and sedimentary basin　formation and how the Integrated Ocean Drilling Program　(IODP can deepen that knowledge Coffin et al., 2006.　Workshop participants discussed a global array of rifted　margins (Fig. 1, formulated the critical problems to beaddressed by future drilling and related investigations, and　identified key rift systems poised for IODP investigations.　

Contamination tracer testing with seabed drills: IODP Expedition 357

Directory of Open Access Journals (Sweden)

B. N. Orcutt

2017-11-01

Full Text Available IODP Expedition 357 utilized seabed drills for the first time in the history of the ocean drilling program, with the aim of collecting intact sequences of shallow mantle core from the Atlantis Massif to examine serpentinization processes and the deep biosphere. This novel drilling approach required the development of a new remote seafloor system for delivering synthetic tracers during drilling to assess for possible sample contamination. Here, we describe this new tracer delivery system, assess the performance of the system during the expedition, provide an overview of the quality of the core samples collected for deep biosphere investigations based on tracer concentrations, and make recommendations for future applications of the system.

Contamination Tracer Testing With Seabed Rock Drills: IODP Expedition 357

Science.gov (United States)

Orcutt, B.; Bergenthal, M.; Freudenthal, T.; Smith, D. J.; Lilley, M. D.; Schneiders, L.; Fruh-Green, G. L.

2016-12-01

IODP Expedition 357 utilized seabed rock drills for the first time in the history of the ocean drilling program, with the aim of collecting intact core of shallow mantle sequences from the Atlantis Massif to examine serpentinization processes and the deep biosphere. This new drilling approach required the development of a new system for delivering synthetic tracers during drilling to assess for possible sample contamination. Here, we describe this new tracer delivery system, assess the performance of the system during the expedition, provide an overview of the quality of the core samples collected for deep biosphere investigations based on tracer concentrations, and make recommendations for future applications of the system.

Arctic Ocean Scientific Drilling: The Next Frontier

Directory of Open Access Journals (Sweden)

Ruediger Stein

2010-04-01

Full Text Available The modern Arctic Ocean appears to be changing faster than any other region on Earth. To understand the potential extent of high latitude climate change, it is necessary to sample the history stored in the sediments filling the basins and covering the ridges of the Arctic Ocean. These sediments have been imaged with seismic reflection data, but except for the superficial record, which has been piston cored, they have been sampled only on the Lomonosov Ridge in 2004 during the Arctic Coring Expedition (ACEX-IODP Leg 302; Backman et al., 2006 and in 1993 in the ice-free waters in the Fram Strait/Yermak Plateau area (ODP Leg 151; Thiede et al., 1996.Although major progress in Arctic Ocean research has been made during the last few decades, the short- and long-term paleoceanographic and paleoclimatic history as well as its plate-tectonic evolution are poorly known compared to the other oceans. Despite the importance of the Arctic in the climate system, the database we have from this area is still very weak. Large segments of geologic time have not been sampled in sedimentary sections. The question of regional variations cannot be addressed.

Active Suppression of Drilling System Vibrations For Deep Drilling

Energy Technology Data Exchange (ETDEWEB)

Raymond, David W.; Blankenship, Douglas A.; Buerger, Stephen; Mesh, Mikhail; Radigan, William Thomas; Su, Jiann-Cherng

2015-10-01

The dynamic stability of deep drillstrings is challenged by an inability to impart controllability with ever-changing conditions introduced by geology, depth, structural dynamic properties and operating conditions. A multi-organizational LDRD project team at Sandia National Laboratories successfully demonstrated advanced technologies for mitigating drillstring vibrations to improve the reliability of drilling systems used for construction of deep, high-value wells. Using computational modeling and dynamic substructuring techniques, the benefit of controllable actuators at discrete locations in the drillstring is determined. Prototype downhole tools were developed and evaluated in laboratory test fixtures simulating the structural dynamic response of a deep drillstring. A laboratory-based drilling applicability demonstration was conducted to demonstrate the benefit available from deployment of an autonomous, downhole tool with self-actuation capabilities in response to the dynamic response of the host drillstring. A concept is presented for a prototype drilling tool based upon the technical advances. The technology described herein is the subject of U.S. Patent Application No. 62219481, entitled "DRILLING SYSTEM VIBRATION SUPPRESSION SYSTEMS AND METHODS", filed September 16, 2015.

Addressing submarine geohazards through scientific drilling

Science.gov (United States)

Camerlenghi, A.

2009-04-01

Natural submarine geohazards (earthquakes, volcanic eruptions, landslides, volcanic island flank collapses) are geological phenomena originating at or below the seafloor leading to a situation of risk for off-shore and on-shore structures and the coastal population. Addressing submarine geohazards means understanding their spatial and temporal variability, the pre-conditioning factors, their triggers, and the physical processes that control their evolution. Such scientific endeavour is nowadays considered by a large sector of the international scientific community as an obligation in order to contribute to the mitigation of the potentially destructive societal effects of submarine geohazards. The study of submarine geohazards requires a multi-disciplinary scientific approach: geohazards must be studied through their geological record; active processes must be monitored; geohazard evolution must be modelled. Ultimately, the information must be used for the assessment of vulnerability, risk analysis, and development of mitigation strategies. In contrast with the terrestrial environment, the oceanic environment is rather hostile to widespread and fast application of high-resolution remote sensing techniques, accessibility for visual inspection, sampling and installation of monitoring stations. Scientific Drilling through the IODP (including the related pre site-survey investigations, sampling, logging and in situ measurements capability, and as a platform for deployment of long term observatories at the surface and down-hole) can be viewed as the centre of gravity of an international, coordinated, multi-disciplinary scientific approach to address submarine geohazards. The IODP Initial Science Plan expiring in 2013 does not address openly geohazards among the program scientific objectives. Hazards are referred to mainly in relation to earthquakes and initiatives towards the understanding of seismogenesis. Notably, the only drilling initiative presently under way is the

North Pacific Mesoscale Coupled Air-Ocean Simulations Compared with Observations

Energy Technology Data Exchange (ETDEWEB)

Koracin, Darko; Cerovecki, Ivana; Vellore, Ramesh; Mejia, John; Hatchett, Benjamin; McCord, Travis; McLean, Julie; Dorman, Clive

2013-04-11

Executive summary The main objective of the study was to investigate atmospheric and ocean interaction processes in the western Pacific and, in particular, effects of significant ocean heat loss in the Kuroshio and Kuroshio Extension regions on the lower and upper atmosphere. It is yet to be determined how significant are these processes are on climate scales. The understanding of these processes led us also to development of the methodology of coupling the Weather and Research Forecasting model with the Parallel Ocean Program model for western Pacific regional weather and climate simulations. We tested NCAR-developed research software Coupler 7 for coupling of the WRF and POP models and assessed its usability for regional-scale applications. We completed test simulations using the Coupler 7 framework, but implemented a standard WRF model code with options for both one- and two-way mode coupling. This type of coupling will allow us to seamlessly incorporate new WRF updates and versions in the future. We also performed a long-term WRF simulation (15 years) covering the entire North Pacific as well as high-resolution simulations of a case study which included extreme ocean heat losses in the Kuroshio and Kuroshio Extension regions. Since the extreme ocean heat loss occurs during winter cold air outbreaks (CAO), we simulated and analyzed a case study of a severe CAO event in January 2000 in detail. We found that the ocean heat loss induced by CAOs is amplified by additional advection from mesocyclones forming on the southern part of the Japan Sea. Large scale synoptic patterns with anomalously strong anticyclone over Siberia and Mongolia, deep Aleutian Low, and the Pacific subtropical ridge are a crucial setup for the CAO. It was found that the onset of the CAO is related to the breaking of atmospheric Rossby waves and vertical transport of vorticity that facilitates meridional advection. The study also indicates that intrinsic parameterization of the surface fluxes

Archive of Geosample Information from Scientific Ocean Drilling

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Texas A and M University (TAMU), JOIDES Resolution Science Operator of the International Ocean Discovery Program (IODP), is a partner in the Index to Marine and...

A perfectly matched layer for fluid-solid problems: Application to ocean-acoustics simulations with solid ocean bottoms

DEFF Research Database (Denmark)

Xie, Zhinan; Matzen, René; Cristini, Paul

2016-01-01

A time-domain Legendre spectral-element method is described for full-wave simulation of ocean acoustics models, i.e., coupled fluid-solid problems in unbounded or semi-infinite domains, taking into account shear wave propagation in the ocean bottom. The technique can accommodate range-dependent a......A time-domain Legendre spectral-element method is described for full-wave simulation of ocean acoustics models, i.e., coupled fluid-solid problems in unbounded or semi-infinite domains, taking into account shear wave propagation in the ocean bottom. The technique can accommodate range......-dependent and depth-dependent wave speed and density, as well as steep ocean floor topography. For truncation of the infinite domain, to efficiently absorb outgoing waves, a fluid-solid complex-frequency-shifted unsplit perfectly matched layer is introduced based on the complex coordinate stretching technique....... The complex stretching is rigorously taken into account in the derivation of the fluid-solid matching condition inside the absorbing layer, which has never been done before in the time domain. Two implementations are designed: a convolutional formulation and an auxiliary differential equation formulation...

Rock Magnetic Characterization Through an Intact Sequence of Oceanic Crust, IODP Hole 1256D

NARCIS (Netherlands)

Herrero-Bervera, E.; Acton, G.; Krasá, D.; Rodriguez, S.; Dekkers, M.J.

2011-01-01

Coring at Site 1256 (6.736◦N, 91.934◦W, 3635 m water depth) during Ocean Drilling Program (ODP) Leg 206 and Integrated Ocean Drilling Program (IODP) Expeditions 309 and 312 successfully sampled a complete section of in situ oceanic crust, including sediments of Seismic Layer 1, lavas and dikes of

A simulation approach to material removal in microwave drilling of soda lime glass at 2.45 GHz

Science.gov (United States)

Lautre, Nitin Kumar; Sharma, Apurbba Kumar; Pradeep, Kumar; Das, Shantanu

2015-09-01

Material removal during microwave drilling is basically due to thermal ablation of the material in the vicinity of the drilling tool. The microtip of the tool, also termed as concentrator, absorbs microwaves and ionizes the dielectric in its proximity creating a zone of plasma. The plasma takes the shape of a sphere owing to the atmospheric sphere, which acts as the source of thermal energy to be used for processing a material. This mechanism of heating, also called localized microwave heating, was used in the present study to drill holes in 1.2-mm-thick soda lime glass. The mechanism of material removal had been analyzed through simulation of the hot spot region, and the results were attempted to explain through experiment observations. It was realized that the glass being a poor conductor of heat, a low power (90 W in this case) yields better drilling results owing to more localized heat corresponding to a low-volume plasma sphere. The low application time prevents further heat transfer, and a localized concentration of heat becomes possible that primarily causes the material ablation. The plasma sphere appears sustain while the tool moves through the bulk of the glass thickness although its volume gets further shrunk. The process needs careful selection of the parameters. The simulation results show relatively low temperature in the top half (opposite to the tool tip) of the plasma sphere which eventually causes the semimolten viscous glass to collapse into the drill cavity as the tool advances into the bulk and stops the movement of the tool. The continued plasma sphere raises the tip temperature, which makes the tip to melt and gets blunt. The plasma formation ceases owing to larger diameter of the tool, and the tool gets stuck which could be verified through experimental results.

Tidal simulation using regional ocean modeling systems (ROMS)

Science.gov (United States)

Wang, Xiaochun; Chao, Yi; Li, Zhijin; Dong, Changming; Farrara, John; McWilliams, James C.; Shum, C. K.; Wang, Yu; Matsumoto, Koji; Rosenfeld, Leslie K.;

Data Drilled for Stellwagen Bank National Marine Sanctuary

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — GeoTif images of chlorophyll, turbidity, and SST were created of the region. Then an EASI script was run on the geotifs to extract the data (drill the data) from...

Visualization and analysis of eddies in a global ocean simulation

Energy Technology Data Exchange (ETDEWEB)

Williams, Sean J [Los Alamos National Laboratory; Hecht, Matthew W [Los Alamos National Laboratory; Petersen, Mark [Los Alamos National Laboratory; Strelitz, Richard [Los Alamos National Laboratory; Maltrud, Mathew E [Los Alamos National Laboratory; Ahrens, James P [Los Alamos National Laboratory; Hlawitschka, Mario [UC DAVIS; Hamann, Bernd [UC DAVIS

2010-10-15

Eddies at a scale of approximately one hundred kilometers have been shown to be surprisingly important to understanding large-scale transport of heat and nutrients in the ocean. Due to difficulties in observing the ocean directly, the behavior of eddies below the surface is not very well understood. To fill this gap, we employ a high-resolution simulation of the ocean developed at Los Alamos National Laboratory. Using large-scale parallel visualization and analysis tools, we produce three-dimensional images of ocean eddies, and also generate a census of eddy distribution and shape averaged over multiple simulation time steps, resulting in a world map of eddy characteristics. As expected from observational studies, our census reveals a higher concentration of eddies at the mid-latitudes than the equator. Our analysis further shows that mid-latitude eddies are thicker, within a range of 1000-2000m, while equatorial eddies are less than 100m thick.

Stability of finite difference numerical simulations of acoustic logging-while-drilling with different perfectly matched layer schemes

Science.gov (United States)

Wang, Hua; Tao, Guo; Shang, Xue-Feng; Fang, Xin-Ding; Burns, Daniel R.

2013-12-01

In acoustic logging-while-drilling (ALWD) finite difference in time domain (FDTD) simulations, large drill collar occupies, most of the fluid-filled borehole and divides the borehole fluid into two thin fluid columns (radius ˜27 mm). Fine grids and large computational models are required to model the thin fluid region between the tool and the formation. As a result, small time step and more iterations are needed, which increases the cumulative numerical error. Furthermore, due to high impedance contrast between the drill collar and fluid in the borehole (the difference is >30 times), the stability and efficiency of the perfectly matched layer (PML) scheme is critical to simulate complicated wave modes accurately. In this paper, we compared four different PML implementations in a staggered grid finite difference in time domain (FDTD) in the ALWD simulation, including field-splitting PML (SPML), multiaxial PML(MPML), non-splitting PML (NPML), and complex frequency-shifted PML (CFS-PML). The comparison indicated that NPML and CFS-PML can absorb the guided wave reflection from the computational boundaries more efficiently than SPML and M-PML. For large simulation time, SPML, M-PML, and NPML are numerically unstable. However, the stability of M-PML can be improved further to some extent. Based on the analysis, we proposed that the CFS-PML method is used in FDTD to eliminate the numerical instability and to improve the efficiency of absorption in the PML layers for LWD modeling. The optimal values of CFS-PML parameters in the LWD simulation were investigated based on thousands of 3D simulations. For typical LWD cases, the best maximum value of the quadratic damping profile was obtained using one d 0. The optimal parameter space for the maximum value of the linear frequency-shifted factor ( α 0) and the scaling factor ( β 0) depended on the thickness of the PML layer. For typical formations, if the PML thickness is 10 grid points, the global error can be reduced to <1

Petroleum drilling and production operations in the Gulf of Mexico

International Nuclear Information System (INIS)

Fang, C.S.

1991-01-01

Decades of offshore and inland petroleum drilling and production in the Gulf of Mexico and on the Gulf Coast have provided the much needed energy and chemical feedstocks to the nation, and also have made an impact on the environment in the area. Our study showed deposits of contaminated sediment on the ocean floor around offshore platforms, old reserve pits, and dump sites next to many surface facilities and compressor stations. The substances found on the ocean floor and in dump sites are simple or emulsified mixtures of silt, hydrocarbons, and water. The cleaning of the ocean floor and pits is an economic and technical challenge. Hydrocarbons are from crude oil and chemical additions fro various operational necessities, including additions of biocides, corrosion inhibitors, antifreezes, and coagulants. When the new government regulations lower the allowable maximum total organic carbon level to the 50 ppm range, these hydrocarbons can no longer be ignored by drilling and production operators

Drill cuttings mount formation study

Science.gov (United States)

Teh, Su Yean; Koh, Hock Lye

2014-07-01

Oil, Gas and Energy sector has been identified as an essential driving force in the Malaysian Economic Transformation Programs (ETP). Recently confirmed discovery of many offshore oil and gas deposits in Malaysian waters has ignited new confidence in this sector. However, this has also spurred intense interest on safeguarding the health and environment of coastal waters in Malaysia from adverse impact resulting from offshore oil and gas production operation. Offshore discharge of spent drilling mud and rock cuttings is the least expensive and simplest option to dispose of large volumes of drilling wastes. But this onsite offshore disposal may have adverse environmental impacts on the water column and the seabed. It may also pose occupational health hazards to the workers living in the offshore platforms. It is therefore important to model the transport and deposition of drilling mud and rock cuttings in the sea to enable proper assessment of their adverse impacts on the environment and the workers. Further, accumulation of drill particles on the seabed may impede proper operation of pipelines on the seabed. In this paper, we present an in-house application model TUNA-PT developed to cater to local oil and gas industry needs to simulate the dispersion and mount formation of drill cuttings by offshore oil and gas exploration and production platforms. Using available data on Malaysian coastal waters, simulation analyses project a pile formation on the seabed with a maximum height of about 1 m and pile radius of around 30 to 50 m. Simulated pile heights are not sensitive to the heights of release of the cuttings as the sensitivity has been mitigated by the depth of water.

Investigation of PDC bit failure base on stick-slip vibration analysis of drilling string system plus drill bit

Science.gov (United States)

Huang, Zhiqiang; Xie, Dou; Xie, Bing; Zhang, Wenlin; Zhang, Fuxiao; He, Lei

2018-03-01

The undesired stick-slip vibration is the main source of PDC bit failure, such as tooth fracture and tooth loss. So, the study of PDC bit failure base on stick-slip vibration analysis is crucial to prolonging the service life of PDC bit and improving ROP (rate of penetration). For this purpose, a piecewise-smooth torsional model with 4-DOF (degree of freedom) of drilling string system plus PDC bit is proposed to simulate non-impact drilling. In this model, both the friction and cutting behaviors of PDC bit are innovatively introduced. The results reveal that PDC bit is easier to fail than other drilling tools due to the severer stick-slip vibration. Moreover, reducing WOB (weight on bit) and improving driving torque can effectively mitigate the stick-slip vibration of PDC bit. Therefore, PDC bit failure can be alleviated by optimizing drilling parameters. In addition, a new 4-DOF torsional model is established to simulate torsional impact drilling and the effect of torsional impact on PDC bit's stick-slip vibration is analyzed by use of an engineering example. It can be concluded that torsional impact can mitigate stick-slip vibration, prolonging the service life of PDC bit and improving drilling efficiency, which is consistent with the field experiment results.

A workshop model simulating fate and effect of drilling muds and cuttings on benthic communities

Science.gov (United States)

Auble, Gregor T.; Andrews, Austin K.; Hamilton, David B.; Roelle, James E.; Shoemaker, Thomas G.

1984-01-01

Oil and gas exploration and production at marine sites has generated concern over potential environmental impacts resulting from the discharge of spent drilling muds and cuttings. This concern has led to a broad array of publicly and privately sponsored research. This report described a cooperative modeling effort designed to focus information resulting from this research through construction of explicit equations that simulate the potential impacts of discharge drilling fluids (muds) and cuttings on marine communities. The model is the result of collaboration among more than 30 scientists. The principal cooperating organizations were the E.S. Environmental Protection Agency, the U.S. Minerals Management Service, the Offshore Operators Committee, and the Alaska Oil and Gas Association. The overall simulation model can be conceptualized as three connected submodels: Discharge and Plume Fate, Sediment Redistribution, and Benthic Community Effects. On each day of simulation, these submodels are executed in sequence, with flows of information between submodels. The Benthic Community Effects submodel can be further divided into sections that calculate mortality due to burial, mortality due to toxicity, mortality due to resuspension disturbance, and growth of the community. The model represents a series of seven discrete 1-m2 plots at specified distances along a transect in one direction away from a discharge point. It consists of coupled difference equations for which parameter values can easily be set to evaluate different conditions or to examine the sensitivity of output to various assumptions. Sets of parameter values were developed to represent four general cases or scenarios: (1) a shallow (5 m), cold environment with ice cover during a substantial fraction of the year, such as might be encountered in the Beaufort Sea, Alaska; (2) a shallow (20 m), temperate environment, such as might be encountered in the Gulf of Mexico; (3) a deeper (80 m), temperate environment

Assimilation of Ocean-Color Plankton Functional Types to Improve Marine Ecosystem Simulations

Science.gov (United States)

Ciavatta, S.; Brewin, R. J. W.; Skákala, J.; Polimene, L.; de Mora, L.; Artioli, Y.; Allen, J. I.

2018-02-01

We assimilated phytoplankton functional types (PFTs) derived from ocean color into a marine ecosystem model, to improve the simulation of biogeochemical indicators and emerging properties in a shelf sea. Error-characterized chlorophyll concentrations of four PFTs (diatoms, dinoflagellates, nanoplankton, and picoplankton), as well as total chlorophyll for comparison, were assimilated into a physical-biogeochemical model of the North East Atlantic, applying a localized Ensemble Kalman filter. The reanalysis simulations spanned the years 1998-2003. The skill of the reference and reanalysis simulations in estimating ocean color and in situ biogeochemical data were compared by using robust statistics. The reanalysis outperformed both the reference and the assimilation of total chlorophyll in estimating the ocean-color PFTs (except nanoplankton), as well as the not-assimilated total chlorophyll, leading the model to simulate better the plankton community structure. Crucially, the reanalysis improved the estimates of not-assimilated in situ data of PFTs, as well as of phosphate and pCO2, impacting the simulation of the air-sea carbon flux. However, the reanalysis increased further the model overestimation of nitrate, in spite of increases in plankton nitrate uptake. The method proposed here is easily adaptable for use with other ecosystem models that simulate PFTs, for, e.g., reanalysis of carbon fluxes in the global ocean and for operational forecasts of biogeochemical indicators in shelf-sea ecosystems.

Towards the design of new and improved drilling fluid additives using molecular dynamics simulations

Directory of Open Access Journals (Sweden)

Richard L. Anderson

2010-03-01

Full Text Available During exploration for oil and gas, a technical drilling fluid is used to lubricate the drill bit, maintain hydrostatic pressure, transmit sensor readings, remove rock cuttings and inhibit swelling of unstable clay based reactive shale formations. Increasing environmental awareness and resulting legislation has led to the search for new, improved biodegradable drilling fluid components. In the case of additives for clay swelling inhibition, an understanding of how existing effective additives interact with clays must be gained to allow the design of improved molecules. Owing to the disordered nature and nanoscopic dimension of the interlayer pores of clay minerals, computer simulations have become an increasingly useful tool for studying clay-swelling inhibitor interactions. In this work we briefly review the history of the development of technical drilling fluids, the environmental impact of drilling fluids and the use of computer simulations to study the interactions between clay minerals and swelling inhibitors. We report on results from some recent large-scale molecular dynamics simulation studies on low molecular weight water-soluble macromolecular inhibitor molecules. The structure and interactions of poly(propylene oxide-diamine, poly(ethylene glycol and poly(ethylene oxide-diacrylate inhibitor molecules with montmorillonite clay are studied.Durante a exploração de óleo e gás um fluido de perfuração é usado para lubrificar 'bit' da perfuradora, manter a pressão hidrostática, transmitir sensores de leitura, remover resíduos da rocha e inibir o inchamento da argila instável baseada nas formações dos folhelhos. O aumento das preocupações ambientais bem como a legislação resultante levou à procura de novos fluidos de perfuração com componentes biodegradáveis. No caso dos aditivos para inibir o inchamento das argilas o entendimento das interações entre os aditivos e as argilas tem que ser adquirido para permitir o

Experimental evaluation of training accelerators for surgical drilling

Directory of Open Access Journals (Sweden)

Gosselin Florian

2011-12-01

Full Text Available In some specific maxillo-facial surgeries, like the Epker, the cortical part of the lower maxilla must be drilled with minimum penetration into the spongy bone to avoid the trigeminal nerve. The result of the surgery is highly dependent on the quality of the drill. Drilling must therefore be mastered by students before acting as surgeon. The study compares the efficiency of two punctual drilling training programs developed on a virtual reality platform with non medical participants. The results show better benefit of training on relevant haptic aspects of the task before introducing multimodal drilling over repeated multimodal simulated drilling exercises.

An IODP proposal to drill the Godzilla Megamullion as a step to Mohole

Science.gov (United States)

Ohara, Y.; Michibayashi, K.; Dick, H. J. B.; Snow, J. E.; Ono, S.

2017-12-01

The year 2017 represents the 60th anniversary of the "original" project Mohole, which was coined by Walter Munk in 1957. Although the project Mohole has not yet been realized, the hard-rock community is now striving hard to understand the upper mantle in a variety of ways. Firstly, the present-day project Mohole, M2M (Moho-to-Mantle) project, will move forward in this September, conducting multi-channel seismic profiling off Hawaii as a site survey. Oman Drilling Project has started last December, and the drilled cores are being described aboard D/V Chikyu from July, this year. Furthermore, the forearc M2M proposal to drill the Bonin Trench forearc mantle was submitted to IODP in April 2016. Being a part of these efforts, we are preparing an IODP proposal to drill the Godzilla Megamullion, the largest known oceanic core complex on the Earth, located in the Parece Vela Basin in the Philippine Sea. A significant fraction of the ocean floor is created in backarc basins, while there have been no single long core of backarc basin lower ocean crust, from which to understand the likely differences in magmatic evolution and crustal structure in this key setting. The opportunity to explore the formation of the backarc basin lower crust and upper mantle is, therefore, an important contribution to understanding the ocean basins. At the same time, a better understanding of the architecture of backarc basin lower crust and upper mantle will greatly aid in the interpretation of the results of ophiolite study, since much of our understanding of the architecture of oceanic lower crust and upper mantle comes from ophiolites, most of which are thought to have at least some arc and/or backarc component. The Godzilla Megamullion is unique in its huge size as well as its development in a backarc basin, a rare tectonic window to study backarc basin lithosphere. The Godzilla Megamullion is prepared for full drilling proposal, with complete bathymetric data, multiple bottom samplings, and

Archive of Core and Site/Hole Data and Photographs from the Deep Sea Drilling Project (DSDP)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Deep Sea Drilling Project (DSDP) operated the D/V GLOMAR CHALLENGER from 1968-1983, drilling 1,112 holes at 624 sites worldwide. The DSDP was funded by the US...

Analysis of the drilling sound in maxillo-facial surgery

DEFF Research Database (Denmark)

Hoffmann, Pablo F.; Gosselin, Florian; Taha, Farid

2009-01-01

Auditory feedback can have a great potential in surgical simulators that aim at training skills associated to the correct interpretation of acoustic information. Here, we present a preliminary analysis of the sound that is produced by the drilling procedure in a maxillo-facial surgery when...... performed by expert surgeons. The motivation of this work is to find relevant acoustic parameters that allow for an efficient synthesis method of the drilling sound and to set the basis of the audio component in the simulator so that expert surgical drilling can effectively be conveyed to users...

Modeling, Simulation, and Experiment of Switched Reluctance Ocean Current Generator System

Directory of Open Access Journals (Sweden)

Hao Chen

2013-01-01

Full Text Available This paper presents nonlinear simulation model of switched reluctance (SR ocean current generator system on MATLAB/SIMULINK with describing the structure of generator system. The developed model is made up of main model, rotor position calculation module, controller module, gate module, power converter module, phase windings module, flux-linkage module, torque module, and power calculation module. The magnetization curves obtained by two-dimensional finite-element electromagnetic field calculation and the conjugated magnetic energy graphics obtained from the three-dimensional graphics of flux linkage are stored in the “Lookup Table” modules on MATLAB/SIMULINK. The hardware of the developed three-phase 12/8 structure SR ocean current generator system prototype with the experimental platform is presented. The simulation of the prototype is performed by the developed models, and the experiments have been carried out under the same condition with different output power, turn-off angle, and rotor speed. The simulated phase current waveforms agree well with the tested phase current waveforms experimentally. The simulated output voltage curves agree well with the tested output voltage curves experimentally. It is shown that the developed nonlinear simulation model of the three-phase 12/8 structure SR ocean current generator system is valid.

Advanced Drilling through Diagnostics-White-Drilling

International Nuclear Information System (INIS)

FINGER, JOHN T.; GLOWKA, DAVID ANTHONY; LIVESAY, BILLY JOE; MANSURE, ARTHUR J.; PRAIRIE, MICHAEL R.

1999-01-01

A high-speed data link that would provide dramatically faster communication from downhole instruments to the surface and back again has the potential to revolutionize deep drilling for geothermal resources through Diagnostics-While-Drilling (DWD). Many aspects of the drilling process would significantly improve if downhole and surface data were acquired and processed in real-time at the surface, and used to guide the drilling operation. Such a closed-loop, driller-in-the-loop DWD system, would complete the loop between information and control, and greatly improve the performance of drilling systems. The main focus of this program is to demonstrate the value of real-time data for improving drilling. While high-rate transfer of down-hole data to the surface has been accomplished before, insufficient emphasis has been placed on utilization of the data to tune the drilling process to demonstrate the true merit of the concept. Consequently, there has been a lack of incentive on the part of industry to develop a simple, low-cost, effective high-speed data link. Demonstration of the benefits of DWD based on a high-speed data link will convince the drilling industry and stimulate the flow of private resources into the development of an economical high-speed data link for geothermal drilling applications. Such a downhole communication system would then make possible the development of surface data acquisition and expert systems that would greatly enhance drilling operations. Further, it would foster the development of downhole equipment that could be controlled from the surface to improve hole trajectory and drilling performance. Real-time data that would benefit drilling performance include: bit accelerations for use in controlling bit bounce and improving rock penetration rates and bit life; downhole fluid pressures for use in the management of drilling hydraulics and improved diagnosis of lost circulation and gas kicks; hole trajectory for use in reducing directional

GRAIN-SCALE FAILURE IN THERMAL SPALLATION DRILLING

Energy Technology Data Exchange (ETDEWEB)

Walsh, S C; Lomov, I; Roberts, J J

2012-01-19

Geothermal power promises clean, renewable, reliable and potentially widely-available energy, but is limited by high initial capital costs. New drilling technologies are required to make geothermal power financially competitive with other energy sources. One potential solution is offered by Thermal Spallation Drilling (TSD) - a novel drilling technique in which small particles (spalls) are released from the rock surface by rapid heating. While TSD has the potential to improve drilling rates of brittle granitic rocks, the coupled thermomechanical processes involved in TSD are poorly described, making system control and optimization difficult for this drilling technology. In this paper, we discuss results from a new modeling effort investigating thermal spallation drilling. In particular, we describe an explicit model that simulates the grain-scale mechanics of thermal spallation and use this model to examine existing theories concerning spalling mechanisms. We will report how borehole conditions influence spall production, and discuss implications for macro-scale models of drilling systems.

Testing sequence stratigraphic models by drilling Miocene foresets on the New Jersey shallow shelf

DEFF Research Database (Denmark)

Miller, Kenneth G.; Mountain, Gregory S.; Browning, James V.

2013-01-01

continental shelf (Integrated Ocean Drilling Program Expedition 313, Sites M27-M29). We recognize stratal surfaces and systems tracts by integrating seismic stratigraphy, litho-facies successions, gamma logs, and foraminiferal paleodepth trends. Our interpretations of systems tracts, particularly......) and coarsening- and shallowing-upward highstand systems tracts (HST). Drilling through the foresets yields thin (

Deep Drilling Results in the Atlantic Ocean: Ocean Crust

Science.gov (United States)

1979-01-01

the volcano Agua de Pau. //i ( ,.which nas eruted 5 tir-es in tile past 4.600 / ye,.rs, the last in 1563. Xumerous not springs S/ o3220 an’ soradic...complex. In a study layered structure and physical properties to of ophiolite complexes in southern Chile , de Wit ce those of oceanic crust...Spooner et al, 1977) and and Govett, 1973). A large lens, for example that S. Chile (Stern et al, 1976). Zeolite to amphib- at Skouriotissa, had a

Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations Part I: Surface fluxes

Directory of Open Access Journals (Sweden)

P. Josse

1999-04-01

Full Text Available A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer

Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations Part I: Surface fluxes

Directory of Open Access Journals (Sweden)

H. Giordani

Full Text Available A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer

Advantages and limitations of remotely operated sea floor drill rigs

Science.gov (United States)

Freudenthal, T.; Smith, D. J.; Wefer, G.

2009-04-01

A variety of research targets in marine sciences including the investigation of gas hydrates, slope stability, alteration of oceanic crust, ore formation and palaeoclimate can be addressed by shallow drilling. However, drill ships are mostly used for deep drillings, both because the effort of building up a drill string from a drill ship to the deep sea floor is tremendous and control on drill bit pressure from a movable platform and a vibrating drill string is poor especially in the upper hundred meters. During the last decade a variety of remotely operated drill rigs have been developed, that are deployed on the sea bed and operated from standard research vessels. These developments include the BMS (Bentic Multicoring System, developed by Williamson and Associates, operated by the Japanese Mining Agency), the PROD (Portable Remotely Operated Drill, developed and operated by Benthic Geotech), the Rockdrill 2 (developed and operated by the British geological Survey) and the MeBo (German abbreviation for sea floor drill rig, developed and operated by Marum, University of Bremen). These drill rigs reach drilling depths between 15 and 100 m. For shallow drillings remotely operated drill rigs are a cost effective alternative to the services of drill ships and have the major advantage that the drilling operations are performed from a stable platform independent of any ship movements due to waves, wind or currents. Sea floor drill rigs can be deployed both in shallow waters and the deep sea. A careful site survey is required before deploying the sea floor drill rig. Slope gradient, small scale topography and soil strength are important factors when planning the deployment. The choice of drill bits and core catcher depend on the expected geology. The required drill tools are stored on one or two magazines on the drill rig. The MeBo is the only remotely operated drill rig world wide that can use wire line coring technique. This method is much faster than conventional

Optimizing drilling performance using a selected drilling fluid

Science.gov (United States)

Judzis, Arnis [Salt Lake City, UT; Black, Alan D [Coral Springs, FL; Green, Sidney J [Salt Lake City, UT; Robertson, Homer A [West Jordan, UT; Bland, Ronald G [Houston, TX; Curry, David Alexander [The Woodlands, TX; Ledgerwood, III, Leroy W.

2011-04-19

To improve drilling performance, a drilling fluid is selected based on one or more criteria and to have at least one target characteristic. Drilling equipment is used to drill a wellbore, and the selected drilling fluid is provided into the wellbore during drilling with the drilling equipment. The at least one target characteristic of the drilling fluid includes an ability of the drilling fluid to penetrate into formation cuttings during drilling to weaken the formation cuttings.

The new version of the Institute of Numerical Mathematics Sigma Ocean Model (INMSOM) for simulation of Global Ocean circulation and its variability

Science.gov (United States)

Gusev, Anatoly; Fomin, Vladimir; Diansky, Nikolay; Korshenko, Evgeniya

2017-04-01

In this paper, we present the improved version of the ocean general circulation sigma-model developed in the Institute of Numerical Mathematics of the Russian Academy of Sciences (INM RAS). The previous version referred to as INMOM (Institute of Numerical Mathematics Ocean Model) is used as the oceanic component of the IPCC climate system model INMCM (Institute of Numerical Mathematics Climate Model (Volodin et al 2010,2013). Besides, INMOM as the only sigma-model was used for simulations according to CORE-II scenario (Danabasoglu et al. 2014,2016; Downes et al. 2015; Farneti et al. 2015). In general, INMOM results are comparable to ones of other OGCMs and were used for investigation of climatic variations in the North Atlantic (Gusev and Diansky 2014). However, detailed analysis of some CORE-II INMOM results revealed some disadvantages of the INMOM leading to considerable errors in reproducing some ocean characteristics. So, the mass transport in the Antarctic Circumpolar Current (ACC) was overestimated. As well, there were noticeable errors in reproducing thermohaline structure of the ocean. After analysing the previous results, the new version of the OGCM was developed. It was decided to entitle is INMSOM (Institute of Numerical Mathematics Sigma Ocean Model). The new title allows one to distingwish the new model, first, from its older version, and second, from another z-model developed in the INM RAS and referred to as INMIO (Institute of Numerical Mathematics and Institute of Oceanology ocean model) (Ushakov et al. 2016). There were numerous modifications in the model, some of them are as follows. 1) Formulation of the ocean circulation problem in terms of full free surface with taking into account water amount variation. 2) Using tensor form of lateral viscosity operator invariant to rotation. 3) Using isopycnal diffusion including Gent-McWilliams mixing. 4) Using atmospheric forcing computation according to NCAR methodology (Large and Yeager 2009). 5

Audio effects on haptics perception during drilling simulation

Directory of Open Access Journals (Sweden)

Yair Valbuena

2017-06-01

Full Text Available Virtual reality has provided immersion and interactions through computer generated environments attempting to reproduce real life experiences through sensorial stimuli. Realism can be achieved through multimodal interactions which can enhance the user’s presence within the computer generated world. The most notorious advances in virtual reality can be seen in computer graphics visuals, where photorealism is the norm thriving to overcome the uncanny valley. Other advances have followed related to sound, haptics, and in a lesser manner smell and taste feedback. Currently, virtual reality systems (multimodal immersion and interactions through visual-haptic-sound are being massively used in entertainment (e.g., cinema, video games, art, and in non-entertainment scenarios (e.g., social inclusion, educational, training, therapy, and tourism. Moreover, the cost reduction of virtual reality technologies has resulted in the availability at a consumer-level of various haptic, headsets, and motion tracking devices. Current consumer-level devices offer low-fidelity experiences due to the properties of the sensors, displays, and other electro-mechanical devices, that may not be suitable for high-precision or realistic experiences requiring dexterity. However, research has been conducted on how toovercome or compensate the lack of high fidelity to provide an engaging user experience using storytelling, multimodal interactions and gaming elements. Our work focuses on analyzing the possible effects of auditory perception on haptic feedback within a drilling scenario. Drilling involves multimodal interactions and it is a task with multiple applications in medicine, crafting, and construction. We compare two drilling scenarios were two groups of participants had to drill through wood while listening to contextual and non-contextual audios. We gathered their perception using a survey after the task completion. From the results, we believe that sound does

A vision for drilling

Energy Technology Data Exchange (ETDEWEB)

Millheim, K. [Montanuniversitaet Leoben (Austria)

1995-12-31

The future of drilling lies in its relationship with the oil and gas industry. This paper examines how the future of drilling is seen from the view point of the exploration manager, the drilling contractor, the drilling engineer and the company president or managing director. The various pressures on the oil and gas industry are examined, such as environmental issues, alternative energy sources, and the price of oil which determines how companies are run. Exploration activity is driven by the price of oil and gas. The development of wells with multiple horizontal wells or multiple horizontal wells with tributaries will reduce the cost of exploration. Companies will rely less and less on reservoir simulation and more on cheap well-bores, multi-lateral well-bores and will exploit oil that could not be exploited before. The cost of exploratory drilling will need to be kept down so that in the future the industry will get better at economically finding fields at the 10 million to 20 million barrel range that would not have been possible before. The future is expected to see drilling contractors tunnelling, making sewerage lines and drilling 10,000 foot wells with purpose built rigs. Franchising will become a feature of the industry as will the use of databases to answer key technical questions. Offshore platforms will be built to be moveable and disposable. The industry is capable of solving problems, meeting challenges and making ideas work, providing much hope for the future. 10 figs., 1 photo.

Indian Ocean and Indian summer monsoon: relationships without ENSO in ocean-atmosphere coupled simulations

Science.gov (United States)

Crétat, Julien; Terray, Pascal; Masson, Sébastien; Sooraj, K. P.; Roxy, Mathew Koll

2017-08-01

The relationship between the Indian Ocean and the Indian summer monsoon (ISM) and their respective influence over the Indo-Western North Pacific (WNP) region are examined in the absence of El Niño Southern Oscillation (ENSO) in two partially decoupled global experiments. ENSO is removed by nudging the tropical Pacific simulated sea surface temperature (SST) toward SST climatology from either observations or a fully coupled control run. The control reasonably captures the observed relationships between ENSO, ISM and the Indian Ocean Dipole (IOD). Despite weaker amplitude, IODs do exist in the absence of ENSO and are triggered by a boreal spring ocean-atmosphere coupled mode over the South-East Indian Ocean similar to that found in the presence of ENSO. These pure IODs significantly affect the tropical Indian Ocean throughout boreal summer, inducing a significant modulation of both the local Walker and Hadley cells. This meridional circulation is masked in the presence of ENSO. However, these pure IODs do not significantly influence the Indian subcontinent rainfall despite overestimated SST variability in the eastern equatorial Indian Ocean compared to observations. On the other hand, they promote a late summer cross-equatorial quadrupole rainfall pattern linking the tropical Indian Ocean with the WNP, inducing important zonal shifts of the Walker circulation despite the absence of ENSO. Surprisingly, the interannual ISM rainfall variability is barely modified and the Indian Ocean does not force the monsoon circulation when ENSO is removed. On the contrary, the monsoon circulation significantly forces the Arabian Sea and Bay of Bengal SSTs, while its connection with the western tropical Indian Ocean is clearly driven by ENSO in our numerical framework. Convection and diabatic heating associated with above-normal ISM induce a strong response over the WNP, even in the absence of ENSO, favoring moisture convergence over India.

Polyethylene glycol drilling fluid for drilling in marine gas hydrates-bearing sediments: an experimental study

Energy Technology Data Exchange (ETDEWEB)

Jiang, G.; Liu, T.; Ning, F.; Tu, Y.; Zhang, L.; Yu, Y.; Kuang, L. [China University of Geosciences, Faculty of Engineering, Wuhan (China)

2011-07-01

Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experimental gas-hydrate integrated simulation system developed by our laboratory. The results of these tests show that drilling fluid with a formulation of artificial seawater, 3% bentonite, 0.3% Na{sub 2}CO{sub 3}, 10% polyethylene glycol, 20% NaCl, 4% SMP-2, 1% LV-PAC, 0.5% NaOH and 1% PVP K-90 performs well in shale swelling and gas hydrate inhibition. It also shows satisfactory rheological properties and lubrication at temperature ranges from -8 {sup o}C to 15 {sup o}C. The PVP K-90, a kinetic hydrate inhibitor, can effectively inhibit gas hydrate aggregations at a dose of 1 wt%. This finding demonstrates that a drilling fluid with a high addition of NaCl and a low addition of PVP K-90 is suitable for drilling in natural marine gas-hydrate-bearing sediments. (authors)

Polyethylene Glycol Drilling Fluid for Drilling in Marine Gas Hydrates-Bearing Sediments: An Experimental Study

Directory of Open Access Journals (Sweden)

Lixin Kuang

2011-01-01

Full Text Available Shale inhibition, low-temperature performance, the ability to prevent calcium and magnesium-ion pollution, and hydrate inhibition of polyethylene glycol drilling fluid were each tested with conventional drilling-fluid test equipment and an experimental gas-hydrate integrated simulation system developed by our laboratory. The results of these tests show that drilling fluid with a formulation of artificial seawater, 3% bentonite, 0.3% Na2CO3, 10% polyethylene glycol, 20% NaCl, 4% SMP-2, 1% LV-PAC, 0.5% NaOH and 1% PVP K-90 performs well in shale swelling and gas hydrate inhibition. It also shows satisfactory rheological properties and lubrication at temperature ranges from −8 °C to 15 °C. The PVP K-90, a kinetic hydrate inhibitor, can effectively inhibit gas hydrate aggregations at a dose of 1 wt%. This finding demonstrates that a drilling fluid with a high addition of NaCl and a low addition of PVP K-90 is suitable for drilling in natural marine gas-hydrate-bearing sediments.

Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations. Part I: Surface fluxes

Science.gov (United States)

Josse, P.; Caniaux, G.; Giordani, H.; Planton, S.

1999-04-01

A mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer to the atmosphere is

Well drilling by rotary percussive drill above ground

International Nuclear Information System (INIS)

Sabatier, G.

1987-01-01

Originally, the Well Drilling Section of Cogema used only the diamond core drilling technique. The appearance of independent rotation for compressed air rock drills has led to the use and to the development of this drilling system, as a drill core is not indispensable, when the material of the search is radioactive. During the last few years, hydraulic drills have replaced the compressed air drills and have resulted in a very marked improvement: - of the penetration rates; - of the depth achieved. The Well Drilling Section of Cogema has to drill about 400 km per year with rock drills above ground and holds also the record for depth achieved with this technique, i.e. 400 m in granite. In France, the costs of these types of drilling are for the same depth of the order of one-quarter of the core drilling and half of the drilling with a down-the-hole drill. Cogema has greatly developed the types of well logging which now permits the extension of this type of drilling to the search for other materials than uranium [fr

Integral analysis of the drill string dynamic behaviour to optimize drilling operation; Analise integrada do comportamento dinamico da coluna para otimizacao de perfuracao

Energy Technology Data Exchange (ETDEWEB)

Lima, Araken [Smith International do Brasil, Macae, RJ (Brazil); Placido, Joao C.R.; Percy, Joseir G.; Falcao, Jose; Freire, Helena; Ono, Eduardo H.; Masculo, Miguel S. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Azuaga, Denise; Frenzel, Mark [Smith International Inc., Houston, TX (United States)

2008-07-01

For a performance preview of a drilling system is necessary a dynamic and integrated modeling for understanding all system forces resulting from the combination of the rock strength, cut structure action, drilling parameters, BHA and all others drilling components. This study must predict, for the drill string, vibrations and torsions, from bit to surface, its origins and its effects, and provides the best way to reduce these vibrations, determining the best bit, BHA and drilling parameters. Thereby, this study eliminates the trial and error approach and the operation risks. This paper aims to present studies of optimization for two drilling wells conducted in Brazil, one in Santos Basin and other in Campos Basin, and compares the numerical simulations results with the data from drilling operations. (author)

Mapping ocean tides with satellites - A computer simulation

Science.gov (United States)

Won, I. J.; Kuo, J. T.; Jachens, R. C.

1978-01-01

As a preliminary study for the future worldwide direct mapping of the open ocean tide with satellites equipped with precision altimeters we conducted a simulated study using sets of artificially generated altimeter data constructed from a realistic geoid and four pairs of major tides in the northeastern Pacific Ocean. Recovery of the original geoid and eight tidal maps is accomplished by a space-time, least squares harmonic analysis scheme. The resultant maps appear fairly satisfactory even when random noises up to + or - 100 cm are added to the altimeter data of sufficient space-time density. The method also produces a refined geoid which is rigorously corrected for the dynamic tides.

Revised tuning of Ocean Drilling Program Site 964 and KC01B (Mediterranean) and implications for the delta 0-18, tephra, calcareous nannofossil, and geomagnetic reversal chronologies of the past 1.1 Myr

NARCIS (Netherlands)

Lourens, L.J.

2004-01-01

High-resolution color reflectance records of KC01 and KC01B (Calabrian Ridge, Ionian Sea) are presented and compared with a modified spliced high-resolution color reflectance record of Ocean Drilling Program (ODP) Site 964. This comparison revealed that KC01B is characterized by intensive

Fatigue analysis of aluminum drill pipes

Directory of Open Access Journals (Sweden)

João Carlos Ribeiro Plácido

2005-12-01

Full Text Available An experimental program was performed to investigate the fundamental fatigue mechanisms of aluminum drill pipes. Initially, the fatigue properties were determined through small-scale tests performed in an optic-mechanical fatigue apparatus. Additionally, full-scale fatigue tests were carried out with three aluminum drill pipe specimens under combined loading of cyclic bending and constant axial tension. Finally, a finite element model was developed to simulate the stress field along the aluminum drill pipe during the fatigue tests and to estimate the stress concentration factors inside the tool joints. By this way, it was possible to estimate the stress values in regions not monitored during the fatigue tests.

