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Electrical resistivity monitoring of the single heater test in Yucca Mountain

Description: Of the several thermal, mechanical and hydrological measurements being used to monitor the rockmass response in the Single Heater Test, electrical resistance tomography (ERT) is being used to monitor the movement of liquid water with a special interest in the movement of condensate out of the system. Images of resistivity change were calculated using data collected before, during and after the heating episode. This report will concentrate on the results obtained after heating ceased; previous reports discuss the results obtained during the heating phase. The changes recovered show a region of increasing resistivity approximately centered around the heater as the rock mass cooled. The size of this region grows with time and the resistivity increases become stronger. The increases in resistivity are caused by both temperature and saturation changes. The Waxman Smits model has been used to calculate rock saturation after accounting for temperature effects. The saturation estimates suggest that during the heating phase, a region of drying forms around the heater. During the cooling phase, the dry region has remained relatively stable. Wetter rock regions which developed below the heater during the heating phase, are slowly becoming smaller in size during the cooling phase. The last set of images indicate that some rewetting of the dry zone may be occurring. The accuracy of the saturation estimates depends on several factors that are only partly understood.
Date: October 1, 1997
Creator: Ramirez, A.
Partner: UNT Libraries Government Documents Department

Temperature limits based on the saturation temperature in Hanford waste storage tanks

Description: This report calculates limits on the measured temperature readings to limit the occurrence of saturation temperatures in Hanford waste storage tanks. The results in this report show that the temperature reported by a thermocouple tree in a double-shell tank can be significantly below the maximum waste temperature and that provisions should be made for that offset in any tank temperature monitoring program. The results for single-shell tanks show that some tanks may be at or above the saturation temperature.
Date: October 14, 1996
Creator: Bander, T.J.
Partner: UNT Libraries Government Documents Department

Unsaturated Groundwater Flow Beneath Upper Mortandad Canyon, Los Alamos, New Mexico

Description: Mortandad Canyon is a discharge site for treated industrial effluents containing radionuclides and other chemicals at Los Alamos National Laboratory, New Mexico. This study was conducted to develop an understanding of the unsaturated hydrologic behavior below the canyon floor. The main goal of this study was to evaluate the hypothetical performance of the vadose zone above the water table. Numerical simulations of unsaturated groundwater flow at the site were conducted using the Finite Element Heat and Mass Transfer (FEHM) code. A two-dimensional cross-section along the canyon's axis was used to model flow between an alluvial groundwater system and the regional aquifer approximately 300 m below. Using recharge estimated from a water budget developed in 1967, the simulations showed waters from the perched water table reaching the regional aquifer in 13.8 years, much faster than previously thought. Additionally, simulations indicate that saturation is occurring in the Guaje pumice bed an d that the Tshirege Unit 1B is near saturation. Lithologic boundaries between the eight materials play an important role in flow and solute transport within the system. Horizontal flow is shown to occur in three thin zones above capillary barriers; however, vertical flow dominates the system. Other simulations were conducted to examine the effects of changing system parameters such as varying recharge inputs, varying the distribution of recharge, and bypassing fast-path fractured basalt of uncertain extent and properties. System sensitivity was also explored by changing model parameters with respect to size and types of grids and domains, and the presence of dipping stratigraphy.
Date: October 15, 1998
Creator: Dander, D.C.
Partner: UNT Libraries Government Documents Department

Integrated approach towards the application of horizontal wells to improve waterflooding performance. Quarterly report, January 1--March 31, 1997

Description: The overall purpose of the proposed project is to improve secondary recovery performance of a marginal oil field through the use of an appropriate reservoir management plan. The selection of plan will be based on the detailed reservoir description using an integrated approach. The authors expect that 2 to 5% of the original oil in place will be recovered using this method. This should extend the life of the reservoir by at least 10 years. The project is divided into two stages. In Stage 1 of the project, the authors selected part of the Glenn Pool Field-Self Unit. They conducted cross borehole tomography surveys and formation micro scanner logs through a newly drilled well. By combining the state-of-the-art data with conventional core and log data, they developed a detailed reservoir description based on an integrated approach. After conducting extensive reservoir simulation studies, they evaluated alternate reservoir management strategies to improve the reservoir performance including drilling of a horizontal injection well. They observed that selective completion of many wells followed by an increase in the injection rate was the most feasible option to improve the performance of the Self Unit. This management plan is currently being implemented and the performance is being monitored. Stage 2 of the project will involve selection of part of the same reservoir (Berryhill Unit-Tract 7), development of reservoir description using only conventional data, simulation of flow performance using developed reservoir description, selection of an appropriate reservoir management plan, and implementation of the plan followed by monitoring of reservoir performance.
Date: October 1, 1997
Creator: Kelkar, M.; Liner, C. & Kerr, D.
Partner: UNT Libraries Government Documents Department

Improved Efficiency of Miscible CO{sub 2} Floods and Enhanced Prospects for CO{sub 2} Flooding Heterogeneous Reservoirs

Description: This work will examine three major areas in which CO{sub 2} flooding can be improved: fluid and matrix interactions, conformance control/sweep efficiency, and reservoir simulation for improved oil recovery. The first full quarter of this project has been completed. We began examining synergistic affects of mixed surfactant versus single surfactant systems to enhance the properties of foams used for improving oil recovery in CO{sub 2} floods. The purpose is to reduce the concentration of surfactants or finding less expensive surfactants. Also, we are examining the effect of oil saturation on the development of foam in CO{sub 2}-surfactant solution systems. CO{sub 2} flooding of low permeability, vugular, and fracture reservoirs are another major thrust of this project. Work conducted this quarter involved simulating gravity stable floods using large core samples; results showed excellent recovery in a low permeability vugular core.
Date: October 31, 1997
Creator: Guo, Boyun (Gordon); Schechter, David S.; Tsau, Jyun-Syung; Grigg, Reid B. & Chang, Shih-Hsien (Eric)
Partner: UNT Libraries Government Documents Department

Increasing waterflood reserves in the Wilmington Oil Field through improved reservoir characterization and reservoir management. Quarterly progress report, July 1, 1995--September 30, 1995

Description: The objectives of this quarterly report are to summarize the work conducted under each task during the reporting period July-September 1995, and to report all technical data and findings as specified in the {open_quotes}Federal Assistance Reporting Checklist{close_quotes}, The main objective of this project is the transfer of technologies, methodologies, and findings developed and applied in this project to other operators of Slope and Basin Clastic Reservoirs. This project will study methods to identify sands with high remaining oil saturation and to recomplete existing wells using advanced completion technology. The identification of the sands with high remaining oil saturation will be accomplished by developing a deterministic three dimensional (3-D) geologic model and by using a state of the art reservoir management computer software. The wells identified by the geologic and reservoir engineering work as having the best potential will be logged with a pulsed acoustic cased-hole logging tool. The application of the logging tools will be optimized in the lab by developing a rock-log model. The wells that are shown to have the best oil production potential will be recompleted. The recompletions will be optimized by evaluating short radius and ultra-short radius lateral recompletions.
Date: October 30, 1995
Creator: Sullivan, D.; Clarke, D. & Walker, S.
Partner: UNT Libraries Government Documents Department

Analysis of Breakthrough Profiles Based on Gamma Ray Emission Along Loaded Packed Bed Columns: Comparative Evaluation of Ionsiv IE-911 and Chabazite Zeolite for the Removal of Radiostrontium and Cesium from Groundwater

Description: A gamma counting system has been assembled that can profile the breakthrough fronts of gamma-emitting radioisotopes longitudinally and axially along a loaded column. This profiling technique has been particularly useful in columns studies such as those performed with IONSP IE-911, a crystalline silicotitanate (CST) manufactured by UOP, in which unusually long operating times are required to observe cesium breakthrough in column effluent. The length of the mass transfer zone and extent of column saturation can be detected early in a column study by viewing the relative emission of gamma emitters along I the length of the column. In this study, gamma scans were used to analyze loaded CST and zeolite columns used in the treatment of process wastewater simulant and actual groundwater. Results indicate good run-to-run reproductibility in acquiring the scans. The longitudinal gamma scans for both {sup 90}Sr and {sup 137}Cs conformed with breakthrough results reported on the basis of column effluent activity. Although not obvious from data obtained by monitoring effluent activity, the gamma scans indicated that both cesium and strontium in the saturated zone of the CST column are slowly displaced by the higher levels of groundwater cations and are then resorbed further down the column. This displacement phenomenon identified by gamma scans was verified using data from a zeolite column, in which both the gamma scan and column effluent data exhibited radionuclide displacement by groundwater cations. The gamma emission intensities from the CST column runs are used to quantitate and compare the distribution coefficient and loading capacity of {sup 137}Cs on CST versus zeolite.
Date: October 18, 1999
Creator: Bostick, D.T.; DePaoli, S.M. & Lucero, A.J.
Partner: UNT Libraries Government Documents Department