Study for increasing micro-drill reliability by vibrating drilling

International Nuclear Information System (INIS)

Yang Zhaojun; Li Wei; Chen Yanhong; Wang Lijiang

1998-01-01

A study for increasing micro-drill reliability by vibrating drilling is described. Under the experimental conditions of this study it is observed, from reliability testing and the fitting of a life-distribution function, that the lives of micro-drills under ordinary drilling follow the log-normal distribution and the lives of micro-drills under vibrating drilling follow the Weibull distribution. Calculations for reliability analysis show that vibrating drilling can increase the lives of micro-drills and correspondingly reduce the scatter of drill lives. Therefore, vibrating drilling increases the reliability of micro-drills

Numerical simulation of water and sand blowouts when penetrating through shallow water flow formations in deep water drilling

Science.gov (United States)

Ren, Shaoran; Liu, Yanmin; Gong, Zhiwu; Yuan, Yujie; Yu, Lu; Wang, Yanyong; Xu, Yan; Deng, Junyu

2018-02-01

In this study, we applied a two-phase flow model to simulate water and sand blowout processes when penetrating shallow water flow (SWF) formations during deepwater drilling. We define `sand' as a pseudo-component with high density and viscosity, which can begin to flow with water when a critical pressure difference is attained. We calculated the water and sand blowout rates and analyzed the influencing factors from them, including overpressure of the SWF formation, as well as its zone size, porosity and permeability, and drilling speed (penetration rate). The obtained data can be used for the quantitative assessment of the potential severity of SWF hazards. The results indicate that overpressure of the SWF formation and its zone size have significant effects on SWF blowout. A 10% increase in the SWF formation overpressure can result in a more than 90% increase in the cumulative water blowout and a 150% increase in the sand blowout when a typical SWF sediment is drilled. Along with the conventional methods of well flow and pressure control, chemical plugging, and the application of multi-layer casing, water and sand blowouts can be effectively reduced by increasing the penetration rate. As such, increasing the penetration rate can be a useful measure for controlling SWF hazards during deepwater drilling.

TWO- AND THREE-DIMENSIONAL SIMULATIONS OF ASTEROID OCEAN IMPACTS

Directory of Open Access Journals (Sweden)

Michael Gittings

2003-01-01

Full Text Available We have performed a series of two-dimensional and three-dimensional simulations of asteroid impacts into an ocean using the SAGE code from Los Alamos National Laboratory and Science Applications International Corporation. The SAGE code is a compressible Eulerian hydrodynamics code using continuous adaptive mesh refinement for following discontinuities with a fine grid while treating the bulk of the simulation more coarsely. We have used realistic equations of state for the atmosphere, sea water, the oceanic crust, and the mantle. In two dimensions, we simulated asteroid impactors moving at 20 km/s vertically through an exponential atmosphere into a 5 km deep ocean. The impactors were composed of mantle material (3.32 g/cc or iron (7.8 g/cc with diameters from 250m to 10 km. In our three-dimensional runs we simulated asteroids of 1 km diameter composed of iron moving at 20 km/s at angles of 45 and 60 degrees from the vertical. All impacts, including the oblique ones, produce a large underwater cavities with nearly vertical walls followed by a collapse starting from the bottom and subsequent vertical jetting. Substantial amounts of water are vaporized and lofted high into the atmosphere. In the larger impacts, significant amounts of crustal and even mantle material are lofted as well. Tsunamis up to a kilometer in initial height are generated by the collapse of the vertical jet. These waves are initially complex in form, and interact strongly with shocks propagating through the water and the crust. The tsunami waves are followed out to 100 km from the point of impact. Their periods and wavelengths show them to be intermediate type waves, and not (in general shallow-water waves. At great distances, the waves decay as the inverse of the distance from the impact point, ignoring sea-floor topography. For all impactors smaller than about 2 km diameter, the impacting body is highly fragmented and its remains lofted into the stratosphere with the water

The great challenges in Arctic Ocean paleoceanography

International Nuclear Information System (INIS)

Stein, Ruediger

2011-01-01

Despite the importance of the Arctic in the climate system, the data base we have from this area is still very weak, and large parts of the climate history have not been recovered at all in sedimentary sections. In order to fill this gap in knowledge, international, multidisciplinary expeditions and projects for scientific drilling/coring in the Arctic Ocean are needed. Key areas and approaches for drilling and recovering undisturbed and complete sedimentary sequences are depth transects across the major ocean ridge systems, i.e., the Lomonosov Ridge, the Alpha-Mendeleev Ridge, and the Chukchi Plateau/Northwind Ridge, the Beaufort, Kara and Laptev sea continental margins, as well as the major Arctic gateways towards the Atlantic and Pacific oceans. The new detailed climate records from the Arctic Ocean spanning time intervals from the Late Cretaceous/Paleogene Greenhouse world to the Neogene-Quaternary Icehouse world and representing short- and long-term climate variability on scales from 10 to 10 6 years, will give new insights into our understanding of the Arctic Ocean within the global climate system and provide an opportunity to test the performance of climate models used to predict future climate change. With this, studying the Arctic Ocean is certainly one of the major challenges in climate research for the coming decades.

Origin and in situ concentrations of hydrocarbons in the Kumano forearc basin from drilling mud gas monitoring during IODP NanTroSEIZE Exp. 319

International Nuclear Information System (INIS)

Wiersberg, Thomas; Schleicher, Anja M.; Horiguchi, Keika; Doan, Mai-Linh; Eguchi, Nobuhisa; Erzinger, Jörg

2015-01-01

Highlights: • Exp. 319 of IODP was the first cruise in the history of scientific ocean drilling with drilling mud gas monitoring. • Hydrocarbons were the only formation-derived gases identified in drilling mud. • Chemical and isotopic compositions of hydrocarbons exhibit a microbial origin. • Absolute CH 4 concentrations in the formation reaching up to 24 L gas /L sediment . - Abstract: NanTroSEIZE Exp. 319 of the Integrated Ocean Drilling Program (IODP) was the first cruise in the history of scientific ocean drilling with drilling mud circulation through a riser. Drilling mud was pumped through the drill string and returned to the drill ship through the riser pipe during drilling of hole C0009A from 703 to 1604 mbsf (meter below sea floor) and hole enlargement from 703 to 1569 mbsf. During riser drilling, gas from returning drilling mud was continuously extracted, sampled and analyzed in real time to reveal information on the gas composition and gas concentrations at depth. Hydrocarbons were the only formation-derived gases identified in drilling mud and reached up to 14 vol.% of methane and 48 ppmv of ethane. The chemical and isotopic compositions of hydrocarbons exhibit a microbial origin. Hydrocarbons released from drilling mud and cuttings correlate with visible allochthonous material (wood, lignite) in drilling cuttings. At greater depth, addition of small but increasing amounts of hydrocarbons probably from low-temperature thermal degradation of organic matter is indicated. The methane content is also tightly correlated with several intervals of low Poisson’s ratio from Vp/Vs observed in sonic velocity logs, suggesting that the gas is situated in the pore space of the rock as free gas. The gas concentrations in the formation, determined from drilling mud gas monitoring, reaching up to 24 L gas /L sediment for methane in hole C0009A, in line with gas concentrations from interpreted downhole sonic logs

Automatic identification of otologic drilling faults: a preliminary report.

Science.gov (United States)

Shen, Peng; Feng, Guodong; Cao, Tianyang; Gao, Zhiqiang; Li, Xisheng

2009-09-01

A preliminary study was carried out to identify parameters to characterize drilling faults when using an otologic drill under various operating conditions. An otologic drill was modified by the addition of four sensors. Under consistent conditions, the drill was used to simulate three important types of drilling faults and the captured data were analysed to extract characteristic signals. A multisensor information fusion system was designed to fuse the signals and automatically identify the faults. When identifying drilling faults, there was a high degree of repeatability and regularity, with an average recognition rate of >70%. This study shows that the variables measured change in a fashion that allows the identification of particular drilling faults, and that it is feasible to use these data to provide rapid feedback for a control system. Further experiments are being undertaken to implement such a system.

Monte Carlo and discrete-ordinate simulations of irradiances in the coupled atmosphere-ocean system.

Science.gov (United States)

Gjerstad, Karl Idar; Stamnes, Jakob J; Hamre, Børge; Lotsberg, Jon K; Yan, Banghua; Stamnes, Knut

2003-05-20

We compare Monte Carlo (MC) and discrete-ordinate radiative-transfer (DISORT) simulations of irradiances in a one-dimensional coupled atmosphere-ocean (CAO) system consisting of horizontal plane-parallel layers. The two models have precisely the same physical basis, including coupling between the atmosphere and the ocean, and we use precisely the same atmospheric and oceanic input parameters for both codes. For a plane atmosphere-ocean interface we find agreement between irradiances obtained with the two codes to within 1%, both in the atmosphere and the ocean. Our tests cover case 1 water, scattering by density fluctuations both in the atmosphere and in the ocean, and scattering by particulate matter represented by a one-parameter Henyey-Greenstein (HG) scattering phase function. The CAO-MC code has an advantage over the CAO-DISORT code in that it can handle surface waves on the atmosphere-ocean interface, but the CAO-DISORT code is computationally much faster. Therefore we use CAO-MC simulations to study the influence of ocean surface waves and propose a way to correct the results of the CAO-DISORT code so as to obtain fast and accurate underwater irradiances in the presence of surface waves.

Effects of drilling fluids on marine organisms

International Nuclear Information System (INIS)

Parrish, P.R.; Duke, T.W.

1990-01-01

This paper reports on drilling fluids, also called drilling muds, which are essential to drilling processes in the exploration and production of oil and gas from the U.S. Outer Continental Shelf (OCS). These fluids are usually discharged from drilling platforms into surrounding waters of the OCS and are regulated by the U.S. Environmental Protection Agency (EPA). In a program carried out by the EPA Environmental research Laboratory at Gulf Breeze, Florida, diverse marine species as well as microbiotic and macrobiotic communities were studied. Drilling fluids were toxic to marine organisms in certain concentrations and exposure regimes. Furthermore, the fluids adversely affected the benthos physically by burying them or by altering the substrates. Toxicity of the drilling-fluid components, used drilling fluids from active Gulf of Mexico sites, and laboratory-prepared drilling fluids varied considerably. for example 96-h LC 50 s were from 25 μ liter -1 to > 1500 μl liter -1 for clams, larval lobsters, mysids, and grass shrimp. In most instances, mortality was significantly (α = 0.05) correlated with the diesel-oil content of the fluids collected from the Gulf of Mexico. Data and model simulations suggest a rapid dilution of drilling fluids released into OCS waters, resulting in concentrations below the acute-effect concentration for the water column organisms tested

States Stepping up Mandates for School Safety Drills

Science.gov (United States)

Shah, Nirvi

2013-01-01

Hundreds of U.S. schools will supplement fire drills and tornado training next fall with simulations of school shootings. In response to the December shootings by an intruder at Sandy Hook Elementary School in Newtown, Connecticut, several states have enacted or are considering laws that require more and new types of school safety drills, more…

Robotic and Human-Tended Collaborative Drilling Automation for Subsurface Exploration

Science.gov (United States)

Glass, Brian; Cannon, Howard; Stoker, Carol; Davis, Kiel

2005-01-01

, either between a robotic drill and humans on Earth, or a human-tended drill and its visiting crew. The Mars Analog Rio Tinto Experiment (MARTE) is a current project that studies and simulates the remote science operations between an automated drill in Spain and a distant, distributed human science team. The Drilling Automation for Mars Exploration (DAME) project, by contrast: is developing and testing standalone automation at a lunar/martian impact crater analog site in Arctic Canada. The drill hardware in both projects is a hardened, evolved version of the Advanced Deep Drill (ADD) developed by Honeybee Robotics for the Mars Subsurface Program. The current ADD is capable of 20m, and the DAME project is developing diagnostic and executive software for hands-off surface operations of the evolved version of this drill. The current drill automation architecture being developed by NASA and tested in 2004-06 at analog sites in the Arctic and Spain will add downhole diagnosis of different strata, bit wear detection, and dynamic replanning capabilities when unexpected failures or drilling conditions are discovered in conjunction with simulated mission operations and remote science planning. The most important determinant of future 1unar and martian drilling automation and staffing requirements will be the actual performance of automated prototype drilling hardware systems in field trials in simulated mission operations. It is difficult to accurately predict the level of automation and human interaction that will be needed for a lunar-deployed drill without first having extensive experience with the robotic control of prototype drill systems under realistic analog field conditions. Drill-specific failure modes and software design flaws will become most apparent at this stage. DAME will develop and test drill automation software and hardware under stressful operating conditions during several planned field campaigns. Initial results from summer 2004 tests show seven identifi

Near-Infrared Monitoring of Volatiles in Frozen Lunar Simulants While Drilling

Science.gov (United States)

Roush, Ted L.; Colaprete, Anthony; Elphic, Richard C.; Forgione, Joshua; White, Bruce; McMurray, Robert; Cook, Amanda M.; Bielawski, Richard; Fritzler, Erin L.; Thompson, Sarah J.;

Recent Multidisciplinary Research Initiatives and IODP Drilling in the South China Sea

Science.gov (United States)

Lin, J.; Li, C. F.; Wang, P.; Kulhanek, D. K.

2016-12-01

The South China Sea (SCS) is the largest low-latitude marginal sea in the world. Its formation and evolution are linked to the complex continental-oceanic tectonic interaction of the Eurasian, Pacific, and Indo-Australian plates. Despite its relatively small size and short history, the SCS has undergone nearly a complete Wilson cycle from continental break-up to seafloor spreading to subduction, serving as a natural laboratory for studying the linkages between tectonic, volcanic, and oceanic processes. The last several years have witnessed significant progress in investigation of the SCS through comprehensive research programs using multidisciplinary approaches and enhanced international collaboration. The International Ocean Discovery Program (IODP) Expedition 349 drilled and cored five sites in the SCS in 2014. The expedition successfully obtained the first basaltic rock samples of the SCS relict spreading center, discovered large and frequent deep-sea turbidity events, and sampled multiple seamount volcaniclastic layers. In addition, high-resolution near-seafloor magnetic surveys were conducted in the SCS with survey lines passing near some of the IODP drilling sites. Together the IODP drilling and deep-tow magnetic survey results confirmed, for the first time, that the entire SCS basin might have stopped seafloor spreading at similar ages in early Miocene, providing important constraints on marginal sea geodynamic models. In 2007, IODP Expeditions 367 and 368 will drill the northern margin of the SCS to investigate the mechanisms of rifting to spreading processes. Meanwhile, major progress in studying the SCS processes has also been made through comprehensive multidisciplinary programs, for example, the eight-year-long "South China Sea Deep" initiative, which also supports and encourages strong international collaboration. This presentation will highlight the recent multidisciplinary research initiatives in investigation of the SCS and the important role of

Simulating the evolution of the Amundsen Sea Sector with a coupled ice-ocean model

Science.gov (United States)

Seroussi, H. L.; Nakayama, Y.; Menemenlis, D.; Larour, E. Y.; Morlighem, M.; Rignot, E. J.

2017-12-01

Ice shelves and floating glacier termini play an important role in the stability of ice sheets and interact strongly with the ocean. They account for much of the buttressing against the flow of inland glaciers that drain the Antarctic ice sheet. Changes in their geometry due to ice-front retreat, thinning or even collapse profoundly affect the flow of their tributary glaciers, which in turn affects the volume of grounded ice carried by these tributary glaciers into the ocean, and the extent of resulting sea level rise. Recent simulations of glaciers in Antarctica show that the largest climatic impact on ice dynamics is the rate of ice shelf melting, which rapidly affects glaciers' speed over several hundreds of kilometers upstream of the grounding line. These melting rates, however, as well as their spatial and temporal evolution remain largely unknown. In the absence of direct long-term observations, coupled ice-ocean models are the best available approach to address this question. In a previous study, we simulated the coupled ice-ocean system near Thwaites Glacier using a new two-way coupled system between the Massachusetts Institute of Technology general circulation model (MITgcm) and the Ice Sheet System Model (ISSM). Our results highlighted the impact of ocean conditions on glacier evolution and demonstrated the importance of simulating the coupled ice-ocean system to produce accurate melting rates under the ice shelf and at the grounding line. In this study, we focus on the entire Amundsen Sea sector, a region that experienced glacier acceleration, thinning and grounding line retreat over the past three decades. We investigate the feedbacks between changes in the ice and ocean, and the dynamic response of the glacier to changes in the ocean circulation. The simulations suggest that this region is likely to undergo substantial changes in the coming decades. This work was performed at the Jet Propulsion Laboratory, California Institute of Technology, under a

Results of the marine biota monitoring during drilling activity on Campos Basin, Brazil

Energy Technology Data Exchange (ETDEWEB)

Petta, Claudia Brigagao de; Bastos, Fabio; Danielski, Monica; Ferreira, Mariana; Gama, Mariana; Coelho, Ana Paula Athanazio; Maia, Decio [Aecom do Brasil Ltda, Rio de Janeiro, RJ (Brazil)

2012-07-01

The Environmental Monitoring Project (PMA) aims to report environmental changes arising from drilling activity, in relation to the marine fauna. This project can also help in the monitoring of accidental spills. Since the professionals spend six hours of the day monitoring the ocean around the rigs, they can locate and identify oil stains, notify the responsible onboard, and also help in the monitoring of the oil stain. Such Project has been developed onboard a drilling unit working in Campos Basin. The results presented here were collected during the drilling activity in Bijupira and Salema fields, by Shell Brasil Petroleo Ltda, from July 13th to October 8th, 2011.

Preliminary Research on Possibilities of Drilling Process Robotization

Science.gov (United States)

Pawel, Stefaniak; Jacek, Wodecki; Jakubiak, Janusz; Zimroz, Radoslaw

2017-12-01

Nowadays, drilling & blasting is crucial technique for deposit excavation using in hard rock mining. Unfortunately, such approach requires qualified staff to perform, and consequently there is a serious risk related to rock mechanics when using explosives. Negative influence of explosives usage on safety issues of underground mine is a main cause of mining demands related to elimination of people from production area. Other aspects worth taking into consideration are drilling precision according to drilling pattern, blasting effectiveness, improvement of drilling tool reliability etc. In the literature different drilling support solutions are well-known in terms of positioning support systems, anti-jamming systems or cavity detection systems. For many years, teleoperation of drilling process is also developed. Unfortunately, available technologies have so far not fully met the industries expectation in hard rock. Mine of the future is expected to incorporate robotic system instead of current approaches. In this paper we present preliminary research related to robotization of drilling process and possibilities of its application in underground mine condition. A test rig has been proposed. To simulate drilling process several key assumptions have been accepted. As a result, algorithms for automation of drilling process have been proposed and tested on the test rig. Experiences gathered so far underline that there is a need for further developing robotic system for drilling process.

Propagation of Measurement-While-Drilling Mud Pulse during High Temperature Deep Well Drilling Operations

Directory of Open Access Journals (Sweden)

Hongtao Li

2013-01-01

Full Text Available Signal attenuates while Measurement-While-Drilling (MWD mud pulse is transmited in drill string during high temperature deep well drilling. In this work, an analytical model for the propagation of mud pulse was presented. The model consists of continuity, momentum, and state equations with analytical solutions based on the linear perturbation analysis. The model can predict the wave speed and attenuation coefficient of mud pulse. The calculated results were compared with the experimental data showing a good agreement. Effects of the angular frequency, static velocity, mud viscosity, and mud density behavior on speed and attenuation coefficients were included in this paper. Simulated results indicate that the effects of angular frequency, static velocity, and mud viscosity are important, and lower frequency, viscosity, and static velocity benefit the transmission of mud pulse. Influenced by density behavior, the speed and attenuation coefficients in drill string are seen to have different values with respect to well depth. For different circulation times, the profiles of speed and attenuation coefficients behave distinctly different especially in lower section. In general, the effects of variables above on speed are seen to be small in comparison.

Archive of Core and Site/Hole Data and Photographs from the International Ocean Discovery Program (IODP)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Texas A&M University operates the drilling vessel JOIDES Resolution for the International Ocean Discovery Program (IODP). The International Ocean Discovery...

Fundamental Research on Percussion Drilling: Improved rock mechanics analysis, advanced simulation technology, and full-scale laboratory investigations

Energy Technology Data Exchange (ETDEWEB)

Michael S. Bruno

2005-12-31

This report summarizes the research efforts on the DOE supported research project Percussion Drilling (DE-FC26-03NT41999), which is to significantly advance the fundamental understandings of the physical mechanisms involved in combined percussion and rotary drilling, and thereby facilitate more efficient and lower cost drilling and exploration of hard-rock reservoirs. The project has been divided into multiple tasks: literature reviews, analytical and numerical modeling, full scale laboratory testing and model validation, and final report delivery. Literature reviews document the history, pros and cons, and rock failure physics of percussion drilling in oil and gas industries. Based on the current understandings, a conceptual drilling model is proposed for modeling efforts. Both analytical and numerical approaches are deployed to investigate drilling processes such as drillbit penetration with compression, rotation and percussion, rock response with stress propagation, damage accumulation and failure, and debris transportation inside the annulus after disintegrated from rock. For rock mechanics modeling, a dynamic numerical tool has been developed to describe rock damage and failure, including rock crushing by compressive bit load, rock fracturing by both shearing and tensile forces, and rock weakening by repetitive compression-tension loading. Besides multiple failure criteria, the tool also includes a damping algorithm to dissipate oscillation energy and a fatigue/damage algorithm to update rock properties during each impact. From the model, Rate of Penetration (ROP) and rock failure history can be estimated. For cuttings transport in annulus, a 3D numerical particle flowing model has been developed with aid of analytical approaches. The tool can simulate cuttings movement at particle scale under laminar or turbulent fluid flow conditions and evaluate the efficiency of cutting removal. To calibrate the modeling efforts, a series of full-scale fluid hammer

Simulation of Logging-while-drilling Tool Response Using Integral Equation Fast Fourier Transform

Directory of Open Access Journals (Sweden)

Sun Xiang-Yang

2017-01-01

Full Text Available We rely on the volume integral equation (VIE method for the simulation of loggingwhile- drilling (LWG tool response using the integral equation fast Fourier transform (IE-FFT algorithm to accelerate the computation of the matrix-vector product in the iterative solver. Depending on the virtue of the Toeplitz structure of the interpolation of the Green’s function on the uniform Cartesian grids, this method uses FFT to calculate the matrix-vector multiplication. At the same time, this method reduce the memory requirement and CPU time. In this paper, IEFFT method is first used in the simulation of LWG. Numerical results are presented to demonstrate the accuracy and efficiency of this method. Compared with the Moment of Method (MOM and other fast algorithms, IE-FFT have distinct advantages in the fact of memory requirement and CPU time. In addition, this paper study the truncation, mesh elements, the size of the interpolation grids of IE-FFT and dip formation, and give some conclusion with wide applicability.

Behaviour of oceanic 137Cs following the Fukushima Daiichi Nuclear Power Plant accident for four years simulated numerically by a regional ocean model

Science.gov (United States)

Tsumune, D.; Tsubono, T.; Aoyama, M.; Misumi, K.; Tateda, Y.

2015-12-01

A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant (1F NPP) following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition.We reconstructed spatiotemporal variability of 137Cs activity in the regional ocean for four years by numerical model, such as a regional scale and the North Pacific scale oceanic dispersion models, an atmospheric transport model, a sediment transport model, a dynamic biological compartment model for marine biota and river runoff model. Direct release rate of 137Cs were estimated for four years after the accident by comparing simulated results and observed activities very close to the site. The estimated total amounts of directly release was 3.6±0.7 PBq. Directly release rate of 137Cs decreased exponentially with time by the end of December 2012 and then, was almost constant. Decrease rate were quite small after 2013. The daily release rate of 137Cs was estimated to be the order of magnitude of 1010 Bq/day by the end of March 2015. The activity of directly released 137Cs was detectable only in the coastal zone after December 2012. Simulated 137Cs activities attributable to direct release were in good agreement with observed activities, a result that implies the estimated direct release rate was reasonable. There is no observed data of 137Cs activity in the ocean from 11 to 21 March 2011. Observed data of marine biota should reflect the history of 137Cs activity in this early period. We reconstructed the history of 137Cs activity in this early period by considering atmospheric deposition, river input, rain water runoff from the 1F NPP site. The comparisons between simulated 137Cs activity of marine biota by a dynamic biological compartment and observed data also suggest that simulated 137Cs activity attributable to atmospheric deposition was underestimated in this early period. The

Basaltic litho-stratigraphy of Ocean Drilling Program Hole 504B

International Nuclear Information System (INIS)

Harvey, P.K.; Lovell, M.A.

1989-01-01

Hole 504B is located in 5.9 Ma old crust to the south of the Costa Rica Rift. It has been drilled and cored successively on three occasions to a total depth of 1562.1 m below the sea floor and penetrates both basaltic pillows and dykes. Appraisal of the drilled section is difficult because of the low proportion of recovered material (average 20%). In September 1986 a suite of downhole nuclear logs were run. Part of this sequence, the interval 4200-4600 m below sea level, which covers the pillow-dyke transition zone, has been used in this study. The log derived geochemical estimates may be explained in terms of the basaltic mineralogy with the superimposed effects of alteration. Poor correlation between laboratory-measured and log-derived geochemical estimates are due to this alteration, problems of sampling and the absence of a boron sleeve when the tools were run. Alteration and sampling account for the much greater observed variations in the log data and the bias in SiO 2 and CaO abundances. Statistical analysis allows the logs to be presented in the form of a ''geochemical stratigraphy'' which correlates well with the known sequence within the interval studied. (author)

Planning additional drilling campaign using two-space genetic algorithm: A game theoretical approach

Science.gov (United States)

Kumral, Mustafa; Ozer, Umit

2013-03-01

Grade and tonnage are the most important technical uncertainties in mining ventures because of the use of estimations/simulations, which are mostly generated from drill data. Open pit mines are planned and designed on the basis of the blocks representing the entire orebody. Each block has different estimation/simulation variance reflecting uncertainty to some extent. The estimation/simulation realizations are submitted to mine production scheduling process. However, the use of a block model with varying estimation/simulation variances will lead to serious risk in the scheduling. In the medium of multiple simulations, the dispersion variances of blocks can be thought to regard technical uncertainties. However, the dispersion variance cannot handle uncertainty associated with varying estimation/simulation variances of blocks. This paper proposes an approach that generates the configuration of the best additional drilling campaign to generate more homogenous estimation/simulation variances of blocks. In other words, the objective is to find the best drilling configuration in such a way as to minimize grade uncertainty under budget constraint. Uncertainty measure of the optimization process in this paper is interpolation variance, which considers data locations and grades. The problem is expressed as a minmax problem, which focuses on finding the best worst-case performance i.e., minimizing interpolation variance of the block generating maximum interpolation variance. Since the optimization model requires computing the interpolation variances of blocks being simulated/estimated in each iteration, the problem cannot be solved by standard optimization tools. This motivates to use two-space genetic algorithm (GA) approach to solve the problem. The technique has two spaces: feasible drill hole configuration with minimization of interpolation variance and drill hole simulations with maximization of interpolation variance. Two-space interacts to find a minmax solution

High Temperature 300°C Directional Drilling System

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Kamalesh [Baker Hughes Oilfield Operations, Houston, TX (United States); Aaron, Dick [Baker Hughes Oilfield Operations, Houston, TX (United States); Macpherson, John [Baker Hughes Oilfield Operations, Houston, TX (United States)

2015-07-31

Many countries around the world, including the USA, have untapped geothermal energy potential. Enhanced Geothermal Systems (EGS) technology is needed to economically utilize this resource. Temperatures in some EGS reservoirs can exceed 300°C. To effectively utilize EGS resources, an array of injector and production wells must be accurately placed in the formation fracture network. This requires a high temperature directional drilling system. Most commercial services for directional drilling systems are rated for 175°C while geothermal wells require operation at much higher temperatures. Two U.S. Department of Energy (DOE) Geothermal Technologies Program (GTP) projects have been initiated to develop a 300°C capable directional drilling system, the first developing a drill bit, directional motor, and drilling fluid, and the second adding navigation and telemetry systems. This report is for the first project, “High Temperature 300°C Directional Drilling System, including drill bit, directional motor and drilling fluid, for enhanced geothermal systems,” award number DE-EE0002782. The drilling system consists of a drill bit, a directional motor, and drilling fluid. The DOE deliverables are three prototype drilling systems. We have developed three drilling motors; we have developed four roller-cone and five Kymera® bits; and finally, we have developed a 300°C stable drilling fluid, along with a lubricant additive for the metal-to-metal motor. Metal-to-metal directional motors require coatings to the rotor and stator for wear and corrosion resistance, and this coating research has been a significant part of the project. The drill bits performed well in the drill bit simulator test, and the complete drilling system has been tested drilling granite at Baker Hughes’ Experimental Test Facility in Oklahoma. The metal-to-metal motor was additionally subjected to a flow loop test in Baker Hughes’ Celle Technology Center in Germany, where it ran for more than 100

Numerical analysis of drilling hole work-hardening effects in hole-drilling residual stress measurement

Science.gov (United States)

Li, H.; Liu, Y. H.

2008-11-01

The hole-drilling strain gage method is an effective semi-destructive technique for determining residual stresses in the component. As a mechanical technique, a work-hardening layer will be formed on the surface of the hole after drilling, and affect the strain relaxation. By increasing Young's modulus of the material near the hole, the work-hardening layer is simplified as a heterogeneous annulus. As an example, two finite rectangular plates submitted to different initial stresses are treated, and the relieved strains are measured by finite element simulation. The accuracy of the measurement is estimated by comparing the simulated residual stresses with the given initial ones. The results are shown for various hardness of work-hardening layer. The influence of the relative position of the gages compared with the thickness of the work-hardening layer, and the effect of the ratio of hole diameter to work-hardening layer thickness are analyzed as well.

The Pacific Equatorial Age Transect, IODP Expeditions 320 and 321: Building a 50-Million-Year-Long Environmental Record of the Equatorial Pacific Ocean

Directory of Open Access Journals (Sweden)

Kusali Gamage

2010-04-01

Full Text Available In March 2009, the R/V JOIDES Resolution returned to operations after its extended refit and began with a drilling program ideally suited to its drilling strengths, the Pacific Equatorial Age Transect (PEAT, IODP Exp 320/321; Fig. 1A. The PEAT drilling program was developed to understand how a major oceanic region evolved over the Cenozoic Era(65–0 Ma and how it interacted with global climate. It specifically targeted the interval between 52 Ma and 0 Ma and drilled a series of sites that originated on the paleoequator. These sites have since been moved to the northwest by plate tectonics.The equatorial Pacific is an important target for paleocean ographic study because it is a significant ‘cog’ in the Earth’s climate machine, representing roughly half of the total tropical oceans that in turn represent roughly half of the total global ocean area. Prior drilling in both the Deep Sea Drilling Project (DSDP and the Ocean Drilling Program (ODP outlined the changes that have occurred through the Cenozoic (e.g., van Andel et al., 1975; Pisias et al., 1995. Not only did the earlier work fail to cover sufficient timeintervals but also many of the sites were cored with ‘first-generation’ scientific drilling technology with incomplete and disturbed sediment recovery and thus cannot be used for detailed studies.

Full-scale laboratory drilling tests on sandstone and dolomite. Final report

Energy Technology Data Exchange (ETDEWEB)

Black, A. D.; Green, S. J.; Rogers, L. A.

1977-08-01

Full-scale laboratory drilling experiments were performed under simulated downhole conditions to determine what effect changing various drilling parameters has on penetration rate. The two rock types, typical of deep oil and gas reservoirs, used for the tests were Colton Sandstone and Bonne Terre Dolomite. Drilling was performed with standard 7/sup 7///sub 8/ inch rotary insert bits and water base mud. The results showed the penetration rate to be strongly dependent on bit weight, rotary speed and borehole mud pressure. There was only a small dependence on mud flow rate. The drilling rate decreased rapidly with increasing borehole mud pressure for borehole pressures up to about 2,000 psi. Above this pressure, the borehole pressure and rotary speeds had a smaller effect on penetration rate. The penetration rate was then dependent mostly on the bit weight. Penetration rate per horsepower input was also shown to decrease at higher mud pressures and bit weights. The ratio of horizontal confining stress to axial overburden stress was maintained at 0.7 for simulated overburden stresses between 0 and 12,800 psi. For this simulated downhole stress state, the undrilled rock sample was within the elastic response range and the confining pressures were found to have only a small or negligible effect on the penetration rate. Visual examination of the bottomhole pattern of the rocks after simulated downhole drilling, however, revealed ductile chipping of the Sandstone, but more brittle behavior in the Dolomite.

Final Report. Coupled simulations of Antarctic Ice-sheet/ocean interactions using POP and CISM

Energy Technology Data Exchange (ETDEWEB)

Asay-Davis, Xylar Storm [Potsdam Institute for Climate Impact Research, Potdam (Germany)

2015-12-30

The project performed under this award, referred to from here on as CLARION (CoupLed simulations of Antarctic Ice-sheet/Ocean iNteractions), included important advances in two models of ice sheet and ocean interactions. Despite its short duration (one year), the project made significant progress on its three major foci. First, together with collaborator Daniel Martin at Lawrence Berkeley National Laboratory (LBNL), I developed the POPSICLES coupled ice sheet-ocean model to the point where it could perform a number of pan-Antarctic simulations under various forcing conditions. The results were presented at a number of major conferences and workshops worldwide, and are currently being incorporated into two manuscripts in preparation.

Numerical simulation of logging-while-drilling density image by Monte-Carlo method

International Nuclear Information System (INIS)

Yue Aizhong; He Biao; Zhang Jianmin; Wang Lijuan

2010-01-01

Logging-while-drilling system is researched by Monte Carlo Method. Model of Logging-while-drilling system is built, tool response and azimuth density image are acquired, methods dealing with azimuth density data is discussed. This outcome lay foundation for optimizing tool, developing new tool and logging explanation. (authors)

New drilling optimization technologies make drilling more efficient

Energy Technology Data Exchange (ETDEWEB)

Chen, D.C.-K. [Halliburton Energy Services, Calgary, AB (Canada). Sperry Division

2004-07-01

Several new technologies have been adopted by the upstream petroleum industry in the past two decades in order to optimize drilling operations and improve drilling efficiency. Since financial returns from an oil and gas investment strongly depend on drilling costs, it is important to reduce non-productive time due to stuck pipes, lost circulation, hole cleaning and well bore stability problems. The most notable new technologies are the use of computer-based instrumentation and data acquisition systems, integrated rig site systems and networks, and Measurement-While-Drilling and Logging-While-Drilling (MWD/LWD) systems. Drilling optimization should include solutions for drillstring integrity, hydraulics management and wellbore integrity. New drilling optimization methods emphasize information management and real-time decision making. A recent study for drilling in shallow water in the Gulf of Mexico demonstrates that trouble time accounts for 25 per cent of rig time. This translates to about $1.5 MM U.S. per well. A reduction in trouble time could result in significant cost savings for the industry. This paper presents a case study on vibration prevention to demonstrate how the drilling industry has benefited from new technologies. 13 refs., 10 figs.

Casing drilling

Energy Technology Data Exchange (ETDEWEB)

Heenan, D. [Tesco Corp., Calgary, AB (Canada)

2003-07-01

This paper reviewed the experience that Tesco has gained by drilling several wells using only casings as the drill stem. Tesco has manufactured a mobile and compact hydraulic drilling rig called the Casing Drilling {sup TM} system. The system could be very effective and efficient for exploration and development of coalbed methane (CBM) reserves which typically require extensive coring. Continuous coring while drilling ahead, along wire line retrieval, can offer time savings and quick core recovery of large diameter core which is typically required for exploration core desorption tests. The proposed system may also have the potential to core or drill typically tight gas sands or underbalanced wells with air or foam. This would reduce drilling fluid damage while simultaneously finding gas. Compared to conventional drill pipes, Casing Drilling {sup TM} could also be effective with water production from shallow sands because of the smaller annual clearance which requires less air volumes to lift any produced water. 9 figs.

An Updated Geophysical Model for AMSR-E and SSMIS Brightness Temperature Simulations over Oceans

Directory of Open Access Journals (Sweden)

Elizaveta Zabolotskikh

2014-03-01

Full Text Available In this study, we considered the geophysical model for microwave brightness temperature (BT simulation for the Atmosphere-Ocean System under non-precipitating conditions. The model is presented as a combination of atmospheric absorption and ocean emission models. We validated this model for two satellite instruments—for Advanced Microwave Sounding Radiometer-Earth Observing System (AMSR-E onboard Aqua satellite and for Special Sensor Microwave Imager/Sounder (SSMIS onboard F16 satellite of Defense Meteorological Satellite Program (DMSP series. We compared simulated BT values with satellite BT measurements for different combinations of various water vapor and oxygen absorption models and wind induced ocean emission models. A dataset of clear sky atmospheric and oceanic parameters, collocated in time and space with satellite measurements, was used for the comparison. We found the best model combination, providing the least root mean square error between calculations and measurements. A single combination of models ensured the best results for all considered radiometric channels. We also obtained the adjustments to simulated BT values, as averaged differences between the model simulations and satellite measurements. These adjustments can be used in any research based on modeling data for removing model/calibration inconsistencies. We demonstrated the application of the model by means of the development of the new algorithm for sea surface wind speed retrieval from AMSR-E data.

ODP Leg 210 Drills the Newfoundland Margin in the Newfoundland-Iberia Non-Volcanic Rift

Science.gov (United States)

Tucholke, B. E.; Sibuet, J.

2003-12-01

The final leg of the Ocean Drilling Project (Leg 210, July-September 2003) was devoted to studying the history of rifting and post-rift sedimentation in the Newfoundland-Iberia rift. For the first time, drilling was conducted in the Newfoundland Basin along a transect conjugate to previous drill sites on the Iberia margin (Legs 149 and 173) to obtain data on a complete `non-volcanic' rift system. The prime site during this leg (Site 1276) was drilled in the transition zone between known continental crust and known oceanic crust at chrons M3 and younger. Extensive geophysical work and deep-sea drilling have shown that this transition-zone crust on the conjugate Iberia margin is exhumed continental mantle that is strongly serpentinized in its upper part. Transition-zone crust on the Newfoundland side, however, is typically a kilometer or more shallower and has much smoother topography, and seismic refraction data suggest that the crust may be thin (about 4 km) oceanic crust. A major goal of Site 1276 was to investigate these differences by sampling basement and a strong, basinwide reflection (U) overlying basement. Site 1276 was cored from 800 to 1737 m below seafloor with excellent recovery (avg. 85%), bottoming in two alkaline diabase sills >10 m thick that are estimated to be 100-200 meters above basement. The sills have sedimentary contacts that show extensive hydrothermal metamorphism. Associated sediment structural features indicate that the sills were intruded at shallow levels within highly porous sediments. The upper sill likely is at the level of the U reflection, which correlates with lower Albian - uppermost Aptian(?) fine- to coarse-grained gravity-flow deposits. Overlying lower Albian to lower Oligocene sediments record paleoceanographic conditions similar to those on the Iberia margin and in the main North Atlantic basin, including deposition of `black shales'; however, they show an extensive component of gravity-flow deposits throughout.

A Study of Specific Fracture Energy at Percussion Drilling

Science.gov (United States)

A, Shadrina; T, Kabanova; V, Krets; L, Saruev

2014-08-01

The paper presents experimental studies of rock failure provided by percussion drilling. Quantification and qualitative analysis were carried out to estimate critical values of rock failure depending on the hammer pre-impact velocity, types of drill bits and cylindrical hammer parameters (weight, length, diameter), and turn angle of a drill bit. Obtained data in this work were compared with obtained results by other researchers. The particle-size distribution in granite-cutting sludge was analyzed in this paper. Statistical approach (Spearmen's rank-order correlation, multiple regression analysis with dummy variables, Kruskal-Wallis nonparametric test) was used to analyze the drilling process. Experimental data will be useful for specialists engaged in simulation and illustration of rock failure.

A Study of Specific Fracture Energy at Percussion Drilling

International Nuclear Information System (INIS)

Shadrina A; Krets V; Saruev L; Kabanova T

2014-01-01

The paper presents experimental studies of rock failure provided by percussion drilling. Quantification and qualitative analysis were carried out to estimate critical values of rock failure depending on the hammer pre-impact velocity, types of drill bits and cylindrical hammer parameters (weight, length, diameter), and turn angle of a drill bit. Obtained data in this work were compared with obtained results by other researchers. The particle-size distribution in granite-cutting sludge was analyzed in this paper. Statistical approach (Spearmen's rank-order correlation, multiple regression analysis with dummy variables, Kruskal-Wallis nonparametric test) was used to analyze the drilling process. Experimental data will be useful for specialists engaged in simulation and illustration of rock failure

Electric drill-string telemetry

CERN Document Server

Carcione, J M

2003-01-01

We design a numerical algorithm for simulation of low-frequency electric-signal transmission through a drill string. This is represented by a transmission line with varying geometrical and electromagnetic properties versus depth, depending on the characteristics of the drill-string/formation system. These properties are implicitly modeled by the series impedance and the shunt admittance of the transmission line. The differential equations are parabolic, since at low frequencies the wave field is diffusive. We use an explicit scheme for the solution of parabolic problems, based on a Chebyshev expansion of the evolution operator and the Fourier pseudospectral method to compute the spatial derivatives. The results are verified by comparison to analytical solutions obtained for the initial-value problem with a voltage source.

Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill

Science.gov (United States)

Sherrit, Stewart (Inventor); Bao, Xiaoqi (Inventor); Badescu, Mircea (Inventor); Bar-Cohen, Yoseph (Inventor)

2014-01-01

A Single Piezo-Actuator Rotary-Hammering (SPaRH) Drill includes a horn actuator having high power piezoelectric materials and a flexure pre-stress to increase the actuators effectiveness. The drill is a low mass, low power, compact coring drill measuring 20-cm high by 7-cm diameter and having a total weight of 2 kg including drive electronics. Using an average power of 50-Watts, the drill basalt is expected to cut basalt at a rate of 0.2 cm/min down to depth of 10-cm and create cuttings and an intact core. The drill is expected to operate under different environments including Martian ambient (6 Torr and down to -50 degree C), and liquid nitrogen temperatures (77 K) and low pressure (<<1 Torr) to simulate lunar polar and Europa conditions. Materials expected to be sampled include Kaolinite, Saddleback Basalt, Limestone, Volcanic Breccia, Siltstone, ice, permafrost and layered rocks with different hardness.

Optimization of Mud Hammer Drilling Performance--A Program to Benchmark the Viability of Advanced Mud Hammer Drilling

Energy Technology Data Exchange (ETDEWEB)

Arnis Judzis

2006-03-01

Operators continue to look for ways to improve hard rock drilling performance through emerging technologies. A consortium of Department of Energy, operator and industry participants put together an effort to test and optimize mud driven fluid hammers as one emerging technology that has shown promise to increase penetration rates in hard rock. The thrust of this program has been to test and record the performance of fluid hammers in full scale test conditions including, hard formations at simulated depth, high density/high solids drilling muds, and realistic fluid power levels. This paper details the testing and results of testing two 7 3/4 inch diameter mud hammers with 8 1/2 inch hammer bits. A Novatek MHN5 and an SDS Digger FH185 mud hammer were tested with several bit types, with performance being compared to a conventional (IADC Code 537) tricone bit. These tools functionally operated in all of the simulated downhole environments. The performance was in the range of the baseline ticone or better at lower borehole pressures, but at higher borehole pressures the performance was in the lower range or below that of the baseline tricone bit. A new drilling mode was observed, while operating the MHN5 mud hammer. This mode was noticed as the weight on bit (WOB) was in transition from low to high applied load. During this new ''transition drilling mode'', performance was substantially improved and in some cases outperformed the tricone bit. Improvements were noted for the SDS tool while drilling with a more aggressive bit design. Future work includes the optimization of these or the next generation tools for operating in higher density and higher borehole pressure conditions and improving bit design and technology based on the knowledge gained from this test program.

Corganiser: a web-based software tool for planning time-sensitive sampling of whole rounds during scientific drilling

DEFF Research Database (Denmark)

Marshall, Ian

2014-01-01

with a wide range of core and section configurations and can thus be used in future drilling projects. Corganiser is written in the Python programming language and is implemented both as a graphical web interface and command-line interface. It can be accessed online at http://130.226.247.137/.......Corganiser is a software tool developed to simplify the process of preparing whole-round sampling plans for time-sensitive microbiology and geochemistry sampling during scientific drilling. It was developed during the Integrated Ocean Drilling Program (IODP) Expedition 347, but is designed to work...

Exploring Subseafloor Life with the Integrated Ocean Drilling Program

Directory of Open Access Journals (Sweden)

Patricia Sobecky

2007-09-01

Full Text Available Deep drilling of marine sediments and igneous crust offers a unique opportunity to explore how life persists and evolves in the Earth’s deepest subsurface ecosystems. Resource availability deep beneath the seafloor may impose constraints on microbial growth and dispersal patterns that differ greatly from those in the surface world. Processes that mediate microbial evolution and diversity may also be very different in these habitats, which approach and probably passthe extreme limits of life. Communities in parts of the deep subsurface may resemble primordial microbial ecosystems, and may serve as analogues of life on other planetary bodies, such as Mars or Europa, that have or once had water.

Importance of drill string assembly swivel in horizontal drilling

Directory of Open Access Journals (Sweden)

Edmund Tasak

2006-10-01

Full Text Available A part of the drill string – the swivel (rotational connector – accomplishes an important task in the horizontal drilling. Its malfunctioning makes it impossible to draw in ( install large diameter and length pipelines. The causes of the connector break-down during the horizontal drilling are investigated in the paper. The drilling has been made for twenty inches gas pipeline installation during reaming operations. A trouble was encountered making good work conditions of a system consisting of the drilling machine drill string reamer swivel tube shield of Cardan joint and the gas pipeline 500 m long. In this case, the swivel brokes down and the planned operation was not finished. The assessment of improper drilling conditions, selection of operation system components, and drilling parameters and the insufficient technological supervising have created an excessive risk of failure. A proper application of technical analysis would considerably decrease the hazard of failure which cause large costs, delays and decrease of confidence to the drilling contractor and pipeline installation.

Drilling comparison in "warm ice" and drill design comparison

DEFF Research Database (Denmark)

Augustin, L.; Motoyama, H.; Wilhelms, F.

2007-01-01

For the deep ice-core drilling community, the 2005/06 Antarctic season was an exciting and fruitful one. In three different Antarctic locations, Dome Fuji, EPICA DML and Vostok, deep drillings approached bedrock (the ice-water interface in the case of Vostok), emulating what had previously been...... achieved at NorthGRIP, Greenland, (summer 2003 and 2004) and at EPICA Dome C2, Antarctica (season 2004/05). For the first time in ice-core drilling history, three different types of drill (KEMS, JARE and EPICA) simultaneously reached the depth of 'warm ice' under high pressure. After excellent progress...... at each site, the drilling rate dropped and the drilling teams had to deal with refrozen ice on cutters and drill heads. Drills have different limits and perform differently. In this comparative study, we examine depth, pressure, temperature, pump flow and cutting speed. Finally, we compare a few...

Simulated effect of calcification feedback on atmospheric CO2 and ocean acidification

Science.gov (United States)

Zhang, Han; Cao, Long

2016-01-01

Ocean uptake of anthropogenic CO2 reduces pH and saturation state of calcium carbonate materials of seawater, which could reduce the calcification rate of some marine organisms, triggering a negative feedback on the growth of atmospheric CO2. We quantify the effect of this CO2-calcification feedback by conducting a series of Earth system model simulations that incorporate different parameterization schemes describing the dependence of calcification rate on saturation state of CaCO3. In a scenario with SRES A2 CO2 emission until 2100 and zero emission afterwards, by year 3500, in the simulation without CO2-calcification feedback, model projects an accumulated ocean CO2 uptake of 1462 PgC, atmospheric CO2 of 612 ppm, and surface pH of 7.9. Inclusion of CO2-calcification feedback increases ocean CO2 uptake by 9 to 285 PgC, reduces atmospheric CO2 by 4 to 70 ppm, and mitigates the reduction in surface pH by 0.003 to 0.06, depending on the form of parameterization scheme used. It is also found that the effect of CO2-calcification feedback on ocean carbon uptake is comparable and could be much larger than the effect from CO2-induced warming. Our results highlight the potentially important role CO2-calcification feedback plays in ocean carbon cycle and projections of future atmospheric CO2 concentrations. PMID:26838480

Application of Numerical Simulation for the Analysis of the Processes of Rotary Ultrasonic Drilling

Science.gov (United States)

Naď, Milan; Čičmancová, Lenka; Hajdu, Štefan

2016-12-01

Rotary ultrasonic machining (RUM) is a hybrid process that combines diamond grinding with ultrasonic machining. It is most suitable to machine hard brittle materials such as ceramics and composites. Due to its excellent machining performance, RUM is very often applied for drilling of hard machinable materials. In the final phase of drilling, the edge deterioration of the drilled hole can occur, which results in a phenomenon called edge chipping. During hole drilling, a change in the thickness of the bottom of the drilled hole occurs. Consequently, the bottom of the hole as a plate structure is exposed to the transfer through the resonance state. This resonance state can be considered as one of the important aspects leading to edge chipping. Effects of changes in the bottom thickness and as well as the fillet radius between the wall and bottom of the borehole on the stress-strain states during RUM are analyzed.

Evaluation of aluminum drill-pipe material and design

Energy Technology Data Exchange (ETDEWEB)

Placido, Joao C. [PETROBRAS, Rio de Janeiro, RJ (Brazil); Lourenco, Marcelo I.; Netto, Theodoro Antoun [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE)

2008-07-01

Experimental program and numerical analyses were carried out to investigate the fatigue mechanisms of aluminum drill pipes designed and manufactured in compliance with ISO 15546. The main objective is to improve the fatigue performance of these components by selecting the appropriate aluminum alloy and by enhancing the mechanical design of the threaded steel connector. This paper presents the experimental test program and numerical analyses conducted on a drill-pipe of different materials (Al-Cu-Mg and Al-Zn-Mg system aluminum alloys) and geometry. Material mechanical properties, including S-N curve, were determined through small-scale tests on specimens cut from actual drill pipes. Full-scale experiments were also performed in laboratory. A finite element model of the drill pipe, including the tool-joint region, was developed. The model simulates, through different load steps, the tool-joint hot assembly, and then reproduces the physical experiments numerically in order to obtain the actual stress distribution. Good correlation between full-scale and small-scale fatigue tests was obtained by adjusting the strain/stress levels monitored in the full-scale tests in light of the numerical simulations and performing fatigue life calculations via multiaxial fatigue models. The weak points of the current practice design are highlighted for further development. (author)

Development of vertical drilling apparatus (Terra-Drill); Entwicklung eines Vertikal-Bohrgeraets (Terra-Drill) - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Jenne, D.

2009-05-15

This well-illustrated final report for the Swiss Federal Office of Energy (SFOE) reports on the development of a vertical drilling apparatus named Terra-Drill. The various stages of the development of the apparatus, which is based on earlier designs, is discussed. New norms issued in Germany for the size of boreholes for buried vertical heat-exchangers and the appropriate linings to be used are discussed. The new Terra Drill 4407 V drilling apparatus and its testing are discussed. The drill is quoted as being particularly suitable for cramped locations. Technical details are presented and a comprehensive collection of photographs is included. Various preliminary reports and development documentation are included.

The Iceland Deep Drilling Project (IDDP): (I) Status and Future Plans.

Science.gov (United States)

Elders, W. A.; Fridleifsson, G. O.; Bird, D. K.; Schiffman, P.; Zierenberg, R.; Reed, M. H.

2006-12-01

The IDDP represents a challenging step forward in the worldwide development of geothermal energy by assessing the potential of power production from natural supercritical fluids. A feasibility study in 2003 concluded that in order to reach fluids at temperatures of >400°C drilling to depths of 4 to 5 km is necessary, but the resultant superheated steam should have a power output ten times that of conventional subcritical steam with the same volumetric flow rate. A consortium of leading Icelandic energy companies together with a government agency, the Icelandic Energy Authority, is carrying out the IDDP. In late 2003 a member of the consortium offered a planned exploratory well to the IDDP for deepening. This is in a geothermal system that produces hydrothermally modified seawater on the Reykjanes peninsula, in southern Iceland, where the Mid-Atlantic Ridge comes on land. Processes at depth at Reykjanes should be similar to those responsible for black smokers on ocean spreading centers. This well reached 3.1 km in February 2005, and research on the downhole samples began. Unfortunately the well became plugged during a flow test and was abandoned in February 2006 after attempts to recondition it failed. This led to the IDDP deciding to move the site for the first deep borehole to Krafla, near the northern end of the central rift zone of Iceland, within a volcanic caldera that has had recent volcanic activity. The Krafla geothermal system has higher temperature gradients than at Reykjanes but produces hydrothermally modified meteoric water with magmatic gases. The drill site chosen is near an existing well that encountered 340°C at only 2.5 km depth. It will be rotary drilled with spot coring to 3.5 km depth, and then deepened to ~4.5 km, using continuous wireline coring for scientific purposes. However, given the competition for drilling rigs internationally, and the year-long lead times in obtaining specialized well casings, it will be a year before IDDP begins

New Proposed Drilling at Surtsey Volcano, Iceland

Science.gov (United States)

Jackson, Marie D.

2014-12-01

Surtsey, an isolated oceanic island and a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization, is a uniquely well-documented natural laboratory for investigating processes of rift zone volcanism, hydrothermal alteration of basaltic tephra, and biological colonization and succession in surface and subsurface pyroclastic deposits. Deposits from Surtsey's eruptions from 1963 to 1967 were first explored via a 181-meter hole drilled in 1979 by the U.S. Geological Survey and Icelandic Museum of Natural History.

On the influence of ocean waves on simulated GNSS-R delay-doppler maps

Science.gov (United States)

Clarizia, M. P.; di Bisceglie, M.; Galdi, C.; Gommenginger, C.; Srokosz, M.

2012-04-01

Global Navigation Satellite System-Reflectometry (GNSS-R), is an established technique that exploits GNSS signals of opportunity reflected from the surface of the ocean, to look primarily at the ocean surface roughness. The strength of this technique, and the primary motivation to carry it forward, is in the fact that GNSS signals are available globally, all the time and over the long term, and could help dramatically improve the monitoring of ocean wind and waves. GNSS-R offers the prospect of high density global measurements of directional sea surface roughness, which are essential for scientific purposes (i.e. quantifying the air-sea exchanges of gases), operational weather and ocean forecasting (i.e. prediction of high winds, dangerous sea states, risk of flooding and storm surges) and to support important climate-relevant Earth Observation techniques (IR SST, or surface salinity retrieval). The retrieval of ocean roughness from GNSS-R data has now been demonstrated with a reasonable level of accuracy from both airborne [1] and spaceborne [2] platforms. In both cases, Directional Mean Square Slopes (DMSS) of the ocean surface have been retrieved from GNSS-R data, in the form of Delay-Doppler Maps (DDMs), using an established theoretical scattering model by Zavorotny and Voronovich (Z-V) [3]. The need for a better assessment of the way the ocean waves influence the scattering of GPS signals has recently led to a different approach, consisting of simulating the scattering of such signals, using a more sophisticated large-scale scattering model than Z-V, and explicit simulations of realistic seas. Initial results produced from these simulations have been recently published in [4], where the emphasis has been put on the effects of different sea states on Radar Cross Section (RCS) and Polarization Ratio (PR) in space domain. Linear wind wave surfaces have been simulated using the Elfouhaily wind wave spectrum [5], for different wind speeds and directions, and with

IODP Expedition 319, NanTroSEIZE Stage 2: First IODP Riser Drilling Operations and Observatory Installation Towards Understanding Subduction Zone Seismogenesis

Directory of Open Access Journals (Sweden)

Sean Toczko

2010-09-01

Full Text Available The Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE is a major drilling project designed to investigate fault mechanics and the seismogenic behavior of subduction zone plate boundaries. Expedition 319 is the first riser drilling operation within scientific ocean drilling. Operations included riser drilling at Site C0009 in the forearc basin above the plate boundary fault, non-riser drilling at Site C0010 across the shallow part of the megasplay faultsystem—which may slip during plate boundary earthquakes—and initial drilling at Site C0011 (incoming oceanic plate for Expedition 322. At Site C0009, new methods were tested, including analysis of drill mud cuttings and gas, and in situ measurements of stress, pore pressure, and permeability. These results, in conjunction with earlier drilling, will provide a the history of forearc basin development (including links to growth of the megasplay fault system and modern prism, b the first in situ hydrological measurements of the plate boundary hanging wall, and c integration of in situ stress measurements (orientation and magnitude across the forearc and with depth. A vertical seismic profile (VSP experiment provides improved constraints on the deeper structure of the subduction zone. At Site C0010, logging-while-drilling measurements indicate significantchanges in fault zone and hanging wall properties over short (<5 km along-strike distances, suggesting different burial and/or uplift history. The first borehole observatory instruments were installed at Site C0010 to monitor pressure and temperature within the megasplay fault zone, and methods of deployment of more complex observatoryinstruments were tested for future operations.

Application of Numerical Simulation for the Analysis of the Processes of Rotary Ultrasonic Drilling

Directory of Open Access Journals (Sweden)

Naď Milan

2016-12-01

Full Text Available Rotary ultrasonic machining (RUM is a hybrid process that combines diamond grinding with ultrasonic machining. It is most suitable to machine hard brittle materials such as ceramics and composites. Due to its excellent machining performance, RUM is very often applied for drilling of hard machinable materials. In the final phase of drilling, the edge deterioration of the drilled hole can occur, which results in a phenomenon called edge chipping. During hole drilling, a change in the thickness of the bottom of the drilled hole occurs. Consequently, the bottom of the hole as a plate structure is exposed to the transfer through the resonance state. This resonance state can be considered as one of the important aspects leading to edge chipping. Effects of changes in the bottom thickness and as well as the fillet radius between the wall and bottom of the borehole on the stress-strain states during RUM are analyzed.

Simulating Freak Waves in the Ocean with CFD Modeling

Science.gov (United States)

Manolidis, M.; Orzech, M.; Simeonov, J.

2017-12-01

Rogue, or freak, waves constitute an active topic of research within the world scientific community, as various maritime authorities around the globe seek to better understand and more accurately assess the risks that the occurrence of such phenomena entail. Several experimental studies have shed some light on the mechanics of rogue wave formation. In our work we numerically simulate the formation of such waves in oceanic conditions by means of Computational Fluid Dynamics (CFD) software. For this purpose we implement the NHWAVE and OpenFOAM software packages. Both are non-hydrostatic, turbulent flow solvers, but NHWAVE implements a shock-capturing scheme at the free surface-interface, while OpenFOAM utilizes the Volume Of Fluid (VOF) method. NHWAVE has been shown to accurately reproduce highly nonlinear surface wave phenomena, such as soliton propagation and wave shoaling. We conducted a range of tests simulating rogue wave formation and horizontally varying currents to evaluate and compare the capabilities of the two software packages. Then we used each model to investigate the effect of ocean currents and current gradients on the formation of rogue waves. We present preliminary results.

Responses of the ocean carbon cycle to climate change: Results from an earth system climate model simulation

Institute of Scientific and Technical Information of China (English)

WANG Shuang-Jing; CAO Long; LI Na

2014-01-01

Based on simulations using the University of Victoria’s Earth System Climate Model, we analyzed the responses of the ocean carbon cycle to increasing atmospheric CO2 levels and climate change from 1800 to 2500 following the RCP 8.5 scenario and its extension. Compared to simulations without climate change, the simulation with a climate sensitivity of 3.0 K shows that in 2100, due to increased atmospheric CO2 concentrations, the simulated sea surface temperature increases by 2.7 K, the intensity of the North Atlantic deep water formation reduces by4.5 Sv, and the oceanic uptake of anthropogenic CO2 decreases by 0.8 Pg C. Climate change is also found to have a large effect on the North Atlantic’s ocean column inventory of anthropogenic CO2. Between the years 1800 and 2500, compared with the simulation with no climate change, the simulation with climate change causes a reduction in the total anthropogenic CO2 column inventory over the entire ocean and in North Atlantic by 23.1% and 32.0%, respectively. A set of simulations with climate sensitivity variations from 0.5 K to 4.5 K show that with greater climate sensitivity climate change would have a greater effect in reducing the ocean’s ability to absorb CO2 from the atmosphere.

Drilling bits for deep drilling and process for their manufacture

Energy Technology Data Exchange (ETDEWEB)

Rhode, H.; Juergens, R.; Feenstra, R.; Busking, B.E.

1978-11-30

The invention concerns a drilling head or a drilling bit for use in deep drilling in underground formations and particularly concerns a drilling bit with a drilling bit body, which has a shank and a hollow space, which is connected with a duct extending through the shank. The drilling bit body has several separate cutting elements for removing material from the floor of a borehole and hydraulic devices for cooling and/or cleaning the cutting elements are provided.

Evaluation of a present-day climate simulation with a new coupled atmosphere-ocean model GENMOM

Directory of Open Access Journals (Sweden)

J. R. Alder

2011-02-01

Full Text Available We present a new, non-flux corrected AOGCM, GENMOM, that combines the GENESIS version 3 atmospheric GCM (Global Environmental and Ecological Simulation of Interactive Systems and MOM2 (Modular Ocean Model version 2 nominally at T31 resolution. We evaluate GENMOM by comparison with reanalysis products (e.g., NCEP2 and three models used in the IPCC AR4 assessment. GENMOM produces a global temperature bias of 0.6 °C. Atmospheric features such as the jet stream structure and major semi-permanent sea level pressure centers are well simulated as is the mean planetary-scale wind structure that is needed to produce the correct position of stormtracks. Most ocean surface currents are reproduced except where they are not resolvable at T31 resolution. Overall, GENMOM captures reasonably well the observed gradients and spatial distributions of annual surface temperature and precipitation and the simulations are on par with other AOGCMs. Deficiencies in the GENMOM simulations include a warm bias in the surface temperature over the southern oceans, a split in the ITCZ and weaker-than-observed overturning circulation.

Adaptation of an unstructured-mesh, finite-element ocean model to the simulation of ocean circulation beneath ice shelves

Science.gov (United States)

Kimura, Satoshi; Candy, Adam S.; Holland, Paul R.; Piggott, Matthew D.; Jenkins, Adrian

2013-07-01

Several different classes of ocean model are capable of representing floating glacial ice shelves. We describe the incorporation of ice shelves into Fluidity-ICOM, a nonhydrostatic finite-element ocean model with the capacity to utilize meshes that are unstructured and adaptive in three dimensions. This geometric flexibility offers several advantages over previous approaches. The model represents melting and freezing on all ice-shelf surfaces including vertical faces, treats the ice shelf topography as continuous rather than stepped, and does not require any smoothing of the ice topography or any of the additional parameterisations of the ocean mixed layer used in isopycnal or z-coordinate models. The model can also represent a water column that decreases to zero thickness at the 'grounding line', where the floating ice shelf is joined to its tributary ice streams. The model is applied to idealised ice-shelf geometries in order to demonstrate these capabilities. In these simple experiments, arbitrarily coarsening the mesh outside the ice-shelf cavity has little effect on the ice-shelf melt rate, while the mesh resolution within the cavity is found to be highly influential. Smoothing the vertical ice front results in faster flow along the smoothed ice front, allowing greater exchange with the ocean than in simulations with a realistic ice front. A vanishing water-column thickness at the grounding line has little effect in the simulations studied. We also investigate the response of ice shelf basal melting to variations in deep water temperature in the presence of salt stratification.

Influence of plasma shock wave on the morphology of laser drilling in different environments

Science.gov (United States)

Zhai, Zhaoyang; Wang, Wenjun; Mei, Xuesong; Wang, Kedian; Yang, Huizhu

2017-05-01

Nanosecond pulse laser was used to study nickel-based alloy drilling and compare processing results of microholes in air environment and water environment. Through analysis and comparison, it's found that environmental medium had obvious influence on morphology of laser drilling. High-speed camera was used to shoot plasma morphology during laser drilling process, theoretical formula was used to calculate boundary dimension of plasma and shock wave velocity, and finally parameters were substituted into computational fluid dynamics simulation software to obtain solutions. Obtained analysis results could intuitively explain different morphological features and forming reasons between laser drilling in air environment and water environment in the experiment from angle of plasma shock waves. By comparing simulation results and experimental results, it could help to get an understanding of formation mechanism of microhole morphology, thus providing basis for further improving process optimization of laser drilling quality.

Impact of a realistic river routing in coupled ocean-atmosphere simulations of the Last Glacial Maximum climate

Energy Technology Data Exchange (ETDEWEB)

Alkama, Ramdane [IPSL, Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette Cedex (France); Universite Pierre et Marie Curie, Structure et fonctionnement des systemes hydriques continentaux (Sisyphe), Paris (France); Kageyama, M.; Ramstein, G.; Marti, O.; Swingedouw, D. [IPSL, Laboratoire des Sciences du Climat et de l' Environnement, Gif-sur-Yvette Cedex (France); Ribstein, P. [Universite Pierre et Marie Curie, Structure et fonctionnement des systemes hydriques continentaux (Sisyphe), Paris (France)

2008-06-15

The presence of large ice sheets over North America and North Europe at the Last Glacial Maximum (LGM) strongly impacted Northern hemisphere river pathways. Despite the fact that such changes may significantly alter the freshwater input to the ocean, modified surface hydrology has never been accounted for in coupled ocean-atmosphere general circulation model simulations of the LGM climate. To reconstruct the LGM river routing, we use the ICE-5G LGM topography. Because of the uncertainties in the extent of the Fennoscandian ice sheet in the Eastern part of the Kara Sea, we consider two more realistic river routing scenarios. The first scenario is characterised by the presence of an ice dammed lake south of the Fennoscandian ice sheet, and corresponds to the ICE-5G topography. This lake is fed by the Ob and Yenisei rivers. In the second scenario, both these rivers flow directly into the Arctic Ocean, which is more consistent with the latest QUEEN ice sheet margin reconstructions. We study the impact of these changes on the LGM climate as simulated by the IPSL{sub C}M4 model and focus on the overturning thermohaline circulation. A comparison with a classical LGM simulation performed using the same model and modern river basins as designed in the PMIP2 exercise leads to the following conclusions: (1) The discharge into the North Atlantic Ocean is increased by 2,000 m{sup 3}/s between 38 and 54 N in both simulations that contain LGM river routing, compared to the classical LGM experiment. (2) The ice dammed lake is shown to have a weak impact, relative to the classical simulation, both in terms of climate and ocean circulation. (3) In contrast, the North Atlantic deep convection and meridional overturning are weaker than during the classical LGM run if the Ob and Yenisei rivers flow directly into the Arctic Ocean. The total discharge into the Arctic Ocean is increased by 31,000 m{sup 3}/s, relative to the classical LGM simulation. Consequentially, northward ocean heat

Reconstruction of the Paleoproterozoic deeper ocean environment: Preliminary Report of the Ghana Birimian Greenstone Belt Drilling Project (GHB)

Science.gov (United States)

Kiyokawa, S.; Yoshimaru, S.; Miki, T.; Sakai, S.; Ikehara, M.; Yamaguchi, K. E.; Ito, T.; Onoue, T.; Takehara, M.; Tetteh, G. M.; Nyame, F. K.

2016-12-01

The Paleoproterozoic Era are one of the most rapid environmental change when the earth surface environment was affected by formation of continents and increasing atmospheric oxygen levels. Major oxidation of Great Oxidation Event (GOE) are reported this ages (eg. Holland, 2006; Condie, 2001; Lyons et al., 2014). The nature of deep sea environments at this time have not been clearly identified and oceanic sediments are mostly involved in subduction. The Paleoproterozoic Birimian Greenstone Belt is an ophiolitic volcaniclastic sequence in Ghana, with depositional age of over 2.3-2.2 Ga (Petersson et al., 2016). Detail research was conducted of the Ashanti (Axim-Konongo) Belt of the Birimian Greenstone Belt along the coast near Cape Three Points area. Very thick volcaniclastic and organic-rich sedimentary rocks, which we now refer to as the Cape Three Points Group, crop out in the lower part of the Birimian Greenstone Belt. Stratigraphically, three unit identified; the lower portion contains thick vesicular volcaniclastic rocks, the middle portion is made up of laminated volcaniclastics and black shale, and the upper portion dominated by fine laminated volcaniclastics with more black shale sequence. Continuous core drilling from Dec 3-12th 2015 of the upper part of the sequence intersected saprolite to a depth of 30m and fresh, well preserved stratigraphy with graded bedding and lamination to a depth of 195m. Half cut cores show well laminated organic rich black shale and relative carbonate rich layers with very fine pyrite grains. SHRIMP age data from a porphyry intrusion into this sequence indicate an age of 2250 Ma. Carbon isotope analysis shows δ13C = -43 to -37‰ for black shale with the very light isotope values for cyanobacterial signature.The fining-upward sequences, well laminated bed and black shales and REE data suggest this sequence situated partly silent stagnant with volcanic activity ocean floor environment around an oceanic island arc condition.

Theoretical simulation of the multipole seismoelectric logging while drilling

Science.gov (United States)

Guan, Wei; Hu, Hengshan; Zheng, Xiaobo

2013-11-01

Acoustic logging-while-drilling (LWD) technology has been commercially used in the petroleum industry. However it remains a rather difficult task to invert formation compressional and shear velocities from acoustic LWD signals due to the unwanted strong collar wave, which covers or interferes with signals from the formation. In this paper, seismoelectric LWD is investigated for solving that problem. The seismoelectric field is calculated by solving a modified Poisson's equation, whose source term is the electric disturbance induced electrokinetically by the travelling seismic wave. The seismic wavefield itself is obtained by solving Biot's equations for poroelastic waves. From the simulated waveforms and the semblance plots for monopole, dipole and quadrupole sources, it is found that the electric field accompanies the collar wave as well as other wave groups of the acoustic pressure, despite the fact that seismoelectric conversion occurs only in porous formations. The collar wave in the electric field, however, is significantly weakened compared with that in the acoustic pressure, in terms of its amplitude relative to the other wave groups in the full waveforms. Thus less and shallower grooves are required to damp the collar wave if the seismoelectric LWD signals are recorded for extracting formation compressional and shear velocities.

A 4.5 km resolution Arctic Ocean simulation with the global multi-resolution model FESOM 1.4

Science.gov (United States)

Wang, Qiang; Wekerle, Claudia; Danilov, Sergey; Wang, Xuezhu; Jung, Thomas

2018-04-01

In the framework of developing a global modeling system which can facilitate modeling studies on Arctic Ocean and high- to midlatitude linkage, we evaluate the Arctic Ocean simulated by the multi-resolution Finite Element Sea ice-Ocean Model (FESOM). To explore the value of using high horizontal resolution for Arctic Ocean modeling, we use two global meshes differing in the horizontal resolution only in the Arctic Ocean (24 km vs. 4.5 km). The high resolution significantly improves the model's representation of the Arctic Ocean. The most pronounced improvement is in the Arctic intermediate layer, in terms of both Atlantic Water (AW) mean state and variability. The deepening and thickening bias of the AW layer, a common issue found in coarse-resolution simulations, is significantly alleviated by using higher resolution. The topographic steering of the AW is stronger and the seasonal and interannual temperature variability along the ocean bottom topography is enhanced in the high-resolution simulation. The high resolution also improves the ocean surface circulation, mainly through a better representation of the narrow straits in the Canadian Arctic Archipelago (CAA). The representation of CAA throughflow not only influences the release of water masses through the other gateways but also the circulation pathways inside the Arctic Ocean. However, the mean state and variability of Arctic freshwater content and the variability of freshwater transport through the Arctic gateways appear not to be very sensitive to the increase in resolution employed here. By highlighting the issues that are independent of model resolution, we address that other efforts including the improvement of parameterizations are still required.

Application of Monte Carlo method in forward simulation of azimuthal gamma imaging while drilling

International Nuclear Information System (INIS)

Yuan Chao; Zhou Cancan; Zhang Feng; Chen Zhi

2014-01-01

Monte Carlo simulation is one of the most important numerical simulation methods in nuclear logging. Formation models can be conveniently built with MCNP code, which provides a simple and effective approach for fundamental study of nuclear logging. Monte Carlo method is employed to set up formation models under logging while drilling condition, and the characteristic of azimuthal gamma imaging is simulated. The results present that the azimuthal gamma imaging shows a sinusoidal curve features. The imaging can be used to accurately calculate the relative dip angle of borehole and thickness of radioactive formation. The larger relative dip angle of borehole and the thicker radioactive formation lead to the larger height of the sinusoidal curve in the imaging. The borehole size has no affect for the calculation of the relative dip angle, but largely affects the determination of formation thickness. The standoff of logging tool has great influence for the calculation of the relative dip angle and formation thickness. If the gamma ray counts meet the demand of counting statistics in nuclear logging, the effect of borehole fluid on the imaging can be ignored. (authors)

Intercomparison of Antarctic ice-shelf, ocean, and sea-ice interactions simulated by MetROMS-iceshelf and FESOM 1.4

Science.gov (United States)

Naughten, Kaitlin A.; Meissner, Katrin J.; Galton-Fenzi, Benjamin K.; England, Matthew H.; Timmermann, Ralph; Hellmer, Hartmut H.; Hattermann, Tore; Debernard, Jens B.

2018-04-01

An increasing number of Southern Ocean models now include Antarctic ice-shelf cavities, and simulate thermodynamics at the ice-shelf/ocean interface. This adds another level of complexity to Southern Ocean simulations, as ice shelves interact directly with the ocean and indirectly with sea ice. Here, we present the first model intercomparison and evaluation of present-day ocean/sea-ice/ice-shelf interactions, as simulated by two models: a circumpolar Antarctic configuration of MetROMS (ROMS: Regional Ocean Modelling System coupled to CICE: Community Ice CodE) and the global model FESOM (Finite Element Sea-ice Ocean Model), where the latter is run at two different levels of horizontal resolution. From a circumpolar Antarctic perspective, we compare and evaluate simulated ice-shelf basal melting and sub-ice-shelf circulation, as well as sea-ice properties and Southern Ocean water mass characteristics as they influence the sub-ice-shelf processes. Despite their differing numerical methods, the two models produce broadly similar results and share similar biases in many cases. Both models reproduce many key features of observations but struggle to reproduce others, such as the high melt rates observed in the small warm-cavity ice shelves of the Amundsen and Bellingshausen seas. Several differences in model design show a particular influence on the simulations. For example, FESOM's greater topographic smoothing can alter the geometry of some ice-shelf cavities enough to affect their melt rates; this improves at higher resolution, since less smoothing is required. In the interior Southern Ocean, the vertical coordinate system affects the degree of water mass erosion due to spurious diapycnal mixing, with MetROMS' terrain-following coordinate leading to more erosion than FESOM's z coordinate. Finally, increased horizontal resolution in FESOM leads to higher basal melt rates for small ice shelves, through a combination of stronger circulation and small-scale intrusions of

Polarization-based enhancement of ocean color signal for estimating suspended particulate matter: radiative transfer simulations and laboratory measurements.

Science.gov (United States)

Liu, Jia; He, Xianqiang; Liu, Jiahang; Bai, Yan; Wang, Difeng; Chen, Tieqiao; Wang, Yihao; Zhu, Feng

2017-04-17

Absorption and scattering by molecules, aerosols and hydrosols, and the reflection and transmission over the sea surface can modify the original polarization state of sunlight. However, water-leaving radiance polarization, containing embedded water constituent information, has largely been neglected. Here, the efficiency of the parallel polarization radiance (PPR) for enhancing ocean color signal of suspended particulate matter is examined via vector radiative transfer simulations and laboratory experiments. The simulation results demonstrate that the PPR has a slightly higher ocean color signal at the top-of-atmosphere as compared with that of the total radiance. Moreover, both the simulations and laboratory measurements reveal that, compared with total radiance, PPR can effectively enhance the normalized ocean color signal for a large range of observation geometries, wavelengths, and suspended particle concentrations. Thus, PPR has great potential for improving the ocean color signal detection from satellite.

CASING DRILLING TECHNOLOGY

Directory of Open Access Journals (Sweden)

Nediljka Gaurina-Međimurec

2005-12-01

Full Text Available Casing drilling is an alternative option to conventional drilling and uses standard oilfield casing instead of drillstring. This technology is one of the greatest developments in drilling operations. Casing drilling involves drilling and casing a well simultaneously. In casing driling process, downhole tools can be retrieved, through the casing on wire-line, meaning tool recovery or replacement of tools can take minutes versus hours under conventional methods. This process employs wireline-retrievable tools and a drill-lock assembly, permitting bit and BHA changes, coring, electrical logging and even directional or horizontal drilling. Once the casing point is reached, the casing is cemented in place without tripping pipe.

HIGH-POWER TURBODRILL AND DRILL BIT FOR DRILLING WITH COILED TUBING

Energy Technology Data Exchange (ETDEWEB)

Robert Radtke; David Glowka; Man Mohan Rai; David Conroy; Tim Beaton; Rocky Seale; Joseph Hanna; Smith Neyrfor; Homer Robertson

2008-03-31

Commercial introduction of Microhole Technology to the gas and oil drilling industry requires an effective downhole drive mechanism which operates efficiently at relatively high RPM and low bit weight for delivering efficient power to the special high RPM drill bit for ensuring both high penetration rate and long bit life. This project entails developing and testing a more efficient 2-7/8 in. diameter Turbodrill and a novel 4-1/8 in. diameter drill bit for drilling with coiled tubing. The high-power Turbodrill were developed to deliver efficient power, and the more durable drill bit employed high-temperature cutters that can more effectively drill hard and abrasive rock. This project teams Schlumberger Smith Neyrfor and Smith Bits, and NASA AMES Research Center with Technology International, Inc (TII), to deliver a downhole, hydraulically-driven power unit, matched with a custom drill bit designed to drill 4-1/8 in. boreholes with a purpose-built coiled tubing rig. The U.S. Department of Energy National Energy Technology Laboratory has funded Technology International Inc. Houston, Texas to develop a higher power Turbodrill and drill bit for use in drilling with a coiled tubing unit. This project entails developing and testing an effective downhole drive mechanism and a novel drill bit for drilling 'microholes' with coiled tubing. The new higher power Turbodrill is shorter, delivers power more efficiently, operates at relatively high revolutions per minute, and requires low weight on bit. The more durable thermally stable diamond drill bit employs high-temperature TSP (thermally stable) diamond cutters that can more effectively drill hard and abrasive rock. Expectations are that widespread adoption of microhole technology could spawn a wave of 'infill development' drilling of wells spaced between existing wells, which could tap potentially billions of barrels of bypassed oil at shallow depths in mature producing areas. At the same time, microhole

Numerical Simulation of Rock Mass Damage Evolution During Deep-Buried Tunnel Excavation by Drill and Blast

Science.gov (United States)

Yang, Jianhua; Lu, Wenbo; Hu, Yingguo; Chen, Ming; Yan, Peng

2015-09-01

Presence of an excavation damage zone (EDZ) around a tunnel perimeter is of significant concern with regard to safety, stability, costs and overall performance of the tunnel. For deep-buried tunnel excavation by drill and blast, it is generally accepted that a combination of effects of stress redistribution and blasting is mainly responsible for development of the EDZ. However, few open literatures can be found to use numerical methods to investigate the behavior of rock damage induced by the combined effects, and it is still far from full understanding how, when and to what degree the blasting affects the behavior of the EDZ during excavation. By implementing a statistical damage evolution law based on stress criterion into the commercial software LS-DYNA through its user-subroutines, this paper presents a 3D numerical simulation of the rock damage evolution of a deep-buried tunnel excavation, with a special emphasis on the combined effects of the stress redistribution of surrounding rock masses and the blasting-induced damage. Influence of repeated blast loadings on the damage extension for practical millisecond delay blasting is investigated in the present analysis. Accompanying explosive detonation and secession of rock fragments from their initial locations, in situ stress in the immediate vicinity of the excavation face is suddenly released. The transient characteristics of the in situ stress release and induced dynamic responses in the surrounding rock masses are also highlighted. From the simulation results, some instructive conclusions are drawn with respect to the rock damage mechanism and evolution during deep-buried tunnel excavation by drill and blast.

Drilling unit

Energy Technology Data Exchange (ETDEWEB)

Umanchik, N P; Demin, A V; Khrustalev, N N; Linnik, G N; Lovchev, S V; Rozin, M M; Sidorov, R V; Sokolov, S I; Tsaregradskiy, Yu P

1981-01-01

A drilling unit is proposed which includes a hydraulic lifter, hydraulic multiple-cylinder pump with valve distribution and sectional drilling pump with separators of the working and flushing fluid. In order to reduce metal consumption and the overall dimensions of the drilling unit, the working cavity of each cylinder of the hydraulic multiple-cylinder pump is equipped with suction and injection valves and is hydraulically connected to the working cavity by one of the sections of the drilling pump.

Environmental assessment report to BEPCo Canada Company on exploratory drilling on EL2407

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-19

BEPCo. Canada Company (BEPCo) is planning to drill exploratory deepwater wells offshore from Nova Scotia. This environmental assessment report was prepared to satisfy regulatory requirements associated with offshore drilling. It focuses on valued environmental components chosen during a scoping process. This report evaluated the potential project-related effects on marine benthos, marine fish, marine mammals, marine turtles, marine birds, special areas, and other ocean users. Discharges and emissions from the project include drilling mud and rock cuttings, small amounts of produced water, ship discharges and atmospheric emissions. This report includes oceanographic plume modelling for allowable discharges of mud and cuttings at sea. The report predicts that the potential adverse effects of the valued environmental components will be short term and highly localized around the drilling rigs. It was suggested that any adverse effects could be mitigated through the use of technically feasible mitigation and standard offshore oil and gas industry procedures for environmental health and safety. It was concluded that BEPCo's proposed drilling program for EL-2407 can be conducted without any significant adverse effects on Nova Scotia's offshore environment. 121 refs., 27 tabs., 24 figs.

LABORATORY EXPERIMENTS TO SIMULATE CO2 OCEAN DISPOSAL

Energy Technology Data Exchange (ETDEWEB)

Stephen M. Masutani

1999-12-31

This Final Technical Report summarizes the technical accomplishments of an investigation entitled ''Laboratory Experiments to Simulate CO{sub 2} Ocean Disposal'', funded by the U.S. Department of Energy's University Coal Research Program. This investigation responds to the possibility that restrictions on greenhouse gas emissions may be imposed in the future to comply with the Framework Convention on Climate Change. The primary objective of the investigation was to obtain experimental data that can be applied to assess the technical feasibility and environmental impacts of oceanic containment strategies to limit release of carbon dioxide (CO{sub 2}) from coal and other fossil fuel combustion systems into the atmosphere. A number of critical technical uncertainties of ocean disposal of CO{sub 2} were addressed by performing laboratory experiments on liquid CO{sub 2} jet break-up into a dispersed droplet phase, and hydrate formation, under deep ocean conditions. Major accomplishments of this study included: (1) five jet instability regimes were identified that occur in sequence as liquid CO{sub 2} jet disintegration progresses from laminar instability to turbulent atomization; (2) linear regression to the data yielded relationships for the boundaries between the five instability regimes in dimensionless Ohnesorge Number, Oh, and jet Reynolds Number, Re, space; (3) droplet size spectra was measured over the full range of instabilities; (4) characteristic droplet diameters decrease steadily with increasing jet velocity (and increasing Weber Number), attaining an asymptotic value in instability regime 5 (full atomization); and (5) pre-breakup hydrate formation appears to affect the size distribution of the droplet phase primary by changing the effective geometry of the jet.

Mechanical model of orthopaedic drilling for augmented-haptics-based training.

Science.gov (United States)

Pourkand, Ashkan; Zamani, Naghmeh; Grow, David

2017-10-01

In this study, augmented-haptic feedback is used to combine a physical object with virtual elements in order to simulate anatomic variability in bone. This requires generating levels of force/torque consistent with clinical bone drilling, which exceed the capabilities of commercially available haptic devices. Accurate total force generation is facilitated by a predictive model of axial force during simulated orthopaedic drilling. This model is informed by kinematic data collected while drilling into synthetic bone samples using an instrumented linkage attached to the orthopaedic drill. Axial force is measured using a force sensor incorporated into the bone fixture. A nonlinear function, relating force to axial position and velocity, was used to fit the data. The normalized root-mean-square error (RMSE) of forces predicted by the model compared to those measured experimentally was 0.11 N across various bones with significant differences in geometry and density. This suggests that a predictive model can be used to capture relevant variations in the thickness and hardness of cortical and cancellous bone. The practical performance of this approach is measured using the Phantom Premium haptic device, with some required customizations. Copyright © 2017 Elsevier Ltd. All rights reserved.

SOLID2: an antibody array-based life-detector instrument in a Mars Drilling Simulation Experiment (MARTE).

Science.gov (United States)

Parro, Víctor; Fernández-Calvo, Patricia; Rodríguez Manfredi, José A; Moreno-Paz, Mercedes; Rivas, Luis A; García-Villadangos, Miriam; Bonaccorsi, Rosalba; González-Pastor, José Eduardo; Prieto-Ballesteros, Olga; Schuerger, Andrew C; Davidson, Mark; Gómez-Elvira, Javier; Stoker, Carol R

2008-10-01

A field prototype of an antibody array-based life-detector instrument, Signs Of LIfe Detector (SOLID2), has been tested in a Mars drilling mission simulation called MARTE (Mars Astrobiology Research and Technology Experiment). As one of the analytical instruments on the MARTE robotic drilling rig, SOLID2 performed automatic sample processing and analysis of ground core samples (0.5 g) with protein microarrays that contained 157 different antibodies. Core samples from different depths (down to 5.5 m) were analyzed, and positive reactions were obtained in antibodies raised against the Gram-negative bacterium Leptospirillum ferrooxidans, a species of the genus Acidithiobacillus (both common microorganisms in the Río Tinto area), and extracts from biofilms and other natural samples from the Río Tinto area. These positive reactions were absent when the samples were previously subjected to a high-temperature treatment, which indicates the biological origin and structural dependency of the antibody-antigen reactions. We conclude that an antibody array-based life-detector instrument like SOLID2 can detect complex biological material, and it should be considered as a potential analytical instrument for future planetary missions that search for life.

Individual Drilling Bit Design and Optimization in Mahu Area

Directory of Open Access Journals (Sweden)

Zhang Wenbo

2017-01-01

Full Text Available There are three sets of gravels in Mahu region. The gravels formation is characterized by high heterogeneity, high abrasiveness and poor drillability. It is so difficult to optimize bit that restrict seriously the overall exploration and development process. The compressive strength, internal friction angle, and drillability of the formation are tested to check the rock mechanical characteristic profile established by logging data. The individual bit design is carried out by the 3D simulation technology. A new PDC bit type is designed to form the drill bit series for Mahu area. Single PDC bit increases 90% of the drilling footage. The trip average footage is improved 3.45 times, the horizontal section average penetration increased 34.8%. The technical achievements have greatly improved economic development benefits of Mahu region by improving drilling speed and saving drilling costs.

Cuttings-carried theory and erosion rule in gas drilling horizontal well

Directory of Open Access Journals (Sweden)

Wei Na

2014-01-01

Full Text Available In gas horizontal drilling, the gas with cuttings will go through the annulus at high speed which will lead strong erosion to the drill tools. This paper proposes a cuttings-carried theory and modified the critical cuttings-carried model for the gas-solid flow. Meanwhile, the erosive energy is obtained through simulating the gas-solid mixture in different conditions. The study result has positive significance on the determination of reasonable injection volume by optimizing construction parameters of horizontal well in gas drilling.

Multiproxy record of the last interglacial (MIS 5e) off central and northern California, U.S.A., from Ocean Drilling Program sites 1018 and 1020

Science.gov (United States)

Poore, Richard Z.; Dowsett, H.J.; Barron, J.A.; Heusser, L.; Ravelo, A.C.; Mix, A.

2000-01-01

Environmental and climatic conditions during the last interglacial (about 125,000 years ago) along the Central and Northern California coastal region are interpreted from study of marine cores recovered by the Ocean Drilling Program at sites 1018 and 1020. Marine microfossil and pollen assemblages, oxygen isotopes in benthic foraminifers, physical properties, and calcium carbonate contents of cored sediments are proxies indicating strong links between the marine and terrestrial environments during marine isotope stage 5 (MIS 5). At the beginning of the last interglacial (MIS 5e), reduction in global ice volume, increase in surface temperature, and warming of air temperature along the Central and Northern California coast were synchronous within the resolution of our sampling record.

A Last Glacial Maximum world-ocean simulation at eddy-permitting resolution - Part 1: Experimental design and basic evaluation

Science.gov (United States)

Ballarotta, M.; Brodeau, L.; Brandefelt, J.; Lundberg, P.; Döös, K.

2013-01-01

Most state-of-the-art climate models include a coarsely resolved oceanic component, which has difficulties in capturing detailed dynamics, and therefore eddy-permitting/eddy-resolving simulations have been developed to reproduce the observed World Ocean. In this study, an eddy-permitting numerical experiment is conducted to simulate the global ocean state for a period of the Last Glacial Maximum (LGM, ~ 26 500 to 19 000 yr ago) and to investigate the improvements due to taking into account these higher spatial scales. The ocean general circulation model is forced by a 49-yr sample of LGM atmospheric fields constructed from a quasi-equilibrated climate-model simulation. The initial state and the bottom boundary condition conform to the Paleoclimate Modelling Intercomparison Project (PMIP) recommendations. Before evaluating the model efficiency in representing the paleo-proxy reconstruction of the surface state, the LGM experiment is in this first part of the investigation, compared with a present-day eddy-permitting hindcast simulation as well as with the available PMIP results. It is shown that the LGM eddy-permitting simulation is consistent with the quasi-equilibrated climate-model simulation, but large discrepancies are found with the PMIP model analyses, probably due to the different equilibration states. The strongest meridional gradients of the sea-surface temperature are located near 40° N and S, this due to particularly large North-Atlantic and Southern-Ocean sea-ice covers. These also modify the locations of the convection sites (where deep-water forms) and most of the LGM Conveyor Belt circulation consequently takes place in a thinner layer than today. Despite some discrepancies with other LGM simulations, a glacial state is captured and the eddy-permitting simulation undertaken here yielded a useful set of data for comparisons with paleo-proxy reconstructions.

Combined simulation of carbon and water isotopes in a global ocean model

Science.gov (United States)

Paul, André; Krandick, Annegret; Gebbie, Jake; Marchal, Olivier; Dutkiewicz, Stephanie; Losch, Martin; Kurahashi-Nakamura, Takasumi; Tharammal, Thejna

2013-04-01

Carbon and water isotopes are included as passive tracers in the MIT general circulation model (MITgcm). The implementation of the carbon isotopes is based on the existing MITgcm carbon cycle component and involves the fractionation processes during photosynthesis and air-sea gas exchange. Special care is given to the use of a real freshwater flux boundary condition in conjunction with the nonlinear free surface of the ocean model. The isotopic content of precipitation and water vapor is obtained from an atmospheric GCM (the NCAR CAM3) and mapped onto the MITgcm grid system, but the kinetic fractionation during evaporation is treated explicitly in the ocean model. In a number of simulations, we test the sensitivity of the carbon isotope distributions to the formulation of fractionation during photosynthesis and compare the results to modern observations of δ13C and Δ14C from GEOSECS, WOCE and CLIVAR. Similarly, we compare the resulting distribution of oxygen isotopes to modern δ18O data from the NASA GISS Global Seawater Oxygen-18 Database. The overall agreement is good, but there are discrepancies in the carbon isotope composition of the surface water and the oxygen isotope composition of the intermediate and deep waters. The combined simulation of carbon and water isotopes in a global ocean model will provide a framework for studying present and past states of ocean circulation such as postulated from deep-sea sediment records.

Viruses in the Oceanic Basement

Directory of Open Access Journals (Sweden)

Olivia D. Nigro

2017-03-01

Full Text Available Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement, but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 105 to 2 × 105 ml−1 (n = 8, higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27. Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%. Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737, 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome.

Effect of drilling fluids on permeability of uranium sandstone. Report of Investigations/1984

International Nuclear Information System (INIS)

Ahlness, J.K.; Johnson, D.I.; Tweeton, D.R.

1984-01-01

The Bureau of Mines conducted laboratory and field experiments to determine the amount of permeability reduction in uranium sandstone after its exposure to different drilling fluids. Seven polymer and two bentonite fluids were laboratory-tested in their clean condition, and six polymer fluids were tested with simulated drill cuttings added. Sandstone cores cut from samples collected at an open pit uranium mine were the test medium. The clean fluid that resulted in the least permeability reduction was an hydroxyethyl cellulose polymer fluid. The greatest permeability reduction of the clean polymers came from a shale-inhibiting synthetic polymer. Six polymer fluids were tested with simulated drill cuttings added to represent field use. The least permeability reduction was obtained from a multi-polymer blend fluid. A field experiment was performed to compare how two polymer fluids affect formation permeability when used for drilling in situ uranium leaching wells

A new drilling method-Earthworm-like vibration drilling.

Science.gov (United States)

Wang, Peng; Ni, Hongjian; Wang, Ruihe

2018-01-01

The load transfer difficulty caused by borehole wall friction severely limits the penetration rate and extended-reach limit of complex structural wells. A new friction reduction technology termed "earthworm-like drilling" is proposed in this paper to improve the load transfer of complex structural wells. A mathematical model based on a "soft-string" model is developed and solved. The results show that earthworm-like drilling is more effective than single-point vibration drilling. The amplitude and frequency of the pulse pressure and the installation position of the shakers have a substantial impact on friction reduction and load transfer. An optimization model based on the projection gradient method is developed and used to optimize the position of three shakers in a horizontal well. The results verify the feasibility and advantages of earthworm-like drilling, and establish a solid theoretical foundation for its application in oil field drilling.

Hydrate formation in drilling fluids: prevention and countering; Formacao de hidratos em fluidos de perfuracao: prevencao e controle

Energy Technology Data Exchange (ETDEWEB)

Villas Boas, Mario Barbosa [PETROBRAS, Macae, RJ (Brazil). Distrito de Perfuracao do Sudeste. Setor de Fluidos de Perfuracao

1988-12-31

The possibility of hydrates forming during deep water well drilling is analyzed under conditions typical of the state of Rio de Janeiro`s coastal ocean bed. Relying on an extensive review of technical literature, an effort has been made to ascertain the conditions which favor the occurrence of such hydrates in gas-contaminated water-based drilling muds. Based on this study, methods are proposed for preventing and countering this problem. (author) 58 refs., 10 figs.

Effects of a Short Drilling Implant Protocol on Osteotomy Site Temperature and Drill Torque.

Science.gov (United States)

Mihali, Sorin G; Canjau, Silvana; Cernescu, Anghel; Bortun, Cristina M; Wang, Hom-Lay; Bratu, Emanuel

2018-02-01

To establish a protocol for reducing the drilling sequence during implant site preparation based on temperature and insertion torque. The traditional conventional drilling sequence (used several drills with 0.6-mm increment each time) was compared with the proposed short drilling protocol (only used 2 drills: initial and final drill). One hundred drilling osteotomies were performed in bovine and porcine bones. Sets of 2 osteotomy sites were created in 5 bone densities using 2 types of drilling protocols. Thermographic pictures were captured throughout all drilling procedures and analyzed using ThermaCAM Researcher Professional 2.10. Torque values were determined during drilling by measuring electrical input and drill speed. There were statistically significant differences in bone temperature between the conventional and short drilling protocols during implant site preparation (analysis of variance P = 0.0008). However, there were no significant differences between the 2 types of drilling protocols for both implant diameters. Implant site preparation time was significantly reduced when using the short drilling protocol compared with the conventional drilling protocol (P drilling protocol proposed herein may represent a safe approach for implant site preparation.

Shipboard Analytical Capabilities on the Renovated JOIDES Resolution, IODP Riserless Drilling Vessel

Science.gov (United States)

Blum, P.; Foster, P.; Houpt, D.; Bennight, C.; Brandt, L.; Cobine, T.; Crawford, W.; Fackler, D.; Fujine, K.; Hastedt, M.; Hornbacher, D.; Mateo, Z.; Moortgat, E.; Vasilyev, M.; Vasilyeva, Y.; Zeliadt, S.; Zhao, J.

2008-12-01

The JOIDES Resolution (JR) has conducted 121 scientific drilling expeditions during the Ocean Drilling Program (ODP) and the first phase of the Integrated Ocean Drilling Program (IODP) (1983-2006). The vessel and scientific systems have just completed an NSF-sponsored renovation (2005-2008). Shipboard analytical systems have been upgraded, within funding constraints imposed by market driven vessel conversion cost increases, to include: (1) enhanced shipboard analytical services including instruments and software for sampling and the capture of chemistry, physical properties, and geological data; (2) new data management capabilities built around a laboratory information management system (LIMS), digital asset management system, and web services; (3) operations data services with enhanced access to navigation and rig instrumentation data; and (4) a combination of commercial and home-made user applications for workflow- specific data extractions, generic and customized data reporting, and data visualization within a shipboard production environment. The instrumented data capture systems include a new set of core loggers for rapid and non-destructive acquisition of images and other physical properties data from drill cores. Line-scan imaging and natural gamma ray loggers capture data at unprecedented quality due to new and innovative designs. Many instruments used to characterize chemical compounds of rocks, sediments, and interstitial fluids were upgraded with the latest technology. The shipboard analytical environment features a new and innovative framework (DESCinfo) and application (DESClogik) for capturing descriptive and interpretive data from geological sub-domains such as sedimentology, petrology, paleontology, structural geology, stratigraphy, etc. This system fills a long-standing gap by providing a global database, controlled vocabularies and taxa name lists with version control, a highly configurable spreadsheet environment for data capture, and

Field Simulation of a Drilling Mission to Mars to Search for Subsurface Life

Science.gov (United States)

Stoker, C. R.; Lemke, L. G.; Cannon, H.; Glass, B.; Dunagan, S.; Zavaleta, J.; Miller, D.; Gomez-Elvira, J.