Well log evaluation of natural gas hydrates

Description: Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question linking gas hydrate resource and hazard issues is: What is the volume of gas hydrates and included gas within a given gas hydrate occurrence Most published gas hydrate resource estimates have, of necessity, been made by broad extrapolation of only general knowledge of local geologic conditions. Gas volumes that may be attributed to gas hydrates are dependent on a number of reservoir parameters, including the areal extent ofthe gas-hydrate occurrence, reservoir thickness, hydrate number, reservoir porosity, and the degree of gas-hydrate saturation. Two of the most difficult reservoir parameters to determine are porosity and degreeof gas hydrate saturation. Well logs often serve as a source of porosity and hydrocarbon saturation data; however, well-log calculations within gas-hydrate-bearing intervals are subject to error. The primary reason for this difficulty is the lack of quantitative laboratory and field studies. The primary purpose of this paper is to review the response of well logs to the presence of gas hydrates.
Date: October 1, 1992
Creator: Collett, T.S.
Partner: UNT Libraries Government Documents Department

Laboratory setup and results of experiments on two-dimensional multiphase flow in porous media

Description: In the event of an accidental release into earth's subsurface of an immiscible organic liquid, such as a petroleum hydrocarbon or chlorinated organic solvent, the spatial and temporal distribution of the organic liquid is of great interest when considering efforts to prevent groundwater contamination or restore contaminated groundwater. An accurate prediction of immiscible organic liquid migration requires the incorporation of relevant physical principles in models of multiphase flow in porous media; these physical principles must be determined from physical experiments. This report presents a series of such experiments performed during the 1970s at the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. The experiments were designed to study the transient, two-dimensional displacement of three immiscible fluids in a porous medium. This experimental study appears to be the most detailed published to date. The data obtained from these experiments are suitable for the validation and test calibration of multiphase flow codes. 73 refs., 140 figs.
Date: October 1, 1990
Creator: McBride, J.F. (ed.) (Pacific Northwest Lab., Richland, WA (USA)); Graham, D.N. (ed.) & Schiegg, H.O. (SIMULTEC Ltd., Meilen/Zurich (Switzerland))
Partner: UNT Libraries Government Documents Department

Potential for Waste Stratification from Back-Dilution in Tank 241-SY-101

Description: Since late 1997, the floating crust layer in Hanford Tank 241-SY-101 (SY-101) has grown about two meters by gas accumulation. To reverse crust growth and reduce its retained gas volume, the waste in SY-101 will be diluted by transferring at least 300,000 gal of waste out of the tank and replacing it with water. In the fall of 1999, approximately 100,000 gal of this waste will be transferred into Tank SY-102; within a few days of that initial transfer, approximately 100,000 gal of water will be added to SY-101. This initial back-dilution is being planned to ensure that the base of the floating crust layer will be lifted away from the mixer pump inlet with minimal effect on the crust itself. The concern is that the added water will pool under the crust, so the resulting fluid mixture will be too light to lift the crust away from the mixer pump and dissolution at the crust base could cause unwanted gas release. To ensure sufficient mixing to prevent such stratification, water will be added near the tank bottom either through an existing sparge ring on the base of the mixer pump or through the dilution line at the inlet of the transfer pump. A number of simulations using the TEMPEST code showed that the mixing of the water and waste by this method is rapid, and the water does not pool under the crust. Although a density gradient is present, its magnitude is small compared with the difference between the slurry and water density. The result is essentially the same whether water is introduced at the base of the mixer pump or at the transfer pump. There is little effect of water flowrate up to the 500 gpm studied. In all cases, the minimum density remained above that required to ...
Date: October 20, 1999
Creator: Antoniak, Z.I. & Meyer, P.A.
Partner: UNT Libraries Government Documents Department

Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems - Revison 1.

Description: This report presents a revision of the procedure and correlations presented earlier in NUREG/CR-4513, ANL-90/42 (June 1991) for predicting the change in mechanical properties of cast stainless steel components due to thermal aging during service in light water reactors at 280-330 C (535-625 F). The correlations presented in this report are based on an expanded data base and have been optimized with mechanical-property data on cast stainless steels aged up to {approx}58,000 h at 290-350 C (554-633 F). The correlations for estimating the change in tensile stress, including the Ramberg/Osgood parameters for strain hardening, are also described. The fracture toughness J-R curve, tensile stress, and Charpy-impact energy of aged cast stainless steels are estimated from known material information. Mechanical properties of a specific cast stainless steel are estimated from the extent and kinetics of thermal embrittlement. Embrittlement of cast stainless steels is characterized in terms of room-temperature Charpy-impact energy. The extent or degree of thermal embrittlement at 'saturation,' i.e., the minimum impact energy that can be achieved for a material after long-term aging, is determined from the chemical composition of the steel. Charpy-impact energy as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which are also determined from the chemical composition. The initial impact energy of the unaged steel is required for these estimations. Initial tensile flow stress is needed for estimating the flow stress of the aged material. The fracture toughness J-R curve for the material is then obtained by correlating room-temperature Charpy-impact energy with fracture toughness parameters. The values of JIC are determined from the estimated J-R curve and flow stress. A common 'predicted lower-bound' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, range of ferrite content, and ...
Date: October 5, 1994
Creator: Chopra, O. K. & Technology, Energy
Partner: UNT Libraries Government Documents Department