2005-01-01

The discovery of near surface ground ice by the Mars Odyssey mission and the abundant evidence for recent Gulley features observed by the Mars Global Surveyor mission support longstanding theoretical arguments for subsurface liquid water on Mars. Thus, implementing the Mars program goal to search for life points to drilling on Mars to reach liquid water, collecting samples and analyzing them with instrumentation to detect in situ organisms and biomarker compounds. Searching for life in the subsurface of Mars will require drilling, sample extraction and handling, and new technologies to find and identify biomarker compounds and search for living organisms. In spite of its obvious advantages, robotic drilling for Mars exploration is in its technological infancy and has yet to be demonstrated in even a terrestrial field environment.

Sensitivity of ocean model simulation in the coastal ocean to the resolution of the meteorological forcing

Science.gov (United States)

Chen, Feng; Shapiro, Georgy; Thain, Richard

2013-04-01

The quality of ocean simulations depends on a number of factors such as approximations in governing equations, errors introduced by the numerical scheme, uncertainties in input parameters, and atmospheric forcing. The identification of relations between the uncertainties in input and output data is still a challenge for the development of numerical models. The impacts of ocean variables on ocean models are still not well known (e.g., Kara et al., 2009). Given the considerable importance of the atmospheric forcing to the air-sea interaction, it is essential that researchers in ocean modelling work need a good understanding about how sensitive the atmospheric forcing is to variations of model results, which is beneficial to the development of ocean models. Also, it provides a proper way to choose the atmospheric forcing in ocean modelling applications. Our previous study (Shapiro et al, 2011) has shown that the basin-wide circulation pattern and the temperature structure in the Black Sea produced by the same model is significantly dependent on the source of the meteorological input, giving remarkably different responses. For the purpose of this study we have chosen the Celtic Sea where high resolution meteo data are available from the UK Met office since 2006. The Celtic Sea is tidally dominated water basin, with the tidal stream amplitude varying from 0.25m/s in the southwest to 2 m/s in the Bristol Channel. It is also filled with mesoscale eddies which contribute to the formation of the residual (tidally averaged) circulation pattern (Young et al, 2003). The sea is strongly stratified from April to November, which adds to the formation of density driven currents. In this paper we analyse how sensitive the model output is to variations in the spatial resolution of meteorological using low (1.6°) and high (0.11°) resolution meteo forcing, giving the quantitative relation between variations of met forcing and the resulted differences of model results, as well as

Experimental investigations and finite element simulation of cutting heat in vibrational and conventional drilling of cortical bone.

Science.gov (United States)

Wang, Yu; Cao, Meng; Zhao, Xiangrui; Zhu, Gang; McClean, Colin; Zhao, Yuanyuan; Fan, Yubo

2014-11-01

Heat generated during bone drilling could cause irreversible thermal damage, which can lead to bone necrosis or even osteomyelitis. In this study, vibrational drilling was applied to fresh bovine bones to investigate the cutting heat in comparison with conventional drilling through experimental investigation and finite element analysis (FEA). The influence of vibrational frequency and amplitude on cutting heat generation and conduction were studied. The experimental results showed that, compared with the conventional drilling, vibrational drilling could significantly reduce the cutting temperature in drilling of cortical bone (P<0.05): the cutting temperature tended to decrease with increasing vibrational frequency and amplitude. The FEA results also showed that the vibrational amplitude holds a significant effect on the cutting heat conduction. Copyright © 2014 IPEM. Published by Elsevier Ltd. All rights reserved.

Lagrangian numerical methods for ocean biogeochemical simulations

Science.gov (United States)

Paparella, Francesco; Popolizio, Marina

2018-05-01

We propose two closely-related Lagrangian numerical methods for the simulation of physical processes involving advection, reaction and diffusion. The methods are intended to be used in settings where the flow is nearly incompressible and the Péclet numbers are so high that resolving all the scales of motion is unfeasible. This is commonplace in ocean flows. Our methods consist in augmenting the method of characteristics, which is suitable for advection-reaction problems, with couplings among nearby particles, producing fluxes that mimic diffusion, or unresolved small-scale transport. The methods conserve mass, obey the maximum principle, and allow to tune the strength of the diffusive terms down to zero, while avoiding unwanted numerical dissipation effects.

Surgical drill system and surgical drill bit to be used therein

NARCIS (Netherlands)

Margallo Balbas, E.; Wieringa, P.A.; French, P.J.; Lee, R.A.; Breedveld, P.

2007-01-01

Surgical drill system comprising a mechanical drill bit and means for imaging the vicinity of the drill bit tip, said means comprising: at least one optical fiber having a distal end and a proximal end, said distal end being located adjacent said drill bit tip, an optical processing unit, said

Intercomparison of numerical simulations on oceanic dispersion of the radioactive cesium released because of the Fukushima disaster

Energy Technology Data Exchange (ETDEWEB)

Kawamura, H.; Kobayshi, T.; Furuno, A. [Japan Atomic Energy Agency, Ibaraki (Japan); Usui, N.; Kamachi, M. [Japan Meteorological Agency, Meteorological Research Inst., Ibaraki (Japan); Nishikawa, S.; Ishikawa, Y. [Japan Agency for Marine-Earth Science and Tech., Kanagawa (Japan)

2014-07-01

We conducted numerical simulations on oceanic dispersion of the radioactive cesium released because of the Fukushima disaster in the North Pacific. Two independent oceanic reanalysis data were used in the simulations. Both simulations suggested that the {sup 137}Cs concentration had been reduced to the pre-Fukushima level around 2.5 years after the disaster. The intercomparison revealed that meso-scale eddies accompanied by the Kuroshio Extension may have efficiently diluted the radioactive cesium at the sea surface. The meso-scale eddies also played an important role in transporting the surface radioactive cesium into the intermediate layer. (author)

Usefulness of temporal bone prototype for drilling training: A prospective study.

Science.gov (United States)

Aussedat, C; Venail, F; Nguyen, Y; Lescanne, E; Marx, M; Bakhos, D

2017-12-01

Dissection of cadaveric temporal bones (TBs) is considered the gold standard for surgical training in otology. For many reasons, access to the anatomical laboratory and cadaveric TBs is difficult for some facilities. The aim of this prospective and comparative study was to evaluate the usefulness of a physical TB prototype for drilling training in residency. Prospective study. Tertiary referral centre. Thirty-four residents were included. Seventeen residents (mean age 26.7±1.6) drilled on only cadaveric TBs ("traditional" group), in the traditional training method, while seventeen residents (mean age 26.5±1.7) drilled first on a prototype and then on a cadaveric TB ("prototype" group). Drilling performance was assessed using a validated scale. Residents completed a mastoid image before and after each drilling to enable evaluation of mental representations of the mastoidectomy. No differences were observed between the groups with respect to age, drilling experience and level of residency. Regarding drilling performance, we found a significant difference across the groups, with a better score in the prototype group (P=.0007). For mental representation, the score was statistically improved (P=.0003) after drilling in both groups, suggesting that TB drilling improves the mental representation of the mastoidectomy whether prototype or cadaveric TB is used. The TB prototype improves the drilling performance and mental representation of the mastoidectomy in the young resident population. A drilling simulation with virtual or physical systems seems to be a beneficial tool to improve TB drilling. © 2017 John Wiley & Sons Ltd.

Slow drilling speeds for single-drill implant bed preparation. Experimental in vitro study.

Science.gov (United States)

Delgado-Ruiz, R A; Velasco Ortega, E; Romanos, G E; Gerhke, S; Newen, I; Calvo-Guirado, J L

2018-01-01

To evaluate the real-time bone temperature changes during the preparation of the implant bed with a single-drill protocol with different drill designs and different slow drilling speeds in artificial type IV bone. For this experimental in vitro study, 600 implant bed preparations were performed in 10 bovine bone disks using three test slow drilling speeds (50/150/300 rpm) and a control drilling speed (1200 rpm). The temperature at crestal and apical areas and time variations produced during drilling with three different drill designs with similar diameter and length but different geometry were recorded with real-life thermographic analysis. Statistical analysis was performed by two-way analysis of variance. Multiple comparisons of temperatures and time with the different drill designs and speeds were performed with the Tukey's test. T Max values for the control drilling speed with all the drill designs (D1 + 1200; D2 + 1200; D3 + 1200) were higher compared to those for the controls for 11 ± 1.32 °C (p drilling at 50 rpm resulted in the lowest temperature increment (22.11 ± 0.8 °C) compared to the other slow drilling speeds of 150 (24.752 ± 1.1 °C) and 300 rpm (25.977 ± 1.2 °C) (p drilling speeds compared to that for the control drilling speed. Slow drilling speeds required significantly more time to finish the preparation of the implant bed shown as follows: 50 rpm > 150 rpm > 300 rpm > control (p drill protocol with slow drilling speeds (50, 150, and 300 rpm) without irrigation in type IV bone increases the temperature at the coronal and apical levels but is below the critical threshold of 47 °C. The drill design in single-drill protocols using slow speeds (50, 150, and 300 rpm) does not have an influence on the thermal variations. The time to accomplish the implant bed preparation with a single-drill protocol in type IV bone is influenced by the drilling speed and not by the drill design. As the speed decreases, then

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2010-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

Reduced abrasion drilling fluid

NARCIS (Netherlands)

2012-01-01

A reduced abrasion drilling fluid system and method of drilling a borehole by circulating the reduced abrasion drilling fluid through the borehole is disclosed. The reduced abrasion drilling fluid comprises a drilling fluid, a first additive and a weighting agent, wherein the weighting agent has a

DYNAMIC MODELLING OF VIBRATIONS ASSISTED DRILLING

Directory of Open Access Journals (Sweden)

Mathieu LADONNE

2015-05-01

Full Text Available The number of multi-materials staking configurations for aeronautical structures is increasing, with the evolution of composite and metallic materials. For drilling the fastening holes, the processes of Vibration Assisted Drilling (VAD expand rapidly, as it permits to improve reliability of drilling operations on multilayer structures. Among these processes of VAD, the solution with forced vibrations added to conventional feed to create a discontinuous cutting is the more developed in industry. The back and forth movement allows to improve the evacuation of chips by breaking it. This technology introduces two new operating parameters, the frequency and the amplitude of the oscillation. To optimize the process, the choice of those parameters requires first to model precisely the operation cutting and dynamics. In this paper, a kinematic modelling of the process is firstly proposed. The limits of the model are analysed through comparison between simulations and measurements. The proposed model is used to develop a cutting force model that allows foreseeing the operating conditions which ensure good chips breaking and tool life improvement.

Numerical modelling for quantitative environmental risk assessment for the disposal of drill cuttings and mud

Science.gov (United States)

Wahab, Mohd Amirul Faiz Abdul; Shaufi Sokiman, Mohamad; Parsberg Jakobsen, Kim

2017-10-01

To investigate the fate of drilling waste and their impacts towards surrounding environment, numerical models were generated using an environmental software; MIKE by DHI. These numerical models were used to study the transportation of suspended drill waste plumes in the water column and its deposition on seabed in South China Sea (SCS). A random disposal site with the model area of 50 km × 25 km was selected near the Madalene Shoal in SCS and the ambient currents as well as other meteorological conditions were simulated in details at the proposed location. This paper was focusing on sensitivity study of different drill waste particle characteristics on impacts towards marine receiving environment. The drilling scenarios were obtained and adapted from the oil producer well at offshore Sabah (Case 1) and data from actual exploration drilling case at Pumbaa location (PL 469) in the Norwegian Sea (Case 2). The two cases were compared to study the effect of different drilling particle characteristics and their behavior in marine receiving environment after discharged. Using the Hydrodynamic and Sediment Transport models simulated in MIKE by DHI, the variation of currents and the behavior of the drilling waste particles can be analyzed and evaluated in terms of multiple degree zones of impacts.

Mineralogy and Origin of Sediments From Drill Holes on the Continental Margin Off Florida, 1965-1969 (NODC Accession 7100714)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Drill cores obtained during the Joint Oceanographic Institutions' Deep Earth Sampling Program from the continental shelf, the Florida-Hatteras Slope, and the Blake...

Ocean response to volcanic eruptions in Coupled Model Intercomparison Project 5 simulations

KAUST Repository

Ding, Yanni

2014-09-01

We examine the oceanic impact of large tropical volcanic eruptions as they appear in ensembles of historical simulations from eight Coupled Model Intercomparison Project Phase 5 models. These models show a response that includes lowering of global average sea surface temperature by 0.1–0.3 K, comparable to the observations. They show enhancement of Arctic ice cover in the years following major volcanic eruptions, with long-lived temperature anomalies extending to the middepth and deep ocean on decadal to centennial timescales. Regional ocean responses vary, although there is some consistent hemispheric asymmetry associated with the hemisphere in which the eruption occurs. Temperature decreases and salinity increases contribute to an increase in the density of surface water and an enhancement in the overturning circulation of the North Atlantic Ocean following these eruptions. The strength of this overturning increase varies considerably from model to model and is correlated with the background variability of overturning in each model. Any cause/effect relationship between eruptions and the phase of El Niño is weak.

Activity plan: Directional drilling and environmental measurements while drilling

International Nuclear Information System (INIS)

Myers, D.A.

1998-01-01

This activity plan describes the testing of directional drilling combined with environmental measurements while drilling at two Hanford Site locations. A cold test is to be conducted at the 105A Mock Tank Leak Facility in the 200 East Area. A hot test is proposed to be run at the 216-B-8 tile field north of the 241-B Tank Farm in 200 East Area. Criteria to judge the success, partial success or failure of various aspects of the test are included. The TWRS program is assessing the potential for use of directional drilling because of an identified need to interrogate the vadose zone beneath the single-shell tanks. Because every precaution must be taken to assure that investigation activities do not violate the integrity of the tanks, control of the drill bit and ability to follow a predetermined drill path are of utmost importance and are being tested

Case drilling - an innovative approach to reducing drilling costs

Energy Technology Data Exchange (ETDEWEB)

Madell, G.; Tessari, R. M. [Tesco Corp., Calgary, AB (Canada); Warren, T. [Tesco Drilling Technology, Calgary, AB (Canada)

1999-11-01

Casing drilling is introduced as a new drilling technique that uses standard oil field casing to simultaneously drill and case the well. The technology includes both rig and downhole equipment, customized to function effectively as an integrated drilling system. This paper describes the testing program designed to identify and overcome technical challenges. Although not fully optimized, it appears that the system is functional. Test results indicate the need for improvements in the pump down cement float equipment and the tools and procedures for drilling up the cement plugs. The pump down latch and retrieval system also needs to be further developed and tested for high angle directional applications. Cost savings in the range of 10 to 15 per cent are expected for trouble-free wells. By eliminating the cost of unscheduled events encountered in troublesome wells, cost savings may reach as high as 30 per cent. 3 refs., 7 figs.

Activity plan: Directional drilling and environmental measurements while drilling

Energy Technology Data Exchange (ETDEWEB)

Myers, D.A.

1998-07-16

This activity plan describes the testing of directional drilling combined with environmental measurements while drilling at two Hanford Site locations. A cold test is to be conducted at the 105A Mock Tank Leak Facility in the 200 East Area. A hot test is proposed to be run at the 216-B-8 tile field north of the 241-B Tank Farm in 200 East Area. Criteria to judge the success, partial success or failure of various aspects of the test are included. The TWRS program is assessing the potential for use of directional drilling because of an identified need to interrogate the vadose zone beneath the single-shell tanks. Because every precaution must be taken to assure that investigation activities do not violate the integrity of the tanks, control of the drill bit and ability to follow a predetermined drill path are of utmost importance and are being tested.

Benchmarking Distance Control and Virtual Drilling for Lateral Skull Base Surgery.

Science.gov (United States)

Voormolen, Eduard H J; Diederen, Sander; van Stralen, Marijn; Woerdeman, Peter A; Noordmans, Herke Jan; Viergever, Max A; Regli, Luca; Robe, Pierre A; Berkelbach van der Sprenkel, Jan Willem

2018-01-01

Novel audiovisual feedback methods were developed to improve image guidance during skull base surgery by providing audiovisual warnings when the drill tip enters a protective perimeter set at a distance around anatomic structures ("distance control") and visualizing bone drilling ("virtual drilling"). To benchmark the drill damage risk reduction provided by distance control, to quantify the accuracy of virtual drilling, and to investigate whether the proposed feedback methods are clinically feasible. In a simulated surgical scenario using human cadavers, 12 unexperienced users (medical students) drilled 12 mastoidectomies. Users were divided into a control group using standard image guidance and 3 groups using distance control with protective perimeters of 1, 2, or 3 mm. Damage to critical structures (sigmoid sinus, semicircular canals, facial nerve) was assessed. Neurosurgeons performed another 6 mastoidectomy/trans-labyrinthine and retro-labyrinthine approaches. Virtual errors as compared with real postoperative drill cavities were calculated. In a clinical setting, 3 patients received lateral skull base surgery with the proposed feedback methods. Users drilling with distance control protective perimeters of 3 mm did not damage structures, whereas the groups using smaller protective perimeters and the control group injured structures. Virtual drilling maximum cavity underestimations and overestimations were 2.8 ± 0.1 and 3.3 ± 0.4 mm, respectively. Feedback methods functioned properly in the clinical setting. Distance control reduced the risks of drill damage proportional to the protective perimeter distance. Errors in virtual drilling reflect spatial errors of the image guidance system. These feedback methods are clinically feasible. Copyright © 2017 Elsevier Inc. All rights reserved.

Development and Application of the Downhole Drilling String Shock-Absorption and Hydraulic Supercharging Device

Directory of Open Access Journals (Sweden)

Yongwang Liu

2016-01-01

Full Text Available It is a hot topic for deep/ultradeep wells to improve rock-breaking efficiency and drilling speed by available downhole energy. Based on different downhole energies and working conditions, specialized plunger pump is proposed to convert longitudinal vibration of drilling string into rock-breaking energy. Technical design is developed to generate high-pressure water jet. And then a simulation model is built to verify feasibility of the technical design. Through simulation, the influence law of key factors is obtained. On this basis, this device is tested in several wells. The result indicates this device can increase drilling speed as much as 136%. Meanwhile the harmful vibration can be absorbed. The energy from drilling string vibration is of high frequency and increases as well depth and formation anisotropy increase. By reducing adverse vibration, this device is able to increase the drilling speed and the service life also meets the demand of field application. The longest working time lasts for more than 130 hours. The performance of this device demonstrates great application prospect in deep/ultradeep resources exploration. To provide more equipment support for deep/ultradeep wells, more effort should be put into fundamental study on downhole drill string vibration and related equipment.

Location Accuracy of INS/Gravity-Integrated Navigation System on the Basis of Ocean Experiment and Simulation.

Science.gov (United States)

Wang, Hubiao; Wu, Lin; Chai, Hua; Bao, Lifeng; Wang, Yong

2017-12-20

An experiment comparing the location accuracy of gravity matching-aided navigation in the ocean and simulation is very important to evaluate the feasibility and the performance of an INS/gravity-integrated navigation system (IGNS) in underwater navigation. Based on a 1' × 1' marine gravity anomaly reference map and multi-model adaptive Kalman filtering algorithm, a matching location experiment of IGNS was conducted using data obtained using marine gravimeter. The location accuracy under actual ocean conditions was 2.83 nautical miles (n miles). Several groups of simulated data of marine gravity anomalies were obtained by establishing normally distributed random error N ( u , σ 2 ) with varying mean u and noise variance σ 2 . Thereafter, the matching location of IGNS was simulated. The results show that the changes in u had little effect on the location accuracy. However, an increase in σ 2 resulted in a significant decrease in the location accuracy. A comparison between the actual ocean experiment and the simulation along the same route demonstrated the effectiveness of the proposed simulation method and quantitative analysis results. In addition, given the gravimeter (1-2 mGal accuracy) and the reference map (resolution 1' × 1'; accuracy 3-8 mGal), location accuracy of IGNS was up to reach ~1.0-3.0 n miles in the South China Sea.

The Swedish Deep Drilling Program - an emerging scientific drilling program and new infrastructure.

Science.gov (United States)

Lorenz, Henning; Juhlin, Christopher

2010-05-01

Scientific drilling projects imply numerous aspects that are difficult to handle for individual research groups. Therefore, about three years ago a joint effort was launched in the Swedish geoscientific community to establish a national program for scientific drilling, the Swedish Deep Drilling Program (SDDP). Soon afterwards, several working groups established drilling proposals with Nordic and, also, international participation. With this serious interest in scientific drilling SDDP was able to successfully promote the Swedish membership in ICDP which commenced in 2008. Two SDDP projects achieved workshop grants from the International Continental Scientific Drilling Program (ICDP) in 2009. In the same year the Swedish Research Council decided to support an application for a truck-mounted drill rig - a big success for the SDDP working group. Scientific Drilling infrastructure: SDDP envisages a mobile platform that is capable of core drilling to at least 2500 m depth. The procurement will be made during 2010 and first operations are planned for 2011. This drill rig is primarily intended for use in the SDDP drilling projects, but will be rented out to other scientific drilling projects or even commercial enterprises in the remaining time to cover maintenance and future upgrade costs. SDDP's drill rig will be unique in Europe and complementary to the deep drilling InnovaRig of the GFZ German Research Centre for Geosciences. Until now, drilling to 2000 - 3000 m implied the use of a full-sized drill rig like the InnovaRig or the mobilization of a core drill rig from another continent. This gap will now be filled by Sweden's upcoming scientific drilling infrastructure. Drilling projects and proposals: Presently, SDDP serves six projects: "Collisional Orogeny in the Scandinavian Caledonides" (COSC; ICDP workshop spring 2010), the "Postglacial Fault Drilling Project" (PFDP; ICDP workshop autumn 2010), a "Deep Rock Laboratory" (DRL), "Palaeoproterozoic Mineralized Volcanic

Drilling cost analysis

International Nuclear Information System (INIS)

Anand, A.B.

1992-01-01

Drilling assumes greater importance in present day uranium exploration which emphasizes to explore more areas on the basis of conceptual model than merely on surface anomalies. But drilling is as costly as it is important and consumes a major share (50% to 60%) of the exploration budget. As such the cost of drilling has great bearing on the exploration strategy as well as on the overall cost of the project. Therefore, understanding the cost analysis is very much important when planning or intensifying an exploration programme. This not only helps in controlling the current operations but also in planning the budgetary provisions for future operations. Also, if the work is entrusted to a private party, knowledge of in-house cost analysis helps in fixing the rates of drilling in different formations and areas to be drilled. Under this topic, various factors that contribute to the cost of drilling per meter as well as ways to minimize the drilling cost for better economic evaluation of mineral deposits are discussed. (author)

Longitudinal biases in the Seychelles Dome simulated by 35 ocean-atmosphere coupled general circulation models

Science.gov (United States)

Nagura, Motoki; Sasaki, Wataru; Tozuka, Tomoki; Luo, Jing-Jia; Behera, Swadhin K.; Yamagata, Toshio

2013-02-01

Seychelles Dome refers to the shallow climatological thermocline in the southwestern Indian Ocean, where ocean wave dynamics efficiently affect sea surface temperature, allowing sea surface temperature anomalies to be predicted up to 1-2 years in advance. Accurate reproduction of the dome by ocean-atmosphere coupled general circulation models (CGCMs) is essential for successful seasonal predictions in the Indian Ocean. This study examines the Seychelles Dome as simulated by 35 CGCMs, including models used in phase five of the Coupled Model Intercomparison Project (CMIP5). Among the 35 CGCMs, 14 models erroneously produce an upwelling dome in the eastern half of the basin whereas the observed Seychelles Dome is located in the southwestern tropical Indian Ocean. The annual mean Ekman pumping velocity in these models is found to be almost zero in the southern off-equatorial region. This result is inconsistent with observations, in which Ekman upwelling acts as the main cause of the Seychelles Dome. In the models reproducing an eastward-displaced dome, easterly biases are prominent along the equator in boreal summer and fall, which result in shallow thermocline biases along the Java and Sumatra coasts via Kelvin wave dynamics and a spurious upwelling dome in the region. Compared to the CMIP3 models, the CMIP5 models are even worse in simulating the dome longitudes.

The offshore disposal of radioactive waste by drilled emplacement: A feasibility study

International Nuclear Information System (INIS)

Bury, M.R.C.

1985-01-01

This book is a report, based on a study by Taylor Woodrow Construction Limited, on the overall feasibility of the disposal of high-level radioactive waste in boreholes drilled deep into the ocean bed. The work comprises an engineering appraisal of the disposal process with a view to establishing technical and operational feasibility and providing overall cost information to enable an economic assessment to be made. Contents: Summary report; Reference criteria; Drilling operation; Transfer of radioactive waste, personnel and other supplies; Handling of radioactive waste on board; Lowering strings of canisters; Emplacement and backfilling of canisters; Preliminary design of marine platform; Retrieval of flasks or canisters lost or misplaced; Variations to the features of the lowering system; Logistics of the operation; Construction cost estimate; Operational costs; Appendix

Robotic Planetary Drill Tests

Science.gov (United States)

Glass, Brian J.; Thompson, S.; Paulsen, G.

2010-01-01

Several proposed or planned planetary science missions to Mars and other Solar System bodies over the next decade require subsurface access by drilling. This paper discusses the problems of remote robotic drilling, an automation and control architecture based loosely on observed human behaviors in drilling on Earth, and an overview of robotic drilling field test results using this architecture since 2005. Both rotary-drag and rotary-percussive drills are targeted. A hybrid diagnostic approach incorporates heuristics, model-based reasoning and vibration monitoring with neural nets. Ongoing work leads to flight-ready drilling software.

Paleomagnetism of the Oman Ophiolite: New Results from Oman Drilling Project Cores

Science.gov (United States)

Horst, A. J.; Till, J. L.; Koornneef, L.; Usui, Y.; Kim, H.; Morris, A.

2017-12-01

The Oman Drilling Project drilled holes at four sites in a transect through the southern massifs of the Samail ophiolite, and recovered 1500 m of igneous and metamorphic rocks. We focus on three sites from the oceanic crustal section including lower layered gabbros (GT1A), the mid-crustal layered to foliated gabbro transition (GT2A), and the shallower transition from sheeted dikes to varitextured gabbros (GT3A). Detailed core descriptions, analyses, and paleomagnetic measurements, were made on D/V Chikyu from July to September 2017 to utilize the core laboratory facilities similar to IODP expeditions. Shipboard measurements included anisotropy of magnetic susceptibility (AMS) and alternating field and thermal demagnetization of 597 discrete samples. Sample demagnetization behavior is varied from each of the cores, with some revealing multiple components of magnetization, and others yielding nearly univectorial data. The interpretation of results from the lower crustal cores is complicated by the pervasive presence of secondary magnetite. In almost all samples, a stable component was resolved (interpreted as a characteristic remanent magnetization) after removal of a lower-coercivity or lower unblocking-temperature component. The inclinations of the stable components in the core reference frame are very consistent in Hole GT1A. However, a transition from negative to positive inclinations in GT2A suggests some structural complexity, possibly as a result of intense late faulting activity. Both abrupt and gradual transitions between multiple zones of negative and positive inclinations occur in Hole GT3A. Interpretation and direct comparison of remanence between drill sites is difficult as recovered core pieces currently remain azimuthally unoriented, and GT2A was drilled at a plunge of 60°, whereas GT1A and GT3A were both drilled vertically. Work is ongoing to use borehole imagery to reorient the core pieces and paleomagnetic data into a geographic in situ reference

Drilling trends in the nineties

International Nuclear Information System (INIS)

1993-01-01

At a conference on various aspects of well drilling in the 1990s, papers were presented on drilling waste management, well completion and workovers, drilling fluids, drilling rig equipment and design, drilling mechanics, drill stem testing and materials, cementing, business management, health and safety, environmental issues, and directional drilling technology. Separate abstracts have been prepared for 46 papers from this conference

Scientific Drilling with the Sea Floor Drill Rig MeBo

Directory of Open Access Journals (Sweden)

Gerold Wefer

2007-09-01

Full Text Available In March 2007 the sea floor drill rig MeBo (short for “Meeresboden-Bohrgerät”, ‘sea floor drill rig’ in German returned from a 17-day scientific cruise with the new German research vessel Maria S. Merian. Four sites between 350 m and 1700 m water depth were sampled at the continental slope off Morocco by push coring and rotary drilling. Up to 41.5-m-long sediment cores were recovered from Miocene, Pliocene, and Pleistocene marls. MeBo bridges the gapbetween conventional sampling methods from standard multipurpose research vessels (gravity corer, piston corer, dredges and drill ships. Most bigger research vessels will be able to support deployment of the MeBo. Since the drill system can be easily transported within 20-ft containers, worldwide operation from vessels of opportunity is possible. With the MeBo a new system is available for marine geosciences that allows the recovery of high quality samples from soft sediments and hard rock from the deep sea withoutrelying on the services of expensive drilling vessels.

Drilling contract issues

International Nuclear Information System (INIS)

Davison, G.B.; Worden, D.R.; Borbridge, G.K.D.

1997-01-01

Some selected issues which are facing both operators and contractors in drilling for oil and gas, such as the allocation of risk by contract and by statute and the implementation of new technologies, were discussed. There are three varieties of written drilling contracts used in Canada: (1) day work and meterage contracts, (2) master drilling agreements, and (3) contracts that are used in construction projects that do not specifically relate to drilling. Issues relevant to the contractual allocation of risk, to implementing new drilling technologies, to reconciling contract and statute liability, and the formation of strategic alliances for mutual benefit, and the factors contributing to the success of such alliances were explored. 12 refs

Flow splitting in numerical simulations of oceanic dense-water outflows

Science.gov (United States)

Marques, Gustavo M.; Wells, Mathew G.; Padman, Laurie; Özgökmen, Tamay M.

2017-05-01

Flow splitting occurs when part of a gravity current becomes neutrally buoyant and separates from the bottom-trapped plume as an interflow. This phenomenon has been previously observed in laboratory experiments, small-scale water bodies (e.g., lakes) and numerical studies of small-scale systems. Here, the potential for flow splitting in oceanic gravity currents is investigated using high-resolution (Δx = Δz = 5 m) two-dimensional numerical simulations of gravity flows into linearly stratified environments. The model is configured to solve the non-hydrostatic Boussinesq equations without rotation. A set of experiments is conducted by varying the initial buoyancy number B0 =Q0N3 /g‧2 (where Q0 is the volume flux of the dense water flow per unit width, N is the ambient stratification and g‧ is the reduced gravity), the bottom slope (α) and the turbulent Prandtl number (Pr). Regardless of α or Pr, when B0 ≤ 0.002 the outflow always reaches the deep ocean forming an underflow. Similarly, when B0 ≥ 0.13 the outflow always equilibrates at intermediate depths, forming an interflow. However, when B0 ∼ 0.016, flow splitting always occurs when Pr ≥ 10, while interflows always occur for Pr = 1. An important characteristic of simulations that result in flow splitting is the development of Holmboe-like interfacial instabilities and flow transition from a supercritical condition, where the Froude number (Fr) is greater than one, to a slower and more uniform subcritical condition (Fr internal hydraulic jump and consequent mixing enhancement. Although our experiments do not take into account three-dimensionality and rotation, which are likely to influence mixing and the transition between flow regimes, a comparison between our results and oceanic observations suggests that flow splitting may occur in dense-water outflows with weak ambient stratification, such as Antarctic outflows.

Drilling to investigate processes in active tectonics and magmatism

Science.gov (United States)

Shervais, J.; Evans, J.; Toy, V.; Kirkpatrick, J.; Clarke, A.; Eichelberger, J.

2014-12-01

Coordinated drilling efforts are an important method to investigate active tectonics and magmatic processes related to faults and volcanoes. The US National Science Foundation (NSF) recently sponsored a series of workshops to define the nature of future continental drilling efforts. As part of this series, we convened a workshop to explore how continental scientific drilling can be used to better understand active tectonic and magmatic processes. The workshop, held in Park City, Utah, in May 2013, was attended by 41 investigators from seven countries. Participants were asked to define compelling scientific justifications for examining problems that can be addressed by coordinated programs of continental scientific drilling and related site investigations. They were also asked to evaluate a wide range of proposed drilling projects, based on white papers submitted prior to the workshop. Participants working on faults and fault zone processes highlighted two overarching topics with exciting potential for future scientific drilling research: (1) the seismic cycle and (2) the mechanics and architecture of fault zones. Recommended projects target fundamental mechanical processes and controls on faulting, and range from induced earthquakes and earthquake initiation to investigations of detachment fault mechanics and fluid flow in fault zones. Participants working on active volcanism identified five themes: the volcano eruption cycle; eruption sustainability, near-field stresses, and system recovery; eruption hazards; verification of geophysical models; and interactions with other Earth systems. Recommended projects address problems that are transferrable to other volcanic systems, such as improved methods for identifying eruption history and constraining the rheological structure of shallow caldera regions. Participants working on chemical geodynamics identified four major themes: large igneous provinces (LIPs), ocean islands, continental hotspot tracks and rifts, and

South African drilling

International Nuclear Information System (INIS)

Anon.

1984-01-01

According to the president of the South African Drilling Association, the drilling industry is meeting head-on the challenges created by the worldwide recession. The paper is a synopsis of several of the papers presented at the SADA symposium and a look at several mining-related drilling projects in South Africa. These papers include grouting techniques, the use of impregnated bits in hard rock drilling, tunnel boring for mines, surveying improvement methods and the use of explosives to increase groundwater yield

A new drilling method—Earthworm-like vibration drilling

Science.gov (United States)

Wang, Peng; Wang, Ruihe

2018-01-01

The load transfer difficulty caused by borehole wall friction severely limits the penetration rate and extended-reach limit of complex structural wells. A new friction reduction technology termed “earthworm-like drilling” is proposed in this paper to improve the load transfer of complex structural wells. A mathematical model based on a “soft-string” model is developed and solved. The results show that earthworm-like drilling is more effective than single-point vibration drilling. The amplitude and frequency of the pulse pressure and the installation position of the shakers have a substantial impact on friction reduction and load transfer. An optimization model based on the projection gradient method is developed and used to optimize the position of three shakers in a horizontal well. The results verify the feasibility and advantages of earthworm-like drilling, and establish a solid theoretical foundation for its application in oil field drilling. PMID:29641615

New optimized drill pipe size for deep-water, extended reach and ultra-deep drilling

Energy Technology Data Exchange (ETDEWEB)

Jellison, Michael J.; Delgado, Ivanni [Grant Prideco, Inc., Hoston, TX (United States); Falcao, Jose Luiz; Sato, Ademar Takashi [PETROBRAS, Rio de Janeiro, RJ (Brazil); Moura, Carlos Amsler [Comercial Perfuradora Delba Baiana Ltda., Rio de Janeiro, RJ (Brazil)

2004-07-01

A new drill pipe size, 5-7/8 in. OD, represents enabling technology for Extended Reach Drilling (ERD), deep water and other deep well applications. Most world-class ERD and deep water wells have traditionally been drilled with 5-1/2 in. drill pipe or a combination of 6-5/8 in. and 5-1/2 in. drill pipe. The hydraulic performance of 5-1/2 in. drill pipe can be a major limitation in substantial ERD and deep water wells resulting in poor cuttings removal, slower penetration rates, diminished control over well trajectory and more tendency for drill pipe sticking. The 5-7/8 in. drill pipe provides a significant improvement in hydraulic efficiency compared to 5-1/2 in. drill pipe and does not suffer from the disadvantages associated with use of 6-5/8 in. drill pipe. It represents a drill pipe assembly that is optimized dimensionally and on a performance basis for casing and bit programs that are commonly used for ERD, deep water and ultra-deep wells. The paper discusses the engineering philosophy behind 5-7/8 in. drill pipe, the design challenges associated with development of the product and reviews the features and capabilities of the second-generation double-shoulder connection. The paper provides drilling case history information on significant projects where the pipe has been used and details results achieved with the pipe. (author)

Rheological behavior of drilling fluids under low temperatures

Energy Technology Data Exchange (ETDEWEB)

Lomba, Rosana F.T.; Sa, Carlos H.M. de; Brandao, Edimir M. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas]. E-mails: rlomba, chsa, edimir@cenpes.petrobras.com.br

2000-07-01

The so-called solid-free fluids represent a good alternative to drill through productive zones. These drill-in fluids are known to be non-damaging to the formation and their formulation comprise polymers, salts and acid soluble solids. Xanthan gum is widely used as viscosifier and modified starch as fluid loss control additive. The salts most commonly used are sodium chloride and potassium chloride, although the use of organic salt brines has been increasing lately. Sized calcium carbonate is used as bridging material, when the situation requires. The low temperatures encountered during deep water drilling demand the knowledge of fluid rheology at this temperature range. The rheological behavior of drill-in fluids at temperatures as low as 5 deg C was experimentally evaluated. Special attention was given to the low shear rate behavior of the fluids. A methodology was developed to come up with correlations to calculate shear stress variations with temperature. The developed correlations do not depend on a previous choice of a rheological model. The results will be incorporated in a numerical simulator to account for temperature effects on well bore cleaning later on. (author)

The Hans Tausen drill

DEFF Research Database (Denmark)

Johnsen, Sigfus Johann; Dahl-Jensen, Dorthe; Steffensen, Jørgen Peder

2007-01-01

In the mid-1990s, excellent results from the GRIP and GISP2 deep drilling projects in Greenland opened up funding for continued ice-coring efforts in Antarctica (EPICA) and Greenland (NorthGRIP). The Glaciology Group of the Niels Bohr Institute, University of Copenhagen, was assigned the task...... of providing drilling capability for these projects, as it had done for the GRIP project. The group decided to further simplify existing deep drill designs for better reliability and ease of handling. The drill design decided upon was successfully tested on Hans Tausen Ice Cap, Peary Land, Greenland, in 1995....... The 5.0 m long Hans Tausen (HT) drill was a prototype for the ~11 m long EPICA and NorthGRIP versions of the drill which were mechanically identical to the HT drill except for a much longer core barrel and chips chamber. These drills could deliver up to 4 m long ice cores after some design improvements...

Drilling contracts and incentives

International Nuclear Information System (INIS)

Osmundsen, Petter; Sorenes, Terje; Toft, Anders

2008-01-01

Shortages of rigs and personnel have encouraged discussion of designing incentive contracts in the drilling sector. However, for the drilling contracts, there are not a large variety of contract types in use. This article describes and analyses incentives for drilling contractors. These are directly represented by the compensation formats utilised in the present and in the consecutive drilling contracts. Indirectly, incentives are also provided by the evaluation criteria that oil companies use for awarding drilling assignments. Changes in contract format pose a number of relevant questions relating to resource management, and the article takes an in-depth look at some of these. Do evaluation criteria for awarding drilling assignments encourage the development of new technology and solutions? How will a stronger focus on drilling efficiency influence reservoir utilisation?

Western Indian Ocean - A glimpse of the tectonic scenario

Digital Repository Service at National Institute of Oceanography (India)

Bhattacharya, G.C.; Chaubey, A.K.

is the en echelon displacement of the NW-SE trending ridge axis by numerous NE-SW trending fracture Western Indian Ocean - A Glimpse of the Tectonic Scenario 693 Table 1. Some information from the scientific drilling campaigns in the western Indian Ocean...: Raman Seamount; P: Panikkar Seamount; W: Wadia Guyot; S: SagarKanya Seamount; SR: ShebaRidge; CR: Carlsberg Ridge; CIR: Central Indian Ridge; SWIR: Southwest Indian Ridge; RTJ: Rodrigues Triple Junction; OFZ: Owen Fracture Zone; LR: Laxmi Ridge; MR...

Wellsite computers--their increasing role in drilling operations

International Nuclear Information System (INIS)

Keenan, P.G.; Dyson, P.M.

1981-01-01

The increasing expense and complexity of exploration drilling, coupled with rapid advances in computer and microprocessor technology, have led to the development of computer-assisted wellsite logging units from their humble beginnings as simple hot wire gas detectors. The main applications of this technology can be recognized in the following areas: (a) Safety of wellsite personnel, rig and downhole equipment. (b) Increased drilling efficiency with the resultant time and cost savings. (c) Simulation of possible events allowing comparisons between actual and expected data to assist decision making at the wellsite. (d) Storage of data on tape/disk to allow rapid retrieval of data for postwell analysis and report production. 6 refs

Study on drilling induced delamination of woven kenaf fiber reinforced epoxy composite using carbide drills

Science.gov (United States)

Suhaily, M.; Hassan, C. H. Che; Jaharah, A. G.; Azmi, H.; Afifah, M. A.; Khairusshima, M. K. Nor

2018-04-01

In this research study, it presents the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates when using the carbide drill bits. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated carbide drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs. The results indicated that the drill diameter has a significant influence on the delamination when drilling the woven kenaf fiber reinforced epoxy composites.

Drilling Performance of Rock Drill by High-Pressure Water Jet under Different Configuration Modes

Directory of Open Access Journals (Sweden)

Songyong Liu

2017-01-01

Full Text Available In the rock drilling progress, the resistant force results in tools failure and the low drilling efficiency; thus, it is necessary to reduce the tools failure and enhance the drilling efficiency. In this paper, different configuration modes of drilling performance assisted with water jet are explored based on the mechanism and experiment analysis of rock drilling assisted with water jet. Moreover, the rotary sealing device with high pressure is designed to achieve the axial and rotation movement simultaneously as well as good sealing effect under high-pressure water jet. The results indicate that the NDB and NFB have better effects on drilling performance compared with that of NSB. Moreover, the high-pressure water jet is helpful not only to reduce the drill rod deflection, but also to reduce the probability of drill rod bending and improve the drill rod service life.

Ocean Hydrodynamics Numerical Model in Curvilinear Coordinates for Simulating Circulation of the Global Ocean and its Separate Basins.

Science.gov (United States)

Gusev, Anatoly; Diansky, Nikolay; Zalesny, Vladimir

2010-05-01

scope of the CMIP-5 (Coupled Model Intercomparison Project). On the base of the complex proposed the Pacific Ocean circulation eddy-resolving model was realized. The integration domain covers the Pacific from Equator to Bering Strait. The model horizontal resolution is 0.125 degree and it has 20 non-uniform sigma-levels in depth. The model adequately reproduces circulation large-scale structure and its variability: Kuroshio meandering, ocean synoptic eddies, frontal zones, etc. Kuroshio high variability is shown. The distribution of contaminant was simulated that is admittedly wasted near Petropavlovsk-Kamchatsky. The results demonstrate contaminant distribution structure and provide us understanding of hydrological fields formation processes in the North-West Pacific.

Simulation of bomb tritium entry into the Atlantic Ocean

International Nuclear Information System (INIS)

Sarmiento, J.L.

1983-01-01

Tritium is used in a model-calibration study that aimed at developing three-dimensional ocean circulation and mixing models for climate and geochemical simulations. The North Atlantic tritium distribution is modeled using a three-dimensional advective field predicted by a primitive equation ocean circulation model. The effect of wintertime convection is parametrized by homogenizing the tracer to the observed March mixed-layer depth. Mixing is parametrized by horizontal and vertical Fickian diffusivities of 5 x 10 -6 cm 2 s -1 and 0.5 cm 2 s -1 , respectively. The spreading of tritium in the model is dominated by advection in the horizontal, and by wintertime convection and advection in the vertical. The horizontal and vertical mixing provided by the model have negligible effect. A comparison of the model tracer fields with observations shows that most of the basic patterns of the tritium field are repreduced. The model's mean vertical penetration of 543 m in 1972 is comparable to the 592 penetration obtained from the data. The major discrepancy between model and data is an inadequate penetration into deeper portions of the northwestern subtropical gyre main thermoclien. Some of the problem that may contribute to this are identified. A tritium simulation with a smoothed input gives a penetration depth of only 395 m. The smoothing puts a high fraction of the tritium into low-latitude, low-penetration regions such as the equator. This suggests that great care needs to be exercised in using simplified models of tritium observations to predict the behavior of tracers with different input functions, like fossil fuel CO 2

Drilling technologies in hydrogeological survey

OpenAIRE

Vorlíček, Petr

2014-01-01

This work deals with the drilling technologies used in hydrogeology. The main aim of the work is to explore types of drilling technologies used at hydrogeological drilling wells and modern technologies that could potentially be used in the future. The work also summarizes a historical development of drilling techniques, a drilling process procedure, information obtained from boreholes and the most common types of drilling fluids.

Design and Exploitation Problems of Drill String in Directional Drilling

Directory of Open Access Journals (Sweden)

Bednarz Stanislaw

2004-09-01

Full Text Available Drill string design for directional drilling requires accounting for a number of factors. First, types and expected values of loads should be determined. Then, elements of the drill string should be so selected as to enable realization of the plan at specified loads. Some of additional factors, e. g. purchase, exploitation cost, geological conditions in the bore-hole, washing of the bore-hole, stability, trajectory, rig parameters, accuracy of gauges, pumps parameters remain in conflict. Drill pipes are made of rolled pipes, upset and welded with tool joints to 9,5 m long; the shorter ones can be made of hot forged rods. Exploitation requirements, being a result of practical experience supported by theoretical and laboratory analyses should be a part of syllabuses of technical staff educational programs. Apart from designing the string, it is also vital to lower the risk of a drilling failure. The significance of these aspects seems to be unquestionable.

Diagnostic System of Drill Condition in Laminated Chipboard Drilling Process

Directory of Open Access Journals (Sweden)

Swiderski Bartosz

2017-01-01

Full Text Available The paper presents an on-line automatic system for recognition of the drill condition in a laminated chipboard drilling process. Two states of the drill are considered: the sharp enough (still able to drill holes acceptable for processing quality and worn out (excessive drill wear, not satisfactory from the quality point of view of the process. The automatic system requires defining the diagnostic features, which are used as the input attributes to the classifier. The features have been generated from 5 registered signals: feed force, cutting torque, noise, vibration and acoustic emission. The statistical parameters defined on the basis of the auto regression model of these signals have been used as the diagnostic features. The sequential step-wise feature selection is applied for choosing the most discriminative set of features. The final step of recognition is done by support vector machine classifier working in leave one out mode. The results of numerical experiments have confirmed good quality of the proposed diagnostic system.

Horizontal drilling under Lake Erie

Energy Technology Data Exchange (ETDEWEB)

Meller, R.

2001-07-01

Drilling oil wells under Lake Erie calls for horizontal drilling wells to be drilled from shore out into the pay-zone under the lake. The nature and characteristics of horizontal wells as compared to vertical wells are explored. Considerations that have to be taken into account in drilling horizontal wells are explained (the degree of curvature, drilling fluid quality, geosteering in the pay-zone, steering instrumentation, measurements while drilling (MWD), logging while drilling (LWD)). The concept and reasons for extended reach wells are outlined, along with characteristic features of multilateral wells.

Evaluation of the parameters affecting bone temperature during drilling using a three-dimensional dynamic elastoplastic finite element model.

Science.gov (United States)

Chen, Yung-Chuan; Tu, Yuan-Kun; Zhuang, Jun-Yan; Tsai, Yi-Jung; Yen, Cheng-Yo; Hsiao, Chih-Kun

2017-11-01

A three-dimensional dynamic elastoplastic finite element model was constructed and experimentally validated and was used to investigate the parameters which influence bone temperature during drilling, including the drill speed, feeding force, drill bit diameter, and bone density. Results showed the proposed three-dimensional dynamic elastoplastic finite element model can effectively simulate the temperature elevation during bone drilling. The bone temperature rise decreased with an increase in feeding force and drill speed, however, increased with the diameter of drill bit or bone density. The temperature distribution is significantly affected by the drilling duration; a lower drilling speed reduced the exposure duration, decreases the region of the thermally affected zone. The constructed model could be applied for analyzing the influence parameters during bone drilling to reduce the risk of thermal necrosis. It may provide important information for the design of drill bits and surgical drilling powers.

Scientific Drilling of Impact Craters - Well Logging and Core Analyses Using Magnetic Methods (Invited)

Science.gov (United States)

Fucugauchi, J. U.; Perez-Cruz, L. L.; Velasco-Villarreal, M.

2013-12-01

Drilling projects of impact structures provide data on the structure and stratigraphy of target, impact and post-impact lithologies, providing insight on the impact dynamics and cratering. Studies have successfully included magnetic well logging and analyses in core and cuttings, directed to characterize the subsurface stratigraphy and structure at depth. There are 170-180 impact craters documented in the terrestrial record, which is a small proportion compared to expectations derived from what is observed on the Moon, Mars and other bodies of the solar system. Knowledge of the internal 3-D deep structure of craters, critical for understanding impacts and crater formation, can best be studied by geophysics and drilling. On Earth, few craters have yet been investigated by drilling. Craters have been drilled as part of industry surveys and/or academic projects, including notably Chicxulub, Sudbury, Ries, Vredefort, Manson and many other craters. As part of the Continental ICDP program, drilling projects have been conducted on the Chicxulub, Bosumtwi, Chesapeake, Ries and El gygytgyn craters. Inclusion of continuous core recovery expanded the range of paleomagnetic and rock magnetic applications, with direct core laboratory measurements, which are part of the tools available in the ocean and continental drilling programs. Drilling studies are here briefly reviewed, with emphasis on the Chicxulub crater formed by an asteroid impact 66 Ma ago at the Cretaceous/Paleogene boundary. Chicxulub crater has no surface expression, covered by a kilometer of Cenozoic sediments, thus making drilling an essential tool. As part of our studies we have drilled eleven wells with continuous core recovery. Magnetic susceptibility logging, magnetostratigraphic, rock magnetic and fabric studies have been carried out and results used for lateral correlation, dating, formation evaluation, azimuthal core orientation and physical property contrasts. Contributions of magnetic studies on impact

International Ocean Discovery Program; Expedition 361 preliminary report; South African climates (Agulhas LGM density profile); 30 January-31 March 2016

NARCIS (Netherlands)

Hall, Ian R.; Hemming, Sidney R.; LeVay, Leah J.; Barker, Stephen R.; Berke, Melissa A.; Brentegani, Luna; Caley, Thibaut; Cartagena-Sierra, Alejandra; Charles, Christopher D.; Coenen, Jason J.; Crespin, Julien G.; Franzese, Allison M.; Gruetzner, Jens; Xibin, Han; Hins, Sophia K. V.; Jimenez Espejo, Francisco J.; Just, Janna; Koutsodendris, Andreas; Kubota, Kaoru; Lathika, Nambiyathodi; Norris, Richard D.; Pereira dos Santos, Thiago; Robinson, Rebecca; Rolison, John M.; Simon, Margit H.; Tangunan, Deborah; van der Lubbe, Jeroen (H,) J. L.; Yamane, Masako; Hucai, Zhang

2016-01-01

International Ocean Discovery Program (IODP) Expedition 361 drilled six sites on the southeast African margin and in the Indian-Atlantic ocean gateway, southwest Indian Ocean, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days

Alteration in the IRDP drill hole compared with other drill holes in Iceland

Science.gov (United States)

Kristmannsdóttir, Hrefna

1982-08-01

The overall alteration pattern in the drill hole at Reydarfjördur is very similar to alteration patterns observed in Icelandic geothermal areas and in low-grade metamorphosed basalts in deep crustal sections elsewhere in Iceland. However more detail is obtained by the study of the IRDP drill core than by study of drill cuttings sampled in previous drill holes in Iceland. A comparatively high fossil thermal gradient is obtained at Reydarfjördur by a combination of mineral stability data and the observed occurence of secondary minerals. This high gradient is consistent with the measured dike dilation at the drill site and the location of the drill site adjacent to a central volcano.

An Approach to Define the Heat Flow in Drilling with Different Cooling Systems Using Finite Element Analysis

Directory of Open Access Journals (Sweden)

Carlos Henrique Lauro

2013-01-01

Full Text Available The heat generated in the cutting zone with high-speed drilling causes damage in the machined part. The heat can affect the dimensions of the hole considering its diameter. Moreover, the heat reduces tool life of uncoated and coated tools. This paper shows experimental tests with high-speed drilling in hardened steel. Drilling was performed on AISI H13 steel with dimensions of 100 × 40 × 14 mm and 52 HRC. The work pieces were drilled with coated drills (TiAlN. A flooded lubricant system and the minimal quantity of lubricant (MQL were applied to investigate the ability to remove heat from the cutting zone and to compare with dry tests. FEM was applied to define the heat flow and the coefficient of convection for the cooling systems. A steepest descent method was employed to minimize the difference between empirical and simulation data. The results showed that the simulation technique used to find values for heat flow and the coefficient of convection were close to the literature reference. In addition, the adjustment errors of the simulated temperature curves were less than 10% when compared with trial curves. Furthermore, the MQL showed a capability of cooling 3.5 times higher than that of the flooded system.

A self propelled drilling system for hard-rock, horizontal and coiled tube drilling

Energy Technology Data Exchange (ETDEWEB)

Biglin, D.; Wassell, M.

1997-12-31

Several advancements are needed to improve the efficiency and reliability of both hard rock drilling and extended reach drilling. This paper will present a Self Propelled Drilling System (SPDS) which can grip the borehole wall in order to provide a stable platform for the application of weight on bit (WOB) and resisting the reactive torque created by the downhole drilling motor, bit and formation interaction. The system will also dampen the damaging effects of drill string vibration. This tool employs two hydraulically activated anchors (front and rear) to grip the borehole wall, and a two-way thrust mandrel to apply both the drilling force to the bit, and a retraction force to pull the drill string into the hole. Forward drilling motion will commence by sequencing the anchor pistons and thrust mandrel to allow the tool to walk in a stepping motion. The SPDS has a microprocessor to control valve timing, sensing and communication functions. An optional Measurement While Drilling (MWD) interface can provide two-way communication of critical operating parameters such as hydraulic pressure and piston location. This information can then be telemetered to the surface, or used downhole to autonomously control system parameters such as anchor and thrust force or damping characteristics.

Impact of Drilling Operations on Lunar Volatiles Capture: Thermal Vacuum Tests

Science.gov (United States)

Kleinhenz, Julie E.; Paulsen, Gale; Zacny, Kris; Smith, Jim

2015-01-01

In Situ Resource Utilization (ISRU) enables future planetary exploration by using local resources to supply mission consumables. This idea of 'living off the land' has the potential to reduce mission cost and risk. On the moon, water has been identified as a potential resource (for life support or propellant) at the lunar poles, where it exists as ice in the subsurface. However, the depth and content of this resource has yet to be confirmed on the ground; only remote detection data exists. The upcoming Resource Prospector mission (RP) will 'ground-truth' the water using a rover, drill, and the RESOLVE science package. As the 2020 planned mission date nears, component level hardware is being tested in relevant lunar conditions (thermal vacuum). In August 2014 a series of drilling tests were performed using the Honeybee Robotics Lunar Prospecting Drill inside a 'dirty' thermal vacuum chamber at the NASA Glenn Research Center. The drill used a unique auger design to capture and retain the lunar regolith simulant. The goal of these tests was to investigate volatiles (water) loss during drilling and sample transfer to a sample crucible in order to validate this regolith sampling method. Twelve soil samples were captured over the course of two tests at pressures of 10(exp-5) Torr and ambient temperatures between -80C to -20C. Each sample was obtained from a depth of 40 cm to 50 cm within a cryogenically frozen bed of NU-LHT-3M lunar regolith simulant doped with 5 wt% water. Upon acquisition, each sample was transferred and hermetically sealed inside a crucible. The samples were later baked out to determine water wt% and in turn volatile loss by following ASTM standard practices. Of the twelve tests, four sealed properly and lost an average of 30% of their available water during drilling and transfer. The variability in the results correlated well with ambient temperature (lower the temperature lower volatiles loss) and the trend agreed with the sublimation rates for the

Numerical Simulation of Salinity and Dissolved Oxygen at Perdido Bay and Adjacent Coastal Ocean

Science.gov (United States)

Environmental Fluid Dynamic Code (EFDC), a numerical estuarine and coastal ocean circulation hydrodynamic model, was used to simulate the distribution of the salinity, temperature, nutrients and dissolved oxygen (DO) in Perdido Bay and adjacent Gulf of Mexico. External forcing fa...

Modeling pellet impact drilling process

Science.gov (United States)

Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Ulyanova, O. S.

2016-03-01

The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling the process of pellet impact drilling, which creates the scientific and methodological basis for engineering design of drilling operations under different geo-technical conditions.

Evolution of organic carbon burial in the Global Ocean during the Neogene

Science.gov (United States)

LI, Z.; Zhang, Y.

2017-12-01

Although only a small fraction of the organic carbon (OC) that rains from surface waters is eventually buried in the sediments, it is a process that controls the organic sub-cycle of the long-term carbon cycle, and the key for atmospheric O2, CO2 and nutrient cycling. Here we constrain the spatiotemporal variability of OC burial by quantifying the total organic carbon (TOC) mass accumulation rate (MAR) over the Neogene (23.0-2.6 Ma) by compiling the TOC, age model and sediment density data from sites retrieved by the Deep Sea Drilling Program, Ocean Drilling Program, and Integrated Ocean Drilling Program. We screened all available sites which yielded 80 sites with adequate data quality, covering all major ocean basins and sedimentary depositional environments. All age models are updated to the GTS 2012 timescale so the TOC MAR records from different sites are comparable. Preliminary results show a clear early Miocene peak of OC burial in many sites related to high sediment flux which might reflect the orogenic uplift and/or glacier erosion. Places that receive high influx of terrigenous inputs become "hotspots" for Neogene burial of OC. At "open ocean" sites, OC burial seems to be more impacted by marine productivity changes, with a pronounced increase during the middle Miocene "Monterey Formation" and late Miocene - early Pliocene "Biogenic Bloom". Upon the completion of the data collection, we will further explore the regional and global OC burial in the context of tectonic uplift, climate change and the evolution of primary producers and consumers during the last 23 million years of Earth history.

Porosity and sonic velocity depth trends of Eocene chalk in Atlantic Ocean: Influence of effective stress and temperature

DEFF Research Database (Denmark)

Awedalkarim, Ahmed; Fabricius, Ida Lykke

2014-01-01

We aimed to relate changes in porosity and sonic velocity data, measured on water-saturated Eocene chalks from 36 Ocean Drilling Program drill sites in the Atlantic Ocean, to vertical effective stress and thermal maturity. We considered only chalk of Eocene age to avoid possible influence...... not show or at least it is difficult to define a clear pore-stiffening contact cementation trend as the Ontong Java Plateau chalk. Mechanical compaction is the principal cause of porosity reduction (at shallow depths) in the studied Eocene chalk, at least down to about 5MPa Terzaghi׳s effective stress...

The use of drilling by the U.S. Antarctic program

Energy Technology Data Exchange (ETDEWEB)

Wade, M.C.; Webb, J.W.; Hedberg, W.H.

1994-08-01

This report on drilling in the Antarctic has been prepared by the U.S. National Science Foundation (NSF) to assist principal investigators and others in complying with the National Environmental Policy Act (NEPA) and the Antarctic Treaty of 1961. Implementing regulations for NEPA are spelled out in 40 CFR 1500-1508. Environmental protection under the Antarctic Treaty is addressed in the Protocol on Environmental Protection to the Antarctic Treaty (hereafter referred to as the Protocol), which was adopted by 26 countries in 1991. In the United States, responsibility for compliance with these requirements rests with the NSF Office of Polar Programs (OPP), which manages the U.S. Antarctic Program (USAP). The USAP recognizes the potentially profound impacts that its presence and activities can have on the antarctic environment. In its extensive support of operations and research in Antarctica, the USAP uses all practical means to foster and maintain natural conditions while supporting scientific endeavors in a safe and healthful manner. Reducing human impacts on the antarctic environment is a major goal of the USAP. The USAP`s operating philosophy is based on broad yet reasonable and practical assumptions concerning environmental protection. The USAP maintains three year-round stations on the continent to support scientific research. Research and associated support operations at these stations and camps sometimes involve drilling into ice, soil, or ocean sediments. In order to comply with NEPA and the Protocol, it is necessary for principal investigators and others to assess the environmental effects of drilling. This report has been prepared to assist in this process by describing various drilling technologies currently available for use in Antarctica, generally characterizing the potential environmental impacts associated with these drilling techniques, and identifying possible mitigation measures to reduce impacts.

Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure Validation Simulation Study

Science.gov (United States)

Murdoch, Jennifer L.; Bussink, Frank J. L.; Chamberlain, James P.; Chartrand, Ryan C.; Palmer, Michael T.; Palmer, Susan O.

2008-01-01

The Enhanced Oceanic Operations Human-In-The-Loop In-Trail Procedure (ITP) Validation Simulation Study investigated the viability of an ITP designed to enable oceanic flight level changes that would not otherwise be possible. Twelve commercial airline pilots with current oceanic experience flew a series of simulated scenarios involving either standard or ITP flight level change maneuvers and provided subjective workload ratings, assessments of ITP validity and acceptability, and objective performance measures associated with the appropriate selection, request, and execution of ITP flight level change maneuvers. In the majority of scenarios, subject pilots correctly assessed the traffic situation, selected an appropriate response (i.e., either a standard flight level change request, an ITP request, or no request), and executed their selected flight level change procedure, if any, without error. Workload ratings for ITP maneuvers were acceptable and not substantially higher than for standard flight level change maneuvers, and, for the majority of scenarios and subject pilots, subjective acceptability ratings and comments for ITP were generally high and positive. Qualitatively, the ITP was found to be valid and acceptable. However, the error rates for ITP maneuvers were higher than for standard flight level changes, and these errors may have design implications for both the ITP and the study's prototype traffic display. These errors and their implications are discussed.

Assimilation of ocean colour to improve the simulation and understanding of the North West European shelf-sea ecosystem

Science.gov (United States)

Ciavatta, Stefano; Brewin, Robert; Skakala, Jozef; Sursham, David; Ford, David

2017-04-01

Shelf-seas and coastal zones provide essential goods and services to humankind, such as fisheries, aquaculture, tourism and climate regulation. The understanding and management of these regions can be enhanced by merging ocean-colour observations and marine ecosystem simulations through data assimilation, which provides (sub)optimal estimates of key biogeochemical variables. Here we present a range of applications of ocean-colour data assimilation in the North West European shelf-sea. A reanalysis application illustrates that assimilation of error-characterized chlorophyll concentrations could provide a map of the shelf sea vulnerability to oxygen deficiency, as well as estimates of the shelf sea uptake of atmospheric carbon dioxide (CO2) in the last decade. The interannual variability of CO2 uptake and its uncertainty were related significantly to interannual fluctuations of the simulated primary production. However, the reanalysis also indicates that assimilation of total chlorophyll did not improve significantly the simulation of some other variables, e.g. nutrients. We show that the assimilation of alternative products derived from ocean colour (i.e. spectral diffuse attenuation coefficient and phytoplankton size classes) can overcome this limitation. In fact, these products can constrain a larger number of model variables, which define either the underwater light field or the structure of the lower trophic levels. Therefore, the assimilation of such ocean-colour products into marine ecosystem models is an advantageous novel approach to improve the understanding and simulation of shelf-sea environments.

Simulation of simultaneously obtaining ocean temperature and salinity using dual-wavelength Brillouin lidar

International Nuclear Information System (INIS)

Yu, Yin; Ma, Yong; Li, Hao; Huang, Jun; Fang, Yu; Liang, Kun; Zhou, Bo

2014-01-01

A method for simultaneously obtaining the ocean temperature and salinity based on dual-wavelength Brillouin lidar is proposed in this letter. On the basis of the relationships between the temperature and salinity and the Brillouin shifts, a retrieval model for retrieving the temperature and salinity is established. By using the retrieval model, the ocean temperature and salinity can be simultaneously obtained through the Brillouin shifts. Simulation based on dual-wavelength Brillouin lidar is also carried out for verification of the accuracy of the retrieval model. Results show that the errors of the retrieval model for temperature and salinity are ±0.27 °C and ±0.33‰. (letter)

Modeling and simulation of ocean wave propagation using lattice Boltzmann method

Science.gov (United States)

Nuraiman, Dian

2017-10-01

In this paper, we present on modeling and simulation of ocean wave propagation from the deep sea to the shoreline. This requires high computational cost for simulation with large domain. We propose to couple a 1D shallow water equations (SWE) model with a 2D incompressible Navier-Stokes equations (NSE) model in order to reduce the computational cost. The coupled model is solved using the lattice Boltzmann method (LBM) with the lattice Bhatnagar-Gross-Krook (BGK) scheme. Additionally, a special method is implemented to treat the complex behavior of free surface close to the shoreline. The result shows the coupled model can reduce computational cost significantly compared to the full NSE model.

A study on directional resistivity logging-while-drilling based on self-adaptive hp-FEM

Science.gov (United States)

Liu, Dejun; Li, Hui; Zhang, Yingying; Zhu, Gengxue; Ai, Qinghui

2014-12-01

Numerical simulation of resistivity logging-while-drilling (LWD) tool response provides guidance for designing novel logging instruments and interpreting real-time logging data. In this paper, based on self-adaptive hp-finite element method (hp-FEM) algorithm, we analyze LWD tool response against model parameters and briefly illustrate geosteering capabilities of directional resistivity LWD. Numerical simulation results indicate that the change of source spacing is of obvious influence on the investigation depth and detecting precision of resistivity LWD tool; the change of frequency can improve the resolution of low-resistivity formation and high-resistivity formation. The simulation results also indicate that the self-adaptive hp-FEM algorithm has good convergence speed and calculation accuracy to guide the geologic steering drilling and it is suitable to simulate the response of resistivity LWD tools.

Experimental evaluation on the damages of different drilling modes to tight sandstone reservoirs

Directory of Open Access Journals (Sweden)

Gao Li

2017-07-01

Full Text Available The damages of different drilling modes to reservoirs are different in types and degrees. In this paper, the geologic characteristics and types of such damages were analyzed. Then, based on the relationship between reservoir pressure and bottom hole flowing pressure corresponding to different drilling modes, the experimental procedures on reservoir damages in three drilling modes (e.g. gas drilling, liquid-based underbalanced drilling and overbalanced drilling were designed. Finally, damage simulation experiments were conducted on the tight sandstone reservoir cores of the Jurassic Ahe Fm in the Tarim Basin and Triassic Xujiahe Fm in the central Sichuan Basin. It is shown that the underbalanced drilling is beneficial to reservoir protection because of its less damage on reservoir permeability, but it is, to some extent, sensitive to the stress and the empirical formula of stress sensitivity coefficient is obtained; and that the overbalanced drilling has more reservoir damages due to the invasion of solid and liquid phases. After the water saturation of cores rises to the irreducible water saturation, the decline of gas logging permeability speeds up and the damage degree of water lock increases. It is concluded that the laboratory experiment results of reservoir damage are accordant with the reservoir damage characteristics in actual drilling conditions. Therefore, this method reflects accurately the reservoir damage characteristics and can be used as a new experimental evaluation method on reservoir damage in different drilling modes.

Hess Deep Interactive Lab: Exploring the Structure and Formation of the Oceanic Crust through Hands-On Models and Online Tools

Science.gov (United States)

Kurtz, N.; Marks, N.; Cooper, S. K.

2014-12-01

Scientific ocean drilling through the International Ocean Discovery Program (IODP) has contributed extensively to our knowledge of Earth systems science. However, many of its methods and discoveries can seem abstract and complicated for students. Collaborations between scientists and educators/artists to create accurate yet engaging demonstrations and activities have been crucial to increasing understanding and stimulating interest in fascinating geological topics. One such collaboration, which came out of Expedition 345 to the Hess Deep Rift, resulted in an interactive lab to explore sampling rocks from the usually inacessible lower oceanic crust, offering an insight into the geological processes that form the structure of the Earth's crust. This Hess Deep Interactive Lab aims to explain several significant discoveries made by oceanic drilling utilizing images of actual thin sections and core samples recovered from IODP expeditions. . Participants can interact with a physical model to learn about the coring and drilling processes, and gain an understanding of seafloor structures. The collaboration of this lab developed as a need to explain fundamental notions of the ocean crust formed at fast-spreading ridges. A complementary interactive online lab can be accessed at www.joidesresolution.org for students to engage further with these concepts. This project explores the relationship between physical and on-line models to further understanding, including what we can learn from the pros and cons of each.

Drilling a better pair : new technologies in SAGD directional drilling

Energy Technology Data Exchange (ETDEWEB)

Zimmer, C.; Richter, D. [Statoil Canada Ltd., Calgary, AB (Canada); Person, J.; Tilley, J.; Bittar, M. [Halliburton Energy Services, Calgary, AB (Canada)

2010-07-01

The Leismer Demonstration Project (LDP) is the first of 8 proposed major steam assisted gravity drainage (SAGD) projects for Statoil's Kai Kos Dehseh (KKD) asset in the Athabasca oil sands deposit. The bitumen resources are expected to produce approximately 2.2 billion barrels of oil over approximately 35 years with a peak production of 220,000 bbl/day. To date, 23 well pairs have been drilled on 4 drilling pads. The precise placement of well pairs is among the most important factors in a successful SAGD drilling program. The producer well must be placed in relation to the reservoir boundaries. It must also be accurately twinned with the injector well. A strong focus on technological innovation is needed in order to deliver on these high expectations in unconsolidated formations, such as the McMurray oil sands. Lateral SAGD pairs are often drilled with conventional steerable mud motors and logging-while-drilling (LWD) resistivity measurements, but this combination imposes certain limitations in terms of wellbore quality and placement. Several industry firsts were successfully implemented at the Statoil LDP, including a combination of the newest and most cutting-edge directional, measurement, and LWD technology. The keystone of these industry firsts was the use of a soft formation modified, point-the-bit rotary steerable system (RSS), used on 20 horizontal wells. The RRS was combined with an ultra deep azimuthal resistivity sensor to provide precise geosteering along the bottom bed boundary in the producer wells, resulting in improved reservoir capture and reservoir characterization. This paper described the new drilling system and its impact on the progressive future of directional drilling in SAGD. 8 refs., 1 tab., 22 figs.

El Margen Atlántico Ibérico al W de Galicia. Evolución en régimen extensional y sedimentación. (Resultados preliminares del Leg. 103, Ocean Drilling Program.

Directory of Open Access Journals (Sweden)

Boillot, G.

1986-06-01

Full Text Available Leg 101 of the Ocean Drilling Program (ODP was devoted discovering the tectonic and sedimentary evolution of the Atlantic Margin of the lberian Peninsula. A transect of five sites, with a total of 14 drill-holes was undertaken to the South of the Galicia Bank on the seaward edge of the margin. The data obtained revealed a complex history of subsidence and rifting preceding the initiation of sea floor spreading between Newfoundland and Iberia. The main findings include: 1 The Upper Jurassic-Lowermost Cretaceous shallow-water carbonate platform are the first Messozoic deposits at the margin. The «basement seismic reflector» is made-up of these carbonates. 2 The platform drowning, tilting of fault blocks and rapid subsidence preceded the spreading by as much as 25 million years. 3 A ridge of serpentiniced peridotites is located near the boundary between the oceanic and continental crusts. 4 The seismic reflector «S» does not, as widely believed represent a ductile-brinle boundary within the continental crust but is instead a reflector at the base of the synrift sediments.

La campaña oceanográfica 103 del Ocean Drilling Program (ODP ha estado dedicada a dilucidar la evolución tectónica y sedimentación del Margen Atlántico-Ibérico. Se realizaron un total de 14 sondeos., en cinco puntos de posicionamiento, sobre el extremo más profundo del margen; al S del Banco de Galicia. Los resultados obtenidos revelan que previamente al inicio de la expansión oceánica entre Terranova e Iberia ocurrió una historia compleja de distensión cortical, fracturación y subsidencia asociadas. Los resultados fundamentales son los siguientes: 1 Carbonatos de plataforma marina somera, de edad Jurásico superior-Cretáceo basal constituyen los primeros depósitos mesozóicos en ese ámbito del margen y dan lugar a un reflector sísmico considerado interiormente como basamento, 2 El hundimiento de la plataforma, fallamiento y basculamiento de los bloques

Real-time drilling mud gas monitoring for qualitative evaluation of hydrocarbon gas composition during deep sea drilling in the Nankai Trough Kumano Basin.

Science.gov (United States)

Hammerschmidt, Sebastian B; Wiersberg, Thomas; Heuer, Verena B; Wendt, Jenny; Erzinger, Jörg; Kopf, Achim

2014-01-01

Integrated Ocean Drilling Program Expedition 338 was the second scientific expedition with D/V Chikyu during which riser drilling was conducted as part of the Nankai Trough Seismogenic Zone Experiment. Riser drilling enabled sampling and real-time monitoring of drilling mud gas with an onboard scientific drilling mud gas monitoring system ("SciGas"). A second, independent system was provided by Geoservices, a commercial mud logging service. Both systems allowed the determination of (non-) hydrocarbon gas, while the SciGas system also monitored the methane carbon isotope ratio (δ(13)CCH4). The hydrocarbon gas composition was predominated by methane (> 1%), while ethane and propane were up to two orders of magnitude lower. δ(13)CCH4 values suggested an onset of thermogenic gas not earlier than 1600 meter below seafloor. This study aims on evaluating the onboard data and subsequent geological interpretations by conducting shorebased analyses of drilling mud gas samples. During shipboard monitoring of drilling mud gas the SciGas and Geoservices systems recorded up to 8.64% and 16.4% methane, respectively. Ethane and propane concentrations reached up to 0.03 and 0.013%, respectively, in the SciGas system, but 0.09% and 0.23% in the Geoservices data. Shorebased analyses of discrete samples by gas chromatography showed a gas composition with ~0.01 to 1.04% methane, 2 - 18 ppmv ethane, and 2 - 4 ppmv propane. Quadruple mass spectrometry yielded similar results for methane (0.04 to 4.98%). With δD values between -171‰ and -164‰, the stable hydrogen isotopic composition of methane showed little downhole variability. Although the two independent mud gas monitoring systems and shorebased analysis of discrete gas sample yielded different absolute concentrations they all agree well with respect to downhole variations of hydrocarbon gases. The data point to predominantly biogenic methane sources but suggest some contribution from thermogenic sources at depth, probably due

Methods to ensure optimal off-bottom and drill bit distance under pellet impact drilling

Science.gov (United States)

Kovalyov, A. V.; Isaev, Ye D.; Vagapov, A. R.; Urnish, V. V.; Ulyanova, O. S.

2016-09-01

The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rock for various purposes. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The paper presents the survey of methods ensuring an optimal off-bottom and a drill bit distance. The analysis of methods shows that the issue is topical and requires further research.

Report Viewgraphs for IC project: Fully-coupled climate simulations with an eddy-permitting ocean component

Energy Technology Data Exchange (ETDEWEB)

Veneziani, Carmela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-02-06

Two sets of simulations were performed within this allocation: 1) a 12-year fully-coupled experiment in preindustrial conditions, using the CICE4 version of the sea-ice model; 2) a set of multi-decadal ocean-ice-only experiments, forced with CORE-I atmospheric fields and using the CICE5 version of the sea-ice model. Results from simulation 1) are presented in Figures 1-3, and specific results from a simulation in 2) with tracer releases are presented in Figure 4.

Ultrasonically assisted drilling of rocks

Science.gov (United States)

Mikhailova, N. V.; Onawumi, P. Y.; Roy, A.; Silberschmidt, V. V.

2018-05-01

Conventional drilling of rocks can generate significant damage in the drilled material; a material layer is often split off a back surface of a sample during drilling, negatively affecting its strength. To improve finish quality, ultrasonically assisted drilling (UAD) was employed in two rocks - sandstone and marble. Damage areas in both materials were reduced in UAD when compared to conventional drilling. Reductions in a thrust force and a torque reduction were observed only for UAD in marble; ultrasonic assistance in sandstone drilling did not result in improvements in this regard.

Early Paleogene variations in the calcite compensation depth: new constraints using old borehole sediments from across Ninetyeast Ridge, central Indian Ocean

Science.gov (United States)

Slotnick, B. S.; Lauretano, V.; Backman, J.; Dickens, G. R.; Sluijs, A.; Lourens, L.

2015-03-01

Major variations in global carbon cycling occurred between 62 and 48 Ma, and these very likely related to changes in the total carbon inventory of the ocean-atmosphere system. Based on carbon cycle theory, variations in the mass of the ocean carbon should be reflected in contemporaneous global ocean carbonate accumulation on the seafloor and, thereby, the depth of the calcite compensation depth (CCD). To better constrain the cause and magnitude of these changes, the community needs early Paleogene carbon isotope and carbonate accumulation records from widely separated deep-sea sediment sections, especially including the Indian Ocean. Several CCD reconstructions for this time interval have been generated using scientific drill sites in the Atlantic and Pacific oceans; however, corresponding information from the Indian Ocean has been extremely limited. To assess the depth of the CCD and the potential for renewed scientific drilling of Paleogene sequences in the Indian Ocean, we examine lithologic, nannofossil, carbon isotope, and carbonate content records for late Paleocene - early Eocene sediments recovered at three sites spanning Ninetyeast Ridge: Deep Sea Drilling Project (DSDP) Sites 213 (deep, east), 214 (shallow, central), and 215 (deep, west). The disturbed, discontinuous sediment sections are not ideal, because they were recovered in single holes using rotary coring methods, but remain the best Paleogene sediments available from the central Indian Ocean. The δ13C records at Sites 213 and 215 are similar to those generated at several locations in the Atlantic and Pacific, including the prominent high in δ13C across the Paleocene carbon isotope maximum (PCIM) at Site 215, and the prominent low in δ13C across the early Eocene Climatic Optimum (EECO) at both Site 213 and Site 215. The Paleocene-Eocene thermal maximum (PETM) and the K/X event are found at Site 213 but not at Site 215, presumably because of coring gaps. Carbonate content at both Sites 213 and

Numerical simulation of vertical transport and oxidation of methane in Arctic Ocean

Science.gov (United States)

Stepanenko, Victor; Iakovlev, Nikolai

2013-04-01

The high abundance of methane in shelf of East Siberian Arctic Seas (ESAS) has been a subject of a number of field studies (e.g. Shakhova et al., 2010). This experimental evidence provoked discussions on probable origins of that methane and possible feedbacks to modern climate change. For instance, the hypothesis of methane hydrates degradation under current ocean warming was tested recently in several modeling studies none of which supported this degradation to be significant feedback for climate change. Regardless the origin of methane the knowledge of its budget in the water column is important to link its bottom flux with emission to the atmosphere (and vice versa). It is frequently assumed that all methane released from a seabed of ESAS shelf reaches the atmosphere. When using ocean circulation models (Biastoch et al., 2011) this simplification is cancelled out but the vertical resolution of 3D models at the shelf (that is several tens meters deep) is not enough to accurately resolve turbulent transport of methane and other gases. Moreover, up the knowledge of authors none of the ocean models includes explicitly bubble transport of gases. These constrains motivate this study. In this study a high-resolution 1D single column ocean model is constructed to explicitly simulate the methane transport, oxidation and emission to the atmosphere. The model accounts for both vertical turbulent transport (using k-ɛ closure) and bubble transport of gases. The ground under the seabed is represented by multilayer heat and moisture transfer model, including methane hydrate evolution. It is forced by time series of atmospheric variables from NCEP reanalysis and horizontal advection terms taken from FEMAO-1 3D ocean model. The baseline simulation is performed for the period 1948-2011. The model is validated using temperature profiles measured at research vessels in ESAS. The annual cycle and multiyear variability of methane profiles in water are studied and compared to

Improving MJO Prediction and Simulation Using AGCM Coupled Ocean Model with Refined Vertical Resolution

Science.gov (United States)

Tu, Chia-Ying; Tseng, Wan-Ling; Kuo, Pei-Hsuan; Lan, Yung-Yao; Tsuang, Ben-Jei; Hsu, Huang-Hsiung

2017-04-01

Precipitation in Taiwan area is significantly influenced by MJO (Madden-Julian Oscillation) in the boreal winter. This study is therefore conducted by toggling the MJO prediction and simulation with a unique model structure. The one-dimensional TKE (Turbulence Kinetic Energy) type ocean model SIT (Snow, Ice, Thermocline) with refined vertical resolution near surface is able to resolve cool skin, as well as diurnal warm layer. SIT can simulate accurate SST and hence give precise air-sea interaction. By coupling SIT with ECHAM5 (MPI-Meteorology), CAM5 (NCAR) and HiRAM (GFDL), the MJO simulations in 20-yrs climate integrations conducted by three SIT-coupled AGCMs are significant improved comparing to those driven by prescribed SST. The horizontal resolutions in ECHAM5, CAM5 and HiRAM are 2-deg., 1-deg and 0.5-deg., respectively. This suggests that the improvement of MJO simulation by coupling SIT is AGCM-resolution independent. This study further utilizes HiRAM coupled SIT to evaluate its MJO forecast skill. HiRAM has been recognized as one of the best model for seasonal forecasts of hurricane/typhoon activity (Zhao et al., 2009; Chen & Lin, 2011; 2013), but was not as successful in MJO forecast. The preliminary result of the HiRAM-SIT experiment during DYNAMO period shows improved success in MJO forecast. These improvements of MJO prediction and simulation in both hindcast experiments and climate integrations are mainly from better-simulated SST diurnal cycle and diurnal amplitude, which is contributed by the refined vertical resolution near ocean surface in SIT. Keywords: MJO Predictability, DYNAMO

Axially symmetrical stresses measurement in the cylindrical tube using DIC with hole-drilling

Science.gov (United States)

Ma, Yinji; Yao, Xuefeng; Zhang, Danwen

2015-03-01

In this paper, a new method combining the digital image correlation (DIC) with the hole-drilling technology to characterize the axially symmetrical stresses of the cylindrical tube is developed. First, the theoretical expressions of the axially symmetrical stresses in the cylindrical tube are derived based on the displacement or strain fields before and after hole-drilling. Second, the release of the axially symmetrical stresses for the cylindrical tube caused by hole-drilling is simulated by the finite element method (FEM), which indicates that the axially symmetrical stresses of the cylindrical tube calculated by the cylindrical solution is more accuracy than that for traditionally planar solution. Finally, both the speckle image information and the displacement field of the cylindrical tube before and after hole-drilling are extracted by combining the DIC with the hole-drilling technology, then the axially symmetrical loading induced stresses of the cylindrical tube are obtained, which agree well with the results from the strain gauge method.

Drilling for the Archean Roots of Life and Tectonic Earth in the Barberton Mountains

Directory of Open Access Journals (Sweden)

Nicola McLoughlin

2009-09-01

Full Text Available In the Barberton Scientific Drilling Program (BSDP we successfully completed three drill holes in 2008 across strategically selected rock formations in the early Archean Barberton Greenstone Belt, South Africa. This collaborative project’s goal is to advance understanding of geodynamic and biogeochemical processes of the young Earth. The program aims to better define and characterize Earth’s earliest preserved ocean crust shear zones and microbial borings in Archean basaltic glass, and to identify biogeochemical fingerprints of ancient ecological niches recorded in rocks. The state-of-the-art analytical and imaging work will address the question of earliest plate tectonics in the Archean, the δ18O composition, the redox state and temperature of Archean seawater, and the origin of life question.

Coupled atmosphere-ocean-wave simulations of a storm event over the Gulf of Lion and Balearic Sea

Science.gov (United States)

Renault, Lionel; Chiggiato, Jacopo; Warner, John C.; Gomez, Marta; Vizoso, Guillermo; Tintore, Joaquin

2012-01-01

The coastal areas of the North-Western Mediterranean Sea are one of the most challenging places for ocean forecasting. This region is exposed to severe storms events that are of short duration. During these events, significant air-sea interactions, strong winds and large sea-state can have catastrophic consequences in the coastal areas. To investigate these air-sea interactions and the oceanic response to such events, we implemented the Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System simulating a severe storm in the Mediterranean Sea that occurred in May 2010. During this event, wind speed reached up to 25 m.s-1 inducing significant sea surface cooling (up to 2°C) over the Gulf of Lion (GoL) and along the storm track, and generating surface waves with a significant height of 6 m. It is shown that the event, associated with a cyclogenesis between the Balearic Islands and the GoL, is relatively well reproduced by the coupled system. A surface heat budget analysis showed that ocean vertical mixing was a major contributor to the cooling tendency along the storm track and in the GoL where turbulent heat fluxes also played an important role. Sensitivity experiments on the ocean-atmosphere coupling suggested that the coupled system is sensitive to the momentum flux parameterization as well as air-sea and air-wave coupling. Comparisons with available atmospheric and oceanic observations showed that the use of the fully coupled system provides the most skillful simulation, illustrating the benefit of using a fully coupled ocean-atmosphere-wave model for the assessment of these storm events.

Review of casing while drilling technology

Directory of Open Access Journals (Sweden)

Pavković Bojan

2016-01-01

Full Text Available Conventional drilling methods have been plagued with huge operational and financial challenges, such as cost of purchasing, inspecting, handling, transporting the drill equipment and most importantly, tripping in-and-out of the drill string whenever the Bottom Hole Assembly (BHA needs a replacement, needs of wiper trip or when total depth is reached. The tripping in-and-out of the drill string not only contributes to Non Productive Time (NPT but also leads to well control difficulties including wellbore instability and lost circulation. All this has led Oil and Gas industry, as well as any other engineering industry, to seek for new ways and methods in order to reduce these problems. Thanks to the advances in technical solutions and constant improvements of conventional drilling methods, a new drilling method - casing while drilling has been developed. Casing Drilling encompasses the process of simultaneously drilling and casing a well, using the active casing and thus optimizes the production. This paper presents a review of casing while drilling method (CwD and its practical usage in drilling wells. The comparison of conventional drilling method and casing while drilling is also presented. The CwD method achieves significantly better results than conventional drilling method.

Deep drilling KLX 02. Drilling and documentation of a 1700 m deep borehole at Laxemar, Sweden

Energy Technology Data Exchange (ETDEWEB)

Andersson, O [VBB VIAK AB, Malmoe (Sweden)

1994-08-01

In this report the preparation and execution of the deep core drilling KLX 02 is described. The hole was drilled with the wireline methods, NQ dimension (diameter 76 mm), to a final depth of 1700.5 m. Prior to core drilling a diameter 215 mm pilot hole was pre drilled to 200 m with controlled hammer drilling (DTH). In this hole casing and air-lift equipment was installed with the aim to support the circulation of drilling fluid. During core drilling there was a measurement of major drilling parameters and drilling fluid in and out of hole. As a fluid tracer uranine was used. Each 300 m of core drilling air-lift pump tests were performed. After completion a flow-meter log was run to finalize the project phase. It can be concluded that both the pre drilling and core drilling methods used proved to be successful. No severe technical problem occurred. However, potential risks have been pointed at in the report. The air-lift system functioned only partly and has to be modified for further use. Also the technique for monitoring of drilling parameters needs improvement as does the method for air-lift pump tests with packer. The organisation model for planning and realization functioned satisfactory and can be recommended for similar future projects. 9 refs, numerous tabs and figs.

Deep drilling KLX 02. Drilling and documentation of a 1700 m deep borehole at Laxemar, Sweden

International Nuclear Information System (INIS)

Andersson, O.

1994-08-01

In this report the preparation and execution of the deep core drilling KLX 02 is described. The hole was drilled with the wireline methods, NQ dimension (diameter 76 mm), to a final depth of 1700.5 m. Prior to core drilling a diameter 215 mm pilot hole was pre drilled to 200 m with controlled hammer drilling (DTH). In this hole casing and air-lift equipment was installed with the aim to support the circulation of drilling fluid. During core drilling there was a measurement of major drilling parameters and drilling fluid in and out of hole. As a fluid tracer uranine was used. Each 300 m of core drilling air-lift pump tests were performed. After completion a flow-meter log was run to finalize the project phase. It can be concluded that both the pre drilling and core drilling methods used proved to be successful. No severe technical problem occurred. However, potential risks have been pointed at in the report. The air-lift system functioned only partly and has to be modified for further use. Also the technique for monitoring of drilling parameters needs improvement as does the method for air-lift pump tests with packer. The organisation model for planning and realization functioned satisfactory and can be recommended for similar future projects. 9 refs, numerous tabs and figs

Trans-Amazon Drilling Project (TADP) : Origins and evolution of the forests, climate, and hydrology of the South American tropics

NARCIS (Netherlands)

Baker, P.A.; Fritz, S.C.; Silva, C.G.; Rigsby, C.A.; Absy, M.L.; Almeida, R.P.; Caputo, M.; Chiessi, C.M.; Cruz, F.W.; Dick, C. W.; Feakins, S.J.; Figueiredo, J.; Freeman, K.H.; Hoorn, C.; Jaramillo, C.; Kern, A.K.; Latrubesse, E.M.; Ledru, M.P.; Marzoli, A.; Myrbo, A.; Noren, A.; Piller, W.E.; Ramos, M.I.F.; Ribas, C.C.; Trnadade, R.; West, A.J.; Wahnfried, I.; Willard, D.A.

2015-01-01

This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this

Drilling subsurface wellbores with cutting structures

Science.gov (United States)

Mansure, Arthur James; Guimerans, Rosalvina Ramona

2010-11-30

A system for forming a wellbore includes a drill tubular. A drill bit is coupled to the drill tubular. One or more cutting structures are coupled to the drill tubular above the drill bit. The cutting structures remove at least a portion of formation that extends into the wellbore formed by the drill bit.

Long term simulation of {sup 137}Cs radioactivity in the regional ocean following the Fukushima Daiichi nuclear power plant accident

Energy Technology Data Exchange (ETDEWEB)

Tsumune, D.; Tsubono, T.; Misumi, K.; Yoshida, Y.; Hayami, H. [Central Research Institute of Electric Power Industry (Japan); Aoyama, M. [Meteorological Research Institute (Japan); Uematsu, M. [University of Tokyo (Japan); Maeda, Y. [CERES, Inc. (Japan)

2014-07-01

A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways, direct release from the accident site and atmospheric deposition. A regional-scale simulation of {sup 137}Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of {sup 137}Cs deposited on the ocean by atmospheric deposition outside the domain of the model for more than two years. Direct releases of {sup 131}I, {sup 134}Cs, and {sup 137}Cs were estimated for 1 year after the accident by comparing simulated results and measured activities. The estimated total amounts of directly released {sup 131}I, {sup 134}Cs, and {sup 137}Cs were 11.1±2.2 PBq, 3.5±0.7 PBq, and 3.6±0.7 PBq, respectively. The contributions of each source were estimated by analysis of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs activity ratios and comparisons between simulated results and measured activities of {sup 137}Cs. Simulated {sup 137}Cs activities attributable to direct release were in good agreement with measured activities close to the accident site, a result that implies that the estimated direct release rate was reasonable, while simulated {sup 137}Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition onto the ocean was underestimated because of a lack of measurements of deposition onto the ocean when atmospheric deposition rates were being estimated. Measured {sup 137}Cs activities attributable to atmospheric deposition helped to improve the accuracy of simulated atmospheric deposition rates. Simulated {sup 137}Cs activities attributable to the inflow of {sup 137}Cs deposited onto the ocean outside the domain of the model were in good agreement with measured activities in the open ocean within the

Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

International Nuclear Information System (INIS)

Washington, W.M.; Meehl, G.A.

1990-01-01

The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming

Characteristics of coupled atmosphere-ocean CO2 sensitivity experiments with different ocean formulations

International Nuclear Information System (INIS)

Washington, W.M.; Meehl, G.A.

1991-01-01

The Community Climate Model at the National Center for Atmospheric Research has been coupled to a simple mixed-layer ocean model and to a coarse-grid ocean general circulation model (OGCM). This paper compares the responses of simulated climate to increases of atmospheric carbon dioxide (CO 2 ) in these two coupled models. Three types of simulations were run: (1) control runs with both ocean models, with CO 2 held constant at present-day concentrations, (2) instantaneous doubling of atmospheric CO 2 (from 330 to 660 ppm) with both ocean models, and (3) a gradually increasing (transient) CO 2 concentration starting at 330 ppm and increasing linearly at 1% per year, with the OGCM. The mixed-layer and OGCM cases exhibit increases of 3.5 C and 1.6 C, respectively, in globally averaged surface air temperature for the instantaneous doubling cases. The transient-forcing case warms 0.7 C by the end of 30 years. The mixed-layer ocean yields warmer-than-observed tropical temperatures and colder-than-observed temperatures in the higher latitudes. The coarse-grid OGCM simulates lower-than-observed sea surface temperatures (SSTs) in the tropics and higher-than-observed SSTs and reduced sea-ice extent at higher latitudes. Sensitivity in the OGCM after 30 years is much lower than in simulations with the same atmosphere coupled to a 50-m slab-ocean mixed layer. The OGCM simulates a weaker thermohaline circulation with doubled CO 2 as the high-latitude ocean-surface layer warms and freshens and the westerly wind stress decreases. Convective overturning in the OGCM decreases substantially with CO 2 warming. 46 refs.; 20 figs.; 1 tab

To drill or not to drill? An econometric analysis of US public opinion

International Nuclear Information System (INIS)

Mukherjee, Deep; Rahman, Mohammad Arshad

2016-01-01

Offshore drilling in the United States (US) has been the subject of public and political discourse due to multiple reasons which include economic impact, energy security, and environmental hazard. Consequently, several polls have been conducted over time to gauge public attitude towards offshore drilling. Nevertheless, the economic literature on this issue is sparse. This paper contributes to the literature and analyzes support for offshore drilling based on demographic, economic, social, belief, and shock (e.g. spill) factors. The data is taken from ten nationwide surveys conducted before, during and after the British Petroleum (BP) oil spill and analyzed within the framework of discrete choice model. The results from an ordinal probit model demonstrate that age, annual household income, affiliation to Republican Party, and residence in oil-rich states positively affect the probability of strong support and reduce the probability of strong opposition for offshore drilling. In contrast, the female gender, higher education, association to Democratic Party, and environmental concern affect opinion in opposite direction. Marginal effects show that belief about environmental consequences of drilling has the highest impact on opinion. Binary probit model also yields a similar result and suggests that BP oil disaster resulted in a transient decrease in support for offshore drilling. - Highlights: •US public opinion on offshore drilling is analyzed based on ten national polls. •Ordinal and binary probit models are utilized to identify the underlying factors that shape public opinion. •Belief about environmental cost of drilling and educational attainment have the highest negative impact on opinion. •Age, income, affiliation to Republican party and oil-rich states positively affect support for drilling. •BP oil spill resulted in a transient decrease in support for offshore drilling.

Percussive Augmenter of Rotary Drills for Operating as a Rotary-Hammer Drill

Science.gov (United States)

Aldrich, Jack Barron (Inventor); Bar-Cohen, Yoseph (Inventor); Sherrit, Stewart (Inventor); Badescu, Mircea (Inventor); Bao, Xiaoqi (Inventor); Scott, James Samson (Inventor)

2014-01-01

A percussive augmenter bit includes a connection shaft for mounting the bit onto a rotary drill. In a first modality, an actuator percussively drives the bit, and an electric slip-ring provides power to the actuator while being rotated by the drill. Hammering action from the actuator and rotation from the drill are applied directly to material being drilled. In a second modality, a percussive augmenter includes an actuator that operates as a hammering mechanism that drives a free mass into the bit creating stress pulses that fracture material that is in contact with the bit.

In-process and post-process measurements of drill wear for control of the drilling process

Science.gov (United States)

Liu, Tien-I.; Liu, George; Gao, Zhiyu

2011-12-01

Optical inspection was used in this research for the post-process measurements of drill wear. A precision toolmakers" microscope was used. Indirect index, cutting force, is used for in-process drill wear measurements. Using in-process measurements to estimate the drill wear for control purpose can decrease the operation cost and enhance the product quality and safety. The challenge is to correlate the in-process cutting force measurements with the post-process optical inspection of drill wear. To find the most important feature, the energy principle was used in this research. It is necessary to select only the cutting force feature which shows the highest sensitivity to drill wear. The best feature selected is the peak of torque in the drilling process. Neuro-fuzzy systems were used for correlation purposes. The Adaptive-Network-Based Fuzzy Inference System (ANFIS) can construct fuzzy rules with membership functions to generate an input-output pair. A 1x6 ANFIS architecture with product of sigmoid membership functions can in-process measure the drill wear with an error as low as 0.15%. This is extremely important for control of the drilling process. Furthermore, the measurement of drill wear was performed under different drilling conditions. This shows that ANFIS has the capability of generalization.

Directional and Spectral Irradiance in Ocean Models: Effects on Simulated Global Phytoplankton, Nutrients, and Primary Production

Science.gov (United States)

Gregg, Watson W.; Rousseaux, Cecile S.

2016-01-01

The importance of including directional and spectral light in simulations of ocean radiative transfer was investigated using a coupled biogeochemical-circulation-radiative model of the global oceans. The effort focused on phytoplankton abundances, nutrient concentrations and vertically-integrated net primary production. The importance was approached by sequentially removing directional (i.e., direct vs. diffuse) and spectral irradiance and comparing results of the above variables to a fully directionally and spectrally-resolved model. In each case the total irradiance was kept constant; it was only the pathways and spectral nature that were changed. Assuming all irradiance was diffuse had negligible effect on global ocean primary production. Global nitrate and total chlorophyll concentrations declined by about 20% each. The largest changes occurred in the tropics and sub-tropics rather than the high latitudes, where most of the irradiance is already diffuse. Disregarding spectral irradiance had effects that depended upon the choice of attenuation wavelength. The wavelength closest to the spectrally-resolved model, 500 nm, produced lower nitrate (19%) and chlorophyll (8%) and higher primary production (2%) than the spectral model. Phytoplankton relative abundances were very sensitive to the choice of non-spectral wavelength transmittance. The combined effects of neglecting both directional and spectral irradiance exacerbated the differences, despite using attenuation at 500 nm. Global nitrate decreased 33% and chlorophyll decreased 24%. Changes in phytoplankton community structure were considerable, representing a change from chlorophytes to cyanobacteria and coccolithophores. This suggested a shift in community function, from light-limitation to nutrient limitation: lower demands for nutrients from cyanobacteria and coccolithophores favored them over the more nutrient-demanding chlorophytes. Although diatoms have the highest nutrient demands in the model, their

One-year, regional-scale simulation of 137Cs radioactivity in the ocean following the Fukushima Dai-ichi Nuclear Power Plant accident

Directory of Open Access Journals (Sweden)

D. Tsumune

2013-08-01

Full Text Available A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the Great East Japan Earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways: direct release from the accident site and atmospheric deposition. A 1 yr, regional-scale simulation of 137Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of 137Cs deposited into the ocean by atmospheric deposition outside the domain of the model. Direct releases of 137Cs were estimated for 1 yr after the accident by comparing simulated results and measured activities adjacent to the accident site. The contributions of each source were estimated by analysis of 131I/137Cs and 134Cs/137Cs activity ratios and comparisons between simulated results and measured activities of 137Cs. The estimated total amounts of directly released 131I, 137Cs, and 137Cs were 11.1 ± 2.2 PBq, 3.5 ± 0.7 PBq, and 3.6 ± 0.7 PBq, respectively. Simulated 137Cs activities attributable to direct release were in good agreement with measured 137Cs activities not only adjacent to the accident site, but also in a wide area in the model domain, therefore this implies that the estimated direct release rate was reasonable. Employment of improved nudging data by JCOPE2 improved both the offshore transport result and the reproducibility of 137Cs activities 30 km offshore. On the other hand, simulated 137Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition into the ocean was underestimated because of a lack of measurements of deposition into the ocean when atmospheric deposition rates were being estimated. Simulated 137Cs activities attributable to the inflow of 137Cs deposited into the ocean outside the domain of the model were in good agreement with measured activities in the open

Viruses in the Oceanic Basement.

Science.gov (United States)

Nigro, Olivia D; Jungbluth, Sean P; Lin, Huei-Ting; Hsieh, Chih-Chiang; Miranda, Jaclyn A; Schvarcz, Christopher R; Rappé, Michael S; Steward, Grieg F

2017-03-07

Microbial life has been detected well into the igneous crust of the seafloor (i.e., the oceanic basement), but there have been no reports confirming the presence of viruses in this habitat. To detect and characterize an ocean basement virome, geothermally heated fluid samples (ca. 60 to 65°C) were collected from 117 to 292 m deep into the ocean basement using seafloor observatories installed in two boreholes (Integrated Ocean Drilling Program [IODP] U1362A and U1362B) drilled in the eastern sediment-covered flank of the Juan de Fuca Ridge. Concentrations of virus-like particles in the fluid samples were on the order of 0.2 × 10 5 to 2 × 10 5  ml -1 ( n = 8), higher than prokaryote-like cells in the same samples by a factor of 9 on average (range, 1.5 to 27). Electron microscopy revealed diverse viral morphotypes similar to those of viruses known to infect bacteria and thermophilic archaea. An analysis of virus-like sequences in basement microbial metagenomes suggests that those from archaeon-infecting viruses were the most common (63 to 80%). Complete genomes of a putative archaeon-infecting virus and a prophage within an archaeal scaffold were identified among the assembled sequences, and sequence analysis suggests that they represent lineages divergent from known thermophilic viruses. Of the clustered regularly interspaced short palindromic repeat (CRISPR)-containing scaffolds in the metagenomes for which a taxonomy could be inferred (163 out of 737), 51 to 55% appeared to be archaeal and 45 to 49% appeared to be bacterial. These results imply that the warmed, highly altered fluids in deeply buried ocean basement harbor a distinct assemblage of novel viruses, including many that infect archaea, and that these viruses are active participants in the ecology of the basement microbiome. IMPORTANCE The hydrothermally active ocean basement is voluminous and likely provided conditions critical to the origins of life, but the microbiology of this vast habitat is not

Simulation Tool for GNSS Ocean Surface Reflections

DEFF Research Database (Denmark)

Høeg, Per; von Benzon, Hans-Henrik; Durgonics, Tibor

2015-01-01

GNSS coherent and incoherent reflected signals have the potential of deriving large scale parameters of ocean surfaces, as barotropic variability, eddy currents and fronts, Rossby waves, coastal upwelling, mean ocean surfaceheights, and patterns of the general ocean circulation. In the reflection...... zone the measurements may deriveparameters as sea surface roughness, winds, waves, heights and tilts from the spectral measurements. Previous measurements from the top of mountains and airplanes have shown such results leading.The coming satellite missions, CYGNSS, COSMIC-2, and GEROS...

Impact of including surface currents on simulation of Indian Ocean variability with the POAMA coupled model

Energy Technology Data Exchange (ETDEWEB)

Zhao, Mei; Wang, Guomin; Hendon, Harry H.; Alves, Oscar [Bureau of Meteorology, Centre for Australian Weather and Climate Research, Melbourne (Australia)

2011-04-15

Impacts on the coupled variability of the Indo-Pacific by including the effects of surface currents on surface stress are explored in four extended integrations of an experimental version of the Bureau of Meteorology's coupled seasonal forecast model POAMA. The first pair of simulations differs only in their treatment of momentum coupling: one version includes the effects of surface currents on the surface stress computation and the other does not. The version that includes the effect of surface currents has less mean-state bias in the equatorial Pacific cold tongue but produces relatively weak coupled variability in the Tropics, especially that related to the Indian Ocean dipole (IOD) and El Nino/Southern Oscillation (ENSO). The version without the effects of surface currents has greater bias in the Pacific cold tongue but stronger IOD and ENSO variability. In order to diagnose the role of changes in local coupling from changes in remote forcing by ENSO for causing changes in IOD variability, a second set of simulations is conducted where effects of surface currents are included only in the Indian Ocean and only in the Pacific Ocean. IOD variability is found to be equally reduced by inclusion of the local effects of surface currents in the Indian Ocean and by the reduction of ENSO variability as a result of including effects of surface currents in the Pacific. Some implications of these results for predictability of the IOD and its dependence on ENSO, and for ocean subsurface data assimilation are discussed. (orig.)

The sensitivity of dimethyl sulfide production to simulated climate change in the Eastern Antarctic Southern Ocean

International Nuclear Information System (INIS)

Gabric, Albert J.; Cropp, Roger; Marchant, Harvey

2003-01-01

Dimethyl sulfide (DMS) is a radiatively active trace gas produced by enzymatic cleavage of its precursor compound, dimethyl sulfoniopropionate (DMSP), which is released by marine phytoplankton in the upper ocean. Once ventilated to the atmosphere, DMS is oxidised to form non-sea-salt sulfate and methane sulfonate (MSA) aerosols, which are a major source of cloud condensation nuclei (CCN) in remote marine air and may thus play a role in climate regulation. Here we simulate the change in DMS flux in the Eastern Antarctic ocean from 1960-2086, corresponding to equivalent CO 2 tripling relative to pre-industrial levels. Calibration to contemporary climate conditions was carried out using a genetic algorithm to fit the model to surface chlorophyll from the 4-yr SeaWiFs satellite archive and surface DMS from an existing global database. Following the methodology used previously in the Subantarctic Southern Ocean, we then simulated DMS emissions under enhanced greenhouse conditions by forcing the DMS model with output from a coupled atmospheric-ocean general circulation model (GCM). The GCM was run in transient mode under the IPCC/IS92a radiative forcing scenario. By 2086, the change simulated in annual integrated DMS flux is around 20% in ice-free waters, with a greater increase of 45% in the seasonal ice zone (SIZ). Interestingly, the large increase in flux in the SIZ is not due to higher in situ production but mainly because of a loss of ice cover during summer-autumn and an increase in sea-to-air ventilation of DMS. These proportional changes in areal mean flux (25%) are much higher than previously estimated for the Subantarctic Southern Ocean (5%), and point to the possibility of a significant DMS-climate feedback at high Southern latitudes. Due to the nexus between ice cover and food-web structure, the potential for ecological community shifts under enhanced greenhouse conditions is high, and the implications for DMS production are discussed

Drilling for scientific purpose

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Shoichi

1987-09-01

Drilling for scientific purpose is a process of conducting geophysical exploration at deep underground and drilling for collecting crust samples directly. This is because earth science has advanced to get a good understanding about the top of the crust and has shifted its main interest to the lower layer of the crust in land regions. The on-land drilling plan in Japan has just started, and the planned drilling spots are areas around the Minami River, Hidaka Mts., kinds of the Mesozoic and Cenozoic granite in outside zone, the extension of Japan Sea, Ogasawara Is., Minami-Tori Is., and active volcanos. The paper also outlines the present situation of on-land drilling in the world, focusing on the SG-3rd super-deep well SG-3 on the Kola Peninsula, USSR, Satori SG-1st well SG-1 in Azerbaidzhan S.S.R, V.S.S.R, Sweden's wells, Cyprus' wells, Bayearn well Plan in West Germany, and Salton Sea Scientific Drilling Program in the U.S. At its end, the paper explains the present situation and the future theme of the Japanese drilling technique and points out the necessity of developing equipment, and techniques. (14 figs, 5 tabs, 26 refs)

Tethyan Anhydrite Preserved in the Lower Ocean Crust of the Samail Ophiolite? Evidence from Oman Drilling Project Holes GT1A and 2A

Science.gov (United States)

Teagle, D. A. H.; Harris, M.; Crispini, L.; Deans, J. R.; Cooper, M. J.; Kelemen, P. B.; Alt, J.; Banerjee, N.; Shanks, W. C., III

2017-12-01

Anhydrite is important in mid-ocean ridge hydrothermal systems because of the high concentrations of calcium and sulfate in modern seawater and anhydrite's retrograde solubility. Because anhydrite hosts many powerful tracers of fluid-rock interactions (87Sr/86Sr, δ18O, δ34S, trace elements, fluid inclusions) it is useful for tracing the chemical evolution of hydrothermal recharge fluids and estimating time-integrated fluid fluxes. Anhydrite can form from heated seawater (>100°C), through water-rock reaction, or by mixing of seawater and hydrothermal fluids. Although abundant in active hydrothermal mounds, and predicted to form from downwelling, warming fluids during convection, anhydrite is rare in drill core from seafloor lavas, sheeted dikes and upper gabbros, with only minor amounts in ODP Holes 504B and 1256D. Because anhydrite can dissolve during weathering, its occurrence in ophiolites is unexpected. Instead, gypsum is present in Macquarie Island lavas and Miocene gypsum fills cavities within the Cretaceous Troodos ore deposits. Thus, the occurrence of numerous anhydrite veins in cores from the gabbroic lower crust of the Samail ophiolite in Oman was unanticipated. To our knowledge, anhydrite in Oman gabbros has not been previously reported. Oman Drilling Project Holes GT1A and GT2A were drilled into the Wadi Gideah section of the Wadi Tayin massif. Both recovered 400 m of continuous core from sections of layered gabbros (GT1) and the foliated-layered gabbro transition (GT2). Anhydrite is present throughout both holes, some in vein networks but more commonly as isolated 1-110 mm veins (>60 mm ave). Anhydrite is mostly the sole vein filling but can occur with greenschist minerals such as epidote, quartz, chlorite and prehnite. Anhydrite commonly exhibits prismatic and bladed textures but can also be capriciously microcrystalline. Though definitive cross cutting relationships are elusive, anhydrite veins cut across some greenschist veins. Anhydrite is

Ultrasonic rotary-hammer drill

Science.gov (United States)

Bar-Cohen, Yoseph (Inventor); Badescu, Mircea (Inventor); Sherrit, Stewart (Inventor); Bao, Xiaoqi (Inventor); Kassab, Steve (Inventor)

2010-01-01

A mechanism for drilling or coring by a combination of sonic hammering and rotation. The drill includes a hammering section with a set of preload weights mounted atop a hammering actuator and an axial passage through the hammering section. In addition, a rotary section includes a motor coupled to a drive shaft that traverses the axial passage through the hammering section. A drill bit is coupled to the drive shaft for drilling by a combination of sonic hammering and rotation. The drill bit includes a fluted shaft leading to a distal crown cutter with teeth. The bit penetrates sampled media by repeated hammering action. In addition, the bit is rotated. As it rotates the fluted bit carries powdered cuttings helically upward along the side of the bit to the surface.

30 CFR 57.7052 - Drilling positions.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drilling positions. 57.7052 Section 57.7052... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling-Surface and Underground § 57.7052 Drilling positions. Persons shall not drill...

Marine Physical Laboratory Multi-Disciplinary Ocean Science and Technology Program

Science.gov (United States)

1991-04-01

ambierit noise were made with the advent of large. of 3800 m. Reflection profiles and drill logs from this hole scale seismome ter arrays." Sensor arrays...Deaion. and S C Webb."A deep-sea differential pressure frequency. The array was too limited in extent to make spa- gauge ." J. Aimos Ocean Tech. 2. 237...75, 847-864 (1985). 2"P. K Spudich andi I A. Orcutt," Petrology and porcisit% of tn oceanic "M E Dougherty and R. A. Stephen."Seismic energy

Simulation of glacial ocean biogeochemical tracer and isotope distributions based on the PMIP3 suite of climate models

Science.gov (United States)

Khatiwala, Samar; Muglia, Juan; Kvale, Karin; Schmittner, Andreas

2016-04-01

In the present climate system, buoyancy forced convection at high-latitudes together with internal mixing results in a vigorous overturning circulation whose major component is North Atlantic Deep Water. One of the key questions of climate science is whether this "mode" of circulation persisted during glacial periods, and in particular at the Last Glacial Maximum (LGM; 21000 years before present). Resolving this question is both important for advancing our understanding of the climate system, as well as a critical test of numerical models' ability to reliably simulate different climates. The observational evidence, based on interpreting geochemical tracers archived in sediments, is conflicting, as are simulations carried out with state-of-the-art climate models (e.g., as part of the PMIP3 suite), which, due to the computational cost involved, do not by and large include biogeochemical and isotope tracers that can be directly compared with proxy data. Here, we apply geochemical observations to evaluate the ability of several realisations of an ocean model driven by atmospheric forcing from the PMIP3 suite of climate models to simulate global ocean circulation during the LGM. This results in a wide range of circulation states that are then used to simulate biogeochemical tracer and isotope (13C, 14C and Pa/Th) distributions using an efficient, "offline" computational scheme known as the transport matrix method (TMM). One of the key advantages of this approach is the use of a uniform set of biogeochemical and isotope parameterizations across all the different circulations based on the PMIP3 models. We compare these simulated distributions to both modern observations and data from LGM ocean sediments to identify similarities and discrepancies between model and data. We find, for example, that when the ocean model is forced with wind stress from the PMIP3 models the radiocarbon age of the deep ocean is systematically younger compared with reconstructions. Changes in

30 CFR 56.7052 - Drilling positions.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drilling positions. 56.7052 Section 56.7052... SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Drilling and Rotary Jet Piercing Drilling § 56.7052 Drilling positions. Persons shall not drill from— (a) Positions which hinder...

Effects of Precipitation on Ocean Mixed-Layer Temperature and Salinity as Simulated in a 2-D Coupled Ocean-Cloud Resolving Atmosphere Model

Science.gov (United States)

Li, Xiaofan; Sui, C.-H.; Lau, K-M.; Adamec, D.

1999-01-01

A two-dimensional coupled ocean-cloud resolving atmosphere model is used to investigate possible roles of convective scale ocean disturbances induced by atmospheric precipitation on ocean mixed-layer heat and salt budgets. The model couples a cloud resolving model with an embedded mixed layer-ocean circulation model. Five experiment are performed under imposed large-scale atmospheric forcing in terms of vertical velocity derived from the TOGA COARE observations during a selected seven-day period. The dominant variability of mixed-layer temperature and salinity are simulated by the coupled model with imposed large-scale forcing. The mixed-layer temperatures in the coupled experiments with 1-D and 2-D ocean models show similar variations when salinity effects are not included. When salinity effects are included, however, differences in the domain-mean mixed-layer salinity and temperature between coupled experiments with 1-D and 2-D ocean models could be as large as 0.3 PSU and 0.4 C respectively. Without fresh water effects, the nocturnal heat loss over ocean surface causes deep mixed layers and weak cooling rates so that the nocturnal mixed-layer temperatures tend to be horizontally-uniform. The fresh water flux, however, causes shallow mixed layers over convective areas while the nocturnal heat loss causes deep mixed layer over convection-free areas so that the mixed-layer temperatures have large horizontal fluctuations. Furthermore, fresh water flux exhibits larger spatial fluctuations than surface heat flux because heavy rainfall occurs over convective areas embedded in broad non-convective or clear areas, whereas diurnal signals over whole model areas yield high spatial correlation of surface heat flux. As a result, mixed-layer salinities contribute more to the density differences than do mixed-layer temperatures.

Sandia's Geothermal Advanced Drill Rig Instrumentation Assists Critical Oil and Gas Drilling Operation

International Nuclear Information System (INIS)

Staller, George E.; Whitlow, Gary

1999-01-01

On November 23, 1998, an 18,000-foot-deep wild-cat natural gas well being drilled near Bakersfield, CA blew out and caught fire. All attempts to kill this well failed, and the well continues to flow under limited control, producing large volumes of natural gas, salt water, and some oil. The oil and some of the water is being separated and trucked off site, and the remaining gas and water is being burned at the well head. A relief well is being drilled approximately one-quarter mile away in an attempt to intercept the first well. If the relief well is successful, it will be used to cement in and kill the first well. Epoch Wellsite Services, Inc., the mud-logging company for the initial well and the relief well, requested Sandia's rolling float meter (RFM) for these critical drilling operations. The RFM is being used to measure the mud outflow rate and detect kicks while drilling the relief well, which will undoubtedly encounter reservoir conditions similar to those responsible for the blow out. Based on its prior experience with the RFM, Epoch believes that it is the only instrument capable of providing the level of accuracy and response to mudflow needed to quickly detect kicks and minimize the risk of a blowout on this second critical well. In response to the urgent request from industry, Sandia and Epoch technicians installed the RFM on the relief well return line, and completed its initial calibration. The data from the RFM is displayed in real-time for the driller, the companyman, and the toolpusher via Epochs RIGWATCH Drilling Instmmentation System. The RFM has already detected several small kicks while drilling toward the annulus of the blown out well. A conventional paddle meter is located downstream of the RFM to provide redundancy and the opportunity to compare the two meters in an actual drilling operation, The relief well is nearing 14,000 feet deep, targeting an intercept of the first well near 17,600 feet. The relief well is expected to be completed in

Optimal parameters to avoid thermal necrosis during bone drilling: A finite element analysis.

Science.gov (United States)

Mediouni, Mohamed; Schlatterer, Daniel R; Khoury, Amal; Von Bergen, Tobias; Shetty, Sunil H; Arora, Manit; Dhond, Amit; Vaughan, Neil; Volosnikov, Alexander

2017-11-01

The drilling bone may potentially cause excessive frictional heat, which can lead to local bone necrosis. This heat generation and local necrosis has been suggested to contribute to the resorption of bone around the placed screws, ending in loss of screw purchase in the bone and inadvertent loosening and/or the bone-implant construct. In vivo studies on this subject have inherent obstacles not the least of which is controlling the variables and real time bone temperature data acquisition. Theoretical models can be generated using computer software and the inclusion of known constants for the mechanical properties of metal and bone. These known Data points for the variables (drill bit and bone) enables finite element analysis of various bone drilling scenarios. An elastic-plastic three-dimensional (3D) acetabular bone mode was developed and finite element model analysis (FEA) was applied to various simulated drilling procedures. The FEA results clearly indicate that the depth of drilling and the drill speed both have a significant effect on the temperature during drilling procedures. The reduction of the feeding speed leads to a reduction in bone temperature. Our data suggests that reducing the feeding speed regardless of RPMs and pressure applied could be a simple useful and effective way to reduce drilling temperatures. This study is the first step in helping any surgeon who drills bone and places screws to better understand the ideal pressure to apply and drill speed to employ and advance rate to avoid osteonecrosis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2386-2391, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

30 CFR 33.34 - Drilling test.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Drilling test. 33.34 Section 33.34 Mineral... MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES Test Requirements § 33.34 Drilling test. (a) A drilling test shall consist of drilling a set of 10 test holes, without...

Simulation of anthropogenic CO2 uptake in the CCSM3.1 ocean circulation-biogeochemical model: comparison with data-based estimates

Directory of Open Access Journals (Sweden)

S. Khatiwala

2012-04-01

Full Text Available The global ocean has taken up a large fraction of the CO2 released by human activities since the industrial revolution. Quantifying the oceanic anthropogenic carbon (Cant inventory and its variability is important for predicting the future global carbon cycle. The detailed comparison of data-based and model-based estimates is essential for the validation and continued improvement of our prediction capabilities. So far, three global estimates of oceanic Cant inventory that are "data-based" and independent of global ocean circulation models have been produced: one based on the Δ C* method, and two that are based on constraining surface-to-interior transport of tracers, the TTD method and a maximum entropy inversion method (GF. The GF method, in particular, is capable of reconstructing the history of Cant inventory through the industrial era. In the present study we use forward model simulations of the Community Climate System Model (CCSM3.1 to estimate the Cant inventory and compare the results with the data-based estimates. We also use the simulations to test several assumptions of the GF method, including the assumption of constant climate and circulation, which is common to all the data-based estimates. Though the integrated estimates of global Cant inventories are consistent with each other, the regional estimates show discrepancies up to 50 %. The CCSM3 model underestimates the total Cant inventory, in part due to weak mixing and ventilation in the North Atlantic and Southern Ocean. Analyses of different simulation results suggest that key assumptions about ocean circulation and air-sea disequilibrium in the GF method are generally valid on the global scale, but may introduce errors in Cant estimates on regional scales. The GF method should also be used with caution when predicting future oceanic anthropogenic carbon uptake.

Design and Optimization of Annular Flow Electromagnetic Measurement System for Drilling Engineering

Directory of Open Access Journals (Sweden)

Liang Ge

2018-01-01

Full Text Available Using the downhole annular flow measurement system to get real-time information of downhole annular flow is the core and foundation of downhole microflux control drilling technology. The research work of electromagnetic flowmeter in recent years creates a challenge to the design of downhole annular flow measurement. This paper proposes a design and optimization of annular flow electromagnetic measurement system for drilling engineering based on the finite element method. Firstly, the annular flow measuring and optimization principle are described. Secondly, a simulation model of an annular flow electromagnetic measurement system with two pairs of coil is built based on the fundamental equation of electromagnetic flowmeter by COMSOL. Thirdly, simulations of the structure of excitation system of the measurement system are carried out, and simulations of the size of the electrode’s radius are also carried out based on the optimized structure, and then all the simulation results are analyzed to evaluate the optimization effect based on the evaluation indexes. The simulation results show that optimized shapes of the excitation system and electrode size can yield a better performance in the annular flow measurement.

Economic environmental management of drilling operations

International Nuclear Information System (INIS)

Longwell, H.J.; Akers, T.J.

1992-01-01

This paper presents significant environmental and regulatory initiatives developed by Exxon's New Orleans Drilling Organization. Specifically, the paper will cover drilling waste minimization techniques and disposal options, recycling of drilling waste streams, and environmentally managed drilling location design considerations. The implementation of some of these initiatives at Exxon's Chalkley field land locations have resulted in a fifty percent reduction in drilling location waste management costs. Some of these same initiatives have been successfully applied to Exxon's barge drilling locations. For operations at the environmentally sensitive Mobile Bay, Exxon contracted with a local company and assisted in the development of an economically and environmentally superior drilling waste disposal and treatment system. In summary, it is possible for drilling operators to pro-actively manage escalating environmental and regulatory challenges through the implementation of economic and practical initiatives

Newberry exploratory slimhole: Drilling and testing

Energy Technology Data Exchange (ETDEWEB)

Finger, J.T.; Jacobson, R.D.; Hickox, C.E.

1997-11-01

During July--November, 1995, Sandia National Laboratories, in cooperation with CE Exploration, drilled a 5,360 feet exploratory slimhole (3.895 inch diameter) in the Newberry Known Geothermal Resource Area (KGRA) near Bend, Oregon. This well was part of Sandia`s program to evaluate slimholes as a geothermal exploration tool. During and after drilling the authors performed numerous temperature logs, and at the completion of drilling attempted to perform injection tests. In addition to these measurements, the well`s data set includes: over 4,000 feet of continuous core (with detailed log); daily drilling reports from Sandia and from drilling contractor personnel; daily drilling fluid record; and comparative data from other wells drilled in the Newberry KGRA. This report contains: (1) a narrative account of the drilling and testing, (2) a description of equipment used, (3) a brief geologic description of the formation drilled, (4) a summary and preliminary interpretation of the data, and (5) recommendations for future work.

Microgravity Drill and Anchor System

Science.gov (United States)

Parness, Aaron; Frost, Matthew A.; King, Jonathan P.

2013-01-01

This work is a method to drill into a rock surface regardless of the gravitational field or orientation. The required weight-on-bit (WOB) is supplied by a self-contained anchoring mechanism. The system includes a rotary percussive coring drill, forming a complete sampling instrument usable by robot or human. This method of in situ sample acquisition using micro - spine anchoring technology enables several NASA mission concepts not currently possible with existing technology, including sampling from consolidated rock on asteroids, providing a bolt network for astronauts visiting a near-Earth asteroid, and sampling from the ceilings or vertical walls of lava tubes and cliff faces on Mars. One of the most fundamental parameters of drilling is the WOB; essentially, the load applied to the bit that allows it to cut, creating a reaction force normal to the surface. In every drilling application, there is a minimum WOB that must be maintained for the system to function properly. In microgravity (asteroids and comets), even a small WOB could not be supported conventionally by the weight of the robot or astronaut. An anchoring mechanism would be needed to resist the reactions, or the robot or astronaut would push themselves off the surface and into space. The ability of the system to anchor itself to a surface creates potential applications that reach beyond use in low gravity. The use of these anchoring mechanisms as end effectors on climbing robots has the potential of vastly expanding the scope of what is considered accessible terrain. Further, because the drill is supported by its own anchor rather than by a robotic arm, the workspace is not constrained by the reach of such an arm. Yet, if the drill is on a robotic arm, it has the benefit of not reflecting the forces of drilling back to the arm s joints. Combining the drill with the anchoring feet will create a highly mobile, highly stable, and highly reliable system. The drilling system s anchor uses hundreds of

Influence of Drilling Parameters on Torque during Drilling of GFRP Composites Using Response Surface Methodology

Science.gov (United States)

Mohan, N. S.; Kulkarni, S. M.

2018-01-01

Polymer based composites have marked their valuable presence in the area of aerospace, defense and automotive industry. Components made of composite, are assembled to main structure by fastener, which require accurate, precise high quality holes to be drilled. Drilling the hole in composite with accuracy require control over various processes parameters viz., speed, feed, drill bit size and thickens of specimen. TRIAC VMC machining center is used to drill the hole and to relate the cutting and machining parameters on the torque. MINITAB 14 software is used to analyze the collected data. As a function of cutting and specimen parameters this method could be useful for predicting torque parameters. The purpose of this work is to investigate the effect of drilling parameters to get low torque value. Results show that thickness of specimen and drill bit size are significant parameters influencing the torque and spindle speed and feed rate have least influence and overlaid plot indicates a feasible and low region of torque is observed for medium to large sized drill bits for the range of spindle speed selected. Response surface contour plots indicate the sensitivity of the drill size and specimen thickness to the torque.

Control procedure for well drilling operations

Energy Technology Data Exchange (ETDEWEB)

Bourdon, J C

1988-09-09

A control procedure of rotary drilling operations is proposed. It uses the Drill off test. The drill-off test permits to determine the rock drill speed variation as a function of the wright applied on the top of the pipe. We can deduce from that a rock drill wear parameter. The method permits to prevent a rupture and its grave economic consequences.

Optimum fluid design for drilling and cementing a well drilled with coil tubing technology

Energy Technology Data Exchange (ETDEWEB)

Swendsen, O.; Saasen, A.; Vassoy, B. [Statoil (Norway); Skogen, E.; Mackin, F.; Normann, S. H.

1998-12-31

The strategy, design and drilling fluid and cementing operations in the first two wells drilled with coil tubing technology in the Gullfaks field in the Tampen Spur Area of the Norwegian sector of the North Sea are discussed. The drilling fluid use was a solids-free potassium formate/polymer brine-based fluid with a density of 1,50-1.56 g/cc, with flow properties characterized by very low fluid loss due to high extensional viscosity, a low viscosity at all shear rates, and a low degree of shear-thinning. The low viscous drilling fluid is considered to have been the major contributing factor in achieving excellent hole cleaning, no differential sticking, successful setting of cement kick-off plugs, problem-free running of the liner, and excellent zonal isolation when cementing the liner. These experiences led the authors to conclude that it is possible to formulate a brine-based solids-free drilling fluid with low viscosity and fluid loss properties for most formation pressure regimes, and that such a drilling fluid is well suited to drilling highly deviated slim hole wells where hole cleaning and differential sticking present special challenges. 12 refs., 2 tabs., 3 figs.

Subsurface Hybrid Power Options for Oil & Gas Production at Deep Ocean Sites

Energy Technology Data Exchange (ETDEWEB)

Farmer, J C; Haut, R; Jahn, G; Goldman, J; Colvin, J; Karpinski, A; Dobley, A; Halfinger, J; Nagley, S; Wolf, K; Shapiro, A; Doucette, P; Hansen, P; Oke, A; Compton, D; Cobb, M; Kopps, R; Chitwood, J; Spence, W; Remacle, P; Noel, C; Vicic, J; Dee, R

2010-02-19

An investment in deep-sea (deep-ocean) hybrid power systems may enable certain off-shore oil and gas exploration and production. Advanced deep-ocean drilling and production operations, locally powered, may provide commercial access to oil and gas reserves otherwise inaccessible. Further, subsea generation of electrical power has the potential of featuring a low carbon output resulting in improved environmental conditions. Such technology therefore, enhances the energy security of the United States in a green and environmentally friendly manner. The objective of this study is to evaluate alternatives and recommend equipment to develop into hybrid energy conversion and storage systems for deep ocean operations. Such power systems will be located on the ocean floor and will be used to power offshore oil and gas exploration and production operations. Such power systems will be located on the oceans floor, and will be used to supply oil and gas exploration activities, as well as drilling operations required to harvest petroleum reserves. The following conceptual hybrid systems have been identified as candidates for powering sub-surface oil and gas production operations: (1) PWR = Pressurized-Water Nuclear Reactor + Lead-Acid Battery; (2) FC1 = Line for Surface O{sub 2} + Well Head Gas + Reformer + PEMFC + Lead-Acid & Li-Ion Batteries; (3) FC2 = Stored O2 + Well Head Gas + Reformer + Fuel Cell + Lead-Acid & Li-Ion Batteries; (4) SV1 = Submersible Vehicle + Stored O{sub 2} + Fuel Cell + Lead-Acid & Li-Ion Batteries; (5) SV2 = Submersible Vehicle + Stored O{sub 2} + Engine or Turbine + Lead-Acid & Li-Ion Batteries; (6) SV3 = Submersible Vehicle + Charge at Docking Station + ZEBRA & Li-Ion Batteries; (7) PWR TEG = PWR + Thermoelectric Generator + Lead-Acid Battery; (8) WELL TEG = Thermoelectric Generator + Well Head Waste Heat + Lead-Acid Battery; (9) GRID = Ocean Floor Electrical Grid + Lead-Acid Battery; and (10) DOC = Deep Ocean Current + Lead-Acid Battery.

One-year, regional-scale simulation of {sup 137}Cs radioactivity in the ocean following the Fukushima Dai-ichi Nuclear Power Plant accident

Energy Technology Data Exchange (ETDEWEB)

Tsumune, D.; Tsubono, T.; Misumi, K.; Maeda, Y.; Yoshida, Y.; Hayami, H. [Central Research Institute of Electric Power Industry, Chiba (Japan). Environmental Science Research Lab.; Aoyama, M. [Meteorological Research Institute, Tsukuba (Japan); Uematsu, M. [The Univ. of Tokyo, Chiba (Japan). Atmosphere and Ocean Research Inst.

2013-07-01

A series of accidents at the Fukushima Dai-ichi Nuclear Power Plant following the Great East Japan Earthquake and tsunami of 11 March 2011 resulted in the release of radioactive materials to the ocean by two major pathways: direct release from the accident site and atmospheric deposition. A 1 yr, regional-scale simulation of {sup 137}Cs activity in the ocean offshore of Fukushima was carried out, the sources of radioactivity being direct release, atmospheric deposition, and the inflow of {sup 137}Cs deposited into the ocean by atmospheric deposition outside the domain of the model. Direct releases of {sup 137}Cs were estimated for 1 yr after the accident by comparing simulated results and measured activities adjacent to the accident site. The contributions of each source were estimated by analysis of {sup 131}I/{sup 137}Cs and {sup 134}Cs/{sup 137}Cs activity ratios and comparisons between simulated results and measured activities of {sup 137}Cs. The estimated total amounts of directly released {sup 131}I, {sup 137}Cs, and {sup 137}Cs were 11.1 ± 2.2 PBq, 3.5 ± 0.7 PBq, and 3.6 ± 0.7 PBq, respectively. Simulated {sup 137}Cs activities attributable to direct release were in good agreement with measured {sup 137}Cs activities not only adjacent to the accident site, but also in a wide area in the model domain, therefore this implies that the estimated direct release rate was reasonable. Employment of improved nudging data by JCOPE2 improved both the offshore transport result and the reproducibility of {sup 137}Cs activities 30 km offshore. On the other hand, simulated {sup 137}Cs activities attributable to atmospheric deposition were low compared to measured activities. The rate of atmospheric deposition into the ocean was underestimated because of a lack of measurements of deposition into the ocean when atmospheric deposition rates were being estimated. Simulated {sup 137}Cs activities attributable to the inflow of {sup 137}Cs deposited into the ocean outside the

Slim hole drilling and testing strategies

Science.gov (United States)

Nielson, Dennis L.; Garg, Sabodh K.; Goranson, Colin

2017-12-01

The financial and geologic advantages of drilling slim holes instead of large production wells in the early stages of geothermal reservoir assessment has been understood for many years. However, the practice has not been fully embraced by geothermal developers. We believe that the reason for this is that there is a poor understanding of testing and reservoir analysis that can be conducted in slim holes. In addition to reservoir engineering information, coring through the cap rock and into the reservoir provides important data for designing subsequent production well drilling and completion. Core drilling requires significantly less mud volume than conventional rotary drilling, and it is typically not necessary to cure lost circulation zones (LCZ). LCZs should be tested by either production or injection methods as they are encountered. The testing methodologies are similar to those conducted on large-diameter wells; although produced and/or injected fluid volumes are much less. Pressure, temperature and spinner (PTS) surveys in slim holes under static conditions can used to characterize temperature and pressure distribution in the geothermal reservoir. In many cases it is possible to discharge slim holes and obtain fluid samples to delineate the geochemical properties of the reservoir fluid. Also in the latter case, drawdown and buildup data obtained using a downhole pressure tool can be employed to determine formation transmissivity and well properties. Even if it proves difficult to discharge a slim hole, an injection test can be performed to obtain formation transmissivity. Given the discharge (or injection) data from a slimhole, discharge properties of a large-diameter well can be inferred using wellbore modeling. Finally, slim hole data (pressure, temperature, transmissivity, fluid properties) together with reservoir simulation can help predict the ability of the geothermal reservoir to sustain power production.

Navigating a sea of values: Understanding public attitudes toward the ocean and ocean energy resources

Science.gov (United States)

Lilley, Jonathan Charles

In examining ocean values and beliefs, this study investigates the moral and ethical aspects of the relationships that exist between humans and the marine environment. In short, this dissertation explores what the American public thinks of the ocean. The study places a specific focus upon attitudes to ocean energy development. Using both qualitative and quantitative methods, this research: elicits mental models that exist in society regarding the ocean; unearths what philosophies underpin people's attitudes toward the ocean and offshore energy development; assesses whether these views have any bearing on pro-environmental behavior; and gauges support for offshore drilling and offshore wind development. Despite the fact that the ocean is frequently ranked as a second-tier environmental issue, Americans are concerned about the state of the marine environment. Additionally, the data show that lack of knowledge, rather than apathy, prevents people from undertaking pro-environmental action. With regard to philosophical beliefs, Americans hold slightly more nonanthropocentric than anthropocentric views toward the environment. Neither anthropocentrism nor nonanthropocentrism has any real impact on pro-environmental behavior, although nonanthropocentric attitudes reduce support for offshore wind. This research also uncovers two gaps between scientific and public perceptions of offshore wind power with respect to: 1) overall environmental effects; and 2) the size of the resource. Providing better information to the public in the first area may lead to a shift toward offshore wind support among opponents with nonanthropocentric attitudes, and in both areas, is likely to increase offshore wind support.

Heat generated by dental implant drills during osteotomy-a review: heat generated by dental implant drills.

Science.gov (United States)

Mishra, Sunil Kumar; Chowdhary, Ramesh

2014-06-01

Osseointegration is the more stable situation and results in a high success rate of dental implants. Heat generation during rotary cutting is one of the important factors influencing the development of osseointegration. To assess the various factors related to implant drills responsible for heat generation during osteotomy. To identify suitable literature, an electronic search was performed using Medline and Pubmed database. Articles published in between 1960 to February 2013 were searched. The search is focused on heat generated by dental implant drills during osteotomy. Various factors related to implant drill such effect of number of blades; drill design, drill fatigue, drill speed and force applied during osteotomies which were responsible for heat generation were reviewed. Titles and abstracts were screened, and literature that fulfilled the inclusion criteria was selected for a full-text reading. The initial literature search resulted in 299 articles out of which only 70 articles fulfils the inclusion criteria and were included in this systematic review. Many factors related to implant drill responsible for heat generation were found. Successful preparation of an implant cavity with minimal damage to the surrounding bone depends on the avoidance of excessive temperature generation during surgical drilling. The relationship between heat generated and implant drilling osteotomy is multifactorial in nature and its complexity has not been fully studied. Lack of scientific knowledge regarding this issue still exists. Further studies should be conducted to determine the various factors which generate less heat while osteotomy such as ideal ratio of force and speed in vivo, exact time to replace a drill, ideal drill design, irrigation system, drill-bone contact area.

Technology strategy for cost-effective drilling and intervention; Technology Target Areas; TTA4 - Cost effective drilling and intervention

Energy Technology Data Exchange (ETDEWEB)

2007-07-01

The main goals of the OG21 initiative are to (1) develop new technology and knowledge to increase the value creation of Norwegian oil and gas resources and (2) enhance the export of Norwegian oil and gas technology. The OG21 Cost-effective Drilling and Intervention (CEDI) Technology Target Area (TTA) has identified some key strategic drilling and well intervention needs to help meet the goals of OG21. These key strategic drilling and well intervention needs are based on a review of present and anticipated future offshore-Norway drilling and well intervention conditions and the Norwegian drilling and well intervention industry. A gap analysis has been performed to assess the extent to which current drilling and well intervention research and development and other activities will meet the key strategic needs. Based on the identified strategic drilling and well intervention needs and the current industry res each and development and other activities, the most important technology areas for meeting the OG21 goals are: environment-friendly and low-cost exploration wells; low-cost methods for well intervention/sidetracks; faster and extended-reach drilling; deep water drilling, completion and intervention; offshore automated drilling; subsea and sub-ice drilling; drilling through basalt and tight carbonates; drilling and completion in salt formation. More specific goals for each area: reduce cost of exploration wells by 50%; reduce cost for well intervention/sidetracks by 50%; increase drilling efficiency by 40%; reduce drilling cost in deep water by 40 %; enable offshore automated drilling before 2012; enable automated drilling from seabed in 2020. Particular focus should be placed on developing new technology for low-cost exploration wells to stem the downward trends in the number of exploration wells drilled and the volume of discovered resources. The CEDI TTA has the following additional recommendations: The perceived gaps in addressing the key strategic drilling and

Computational modeling of pitching cylinder-type ocean wave energy converters using 3D MPI-parallel simulations

Science.gov (United States)

Freniere, Cole; Pathak, Ashish; Raessi, Mehdi

2016-11-01

Ocean Wave Energy Converters (WECs) are devices that convert energy from ocean waves into electricity. To aid in the design of WECs, an advanced computational framework has been developed which has advantages over conventional methods. The computational framework simulates the performance of WECs in a virtual wave tank by solving the full Navier-Stokes equations in 3D, capturing the fluid-structure interaction, nonlinear and viscous effects. In this work, we present simulations of the performance of pitching cylinder-type WECs and compare against experimental data. WECs are simulated at both model and full scales. The results are used to determine the role of the Keulegan-Carpenter (KC) number. The KC number is representative of viscous drag behavior on a bluff body in an oscillating flow, and is considered an important indicator of the dynamics of a WEC. Studying the effects of the KC number is important for determining the validity of the Froude scaling and the inviscid potential flow theory, which are heavily relied on in the conventional approaches to modeling WECs. Support from the National Science Foundation is gratefully acknowledged.

Oceanic Channel of the IOD-ENSO teleconnection over the Indo-Pacific Ocean

Science.gov (United States)

Yuan, Dongliang; Wang, Jing; Zhao, Xia; Zhou, Hui; Xu, Tengfei; Xu, Peng

2017-04-01

The lag correlations of observations and model simulated data that participate the Coupled Model Intercomparison Project phase-5 (CMIP5) are used to study the precursory teleconnection between the Indian Ocean Dipole (IOD) and the Pacific ENSO one year later through the Indonesian seas. The results suggest that Indonesian Throughflow (ITF) play an important role in the IOD-ENSO teleconnection. Numerical simulations using a hierarchy of ocean models and climate coupled models have shown that the interannual sea level depressions in the southeastern Indian Ocean during IOD force enhanced ITF to transport warm water of the Pacific warm pool to the Indian Ocean, producing cold subsurface temperature anomalies, which propagate to the eastern equatorial Pacific and induce significant coupled ocean-atmosphere evolution. The teleconnection is found to have decadal variability. Similar decadal variability has also been identified in the historical simulations of the CMIP5 models. The dynamics of the inter-basin teleconnection during the positive phases of the decadal variability are diagnosed to be the interannual variations of the ITF associated with the Indian Ocean Dipole (IOD). During the negative phases, the thermocline in the eastern equatorial Pacific is anomalously deeper so that the sea surface temperature anomalies in the cold tongue are not sensitive to the thermocline depth changes. The IOD-ENSO teleconnection is found not affected significantly by the anthropogenic forcing.

Estimating Drilling Cost and Duration Using Copulas Dependencies Models

Directory of Open Access Journals (Sweden)

M. Al Kindi

2017-03-01

Full Text Available Estimation of drilling budget and duration is a high-level challenge for oil and gas industry. This is due to the many uncertain activities in the drilling procedure such as material prices, overhead cost, inflation, oil prices, well type, and depth of drilling. Therefore, it is essential to consider all these uncertain variables and the nature of relationships between them. This eventually leads into the minimization of the level of uncertainty and yet makes a "good" estimation points for budget and duration given the well type. In this paper, the copula probability theory is used in order to model the dependencies between cost/duration and MRI (mechanical risk index. The MRI is a mathematical computation, which relates various drilling factors such as: water depth, measured depth, true vertical depth in addition to mud weight and horizontal displacement. In general, the value of MRI is utilized as an input for the drilling cost and duration estimations. Therefore, modeling the uncertain dependencies between MRI and both cost and duration using copulas is important. The cost and duration estimates for each well were extracted from the copula dependency model where research study simulate over 10,000 scenarios. These new estimates were later compared to the actual data in order to validate the performance of the procedure. Most of the wells show moderate - weak relationship of MRI dependence, which means that the variation in these wells can be related to MRI but to the extent that it is not the primary source.

The Auto-Gopher Deep Drill

Science.gov (United States)

Badescu, Mircea

2014-01-01

Subsurface penetration by coring, drilling or abrading is of great importance for a large number of space and earth applications. An Ultrasonic/Sonic Drill/Corer (USDC) has been in development at JPL's Nondestructive Evaluation and Advanced Actuators (NDEAA) lab as an adaptable tool for many of these applications. The USDC uses a novel drive mechanism to transform the high frequency ultrasonic or sonic vibrations of the tip of a horn into a lower frequency sonic hammering of a drill bit through an intermediate free-flying mass. The USDC device idea has been implemented at various scales from handheld drills to large diameter coring devices. A series of computer programs that model the function and performance of the USDC device were developed and were later integrated into an automated modeling package. The USDC has also evolved from a purely hammering drill to a rotary hammer drill as the design requirements increased form small diameter shallow drilling to large diameter deep coring. A synthesis of the Auto-Gopher development is presented in this paper.

DETERMINATION OF STRESS AT TORSIONAL VIBRATIONS OF THE DRILL PIPE STRING

International Nuclear Information System (INIS)

Machabeli, G.; Mchedlishvili, N.; Gelashvili, G.

2008-01-01

The stresses at torsional vibrations of the drill pipe string were simulated using the Matlab software. It is demonstrated that, if the moment of inertia of gyrating mass on the pipe increases, relation β between the reduced moment of inertia I_1 and the polar moment of inertia I_0 of the pipe cross-section also increases, which results in a decrease in the stress of the string τ. At the same time, if the moment of inertia I of the drill pipe string increases, i.e. the relation β decreases, the stress τ also increases. (author)

Ocean Science for Decision-Making: Current Activities of the National Research Council's Ocean Studies Board

Science.gov (United States)

Roberts, S.; Glickson, D.; Mengelt, C.; Forrest, S.; Waddell, K.

2012-12-01

The National Research Council is a private, nonprofit organization chartered by Congress in 1916 as an expansion of the U.S. National Academy of Sciences. Its mission is to improve the use of science in government decision making and public policy, increase public understanding, and promote the acquisition and dissemination of knowledge in matters involving science, engineering, technology, and health. Within the National Research Council, the Ocean Studies Board (OSB) mission is to explore the science, policies, and infrastructure needed to understand, manage, and conserve coastal and marine environments and resources. OSB undertakes studies and workshops on emerging scientific and policy issues at the request of federal agencies, Congress, and others; provides program reviews and guidance; and facilitates communication on oceanographic issues among different sectors. OSB also serves as the U.S. National Committee to the international, nongovernmental Scientific Committee on Oceanic Research (SCOR). OSB has produced reports on a wide range of topics of interest to researchers and educators, the federal government, the non-profit sector, and industry. Recent reports have focused on ecosystem services in the Gulf of Mexico after the Deepwater Horizon oil spill, sea level rise on the U.S. west coast, scientific ocean drilling needs and accomplishments, requirements for sustained ocean color measurements, critical infrastructure for ocean research, tsunami warning and preparedness, ocean acidification, and marine and hydrokinetic power resource assessments. Studies that are currently underway include responding to oil spills in the Arctic, evaluating the effectiveness of fishery stock rebuilding plans, and reviewing the National Ocean Acidification Research Plan. OSB plays an important role in helping create policy decisions and disseminating important information regarding various aspects of ocean science.

Research Drilling on the Mid-Atlantic Ridge: IDDP Wells of Opportunity at Reykjanes, Iceland

Science.gov (United States)

Fridleifsson, G. O.; Franzson, H.; Thorhallsson, S.; Elders, W. A.

2005-12-01

There are some 10 new geothermal wells at Reykjanes, in SW-Iceland, being considered by the Iceland Deep Drilling Project (IDDP) as potential candidate wells of opportunity to explore for deep (4-5 km) supercritical fluids. The drill field is located where the Mid-Atlantic Ridge emerges from the Atlantic ocean at the tip of the Reykjanes Peninsula. The site is an ideal locality for a combined study on the evolution of a rifted oceanic crust and an active black smoker-type geothermal system. However, the oceanic pillow basaltic crust at Reykjanes is some 2-3 times thicker than normal ocean floor crust, which undoubtedly relates to it being part of the Icelandic Large Igneous Province. The deepest of the geothermal wells at Reykjanes is Drillhole RN-17, that was completed to 3082 m depth in February 2005. It is currently the prime candidate for deepening by the IDDP. The plan is to deepen it to 4 km in 2006, and to 5 km depth in 2007, with funding coming from Icelandic energy companies (Hitaveita Sudurnesja, Landsvirkjun and Orkuveita Reykjavikur), the Government of Iceland, the International Scientific Continental Drilling Program (ICDP) and the US National Science Foundation (NSF). The well RN-17 was drilled as a conventional production well with a 12 ¼ inch drillbit to 3082 m depth, and left barefoot, with a 13 3/8 inch production casing cemented down to 900 m. It will be flow tested this autumn. If the RN-17 well is selected by the IDDP for deepening, a 9 5/8 inch in casing will be cemented to 3081 m and drilling will be continued with an 8 ½ inch tricone bit to 4 km in the autumn of 2006. The ICDP and NSF will fund spot coring for scientific studies in this depth interval and a second flow test would be performed in winter 2007. The following autumn, a 7 inch casing would be cemented to 4 km depth and then a 5 inch retrievable liner would be inserted to support a hybrid coring system to continuously core down to 5 km depth, retrieving HQ sized core. A third

Simulations of radiocarbon in a coarse-resolution world ocean model 2. Distributions of bomb-produced Carbon 14

International Nuclear Information System (INIS)

Toggweiler, J.R.; Dixon, K.; Bryan, K.

1989-01-01

Part 1 of this study examined the ability of the Geophysical Fluid Dynamics Laboratory (GFDL) primitive equation ocean general circulation model to simulate the steady state distribution of naturally produced 14 C in the ocean prior to the nuclear bomb tests of the 1950's and early 1960's. In part 2 begin with the steady state distributions of part 1 and subject the model to the pulse of elevated atmospheric 14 C concentrations observed since the 1950's

Simulating and understanding the gap outflow and oceanic response over the Gulf of Tehuantepec during GOTEX

Science.gov (United States)

Hong, Xiaodong; Peng, Melinda; Wang, Shouping; Wang, Qing

2018-06-01

Tehuantepecer is a strong mountain gap wind traveling through Chivela Pass into eastern Pacific coast in southern Mexico, most commonly between October and February and brings huge impacts on local and surrounding meteorology and oceanography. Gulf of Tehuantepec EXperiment (GOTEX) was conducted in February 2004 to enhance the understanding of the strong offshore gap wind, ocean cooling, vertical circulations and interactions among them. The gap wind event during GOTEX was simulated using the U.S. Navy Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS®). The simulations are compared and validated with the observations retrieved from several satellites (GOES 10-12, MODIS/Aqua/Terra, TMI, and QuikSCAT) and Airborne EXpendable BathyThermograph (AXBT). The study shows that the gap wind outflow has a fanlike pattern expending from the coast and with a strong diurnal variability. The surface wind stress and cooling along the axis of the gap wind outflow caused intense upwelling and vertical mixing in the upper ocean; both contributed to the cooling of the ocean mixed layer under the gap wind. The cooling pattern of sea surface temperature (SST) also reflects temperature advection by the nearby ocean eddies to have a crescent shape. Two sensitivity experiments were conducted to understand the relative roles of the wind stress and heat flux on the ocean cooling. The control has more cooling right under the gap flow region than either the wind-stress-only or the heat-flux-only experiment. Overall, the wind stress has a slightly larger effect in bringing down the ocean temperature near the surface and plays a more important role in local ocean circulations beneath the mixed layer. The impact of surface heat flux on the ocean is more limited to the top 30 m within the mixed layer and is symmetric to the gap flow region by cooling the ocean under the gap flow region and reducing the warming on both sides. The effect of surface wind stress is to induce more cooling

Evacuation drill at CMS

CERN Multimedia

Niels Dupont-Sagorin and Christoph Schaefer

2012-01-01

Training personnel, including evacuation guides and shifters, checking procedures, improving collaboration with the CERN Fire Brigade: the first real-life evacuation drill at CMS took place on Friday 3 February from 12p.m. to 3p.m. in the two caverns located at Point 5 of the LHC.   CERN personnel during the evacuation drill at CMS. Evacuation drills are required by law and have to be organized periodically in all areas of CERN, both above and below ground. The last drill at CMS, which took place in June 2007, revealed some desiderata, most notably the need for a public address system. With this equipment in place, it is now possible to broadcast audio messages from the CMS control room to the underground areas.   The CMS Technical Coordination Team and the GLIMOS have focused particularly on preparing collaborators for emergency situations by providing training and organizing regular safety drills with the HSE Unit and the CERN Fire Brigade. This Friday, the practical traini...

Stakeholder acceptance analysis ResonantSonic drilling

International Nuclear Information System (INIS)

Peterson, T.

1995-12-01

This report presents evaluations, recommendations, and requirements concerning ResonantSonic Drilling (Sonic Drilling), derived from a three-year program of stakeholder involvement. Sonic Drilling is an innovative method to reach contamination in soil and groundwater. The resonant sonic drill rig uses counter-rotating weights to generate energy, which causes the drill pipe to vibrate elastically along its entire length. In the resonant condition, forces of up to 200,000 pounds are transmitted to the drill bit face to create a cutting action. The resonant energy causes subsurface materials to move back into the adjacent formation, permitting the drill pipe to advance. This report is for technology developers and those responsible for making decisions about the use of technology to remediate contamination by volatile organic compounds. Stakeholders' perspectives help those responsible for technology deployment to make good decisions concerning the acceptability and applicability of sonic drilling to the remediation problems they face

Drilling of bone: A comprehensive review

Science.gov (United States)

Pandey, Rupesh Kumar; Panda, S.S.

2013-01-01

Background Bone fracture treatment usually involves restoring of the fractured parts to their initial position and immobilizing them until the healing takes place. Drilling of bone is common to produce hole for screw insertion to fix the fractured parts for immobilization. Orthopaedic drilling during surgical process causes increase in the bone temperature and forces which can cause osteonecrosis reducing the stability and strength of the fixation. Methods A comprehensive review of all the relevant investigations carried on bone drilling is conducted. The experimental method used, results obtained and the conclusions made by the various researchers are described and compared. Result Review suggests that the further improvement in the area of bone drilling is possible. The systematic review identified several consequential factors (drilling parameters and drill specifications) affecting bone drilling on which there no general agreement among investigators or are not adequately evaluated. These factors are highlighted and use of more advanced methods of drilling is accentuated. The use of more precise experimental set up which resembles the actual situation and the development of automated bone drilling system to minimize human error is addressed. Conclusion In this review, an attempt has been made to systematically organize the research investigations conducted on bone drilling. Methods of treatment of bone fracture, studies on the determination of the threshold for thermal osteonecrosis, studies on the parameters influencing bone drilling and methods of the temperature measurement used are reviewed and the future work for the further improvement of bone drilling process is highlighted. PMID:26403771

Well successfully drilled with high performance water-based fluid: Santos Basins, offshore Brazil

Energy Technology Data Exchange (ETDEWEB)

Fornasier, Frank C.; Luzardo, Juan P. [Halliburton Company, Houston, TX (United States); Bishnoi, M.L. [Oil and Natural Gas Corporation Ltda. (ONGC), Dehradun (India)

2012-07-01

Santos Basin is a 352,260 square kilometers (136,010 sq mi) offshore pre-salt basin. It is located in the South Atlantic Ocean, some 300 kilometers (190 mi) South East of Sao Paulo, Brazil. One of the largest Brazilian sedimentary basins, it is the site of several recent significant oil fields, including Tupi and Jupiter. The criteria for drilling fluid selection is based upon the following factors: maximum cost efficiency, environmental friendliness, optimum borehole stability, and ease of use. The recommended drilling fluid formulation takes into consideration the experience gained during the drilling of wells in the Santos Basin area. The operator wanted to use a high-performance water-based fluid (HPWBF) that could provide shale inhibition, wellbore stability, lubricity and improved rate of penetration (ROP) as an alternative to synthetic-based drilling fluids to present value in terms of economics and environmental friendliness. The HPWBF consists of three synergistic products: a hydration suppressant, a dispersion suppressant, and an accretion suppressant. The system is formulated based on customized solutions for managing the clay reactivity. High logistics costs require drilling fluids that can be prepared with sea water and discharged to the sea without environmental impact. The HPWBF is a clay-free system designed for maximum shale inhibition in highly reactive formations. The system can provide wellbore stability, high rates of penetration, and acceptable rheological properties over a wide range of temperatures, with the added benefit of allowing cuttings discharge based upon water base environmental restrictions. Since no oil is used in the formulation, the HPWBF eliminates the need for cuttings processing and monitoring equipment, and exceeds the environmental requirements by achieving an LC50 value of 345,478.22 ppm in comparison with the minimum requirement (LC50 > 30,000 ppm in 96 hr), permitting use and discharge to the sea. The HPWBF selected

Influence of drill helical direction on exit damage development in drilling carbon fiber reinforced plastic

Science.gov (United States)

Bai, Y.; Jia, Z. Y.; Wang, F. J.; Fu, R.; Guo, H. B.; Cheng, D.; Zhang, B. Y.

2017-06-01

Drilling is inevitable for CFRP components’ assembling process in the aviation industry. The exit damage frequently occurs and affects the load carrying capacity of components. Consequently, it is of great urgency to enhance drilling exit quality on CFRP components. The article aims to guide the reasonable choice of drill helical direction and effectively reduce exit damage. Exit observation experiments are carried out with left-hand helical, right-hand helical and straight one-shot drill drilling T800S CFRP laminates separately. The development rules of exit damage and delamination factor curves are obtained. Combined with loading conditions and fracture modes of push-out burrs, and thrust force curves, the influence of drill helical direction on exit damage development is derived. It is found that the main fracture modes for left-hand helical, right-hand helical, and straight one-shot drill are mode I, extrusive fracture, mode III respectively. Among them, mode III has the least effect on exit damage development. Meanwhile, the changing rate of thrust force is relative slow for right-hand helical and straight one-shot drill in the thrust force increasing phase of stage II, which is disadvantaged for exit damage development. Therefore, straight one-shot drill’s exit quality is the best.

Long-term simulation of 137Cs in the Irish Sea by using ocean environment assessment system

International Nuclear Information System (INIS)

Kobayashi, Takuya; Otosaka, Shigeyoshi; Togawa, Orihiko; Hayashi, Keisuke

2007-01-01

An ocean environment assessment system that forecasts the detailed migration processes of radionuclides in the ocean has been developed. This system consists of an ocean current model and a particle random-walk model. The ocean current model is the modified Princeton Ocean Model (POM). The POM calculates tidal currents by giving tide levels at the open boundary. The particle random-walk model, SEA-GEARN, calculates the radionuclides migration in the ocean. Radionuclides that exist in the ocean are modeled in three phases, such as dissolved in seawater, adsorbed with large particulate matter (LPM) and adsorbed with active bottom sediment. The adsorption and desorption processes between the dissolved and solid phases are solved with the kinetic transfer coefficients by the stochastic method. Deposition of LPM and resuspension from bottom sediment are also considered. As model validation, the system has been applied to the Irish Sea to simulate the long-term dispersion of 137 Cs actually released from the BNFL spent nuclear fuel reprocessing plant at Sellafield in UK. Calculation results of surface dissolved 137 Cs have been compared with the observed data. The observed data are extracted from a database, Marine Information System (MARIS), which is released from the International Atomic Energy Agency's Marine Environment Laboratory (IAEA-MEL) in Monaco. The calculation well reproduces the main characteristics of migration of surface dissolved 137 Cs concentration in the Irish Sea. (author)

Heat accumulation during sequential cortical bone drilling.

Science.gov (United States)

Palmisano, Andrew C; Tai, Bruce L; Belmont, Barry; Irwin, Todd A; Shih, Albert; Holmes, James R

2016-03-01

Significant research exists regarding heat production during single-hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two-flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37 °C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery-driven hand drill guided by a servo-controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5 °C at the first hole to 20 °C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist-drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Design and Construction of Wireless Control System for Drilling Machine

Directory of Open Access Journals (Sweden)

Nang Su Moan Hsam

2015-06-01

Full Text Available Abstract Drilling machine is used for boring holes in various materials and used in woodworking metalworking construction and do-it-yourself projects. When the machine operate for a long time the temperature increases and so we need to control the temperature of the machine and some lubrication system need to apply to reduce the temperature. Due to the improvement of technology the system can be controlled with wireless network. This control system use Window Communication Foundation WCF which is the latest service oriented technology to control all drilling machines in industries simultaneously. All drilling machines are start working when they received command from server. After the machine is running for a long time the temperature is gradually increased. This system used LM35 temperature sensor to measure the temperature. When the temperature is over the safely level that is programmed in host server the controller at the server will command to control the speed of motor and applying some lubrication system at the tip and edges of drill. The command from the server is received by the client and sends to PIC. In this control system PIC microcontroller is used as an interface between the client computer and the machine. The speed of motor is controlled with PWM and water pump system is used for lubrication. This control system is designed and simulated with 12V DC motor LM35 sensor LCD displayand relay which is to open the water container to spray water between drill and work piece. The host server choosing to control the drilling machine that are overheat by selecting the clients IP address that is connected with that machine.

Quality in drilling operations

Energy Technology Data Exchange (ETDEWEB)

Duncan, E; Gervais, I [Sedco Forex Jacintoport Facility, Channelview, TX (United States); Le Moign, Y; Pangarkar, S; Stibbs, B [Sedco Forex, Montrouge (France); McMorran, P [Sedco Forex, Pau (France); Nordquist, E [Dubai Petroleum Company, Dubai (United Arab Emirates); Pittman, T [Sedco Forex, Perth (Australia); Schindler, H [Sedco Forex, Dubai (United Arab Emirates); Scott, P [Woodside Offshore Petroleum Pty. Ltd., Perth (Australia)

1997-12-31

Driven by cost and profitability pressures, quality has taken on new meaning and importance in the oil field during the past decade. In drilling operations, new initiatives have led to cooperative team efforts between operators and drilling contractors to enhance quality. In this article examples are given of how one drilling contractor, by adopting a quality culture, is reaping major benefits for its clients as well as its employees. 22 figs., 19 refs.

Quality in drilling operations

Energy Technology Data Exchange (ETDEWEB)

Duncan, E.; Gervais, I. [Sedco Forex Jacintoport Facility, Channelview, TX (United States); Le Moign, Y.; Pangarkar, S.; Stibbs, B. [Sedco Forex, Montrouge (France); McMorran, P. [Sedco Forex, Pau (France); Nordquist, E. [Dubai Petroleum Company, Dubai (United Arab Emirates); Pittman, T. [Sedco Forex, Perth (Australia); Schindler, H. [Sedco Forex, Dubai (United Arab Emirates); Scott, P. [Woodside Offshore Petroleum Pty. Ltd., Perth (Australia)

1996-12-31

Driven by cost and profitability pressures, quality has taken on new meaning and importance in the oil field during the past decade. In drilling operations, new initiatives have led to cooperative team efforts between operators and drilling contractors to enhance quality. In this article examples are given of how one drilling contractor, by adopting a quality culture, is reaping major benefits for its clients as well as its employees. 22 figs., 19 refs.

Drilling history of core hole DB-15

International Nuclear Information System (INIS)

Diediker, L.D.; Ledgerwood, R.K.

1980-09-01

This core hole was drilled to obtain hydrologic and chemical data on the permeable zones of the Saddle Mountains and Wanapum Formations. These data were obtained by testing the zones that were penetrated during drilling. This testing-as-drilled method reduced the potential problems of interflow and water contamination. This report summarizes the drilling and coring operations; geologic logging, hydrologic testing, and geophysical logging activities; and cementing operations of DB-15 during drilling. The successful completion of DB-15 demonstrated that hydrologic testing can be conducted during core drilling operations. More reliable head measurements and uncontaminated representative water samples from isolated permeable zones, which have not been exposed to potential open borehole cross-flow and head equilibration problems, were benefits derived from the testing-as-drilled method. Disadvantages of the technique were a longer time to complete the borehole caused by time required for testing and increased drilling costs due to rig standby time during testing. Extension of the testing-as-drilled method to the drilling of future core holes is recommended. An evaluation should be made of the required hydrologic data and expected borehole stratigraphy before and during drilling to allow uninterrupted drilling in zones of low permeability that can be tested after drilling is complete

Deep-Time drilling in the Australian Archean: the Agouron Institute geobiological drilling project. (Invited)

Science.gov (United States)

Buick, R.

2010-12-01

The Agouron Institute has sponsored deep-time drilling across the South African Archean-Proterozoic boundary, investigating the rise of oxygen over an onshore-offshore environmental transect. It is now supporting a drilling program in the Australian Archean of the Pilbara Craton, addressing a similar theme but with the added goal of resolving controversy over the age and origin of hydrocarbon biomarker molecules in ancient kerogenous shales. As these have been claimed to provide evidence for the evolution of oxygenic photosynthesis long before the rise of atmospheric oxygen to persistently high levels during the ~2.3 Ga “Great Oxidation Event”, their syngenesis with their host shales is thus of critical importance for the interpretation of Earth’s early oxygenation history. During the first drilling season, 3 holes were drilled using techniques and equipment to minimize organic geochemical contamination (new drill-string components cleaned before drilling potentially biomarker-bearing rocks, pre-contamination of drilling fluid with a synthetic organic compound of similar geochemical characteristics to biomarkers, sterile cutting and storage of samples immediately upon retrieval from the core-barrel). The initial hole was a blank control for organic geochemistry, drilled into rocks too metamorphosed to retain biomarker molecules. These rocks, cherts, carbonates and pelites of the 3.52 Ga Coucal Formation, Coonterunah Group, have been metamorphosed to upper greenschist facies at temperatures near 500°C and so should have had any ancient soluble hydrocarbons destroyed. However, because they contain both carbonate and organic carbon, these rocks can instead provide isotopic information about the earliest evolution of biological metabolism as they possess residues of both the reactant and product sides of the carbon-fixation reaction. The second hole sampled an on-shore section of carbonates and kerogenous shales in the ~2.65 Ga Carawine Dolomite and Lewin Shale

Drilling miniature holes, Part III

Energy Technology Data Exchange (ETDEWEB)

Gillespie, L.K.

1978-07-01

Miniature components for precision electromechanical mechanisms such as switches, timers, and actuators typically require a number of small holes. Because of the precision required, the workpiece materials, and the geometry of the parts, most of these holes must be produced by conventional drilling techniques. The use of such techniques is tedious and often requires considerable trial and error to prevent drill breakage, minimize hole mislocation and variations in hole diameter. This study of eight commercial drill designs revealed that printed circuit board drills produced better locational and size repeatability than did other drills when centerdrilling was not used. Boring holes 1 mm in dia, or less, as a general rule did not improve hole location in brass or stainless steel. Hole locations of patterns of 0.66-mm holes can be maintained within 25.4-..mu..m diametral positional tolerance if setup misalignments can be eliminated. Size tolerances of +- 3.8 ..mu..m can be maintained under some conditions when drilling flat plates. While these levels of precision are possible with existing off-the-shelf drills, they may not be practical in many cases.

Effect of diameter of the drill hole on torque of screw insertion and pushout strength for headless tapered compression screws in simulated fractures of the lateral condyle of the equine third metacarpal bone.

Science.gov (United States)

Carpenter, Ryan S; Galuppo, Larry D; Stover, Susan M

2006-05-01

To compare variables for screw insertion, pushout strength, and failure modes for a headless tapered compression screw inserted in standard and oversize holes in a simulated lateral condylar fracture model. 6 pairs of third metacarpal bones from horse cadavers. Simulated lateral condylar fractures were created, reduced, and stabilized with a headless tapered compression screw by use of a standard or oversize hole. Torque, work, and time for drilling, tapping, and screw insertion were measured during site preparation and screw implantation. Axial load and displacement were measured during screw pushout. Effects of drill hole size on variables for screw insertion and screw pushout were assessed by use of Wilcoxon tests. Drill time was 59% greater for oversize holes than for standard holes. Variables for tapping (mean maximum torque, total work, positive work, and time) were 42%, 70%, 73%, and 58% less, respectively, for oversize holes, compared with standard holes. Variables for screw pushout testing (mean yield load, failure load, failure displacement, and failure energy) were 40%, 40%, 47%, and 71% less, respectively, for oversize holes, compared with standard holes. Screws could not be completely inserted in 1 standard and 2 oversize holes. Enlarging the diameter of the drill hole facilitated tapping but decreased overall holding strength of screws. Therefore, holes with a standard diameter are recommended for implantation of variable pitch screws whenever possible. During implantation, care should be taken to ensure that screw threads follow tapped bone threads.

Numerical simulation of small-scale mixing processes in the upper ocean and atmospheric boundary layer

International Nuclear Information System (INIS)

Druzhinin, O; Troitskaya, Yu; Zilitinkevich, S

2016-01-01

The processes of turbulent mixing and momentum and heat exchange occur in the upper ocean at depths up to several dozens of meters and in the atmospheric boundary layer within interval of millimeters to dozens of meters and can not be resolved by known large- scale climate models. Thus small-scale processes need to be parameterized with respect to large scale fields. This parameterization involves the so-called bulk coefficients which relate turbulent fluxes with large-scale fields gradients. The bulk coefficients are dependent on the properties of the small-scale mixing processes which are affected by the upper-ocean stratification and characteristics of surface and internal waves. These dependencies are not well understood at present and need to be clarified. We employ Direct Numerical Simulation (DNS) as a research tool which resolves all relevant flow scales and does not require closure assumptions typical of Large-Eddy and Reynolds Averaged Navier-Stokes simulations (LES and RANS). Thus DNS provides a solid ground for correct parameterization of small-scale mixing processes and also can be used for improving LES and RANS closure models. In particular, we discuss the problems of the interaction between small-scale turbulence and internal gravity waves propagating in the pycnocline in the upper ocean as well as the impact of surface waves on the properties of atmospheric boundary layer over wavy water surface. (paper)

Extended Horizontal Jet Drilling for EGS applications in Petrothermal Environments

Science.gov (United States)

Hahn, Simon; Duda, Mandy; Stoeckhert, Ferdinand; Wittig, Volker; Bracke, Rolf

2017-04-01

Extended Horizontal Jet Drilling for EGS applications in Petrothermal Environments S. Hahn, M. Duda, F. Stoeckhert, V. Wittig, R. Bracke International Geothermal Centre Bochum High pressure water jet drilling technologies are widely used in the drilling industry. Especially in geothermal and hard rock applications, horizontal (radial) jet drilling is, however, confronted with several limitations like lateral length, hole size and steerability. In order to serve as a serious alternative to conventional stimulation techniques these high pressure jetting techniques are experimentally investigated to gain fundamental knowledge about the fluid-structure interaction, to enhance the rock failing process and to identify the governing drilling parameters. The experimental program is divided into three levels. In a first step jetting experiments are performed under free surface conditions while logging fluid pressures, flow speeds and extracted rock volume. All process parameters are quantified with a self-developed jet-ability index and compared to the rock properties (density, porosity, permeability, etc.). In a second step experiments will be performed under pressure-controlled conditions. A test bench is currently under construction offering the possibility to assign an in-situ stress field to the specimen while penetrating the rock sample with a high pressure water jet or a radial jet drilling device. The experimental results from levels 1 and 2 allow to identify the governing rock failure mechanisms and to correlate them with physical rock properties and limited reservoir conditions. Results of the initial tests do show a clear dependency of achievable penetration depth on the interaction of jetting and rock parameters and an individual threshold of the nozzle outlet velocity can be noticed in order to successfully penetrate different formation types. At level 3 jetting experiments will be performed at simulated reservoir conditions corresponding to 5.000 m depth (e

Horizontal Directional Drilling-Length Detection Technology While Drilling Based on Bi-Electro-Magnetic Sensing

Directory of Open Access Journals (Sweden)

Yudan Wang

2017-04-01

Full Text Available The drilling length is an important parameter in the process of horizontal directional drilling (HDD exploration and recovery, but there has been a lack of accurate, automatically obtained statistics regarding this parameter. Herein, a technique for real-time HDD length detection and a management system based on the electromagnetic detection method with a microprocessor and two magnetoresistive sensors employing the software LabVIEW are proposed. The basic principle is to detect the change in the magnetic-field strength near a current coil while the drill stem and drill-stem joint successively pass through the current coil forward or backward. The detection system consists of a hardware subsystem and a software subsystem. The hardware subsystem employs a single-chip microprocessor as the main controller. A current coil is installed in front of the clamping unit, and two magneto resistive sensors are installed on the sides of the coil symmetrically and perpendicular to the direction of movement of the drill pipe. Their responses are used to judge whether the drill-stem joint is passing through the clamping unit; then, the order of their responses is used to judge the movement direction. The software subsystem is composed of a visual software running on the host computer and a software running in the slave microprocessor. The host-computer software processes, displays, and saves the drilling-length data, whereas the slave microprocessor software operates the hardware system. A combined test demonstrated the feasibility of the entire drilling-length detection system.

Ocean eddies and climate predictability.

Science.gov (United States)

Kirtman, Ben P; Perlin, Natalie; Siqueira, Leo

2017-12-01

A suite of coupled climate model simulations and experiments are used to examine how resolved mesoscale ocean features affect aspects of climate variability, air-sea interactions, and predictability. In combination with control simulations, experiments with the interactive ensemble coupling strategy are used to further amplify the role of the oceanic mesoscale field and the associated air-sea feedbacks and predictability. The basic intent of the interactive ensemble coupling strategy is to reduce the atmospheric noise at the air-sea interface, allowing an assessment of how noise affects the variability, and in this case, it is also used to diagnose predictability from the perspective of signal-to-noise ratios. The climate variability is assessed from the perspective of sea surface temperature (SST) variance ratios, and it is shown that, unsurprisingly, mesoscale variability significantly increases SST variance. Perhaps surprising is the fact that the presence of mesoscale ocean features even further enhances the SST variance in the interactive ensemble simulation beyond what would be expected from simple linear arguments. Changes in the air-sea coupling between simulations are assessed using pointwise convective rainfall-SST and convective rainfall-SST tendency correlations and again emphasize how the oceanic mesoscale alters the local association between convective rainfall and SST. Understanding the possible relationships between the SST-forced signal and the weather noise is critically important in climate predictability. We use the interactive ensemble simulations to diagnose this relationship, and we find that the presence of mesoscale ocean features significantly enhances this link particularly in ocean eddy rich regions. Finally, we use signal-to-noise ratios to show that the ocean mesoscale activity increases model estimated predictability in terms of convective precipitation and atmospheric upper tropospheric circulation.

Model based flow measurement using venturi flumes for return flow during drilling

Directory of Open Access Journals (Sweden)

Ivan Pirir

2017-07-01

Full Text Available In an oil well drilling operation, a proper knowledge of the return fluid flowrate is necessary both for the stabilization of the bottom hole pressure of the well and also as a primary indication of a kick or loss. In practice, the drill fluid flowing through the return line is usually measured with Coriolis meters. However this method is both expensive and has some downsides. For instance there is a risk of blockage due to drill cuttings while measuring the discharge. The presence of gas and cuttings in the drilling fluid will also have a negative effect in the measurement i.e. for multi-phase fluid, the readings from Coriolis meters may not be accurate. A cheaper alternative would be to use an open channel for the measurement of the discharge from the return flowline. In this paper, a venturi rig is used as the open channel and modeled by the Saint Venant equations. Experimental verification of the simulation results show a promising behavior of the model based measurement of the return fluid flow.

A Long-Term Performance Enhancement Method for FOG-Based Measurement While Drilling.

Science.gov (United States)

Zhang, Chunxi; Lin, Tie

2016-07-28

In the oil industry, the measurement-while-drilling (MWD) systems are usually used to provide the real-time position and orientation of the bottom hole assembly (BHA) during drilling. However, the present MWD systems based on magnetic surveying technology can barely ensure good performance because of magnetic interference phenomena. In this paper, a MWD surveying system based on a fiber optic gyroscope (FOG) was developed to replace the magnetic surveying system. To accommodate the size of the downhole drilling conditions, a new design method is adopted. In order to realize long-term and high position precision and orientation surveying, an integrated surveying algorithm is proposed based on inertial navigation system (INS) and drilling features. In addition, the FOG-based MWD error model is built and the drilling features are analyzed. The state-space system model and the observation updates model of the Kalman filter are built. To validate the availability and utility of the algorithm, the semi-physical simulation is conducted under laboratory conditions. The results comparison with the traditional algorithms show that the errors were suppressed and the measurement precision of the proposed algorithm is better than the traditional ones. In addition, the proposed method uses a lot less time than the zero velocity update (ZUPT) method.

A drilling tool design and in situ identification of planetary regolith mechanical parameters

Science.gov (United States)

Zhang, Weiwei; Jiang, Shengyuan; Ji, Jie; Tang, Dewei

2018-05-01

The physical and mechanical properties as well as the heat flux of regolith are critical evidence in the study of planetary origin and evolution. Moreover, the mechanical properties of planetary regolith have great value for guiding future human planetary activities. For planetary subsurface exploration, an inchworm boring robot (IBR) has been proposed to penetrate the regolith, and the mechanical properties of the regolith are expected to be simultaneously investigated during the penetration process using the drilling tool on the IBR. This paper provides a preliminary study of an in situ method for measuring planetary regolith mechanical parameters using a drilling tool on a test bed. A conical-screw drilling tool was designed, and its drilling load characteristics were experimentally analyzed. Based on the drilling tool-regolith interaction model, two identification methods for determining the planetary regolith bearing and shearing parameters are proposed. The bearing and shearing parameters of lunar regolith simulant were successfully determined according to the pressure-sinkage tests and shear tests conducted on the test bed. The effects of the operating parameters on the identification results were also analyzed. The results indicate a feasible scheme for future planetary subsurface exploration.

Surface Studies of Ultra Strength Drilling Steel after Corrosion Fatigue in Simulated Sour Environment

Energy Technology Data Exchange (ETDEWEB)

M. Ziomek-Moroz; J.A. Hawk; R. Thodla; F. Gui

2012-05-06

The Unites States predicted 60% growth in energy demand by 2030 makes oil and natural gas primary target fuels for energy generation. The fact that the peak of oil production from shallow wells (< 5000 m) is about to be reached, thereby pushing the oil and natural gas industry into deeper wells. However, drilling to depths greater than 5000 m requires increasing the strength-to weight ratio of the drill pipe materials. Grade UD-165 is one of the ultra- high yield strength carbon steels developed for ultra deep drilling (UDD) activities. Drilling UDD wells exposes the drill pipes to Cl{sup -}, HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}, and H{sub 2}S-containig corrosive environments (i.e., sour environments) at higher pressures and temperatures compared to those found in conventional wells. Because of the lack of synergism within the service environment, operational stresses can result in catastrophic brittle failures characteristic for environmentally assisted cracking (EAC). Approximately 75% of all drill string failures are caused by fatigue or corrosion fatigue. Since there is no literature data on the corrosion fatigue performance of UD-165 in sour environments, research was initiated to better clarify the fatigue crack growth (FCGR) behavior of this alloy in UDD environments. The FCGR behavior of ultra-strength carbon steel, grade UD-165, was investigated by monitoring crack growth rate in deaerated 5%NaCl solution buffered with NaHCO{sub 3}/Na{sub 2}CO{sub 3} and in contact with H{sub 2}S. The partial pressure of H{sub 2}S (p{sub H2S}) was 0.83 kPa and pH of the solution was adjusted by NaOH to 12. The fatigue experiments were performed at 20 and 85 C in an autoclave with surface investigations augmented by scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. In this study, research focused on surface analyses supported by the fatigue crack growth rate measurements. Fig. 1 shows an SEM micrograph of the crack that propagated from the

The effect of drilling parameters for surface roughness in drilling of AA7075 alloy

Directory of Open Access Journals (Sweden)

Yaşar Nafiz

2017-01-01

Full Text Available AA7075 aluminum alloy has been very popular significantly interest in the production of structural components in automotive and aviation applications due to its high strength, low density, good plasticity and better machinability comparable to many metals. Particularly, final products must have uniformly high quality to ensure essential safety standards in the aircraft industry. The optimization of hole quality which can variable according to tool geometry and drilling parameters is important in spite of high machinability rate of AA7075 alloy. In this study, the effects of drilling parameters on average surface roughness (Ra has been investigated in drilling of AA7075 with tungsten carbide drills. Machining experiments were performed with three different drill point angles and three different levels of cutting parameters (feed rate, cutting speed. The effects of drilling parameters on thrust force has been determined with ANOVA in %95 confidence level. Feed rate was determined as the most important factor on Ra according to ANOVA results. Moreover, it was shown that increasing feed rate leads to increase of Ra while increasing drill point angle leads to decrease of Ra. The optimum surface roughness was obtained with point angle of 130°, cutting speed of 40 m/min and feed rate of 0.1 mm/rev, thereby the validity of optimization was confirmed with Taguchi method.

Changes in In Situ Stress Across the Nankai and Cascadia Convergent Margins From Borehole Breakout Measurements During Ocean Drilling

Science.gov (United States)

McNeill, L.; Moore, J. C.; Yamada, Y.; Chang, C.; Tobin, H.; Kinoshita, M.; Gulick, S.; Moore, G.; Iodp Exp. 314/315/316 Science Party, &

2008-12-01

Borehole breakouts are commonly observed in borehole images shortly after drilling of continental margin sites. This study aims to compile and compare these results to determine what in situ shallow stress measurements can tell us about the larger scale tectonic regime. Recent Logging While Drilling resistivity images across the Kumano transect of the Nankai subduction zone, during Expedition 314, Stage 1 of the IODP NanTroSEIZE project, add to this dataset. Expedition 314 site data within the prism (C0001, C0004, C0006, including the megasplay fault system which may overlie the seismogenic updip limit) suggest maximum compressive stress (SHmax) is perpendicular to the margin (not parallel to the convergence vector) but is rotated through 90° at the forearc basin site (C0002). These results may point to changes in stress state of the shallow forearc from east to west: compression in the aseismic active prism (with evidence of strain partitioning of oblique convergence); and extension above the updip seismogenic zone suggesting focus of plate coupling at the plate boundary and not in the shallow forearc. Further south, ODP Leg 196 drilled the prism toe (808) with breakouts indicating SHmax parallel to the convergence vector, in contrast to Exp. 314 results. The stress state in the shallow prism at Site 808 may be affected by nearby seamount subduction or may represent differences in strain partitioning. On the Cascadia margin, two drilling legs have collected LWD borehole images (Leg 204 and Exp. 311). Leg 204 drilled 3 sites at hydrate ridge in the C Cascadia outer prism with breakout orientations variable between closely spaced sites. Prism fold axes are parallel to the margin so we might expect SHmax perpendicular to the margin as in Exp. 314. Deviations from this orientation may reflect local and surface effects (Goldberg and Janik, 2006). Exp. 311, N Cascadia, drilled 5 sites across the prism with breakouts in LWD images. Subduction is not oblique here, in

Simulated ocean acidification reveals winners and losers in coastal phytoplankton.

Directory of Open Access Journals (Sweden)

Lennart T Bach

Full Text Available The oceans absorb ~25% of the annual anthropogenic CO2 emissions. This causes a shift in the marine carbonate chemistry termed ocean acidification (OA. OA is expected to influence metabolic processes in phytoplankton species but it is unclear how the combination of individual physiological changes alters the structure of entire phytoplankton communities. To investigate this, we deployed ten pelagic mesocosms (volume ~50 m3 for 113 days at the west coast of Sweden and simulated OA (pCO2 = 760 μatm in five of them while the other five served as controls (380 μatm. We found: (1 Bulk chlorophyll a concentration and 10 out of 16 investigated phytoplankton groups were significantly and mostly positively affected by elevated CO2 concentrations. However, CO2 effects on abundance or biomass were generally subtle and present only during certain succession stages. (2 Some of the CO2-affected phytoplankton groups seemed to respond directly to altered carbonate chemistry (e.g. diatoms while others (e.g. Synechococcus were more likely to be indirectly affected through CO2 sensitive competitors or grazers. (3 Picoeukaryotic phytoplankton (0.2-2 μm showed the clearest and relatively strong positive CO2 responses during several succession stages. We attribute this not only to a CO2 fertilization of their photosynthetic apparatus but also to an increased nutrient competitiveness under acidified (i.e. low pH conditions. The stimulating influence of high CO2/low pH on picoeukaryote abundance observed in this experiment is strikingly consistent with results from previous studies, suggesting that picoeukaryotes are among the winners in a future ocean.

Simulated ocean acidification reveals winners and losers in coastal phytoplankton.

Science.gov (United States)

Bach, Lennart T; Alvarez-Fernandez, Santiago; Hornick, Thomas; Stuhr, Annegret; Riebesell, Ulf

2017-01-01

The oceans absorb ~25% of the annual anthropogenic CO2 emissions. This causes a shift in the marine carbonate chemistry termed ocean acidification (OA). OA is expected to influence metabolic processes in phytoplankton species but it is unclear how the combination of individual physiological changes alters the structure of entire phytoplankton communities. To investigate this, we deployed ten pelagic mesocosms (volume ~50 m3) for 113 days at the west coast of Sweden and simulated OA (pCO2 = 760 μatm) in five of them while the other five served as controls (380 μatm). We found: (1) Bulk chlorophyll a concentration and 10 out of 16 investigated phytoplankton groups were significantly and mostly positively affected by elevated CO2 concentrations. However, CO2 effects on abundance or biomass were generally subtle and present only during certain succession stages. (2) Some of the CO2-affected phytoplankton groups seemed to respond directly to altered carbonate chemistry (e.g. diatoms) while others (e.g. Synechococcus) were more likely to be indirectly affected through CO2 sensitive competitors or grazers. (3) Picoeukaryotic phytoplankton (0.2-2 μm) showed the clearest and relatively strong positive CO2 responses during several succession stages. We attribute this not only to a CO2 fertilization of their photosynthetic apparatus but also to an increased nutrient competitiveness under acidified (i.e. low pH) conditions. The stimulating influence of high CO2/low pH on picoeukaryote abundance observed in this experiment is strikingly consistent with results from previous studies, suggesting that picoeukaryotes are among the winners in a future ocean.

Simulated ocean acidification reveals winners and losers in coastal phytoplankton

Science.gov (United States)

Alvarez-Fernandez, Santiago; Hornick, Thomas; Stuhr, Annegret; Riebesell, Ulf

2017-01-01

The oceans absorb ~25% of the annual anthropogenic CO2 emissions. This causes a shift in the marine carbonate chemistry termed ocean acidification (OA). OA is expected to influence metabolic processes in phytoplankton species but it is unclear how the combination of individual physiological changes alters the structure of entire phytoplankton communities. To investigate this, we deployed ten pelagic mesocosms (volume ~50 m3) for 113 days at the west coast of Sweden and simulated OA (pCO2 = 760 μatm) in five of them while the other five served as controls (380 μatm). We found: (1) Bulk chlorophyll a concentration and 10 out of 16 investigated phytoplankton groups were significantly and mostly positively affected by elevated CO2 concentrations. However, CO2 effects on abundance or biomass were generally subtle and present only during certain succession stages. (2) Some of the CO2-affected phytoplankton groups seemed to respond directly to altered carbonate chemistry (e.g. diatoms) while others (e.g. Synechococcus) were more likely to be indirectly affected through CO2 sensitive competitors or grazers. (3) Picoeukaryotic phytoplankton (0.2–2 μm) showed the clearest and relatively strong positive CO2 responses during several succession stages. We attribute this not only to a CO2 fertilization of their photosynthetic apparatus but also to an increased nutrient competitiveness under acidified (i.e. low pH) conditions. The stimulating influence of high CO2/low pH on picoeukaryote abundance observed in this experiment is strikingly consistent with results from previous studies, suggesting that picoeukaryotes are among the winners in a future ocean. PMID:29190760

Investigation on the Effects of Process Parameters on Laser Percussion Drilling Using Finite Element Methodology; Statistical Modelling and Optimization

Directory of Open Access Journals (Sweden)

Mahmoud Moradi

Full Text Available Abstract In the present research, the simulation of the Nickel-base superalloy Inconel 718 fiber-laser drilling process with the thickness of 1mm is investigated through the Finite Element Method. In order to specify the appropriate Gaussian distribution of laser beam, the results of an experimental research on glass laser drilling were simulated using three types of Gaussian distribution. The DFLUX subroutine was used to implement the laser heat sources of the models using the Fortran language. After the appropriate Gaussian distribution was chosen, the model was validated with the experimental results of the Nickel-base superalloy Inconel 718 laser drilling process. The negligible error percentage among the experimental and simulation results demonstrates the high accuracy of this model. The experiments were performed based on the Response Surface Methodology (RSM as a statistical design of experiment (DOE approach to investigate the influence of process parameters on the responses, obtaining the mathematical regressions and predicting the new results. Four parameters i.e. laser pulse frequency (150 to 550 Hz, laser power (200 to 500 watts, laser focal plane position (-0.5 to +0.5 mm and the duty cycle (30 to 70% were considered to be the input variables in 5 levels and four external parameters i.e. the hole's entrance and exit diameters, hole taper angle and the weight of mass removed from the hole, were observed to be the process output responses of this central composite design. By performing the statistical analysis, the input and output parameters were found to have a direct relation with each other. By an increase in each of the input variables, the entrance and exit hole diameters, the hole taper angel, and the weight of mass removed from the hole increase. Finally, the results of the conducted simulations and statistical analyses having been used, the laser drilling process was optimized by means of the desire ability approach. Good

Drilling technology advances on four fronts

Energy Technology Data Exchange (ETDEWEB)

Budd, G.

2002-01-01

Trends and advances in drilling technology are discussed. Four different major trends have been identified. One of these is proprietary case drilling which is said to allow operators to simultaneously drill, case, and evaluate oil and gas wells. In proprietary case drilling, the well is drilled with standard oil field casing which remains in the hole all the time, eliminating the need for tripping. Drill bits and other downhole tools are lowered via wireline inside the casing and latched to the last joint of casing. Wells are drilled either by rotating the casing or by using a downhole mud motor for steering, using conventional directional tools. This technology was introduced by Tesco and is marketed in 25 countries along with a full range of drilling products and services. Super single rigs are an other trend which, owing to their versatility, combined with relatively small environmental footprint have become the rig of choice in a growing number of drilling programs. Super single rigs use 45-ft. joints of drill pipe, more versatile top drives and they have an automated pipe handling system. Super singles can be used on both vertical and slant wells and offer advantages of lower costs, higher efficiencies and greater drilling depths. Given their low environmental impact hydraulic capability, super singles also find application where zero disturbance rules are in effect, as for example, in some parts of southern Alberta. Directional drilling and MWD are most associated with SAGD projects but they also have been used and made significant difference in other spheres of oil recovery as well. The fact is that about 35 percent of wells drilled today are drilled with some form of directional drilling; this will stimulate the growth of ever more advanced MWD technology. Northern rigs are in a class of their own in that here the emphasis is on keeping the crew warm, as opposed to lots of gadgets. The most immediately-visible heat-conserving modification is the 60-ft wind

The impact of weather and ocean forecasting on hydrocarbon production and pollution management in the Gulf of Mexico

International Nuclear Information System (INIS)

Kaiser, Mark J.; Pulsipher, Allan G.

2007-01-01

Over the past 2 years, the vulnerability of offshore production in the Gulf of Mexico (GOM) has been brought to light by extensive damage to oil and gas facilities and pipelines resulting from Hurricanes Ivan, Katrina, and Rita. The occurrences of extreme weather regularly force operators to shut-down production, cease drilling and construction activities, and evacuate personnel. Loop currents and eddies can also impact offshore operations and delay installation and drilling activities and reduce the effectiveness of oil spill response strategies. The purpose of this paper is to describe how weather and ocean forecasting impact production activities and pollution management in the GOM. Physical outcome and decision models in support of production and development activities and oil spill response management are presented, and the expected economic benefits that may result from the implementation of an integrated ocean observation network in the region are summarized. Improved ocean observation systems are expected to reduce the uncertainty of forecasting and to enhance the value of ocean/weather information throughout the Gulf region. The source of benefits and the size of activity from which improved ocean observation benefits may be derived are estimated for energy development and production activities and oil spill response management

Drillings at Veitsivaara in Hyrynsalmi

International Nuclear Information System (INIS)

Hinkkanen, H.; Oehberg, A.

1990-04-01

According to Governmen's decision in principle Teollisuuden Voima Oy is obliged to make bedrock investigations for the final disposal of the spent fuel produced by its power plant in Olkiluoto. Areas in Kuhmo, Hyrynsalmi, Sievi, Konginkangas and Olkiluoto were selected for the preliminary site investigations to be carried out during years 1987-1992. In Veitsivaara, Hyrynsalmi the investigation program was started in April 1987. During years 1987-1988 a deep borehole (1002 m) and 4 and 500 m deep additional boreholes were core drilled in the area. Various parameters were measured from the flushing water during the drilling. Corelogging included collecting detailed data of fractures and determining the weathering degree and petrographical properties. Rock mechanical properties, uniaxial compressive strength, Young's modulus and Poisso's ratio were measured from core samples. The flushing water needed in the drillings was pumped from 100 m deep borehole wells drilled with down-the-hole method in the vicinity of the borehole. The water was labeled with 2 tracers before use. About 75 m deep hole was percussion drilled near the borehole KR1. The spreading of the flushing water in the upper part of bedrock and the quality off the ground of the groundwater were studied by taking watersamples from the hole. 30 vertical holes were core drilled down to the depth of 10 m in bedrock with a light drilling unit. Drilling was carried out in order to determine the thickness of the overburden, to investigate the geophysical anomaly sources and to support geological mapping in areas covered with overburden. Groundwater hydraulics is one of the main subjects during the preliminary site investigation phase. For that reason 7 multilevel piezometers were installed on the site to monitore hydraulic head in 3 levels in the uppermost part of bedrock. The work consisted of borehole drillings to the depth of 100 m, geophysical borehole loggings and installation of piezometers. In addition

OPTIMIZATION OF INFILL DRILLING IN NATURALLY-FRACTURED TIGHT-GAS RESERVOIRS

Energy Technology Data Exchange (ETDEWEB)

Lawrence W. Teufel; Her-Yuan Chen; Thomas W. Engler; Bruce Hart

2004-05-01

A major goal of industry and the U.S. Department of Energy (DOE) fossil energy program is to increase gas reserves in tight-gas reservoirs. Infill drilling and hydraulic fracture stimulation in these reservoirs are important reservoir management strategies to increase production and reserves. Phase II of this DOE/cooperative industry project focused on optimization of infill drilling and evaluation of hydraulic fracturing in naturally-fractured tight-gas reservoirs. The cooperative project involved multidisciplinary reservoir characterization and simulation studies to determine infill well potential in the Mesaverde and Dakota sandstone formations at selected areas in the San Juan Basin of northwestern New Mexico. This work used the methodology and approach developed in Phase I. Integrated reservoir description and hydraulic fracture treatment analyses were also conducted in the Pecos Slope Abo tight-gas reservoir in southeastern New Mexico and the Lewis Shale in the San Juan Basin. This study has demonstrated a methodology to (1) describe reservoir heterogeneities and natural fracture systems, (2) determine reservoir permeability and permeability anisotropy, (3) define the elliptical drainage area and recoverable gas for existing wells, (4) determine the optimal location and number of new in-fill wells to maximize economic recovery, (5) forecast the increase in total cumulative gas production from infill drilling, and (6) evaluate hydraulic fracture simulation treatments and their impact on well drainage area and infill well potential. Industry partners during the course of this five-year project included BP, Burlington Resources, ConocoPhillips, and Williams.

Casing drilling - first experience in Brazil; Casing drilling - primeira experiencia no Brasil

Energy Technology Data Exchange (ETDEWEB)

Placido, Joao Carlos Ribeiro; Medeiros, Fernando; Lucena, Humberto; Medeiros, Joao Carlos Martins de; Costa, Vicente Abel Soares Rosa da; Silva, Paulo Roberto Correa da [PETROBRAS, Rio de Janeiro, RJ (Brazil); Alves, Renato J.M. [Tesco, London (United Kingdom)

2004-07-01

This paper describes the 'Casing Drilling' technology and its first experience in Brazil. This new process of casing while drilling was first developed to reduce costs. This system integrates the drilling process and casing running in one operation, promoting a more efficient well construction system, reducing trip time and costs of drill pipes and their transportation. Besides, this methodology intends to eliminate hole problems related to trouble zones with abnormal pressure with loss circulation, to overcome zones with wellbore instabilities, and to facilitate well control. Two companies have been identified using this technology: Tesco and Weatherford. However, there are differences between the techniques used by these companies, which are described in this paper. In the first experience in Brazil, it was decided to field test the technology developed by Tesco. This paper describes the preparation, the operation and the results of this first test. (author)

Slant rigs offer big payoffs in shallow drilling

International Nuclear Information System (INIS)

Smith, J.; Edwards, B.

1992-01-01

Slant hole drilling technology can result in considerable savings over conventionally drilled deviated holes because mud motors and deviation control with measurement while drilling tools are usually unnecessary. The benefits of using slant hole rigs for development drilling improve after the bit walk tendencies and the correct bottom hole assemblies have been determined for a particular area. This article discusses three recent drilling operations that successfully used slant drilling technology on land-based projects: drilling for heavy oil in Alberta, drilling for gas in Alberta, and drilling a river crossing for a gas pipeline in British Columbia. These examples demonstrate the flexibility of slant drilling technology

MODELING AND ANALYSIS OF UNSTEADY FLOW BEHAVIOR IN DEEPWATER CONTROLLED MUD-CAP DRILLING

Directory of Open Access Journals (Sweden)

Jiwei Li

Full Text Available Abstract A new mathematical model was developed in this study to simulate the unsteady flow in controlled mud-cap drilling systems. The model can predict the time-dependent flow inside the drill string and annulus after a circulation break. This model consists of the continuity and momentum equations solved using the explicit Euler method. The model considers both Newtonian and non-Newtonian fluids flowing inside the drill string and annular space. The model predicts the transient flow velocity of mud, the equilibrium time, and the change in the bottom hole pressure (BHP during the unsteady flow. The model was verified using data from U-tube flow experiments reported in the literature. The result shows that the model is accurate, with a maximum average error of 3.56% for the velocity prediction. Together with the measured data, the computed transient flow behavior can be used to better detect well kick and a loss of circulation after the mud pump is shut down. The model sensitivity analysis show that the water depth, mud density and drill string size are the three major factors affecting the fluctuation of the BHP after a circulation break. These factors should be carefully examined in well design and drilling operations to minimize BHP fluctuation and well kick. This study provides the fundamentals for designing a safe system in controlled mud-cap drilling operati.

Drillings at Kivetty in Konginkangas

International Nuclear Information System (INIS)

Hinkkanen, H.; Oehberg, A.

1990-05-01

According to Government's decision in principle Teollisuuden Voima Oy is obliged to make bedrock investigations for the final disposal of the spent fuel produced by its power plant in Olkiluoto. Areas in Kuhmo, Hyrynsalmi, Sievi, Konginkangas and Olkiluoto were selected for the preliminary site investigations to be carried out during years 1987-1992. In Kivetty, Konginkangas the investigation program was started in spring 1988. During years 1988-1989 a deep borehole (1019 m) and 4 about 500 m deep additional boreholes were core drilled in the area. The structure of the holes makes it possible to carry out many investigations in the holes. Various parameters were measured from the flushing water during the drilling. Corelogging included collecting detailed data of fractures and determining the weathering degree and petrographical properties. Rock mechanical properties, uniaxial compressive strength, Young's modulus and Poisson's ratio were measured from core samples. The flushing water needed in the drillings was pumped from 100 m deep borehole wells drilled with down-the-hole method in the vicinity of the borehole. The water was labeled with 2 tracers before use. 30 vertical holes were core drilled down to the depth of 10 m in bedrock with a light drilling unit. Drilling was carried out in order to determine the thickness of the overburden to investigate the geophysical anomaly sources and to support geological mapping in areas covered with overburden. Groundwater hydraulics is one of the main subjects during the preliminary site investigation phase. For that reason 7 multilevel piezometers were installed on the site to monitore hydraulic head in 3 levels in the uppermost part of bedrock. The work consisted of borehole drillings to the depth of 100 m, geophysical borehole loggings and installation of piezometers. In addition about 65 shotholes were drilled for VSP-, tubewave and seismic measurements

Drillings at Syyry in Sievi

International Nuclear Information System (INIS)

Hinkkanen, H.; Oehberg, A.

1990-10-01

According to Government's decision in principle Teollisuuden Voima Oy is obliged to make bedrock investigations for the final disposal of the spent fuel produced by its power plant in Olkiluoto. Areas in Kuhmo, Hyrynsalmi, Sievi, Konginkangas and Olkiluoto were selected for the preliminary site investigations to be carried out during years 1987-1992. In Syyry, Sievi the investigation program was started in spring 1988. During years 1988-1989 a deep borehole (1022 m) and 4 about 500-700 m deep additional boreholes were core drilled in the area. The structure of the holes makes it possible to carry out many investigations in the holes. Various parameters were measured from the flushing water during the drilling. Corelogging included collecting detailed data of fractures and determining the weathering degree and petrographical properties. Rock mechanical properties, uniaxial compressive strength, Young's modulus and Poisson's ratio were measured from core samples. The flushing water needed in the drillings was pumped from 100 m deep borehole wells drilled with down-the-hole method in the vicinity of the borehole. The water was labeled with 2 tracers before use. 35 vertical holes were core drilled down to the depth of 10-20 m in bedrock with a light drilling unit. Drilling was carried out in order to determine the thickness of the overburden, to investigate the geophysical anomaly sources and to support geological mapping in areas covered with overburden. Groundwater hydraulics is one of the main subjects during the preliminary site investigation phase. For that reason 7 multilevel piezometers were installed on the site to monitore hydraulic head in 3 levels in the uppermost part of bedrock. The work consisted of borehole drillings to the depth of 100 m, geophysical borehole loggings and installation of piezometers. In addition about 85 shotholes were drilled for VSP-, tubewave and seismic measurements

Study on a Mechanical Semi-Active Heave Compensation System of Drill String for Use on Floating Drilling Platform

Science.gov (United States)

Liu, Qingyou; Tang, Yang; Huang, Chongjun; Xie, Chong

2015-01-01

There are some disadvantages for existing heave compensation systems of drill string used for the Floating Drilling Platform (FDP), including high energy consumption, large and complex structure, and expensive manufacturing and maintenance costs. In view of the above, we present a streamlined mechanical semi-active heave compensation system (MSAHC) in this study. This system consists of active compensation part with the pinion and rack and passive compensation part. In order to evaluate system performance of the MSAHC, we establish its simulation model with AMEsim software. In the process of simulation, displacement of rotary hook and energy consumption is regarded as performance parameters of the system. And the change rule of two performance parameters are analyzed by changing these design parameters including gear radius of the pinion and rack, scale coefficient of PID, rotary hook load, heave height and heave period of the FDP, and accumulator volume. Then, based on the simulation results of the MSAHC system performance, we have selected out a best set of design parameters from them. Moreover, the feasibility of the design scheme of the MSAHC is effectively verified by comparison with the existing three heave compensation system. The result shows that the energy consumption of the MSAHC is lower than the active heave compensation system (AHC) and the semi-active heave compensation system (SAHC) when achieving a same compensation effect as well as the accumulator volume of MSAHC is half of the passive heave compensation system (PHC). Therefore, the new designed MSAHC not only ensure compensation effect but also lower energy consumption, and its structure is simplified by adopting the simple mechanical structure to decrease manufacturing cost, maintenance cost and floor space. PMID:26186620

Drilling rig

Energy Technology Data Exchange (ETDEWEB)

Galiopa, A A; Yegorov, E K

1981-01-04

A drilling rig is proposed which contains a tower, lifter in the form of n infinite chain, and mobile rotator with holding device connected to the chain, and pipe holder. In order to accelerate the auxiliary operations to move the drilling string and unloaded rotator, the rotator is equipped with a clamp with means for transverse connection of it to both branches of the chain, while the pipe holders equipped with a clamp with means of connecting it to one of the branches of the chain.

Analysis of the drilling sound component from expert performance in a maxillo-facial surgery

DEFF Research Database (Denmark)

Hoffmann, Pablo F.; Gosselin, Florian; Taha, Farid

2009-01-01

Auditory displays can have a great potential in surgical simulators that aim at training skills associated to the correct interpretation of auditory information. Here, we present preliminary results in the analysis of the sound produced by the drilling procedure in a maxillo-facial surgery when...... performed by expert surgeons. The motivation of this work is to find relevant acoustic parameters that allow for an efficient synthesis method of auditory displays so that they can effectively convey information on expert surgical drilling....

Pressured drilling riser design for drilling in ultra deep water with surface bop

Energy Technology Data Exchange (ETDEWEB)

Zhang, J.; Morrison, D.; Efthymiou, M.; Lo, K.H. [Shell Global Solutions, 78 - Velizy Villacoublay (France); Magne, E.; Leach, C. [Shell Internationale Exploration and Production (Netherlands)

2002-12-01

In conventional drilling with a semi-submersible rig valuable rig time is used to run and retrieve the BOP and its accessories on the seabed, and this time increases with water depth. Furthermore, use of the conventional sub-sea BOP requires a large-diameter riser, which requires substantial rig storage and deck load capacity prior to installation. It also requires high riser-tensioning capacity or additional buoyancy. Thus as the water depth increases, it leads to a need for heavy duty 4. and 5. generation rigs with escalation in costs. The high cost of deep-water drill rigs is leading to the development of Surface BOP technology. In this development, the BOP is placed above sea level and the riser is simply a continuation of the casing (typical diameter 13-3/8''). This eliminates the need for a heavy 21'' riser and for running the BOP to the sea bed and retrieving it. Moreover, the reduced tension requirement for the smaller riser extends the water depth capability of 3. generation drilling semi-submersibles, enabling them to drill in deeper waters. A critical success factor for this development is the ability to design the riser/casing to withstand high internal pressures due to well kicks, in addition to environmental loads, and to restrict vessel offsets within certain limits so as not to overload the riser under the prevailing weather conditions. This paper addresses the design considerations of a pressured drilling riser that can be used with a surface BOP in deep-water. Key design issues that are sensitive to ultra-deep-water applications are discussed. The technical aspects of using (disposable) standard casing with threaded connector for the drilling riser are discussed, with a particular emphasis on the connector fatigue-testing program to quantify the stress concentration factor for fatigue design. Emerging composite material offers some alternatives to the steel riser when drilling in ultra-deep water Design issues related to the

A drill-soil system modelization for future Mars exploration

Science.gov (United States)

Finzi, A. E.; Lavagna, M.; Rocchitelli, G.

2004-01-01

This paper presents a first approach to the problem of modeling a drilling process to be carried on in the space environment by a dedicated payload. Systems devoted to work in space present very strict requirements in many different fields such as thermal response, electric power demand, reliability and so on. Thus, models devoted to the operational behaviour simulation represent a fundamental help in the design phase and give a great improvement in the final product quality. As the required power is the crucial constraint within drilling devices, the tool-soil interaction modelization and simulation are finalized to the computation of the power demand as a function of both the drill and the soil parameters. An accurate study of the tool and the soil separately has been firstly carried on and, secondly their interaction has been analyzed. The Dee-Dri system, designed by Tecnospazio and to be part of the lander components in the NASA's Mars Sample Return Mission, has been taken as the tool reference. The Deep-Drill system is a complex rotary tool devoted to the soil perforation and sample collection; it has to operate in a Martian zone made of rocks similar to the terrestrial basalt, then the modelization is restricted to the interaction analysis between the tool and materials belonging to the rock set. The tool geometric modelization has been faced by a finite element approach with a Langrangian formulation: for the static analysis a refined model is assumed considering both the actual geometry of the head and the rod screws; a simplified model has been used to deal with the dynamic analysis. The soil representation is based on the Mohr-Coulomb crack criterion and an Eulerian approach has been selected to model it. However, software limitations in dealing with the tool-soil interface definition required assuming a Langrangian formulation for the soil too. The interaction between the soil and the tool has been modeled by extending the two-dimensional Nishimatsu

GNSS reflectometry aboard the International Space Station: phase-altimetry simulation to detect ocean topography anomalies

Science.gov (United States)

Semmling, Maximilian; Leister, Vera; Saynisch, Jan; Zus, Florian; Wickert, Jens

2016-04-01

An ocean altimetry experiment using Earth reflected GNSS signals has been proposed to the European Space Agency (ESA). It is part of the GNSS Reflectometry Radio Occultation Scatterometry (GEROS) mission that is planned aboard the International Space Station (ISS). Altimetric simulations are presented that examine the detection of ocean topography anomalies assuming GNSS phase delay observations. Such delay measurements are well established for positioning and are possible due to a sufficient synchronization of GNSS receiver and transmitter. For altimetric purpose delays of Earth reflected GNSS signals can be observed similar to radar altimeter signals. The advantage of GNSS is the synchronized separation of transmitter and receiver that allow a significantly increased number of observation per receiver due to more than 70 GNSS transmitters currently in orbit. The altimetric concept has already been applied successfully to flight data recorded over the Mediterranean Sea. The presented altimetric simulation considers anomalies in the Agulhas current region which are obtained from the Region Ocean Model System (ROMS). Suitable reflection events in an elevation range between 3° and 30° last about 10min with ground track's length >3000km. Typical along-track footprints (1s signal integration time) have a length of about 5km. The reflection's Fresnel zone limits the footprint of coherent observations to a major axis extention between 1 to 6km dependent on the elevation. The altimetric performance depends on the signal-to-noise ratio (SNR) of the reflection. Simulation results show that precision is better than 10cm for SNR of 30dB. Whereas, it is worse than 0.5m if SNR goes down to 10dB. Precision, in general, improves towards higher elevation angles. Critical biases are introduced by atmospheric and ionospheric refraction. Corresponding correction strategies are still under investigation.

Simulated 21st century's increase in oceanic suboxia by CO2-enhanced biotic carbon export

Science.gov (United States)

Oschlies, Andreas; Schulz, Kai G.; Riebesell, Ulf; Schmittner, Andreas

2008-12-01

The primary impacts of anthropogenic CO2 emissions on marine biogeochemical cycles predicted so far include ocean acidification, global warming induced shifts in biogeographical provinces, and a possible negative feedback on atmospheric CO2 levels by CO2-fertilized biological production. Here we report a new potentially significant impact on the oxygen-minimum zones of the tropical oceans. Using a model of global climate, ocean circulation, and biogeochemical cycling, we extrapolate mesocosm-derived experimental findings of a pCO2-sensitive increase in biotic carbon-to-nitrogen drawdown to the global ocean. For a simulation run from the onset of the industrial revolution until A.D. 2100 under a "business-as-usual" scenario for anthropogenic CO2 emissions, our model predicts a negative feedback on atmospheric CO2 levels, which amounts to 34 Gt C by the end of this century. While this represents a small alteration of the anthropogenic perturbation of the carbon cycle, the model results reveal a dramatic 50% increase in the suboxic water volume by the end of this century in response to the respiration of excess organic carbon formed at higher CO2 levels. This is a significant expansion of the marine "dead zones" with severe implications not only for all higher life forms but also for oxygen-sensitive nutrient recycling and, hence, for oceanic nutrient inventories.

Contrasting spatial structures of Atlantic Multidecadal Oscillation between observations and slab ocean model simulations

Science.gov (United States)

Sun, Cheng; Li, Jianping; Kucharski, Fred; Xue, Jiaqing; Li, Xiang

2018-04-01

The spatial structure of Atlantic multidecadal oscillation (AMO) is analyzed and compared between the observations and simulations from slab ocean models (SOMs) and fully coupled models. The observed sea surface temperature (SST) pattern of AMO is characterized by a basin-wide monopole structure, and there is a significantly high degree of spatial coherence of decadal SST variations across the entire North Atlantic basin. The observed SST anomalies share a common decadal-scale signal, corresponding to the basin-wide average (i. e., the AMO). In contrast, the simulated AMO in SOMs (AMOs) exhibits a tripole-like structure, with the mid-latitude North Atlantic SST showing an inverse relationship with other parts of the basin, and the SOMs fail to reproduce the observed strong spatial coherence of decadal SST variations associated with the AMO. The observed spatial coherence of AMO SST anomalies is identified as a key feature that can be used to distinguish the AMO mechanism. The tripole-like SST pattern of AMOs in SOMs can be largely explained by the atmosphere-forced thermodynamics mechanism due to the surface heat flux changes associated with the North Atlantic Oscillation (NAO). The thermodynamic forcing of AMOs by the NAO gives rise to a simultaneous inverse NAO-AMOs relationship at both interannual and decadal timescales and a seasonal phase locking of the AMOs variability to the cold season. However, the NAO-forced thermodynamics mechanism cannot explain the observed NAO-AMO relationship and the seasonal phase locking of observed AMO variability to the warm season. At decadal timescales, a strong lagged relationship between NAO and AMO is observed, with the NAO leading by up to two decades, while the simultaneous correlation of NAO with AMO is weak. This lagged relationship and the spatial coherence of AMO can be well understood from the view point of ocean dynamics. A time-integrated NAO index, which reflects the variations in Atlantic meridional overturning

Neurosurgical robotic arm drilling navigation system.

Science.gov (United States)

Lin, Chung-Chih; Lin, Hsin-Cheng; Lee, Wen-Yo; Lee, Shih-Tseng; Wu, Chieh-Tsai

2017-09-01

The aim of this work was to develop a neurosurgical robotic arm drilling navigation system that provides assistance throughout the complete bone drilling process. The system comprised neurosurgical robotic arm navigation combining robotic and surgical navigation, 3D medical imaging based surgical planning that could identify lesion location and plan the surgical path on 3D images, and automatic bone drilling control that would stop drilling when the bone was to be drilled-through. Three kinds of experiment were designed. The average positioning error deduced from 3D images of the robotic arm was 0.502 ± 0.069 mm. The correlation between automatically and manually planned paths was 0.975. The average distance error between automatically planned paths and risky zones was 0.279 ± 0.401 mm. The drilling auto-stopping algorithm had 0.00% unstopped cases (26.32% in control group 1) and 70.53% non-drilled-through cases (8.42% and 4.21% in control groups 1 and 2). The system may be useful for neurosurgical robotic arm drilling navigation. Copyright © 2016 John Wiley & Sons, Ltd.

Computalog's LWD system designed for deepwater drilling environments

Energy Technology Data Exchange (ETDEWEB)

Brady, K. [Precision Drilling Corporation, (Canada)

2002-08-01

To keep up with the ever changing requirements of drilling engineers for MWD and LWD (measuring -while-drilling and logging-while- drilling) equipment capable to withstand bore pressures of 20,000 to 25,000 psi and flow rates above industry average, is part of Computalog's ongoing effort to provide innovative technology for the industry's evolving drilling requirements. This paper describes the new PrecisionLWD'TM' system which is rated at 30,000 psi and is designed with the extra margin of reliability and performance needed for hostile deepwater environments. The system is made up of a series of high temperature tools and sensors. The entire system and all its individual tools are rated to 30,000 psi and have flow ratings of 400 gallons/minute, 1,000 gallons/minute, and 1,800 gallons/minute respectively, depending on tool size. The tools are manufactured at Houston, TX, at a facility that is equipped with testing equipment to simulate all aspects of extreme drilling conditions, including thermal cycling, vibration and pressure testing. The facility also features a 6,000-ft flow-loop for erosion and lost circulation testing and a computer array with the power equivalent of several Cray mainframes. The finished tools are calibrated and tested to a number of known standards and hole sizes, including aluminum and magnesium blocks, and a variety of formation types. Research and development efforts are also underway to make these tools compatible with the Precision Impulse'TM' Electromagnetic MWD system.

Extended Reach Drilling on the example of Reelwell Drilling Method: Influence examination of different drill pipes on drilling performance on Idun field on the Norwegian Continental Shelf by PGNiG Norway AS.

OpenAIRE

Krol, Dariusz Pawel

2011-01-01

Master's thesis in Petroleum engineering Horizontal or extended reach drilling is incredibly fast growing technology. Although in some areas of the world ERD is still novelty, most of oil companies have been using the technology reliably and successfully for dozens of years. And those companies want to improve well-worn solutions to obtain better performance, thereby reducing costs. One of the main aspects that affects drilling performance and efficiency is adequate choice of drill pipe...

Corrosion behavior of beryllium copper and other nonmagnetic alloys in simulated drilling environments

International Nuclear Information System (INIS)

Cribb, W.R.; Booker, J.; Kane, R.D.; Turn, J.C.

1984-01-01

Beryllium copper (BeCu) alloys are known to exhibit high strength and good electrical conductivity. Other attractive properties, low magnetic susceptibility and resistance to galling, make these alloys strong contenders for use as drill collars and instrument housings in drilling equipment. Environmental cracking and corrosion tests were conducted in autoclaves at 66, 121 and 149 C (150, 250 and 300 F) in environments as severe as 10% H 2 S, 20% CO 2 balance N 2 . The results indicate Brush Alloy 25 adequately resists environmental cracking for these conditions, whereas certain nonmagnetic stainless steel cracked. Brush Alloy 25 exhibits acceptable corrosion rates at or below temperatures of 149 C (300 F) in environments with up to 1% H 2 S. Acceptable rates were also observed for environments containing up to 10% H 2 S at 66 C (150 F). The alloy showed this similar acceptable behavior in billet or tube form regardless of the aging treatment

Reverse engineering of wörner type drilling machine structure.

Science.gov (United States)

Wibowo, A.; Belly, I.; llhamsyah, R.; Indrawanto; Yuwana, Y.

2018-03-01

A product design needs to be modified based on the conditions of production facilities and existing resource capabilities without reducing the functional aspects of the product itself. This paper describes the reverse engineering process of the main structure of the wörner type drilling machine to obtain a machine structure design that can be made by resources with limited ability by using simple processes. Some structural, functional and the work mechanism analyzes have been performed to understand the function and role of each basic components. The process of dismantling of the drilling machine and measuring each of the basic components was performed to obtain sets of the geometry and size data of each component. The geometric model of each structure components and the machine assembly were built to facilitate the simulation process and machine performance analysis that refers to ISO standard of drilling machine. The tolerance stackup analysis also performed to determine the type and value of geometrical and dimensional tolerances, which could affect the ease of the components to be manufactured and assembled

Improving Site Characterization for Rock Dredging using a Drilling Parameter Recorder and the Point Load Test

Science.gov (United States)

1994-09-01

materials. Also, available data from drilling rates in the mining and tunneling industries (Howarth and Rowlands 1987, Somerton 1959) indicate a...selected uniform natural rock materials and several man -made rock simulants were used to obtain drilling parameter records for materials of known...Dredging Seminar, Atlantic City, NJ, May 1993. Western Dredging Association (WEDA) and Texas A&M University. Somerton , W. H. (1959). "A laboratory study of

Trends in the Drilling Waste Management

Directory of Open Access Journals (Sweden)

Lucyna Czekaj

2006-10-01

Full Text Available Petroleum Industry is trying to achieve sustainable development goals. Each year new solutions are implemented to minimize the environmental impact of drilling operations. The paper presents trends in the drilling waste management caused by introducing the sustainable development into the petroleum industry. Old solutions such as the drilling waste disposal at the waste dump or dumping ground are not acceptable from the environmental point of view. The paper presents an analysis of new solutions as the sustainable solutions. The most important problem is the chemical pollution in cuttings and the waste drilling mud. The industrial solutions as well as the laboratory research on the pollution removing from drilling wastes are analysed. The most promising method seems to be the recycling and design for the environment of drilling mud.

Investigating Miocene Mediterranean-Atlantic Gateway Exchange (IMMAGE) - an amphibious drilling proposal

Science.gov (United States)

Flecker, Rachel

2017-04-01

Today Mediterranean seawater flows out through the Gibraltar Straits, forming a saline plume at intermediate depths in the Atlantic. The plume's sedimentary record of distinctive, contouritic deposits has recently been recovered during IODP Leg 339 in the Gulf of Cadiz documenting a Mediterranean contribution to Atlantic thermohaline circulation since the Pliocene. However, before the Pliocene, the conduit for Mediterranean-Atlantic exchange is unclear. Gibraltar may have already been open, but two additional marine corridors also existed through northern Morocco and southern Spain. The restriction and closure of these Miocene connections resulted in extreme salinity fluctuations in the Mediterranean, leading to the precipitation of thick evaporites. This event is known as the Messinian Salinity Crisis (MSC) and recovering a complete record of the MSC is the target of current IODP drilling proposals (e.g. DREAM). Understanding both the causes of high-amplitude salinity change in the Mediterranean and its global consequences for thermohaline circulation in the Atlantic is dependent on recovering a complete record of Mediterranean-Atlantic exchange before, during and after the MSC. This key objective of the IMMAGE drilling proposal requires core recovery on-shore at the mouths of the Betic and Rifian corridors which are now exposed on land, as well as offshore, in the Alborán Sea and on the Atlantic continental margin. Consequently to meet this objective, an amphibious drilling strategy is necessary, involving both IODP and ICDP targets. In addition to allowing us to reconstruct Mediterranean-Atlantic exchange during high amplitude salinity fluctuations and identify the conduit through which exchange occurred, the sediments recovered from IMMAGE drilling will also provide us with a unique and explicit test for ocean physics hypotheses describing the location, size and velocity of overflow plumes under conditions where the density contrast between the two water

CFPL installs products pipeline with directional drilling

International Nuclear Information System (INIS)

Anon.

1996-01-01

Central Florida Pipeline Company (CFPL), a subsidiary of GATX Terminals Corp., Tampa, FL, has used directional drilling under seven water bodies in Hillsborough, Polk and Osceola Counties in constructing its new pipeline from Tampa to Orlando. Primary reason for using directional drilling is to protect the environment by minimizing water turbidity while the 16-inch diameter, 109-mile refined petroleum products pipeline is being installed. Total cost of the project is pegged at $68.5 million. Directional drilling enabled the pipe to be placed about 20 feet below the bottom of: The Alafia River in Riverview with 999 feet drilled; Port Sutton Channel near the Port of Tampa with 2,756 feet drilled; Reedy Creek Swamp at the intersection of Interstate 4 and Highway 192 which had 1,111 feet drilled; Wetland number-sign 70 southwest of Lake Wales with 1,575 feet drilled; Peace River south of Bartow had 2,470 feet drilled; Bonnet Creek west of Kissimmee had 693 feet drilled. Shingle Creek near the borders of Osceola and Orange Counties with 1,700 feet drilled. This paper reviews the design plans for construction and the emergency response plans should a rupture occur in the line

Aerated drilling cutting transport analysis in geothermal well

Science.gov (United States)

Wakhyudin, Aris; Setiawan, Deni; Dwi Marjuan, Oscar

2017-12-01

Aeratad drilling widely used for geothermal drilling especially when drilled into predicted production zone. Aerated drilling give better performance on preventing lost circulation problem, improving rate of penetration, and avoiding drilling fluid invasion to productive zone. While well is drilled, cutting is produced and should be carried to surface by drilling fluid. Hole problem, especially pipe sticking will occur while the cutting is not lifted properly to surface. The problem will effect on drilling schedule; non-productive time finally result more cost to be spent. Geothermal formation has different characteristic comparing oil and gas formation. Geothermal mainly has igneous rock while oil and gas mostly sedimentary rock. In same depth, formation pressure in geothermal well commonly lower than oil and gas well while formation temperature geothermal well is higher. While aerated drilling is applied in geothermal well, Igneous rock density has higher density than sedimentary rock and aerated drilling fluid is lighter than water based mud hence minimum velocity requirement to transport cutting is larger than in oil/gas well drilling. Temperature and pressure also has impact on drilling fluid (aerated) density. High temperature in geothermal well decrease drilling fluid density hence the effect of pressure and temperature also considered. In this paper, Aerated drilling cutting transport performance on geothermal well will be analysed due to different rock and drilling fluid density. Additionally, temperature and pressure effect on drilling fluid density also presented to merge.

Report Viewgraphs for IC Project: Fully-coupled climate simulations with an eddy-permitting ocean component

Energy Technology Data Exchange (ETDEWEB)

Veneziani, Carmela [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-07-25

Two sets of simulations were performed within this allocation: 1) a 12-year fully-coupled experiment in pre-industrial conditions, using the CICE4 version of the sea-ice model; 2) a set of multi-decadal ocean-ice-only experiments, forced with CORE-I atmospheric fields and using the CICE5 version of the sea-ice model.

Propagation of Measurement-While-Drilling Mud Pulse during High Temperature Deep Well Drilling Operations

OpenAIRE

Li, Hongtao; Meng, Yingfeng; Li, Gao; Wei, Na; Liu, Jiajie; Ma, Xiao; Duan, Mubai; Gu, Siman; Zhu, Kuanliang; Xu, Xiaofeng

2013-01-01

Signal attenuates while Measurement-While-Drilling (MWD) mud pulse is transmited in drill string during high temperature deep well drilling. In this work, an analytical model for the propagation of mud pulse was presented. The model consists of continuity, momentum, and state equations with analytical solutions based on the linear perturbation analysis. The model can predict the wave speed and attenuation coefficient of mud pulse. The calculated results were compared with the experimental dat...

Coupling atmospheric and ocean wave models for storm simulation

DEFF Research Database (Denmark)

Du, Jianting

the atmosphere must, by conservation, result in the generation of the surface waves and currents. The physics-based methods are sensitive to the choice of wind-input source function (Sin), parameterization of high-frequency wave spectra tail, and numerical cut-off frequencies. Unfortunately, literature survey......This thesis studies the wind-wave interactions through the coupling between the atmospheric model and ocean surface wave models. Special attention is put on storm simulations in the North Sea for wind energy applications in the coastal zones. The two aspects, namely storm conditions and coastal...... shows that in most wind-wave coupling systems, either the Sin in the wave model is different from the one used for the momentum flux estimation in the atmospheric model, or the methods are too sensitive to the parameterization of high-frequency spectra tail and numerical cut-off frequencies. To confront...

Numerical Modeling of Foam Drilling Hydraulics

Directory of Open Access Journals (Sweden)

Ozcan Baris

2007-12-01

Full Text Available The use of foam as a drilling fluid was developed to meet a special set of conditions under which other common drilling fluids had failed. Foam drilling is defined as the process of making boreholes by utilizing foam as the circulating fluid. When compared with conventional drilling, underbalanced or foam drilling has several advantages. These advantages include: avoidance of lost circulation problems, minimizing damage to pay zones, higher penetration rates and bit life. Foams are usually characterized by the quality, the ratio of the volume of gas, and the total foam volume. Obtaining dependable pressure profiles for aerated (gasified fluids and foam is more difficult than for single phase fluids, since in the former ones the drilling mud contains a gas phase that is entrained within the fluid system. The primary goal of this study is to expand the knowledge-base of the hydrodynamic phenomena that occur in a foam drilling operation. In order to gain a better understanding of foam drilling operations, a hydrodynamic model is developed and run at different operating conditions. For this purpose, the flow of foam through the drilling system is modeled by invoking the basic principles of continuum mechanics and thermodynamics. The model was designed to allow gas and liquid flow at desired volumetric flow rates through the drillstring and annulus. Parametric studies are conducted in order to identify the most influential variables in the hydrodynamic modeling of foam flow.

Underground localization using dual magnetic field sequence measurement and pose graph SLAM for directional drilling

International Nuclear Information System (INIS)

Park, Byeolteo; Myung, Hyun

2014-01-01

With the development of unconventional gas, the technology of directional drilling has become more advanced. Underground localization is the key technique of directional drilling for real-time path following and system control. However, there are problems such as vibration, disconnection with external infrastructure, and magnetic field distortion. Conventional methods cannot solve these problems in real time or in various environments. In this paper, a novel underground localization algorithm using a re-measurement of the sequence of the magnetic field and pose graph SLAM (simultaneous localization and mapping) is introduced. The proposed algorithm exploits the property of the drilling system that the body passes through the previous pass. By comparing the recorded measurement from one magnetic sensor and the current re-measurement from another magnetic sensor, the proposed algorithm predicts the pose of the drilling system. The performance of the algorithm is validated through simulations and experiments. (paper)

Underground localization using dual magnetic field sequence measurement and pose graph SLAM for directional drilling

Science.gov (United States)

Park, Byeolteo; Myung, Hyun

2014-12-01

With the development of unconventional gas, the technology of directional drilling has become more advanced. Underground localization is the key technique of directional drilling for real-time path following and system control. However, there are problems such as vibration, disconnection with external infrastructure, and magnetic field distortion. Conventional methods cannot solve these problems in real time or in various environments. In this paper, a novel underground localization algorithm using a re-measurement of the sequence of the magnetic field and pose graph SLAM (simultaneous localization and mapping) is introduced. The proposed algorithm exploits the property of the drilling system that the body passes through the previous pass. By comparing the recorded measurement from one magnetic sensor and the current re-measurement from another magnetic sensor, the proposed algorithm predicts the pose of the drilling system. The performance of the algorithm is validated through simulations and experiments.

Determination of transient temperature distribution inside a wellbore considering drill string assembly and casing program

International Nuclear Information System (INIS)

Yang, Mou; Zhao, Xiangyang; Meng, Yingfeng; Li, Gao; Zhang, Lin; Xu, Haiming; Tang, Daqian

2017-01-01

Highlights: • The different wellbore conditions of heat transfer models were developed. • Drill string assembly and casing programs impact on down-hole temperatures. • The thermal performance in circulation and shut-in stages were deeply investigated. • Full-scale model coincided with the measured field data preferably. - Abstract: Heat exchange efficiency between each region of the wellbore and formation systems is influenced by the high thermal conductivity of the drill string and casing, which further affects temperature distribution of the wellbore. Based on the energy conservation principle, the Modified Raymond, Simplified and Full-scale models were developed, which were solved by the fully implicit finite difference method. The results indicated that wellbore and formation temperatures were significantly influenced at the connection points between the drill collar and drill pipe, as well as the casing shoe. Apart from the near surface, little change was observed in temperature distribution in the cement section. In the open-hole section, the temperature rapidly decreased in the circulation stage and gradually increased in the shut-in stage. Most important, the simulated result from the full-scale model coincided with the measured field data better than the other numerical models. These findings not only confirm the effect of the drill string assembly and casing programs on the wellbore and formation temperature distribution, but also contribute to resource exploration, drilling safety and reduced drilling costs.

Chemical Speciation of Chromium in Drilling Muds

International Nuclear Information System (INIS)

Taguchi, Takeyoshi; Yoshii, Mitsuru; Shinoda, Kohzo

2007-01-01

Drilling muds are made of bentonite and other clays, and/or polymers, mixed with water to the desired viscosity. Without the drilling muds, corporations could not drill for oil and gas and we would have hardly any of the fuels and lubricants considered essential for modern industrial civilization. There are hundreds of drilling muds used and some kinds of drilling muds contain chromium. The chemical states of chromium in muds have been studied carefully due to concerns about the environmental influence. However it is difficult to determine the chemical state of chromium in drilling muds directly by conventional analytical methods. We have studied the chemical form of chromium in drilling muds by using a laboratory XAFS system and a synchrotron facility

Automated Kick Control Procedure for an Influx in Managed Pressure Drilling Operations

Directory of Open Access Journals (Sweden)

Jing Zhou

2016-01-01

Full Text Available Within drilling of oil and gas wells, the Managed Pressure Drilling (MPD method with active control of wellbore pressure during drilling has partly evolved from conventional well control procedures. However, for MPD operations the instrumentation is typically more extensive compared to conventional drilling. Despite this, any influx of formation fluids (commonly known as a kick during MPD operations is typically handled by conventional well control methods, at least if the kick is estimated to be larger than a threshold value. Conventional well control procedures rely on manual control of the blow out preventer, pumps, and choke valves and do not capitalize on the benefits from the instrumentation level associated with MPD. This paper investigates two alternative well control procedures specially adapted to backpressure MPD: the dynamic shut-in (DSI procedure and the automatic kick control (AKC procedure. Both methods capitalize on improvements in Pressure While Drilling (PWD technology. A commercially available PWD tool buffers high-resolution pressure measurements, which can be used in an automated well control procedure. By using backpressure MPD, the choke valve opening is tuned automatically using a feedback-feedforward control method. The two procedures are evaluated using a high fidelity well flow model and cases from a North Sea drilling operation are simulated. The results show that using AKC procedure reduces the time needed to establish control of the well compared to DSI procedure. It also indicates that the AKC procedure reduces the total kick size compared to the DSI procedure, and thereby reduces the risk of lost circulation.

Eddy-resolving simulations of the Fimbul Ice Shelf cavity circulation: Basal melting and exchange with open ocean

Science.gov (United States)

Hattermann, T.; Smedsrud, L. H.; Nøst, O. A.; Lilly, J. M.; Galton-Fenzi, B. K.

2014-10-01

Melting at the base of floating ice shelves is a dominant term in the overall Antarctic mass budget. This study applies a high-resolution regional ice shelf/ocean model, constrained by observations, to (i) quantify present basal mass loss at the Fimbul Ice Shelf (FIS); and (ii) investigate the oceanic mechanisms that govern the heat supply to ice shelves in the Eastern Weddell Sea. The simulations confirm the low melt rates suggested by observations and show that melting is primarily determined by the depth of the coastal thermocline, regulating deep ocean heat fluxes towards the ice. Furthermore, the uneven distribution of ice shelf area at different depths modulates the melting response to oceanic forcing, causing the existence of two distinct states of melting at the FIS. In the simulated present-day state, only small amounts of Modified Warm Deep Water enter the continental shelf, and ocean temperatures beneath the ice are close to the surface freezing point. The basal mass loss in this so-called state of "shallow melting" is mainly controlled by the seasonal inflow of solar-heated surface water affecting large areas of shallow ice in the upper part of the cavity. This is in contrast to a state of "deep melting", in which the thermocline rises above the shelf break depth, establishing a continuous inflow of Warm Deep Water towards the deep ice. The transition between the two states is found to be determined by a complex response of the Antarctic Slope Front overturning circulation to varying climate forcings. A proper representation of these frontal dynamics in climate models will therefore be crucial when assessing the evolution of ice shelf basal melting along this sector of Antarctica.

Accuracy of linear drilling in temporal bone using drill press system for minimally invasive cochlear implantation.

Science.gov (United States)

Dillon, Neal P; Balachandran, Ramya; Labadie, Robert F

2016-03-01

A minimally invasive approach for cochlear implantation involves drilling a narrow linear path through the temporal bone from the skull surface directly to the cochlea for insertion of the electrode array without the need for an invasive mastoidectomy. Potential drill positioning errors must be accounted for to predict the effectiveness and safety of the procedure. The drilling accuracy of a system used for this procedure was evaluated in bone surrogate material under a range of clinically relevant parameters. Additional experiments were performed to isolate the error at various points along the path to better understand why deflections occur. An experimental setup to precisely position the drill press over a target was used. Custom bone surrogate test blocks were manufactured to resemble the mastoid region of the temporal bone. The drilling error was measured by creating divots in plastic sheets before and after drilling and using a microscope to localize the divots. The drilling error was within the tolerance needed to avoid vital structures and ensure accurate placement of the electrode; however, some parameter sets yielded errors that may impact the effectiveness of the procedure when combined with other error sources. The error increases when the lateral stage of the path terminates in an air cell and when the guide bushings are positioned further from the skull surface. At contact points due to air cells along the trajectory, higher errors were found for impact angles of [Formula: see text] and higher as well as longer cantilevered drill lengths. The results of these experiments can be used to define more accurate and safe drill trajectories for this minimally invasive surgical procedure.

Seismic Prediction While Drilling (SPWD: Looking Ahead of the Drill Bit by Application of Phased Array Technology

Directory of Open Access Journals (Sweden)

Marco Groh

2010-04-01

Full Text Available Geophysical exploration is indispensable for planning deep drilling. Usually 2D- or 3D-seismics investigations are applied and, depending on the resulting geologic model for the underground, the drill site and drilling path are determined. In recent years the focus of exploration has shifted towards small-scale geological structures such as local layers and faults. Depending on the source frequencies and the target depth, 2D- or 3D-seismics from surface cannot always resolve such structures in particular at larger depths. In general, signal frequencies of about 30–70 Hz are typical for surface seismic methods. The deeper and smaller the sought-after structures are, the worse will be the resolution. Therefore, borehole seismic measurements like Vertical Seismic Profile (VSP or Seismic While Drilling (SWD have been developed (Fig. 1. For the VSP method geophones are normally integrated in the borehole, while the seismicsource generates seismic waves at the surface. The SWD method uses the drill bit as the seismic source. Hence, the quality of the seismic signals is highly dependent on the drilled rock and the type of drill bit, but even well-suited rock conditions and adequate drilling may not provide sufficient data quality.

Differing opinions about natural gas drilling in two adjacent counties with different levels of drilling activity

International Nuclear Information System (INIS)

Kriesky, J.; Goldstein, B.D.; Zell, K.; Beach, S.

2013-01-01

The pace of development of shale gas plays varies greatly among US states and globally. Through analysis of telephone survey responses, we explore support for natural gas drilling in residents of Washington County (WC), PA (n=502) vs. residents of Allegheny County (AC), PA (n=799). WC has had intense Marcellus Shale (MS) drilling activity, in comparison to adjacent AC, which has had little drilling activity. WC residents are marginally more supportive of MS drilling than are AC residents (p=0.0768). Residents of WC are more likely to perceive MS as an economic opportunity than are AC residents (p=0.0015); to be in a family that has signed a MS lease (p<0.0001); to follow the MS issue closely (p=0.0003); to get MS information from neighbors, friends, and relatives (p<0.0001); and are marginally less likely to perceive MS as an environmental threat (p=0.1090). WC leaseholders are significantly more supportive of MS drilling than WC non-leaseholders and AC non-leaseholders (p=0.0024). Mediation analyses show that county-based differences in support of MS drilling are due to WC residents seeing more of an economic opportunity in the MS and their greater likelihood of having a family-held lease. - Highlights: • Telephone survey analysis of sources of support for Marcellus Shale drilling. • Perceived positive economic impact of drilling drives support among respondents. • Mineral rights leaseholders are significantly more supportive than non-leaseholders

Experimental Analysis of Temperature Differences During Implant Site Preparation: Continuous Drilling Technique Versus Intermittent Drilling Technique.

Science.gov (United States)

Di Fiore, Adolfo; Sivolella, Stefano; Stocco, Elena; Favero, Vittorio; Stellini, Edoardo

2018-02-01

Implant site preparation through drilling procedures may cause bone thermonecrosis. The aim of this in vitro study was to evaluate, using a thermal probe, overheating at implant sites during osteotomies through 2 different drilling methods (continuous drilling technique versus intermittent drilling technique) using irrigation at different temperatures. Five implant sites 13 mm in length were performed on 16 blocks (fresh bovine ribs), for a total of 80 implant sites. The PT-100 thermal probe was positioned 5 mm from each site. Two physiological refrigerant solutions were used: one at 23.7°C and one at 6.0°C. Four experimental groups were considered: group A (continuous drilling with physiological solution at 23.7°C), group B (intermittent drilling with physiological solution at 23.7°C), group C (continuous drilling with physiological solution at 6.0°C), and group D (intermittent drilling with physiological solution at 6.0°C). The Wilcoxon rank-sum test (2-tailed) was used to compare groups. While there was no difference between group A and group B (W = 86; P = .45), statistically significant differences were observed between experimental groups A and C (W = 0; P =.0001), B and D (W = 45; P =.0005), and C and D (W = 41; P = .003). Implant site preparation did not affect the overheating of the bone. Statistically significant differences were found with the refrigerant solutions. Using both irrigating solutions, bone temperature did not exceed 47°C.

Drilling rig mast

Energy Technology Data Exchange (ETDEWEB)

Bulgakov, E.S.; Barashkov, V.A.; Lebedev, A.I.; Panin, N.M.; Sirotkin, N.V.

1981-01-07

A drilling rig mast is proposed that contains a portal with a carrier shaft hinged to it and struts with stays. In order to decrease the time expended in the assembly and dessembly of the drilling rig, the portal is constructed from mobile and immobile parts that are connected together by a ball pivot; the immobile section of the portal has a T-shaped recess for directing the mobile section.

The Marskhod Egyptian Drill Project

Science.gov (United States)

Shaltout, M. A. M.

We describe a possible participation of Egypt in a future Mars rover Mission. It was suggested that Egypt participate through involvement in the design, building and testing of a drill to obtain sub-surface samples. The Space Research Institute of the Russian Academy of Sciences (IKI), formally invited the Egyptian Ministry of Scientific Research to study the concept for potential use on the Russian Mars 2001 Mission. As one of the objectives of the Marskhod mission was the analysis of sub-surface samples, a drilling mechanism in the payload would be essential. The Egyptian expertise in drill development is associated with the archaeological exploration of the Pyramids. A sophisticated drilling system perforated limestone to a depth of 2 m without the use of lubricants or cooling fluids that might have contaminated the Pit's environment. This experience could have been applied to a drill development Mars 2001 mission, which was unfortunately canceled due to economic problems.

Trans-Amazon Drilling Project (TADP): origins and evolution of the forests, climate, and hydrology of the South American tropics

Science.gov (United States)

Baker, P. A.; Fritz, S. C.; Silva, C. G.; Rigsby, C. A.; Absy, M. L.; Almeida, R. P.; Caputo, M.; Chiessi, C. M.; Cruz, F. W.; Dick, C. W.; Feakins, S. J.; Figueiredo, J.; Freeman, K. H.; Hoorn, C.; Jaramillo, C.; Kern, A. K.; Latrubesse, E. M.; Ledru, M. P.; Marzoli, A.; Myrbo, A.; Noren, A.; Piller, W. E.; Ramos, M. I. F.; Ribas, C. C.; Trnadade, R.; West, A. J.; Wahnfried, I.; Willard, D. A.

2015-12-01

This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this project are to document the evolution of plant biodiversity in the Amazon forests and to relate biotic diversification to changes in the physical environment, including climate, tectonism, and the surface landscape. These goals require long sedimentary records from each of the major sedimentary basins across the heart of the Brazilian Amazon, which can only be obtained by drilling because of the scarcity of Cenozoic outcrops. The proposed drilling will provide the first long, nearly continuous regional records of the Cenozoic history of the forests, their plant diversity, and the associated changes in climate and environment. It also will address fundamental questions about landscape evolution, including the history of Andean uplift and erosion as recorded in Andean foreland basins and the development of west-to-east hydrologic continuity between the Andes, the Amazon lowlands, and the equatorial Atlantic. Because many modern rivers of the Amazon basin flow along the major axes of the old sedimentary basins, we plan to locate drill sites on the margin of large rivers and to access the targeted drill sites by navigation along these rivers.

Trans-Amazon Drilling Project (TADP): origins and evolution of the forests, climate, and hydrology of the South American tropics

Science.gov (United States)

Baker, P.A.; Fritz, S.C.; Silva, C.G.; Rigsby, C.A.; Absy, M.L.; Almeida, R.P.; Caputo, Maria C.; Chiessi, C.M.; Cruz, F.W.; Dick, C.W.; Feakins, S.J.; Figueiredo, J.; Freeman, K.H.; Hoorn, C.; Jaramillo, C.A.; Kern, A.; Latrubesse, E.M.; Ledru, M.P.; Marzoli, A.; Myrbo, A.; Noren, A.; Piller, W.E.; Ramos, M.I.F.; Ribas, C.C.; Trinadade, R.; West, A.J.; Wahnfried, I.; Willard, Debra A.

2015-01-01

This article presents the scientific rationale for an ambitious ICDP drilling project to continuously sample Late Cretaceous to modern sediment in four different sedimentary basins that transect the equatorial Amazon of Brazil, from the Andean foreland to the Atlantic Ocean. The goals of this project are to document the evolution of plant biodiversity in the Amazon forests and to relate biotic diversification to changes in the physical environment, including climate, tectonism, and the surface landscape. These goals require long sedimentary records from each of the major sedimentary basins across the heart of the Brazilian Amazon, which can only be obtained by drilling because of the scarcity of Cenozoic outcrops. The proposed drilling will provide the first long, nearly continuous regional records of the Cenozoic history of the forests, their plant diversity, and the associated changes in climate and environment. It also will address fundamental questions about landscape evolution, including the history of Andean uplift and erosion as recorded in Andean foreland basins and the development of west-to-east hydrologic continuity between the Andes, the Amazon lowlands, and the equatorial Atlantic. Because many modern rivers of the Amazon basin flow along the major axes of the old sedimentary basins, we plan to locate drill sites on the margin of large rivers and to access the targeted drill sites by navigation along these rivers.

Drilling mud

Energy Technology Data Exchange (ETDEWEB)

Rusayev, A A; Bibikov, K V; Simonenkov, I D; Surkova, K I

1982-01-01

Drilling mud is proposed which contains clay, water, water output reducer, pH regulator, viscosity reducer and hydrogen sulfide absorber. In order to improve the absorbing capacity of the drilling mud with pH 8-11 and simultaneously preservation of the technological properties of the mud, it contains as the absorber of hydrogen sulfide pyrite cinders with the following ratio of components, % by mass: clay 5.0-35.0; water output reducer 0.2-2.0; pH regulator 0.05-0.25; viscosity reducer 0.1-1.0; pyrite cinders 0.5-4.0; water--the rest.

Volcanic signals in oceans

KAUST Repository