Oxidation and Volatilization of TZM Alloy in Air

Description: The excellent high temperature strength and thermal conductivity of molybdenum-base alloys provide attractive features for components in advanced magnetic and inertial fusion devices. Refractory metal base alloys react readily with oxygen and other gases, and molybdenum alloys are susceptible to losses from highly volatile molybdenum trioxide (MoOsub3) species. Transport of radioactivity by the volatilization, migration, and re-deposition of MoO3 during a potential accident involving a loss of vacuum or inert environment represents a safety issue. We have experimentally measured the oxidation, volatilization and re-deposition of molybdenum from TZM in flowing air between 400 and 800°C. Calculations using chemical thermodynamic data for vapor pressures over pure MoOsub3 and a vaporization mass transfer model correlate well with experimental data between 600 and 800°C. Partial saturation of (MoOsub3) gas species account for influences of flow rate at 700°C. Some anomalies in oxidation rate below 650°C, suggesting that other phases, e.g., MoOsub2 or other non-stoichiometric oxides may influence oxidation and volatilization processes under some limited conditions.
Date: October 1, 1999
Creator: Smolik, Galen Richard; Petti, David Andrew & Schuetz, Stanley Thomas
Partner: UNT Libraries Government Documents Department

SCDAP/RELAP5 Modeling of Movement of Melted Material through Porous Debris in Lower Head (Rev. 2)

Description: A model is described for the movement of melted metallic material through a ceramic porous debris bed. The model is designed for the analysis of severe accidents in LWRs, wherein melted core plate material may slump onto the top of a porous bed of relocated core material supported by the lower head. The permeation of the melted core plate material into the porous debris bed influences the heatup of the debris bed and the heatup of the lower head supporting the debris. A model for mass transport of melted metallic material is applied that includes terms for viscosity and turbulence but neglects inertial and capillary terms because of their small value relative to gravity and viscous terms in the momentum equation. The relative permeability and passability of the porous debris are calculated as functions of debris porosity, particle size, and effective saturation. An iterative numerical solution is used to solve the set of nonlinear equations for mass transport. The effective thermal conductivity of the debris is calculated as a function of porosity, particle size, and saturation. The model integrates the equations for mass transport with a model for the two-dimensional conduction of heat through porous debris. The integrated model has been implemented into the SCDAP/RELAP5 code for the analysis of the integrity of LWR lower heads during severe accidents. The results of the model indicate that melted core plate material my permeate in about 120 s to the bottom of a 1 m deep hot porous debris bed supported by the lower head. The presence of the relocated core plate material at the bottom of the debris bed decreases the thermal resistance of the interface between the debris bed and the lower head. This report is a revision of the report with the identifier of INEEL/EXT-98-01178 REV 1, entitled "SCDAP/RELAP5 ...
Date: October 1, 1999
Creator: Siefken, Larry James
Partner: UNT Libraries Government Documents Department

Revitalizing a mature oil play: Strategies for finding and producing unrecovered oil in Frio fluvial-deltaic reservoirs of South Texas. Technical progress report, July 1--September 30, 1995

Description: Advanced reservoir characterization techniques are being applied to selected reservoirs in the Frio fluvial-deltaic sandstone trend in order to maximize the economic producibility of resources in this mature oil play. More than half of the reservoirs in this play have already been abandoned, and large volumes of oil may remain unproduced unless advanced characterization techniques are applied to define untapped, incompletely drained, and new pool reservoirs as suitable targets for near-term recovery methods. This project is developing interwell-scale geological facies models and assessing engineering attributes of reservoirs in selected fields in order to characterize reservoir architecture, flow unit boundaries, and the controls that these characteristics exert on the location and volume of unrecovered mobile and residual oil. Phase 1 consisted of reservoir selection and initial framework characterization. Phase 2 involved advanced characterization to delineate incremental resource opportunities. Subtasks included volumetric assessments of untapped and incompletely drained oil along with an analysis of specific targets for recompletion and strategic infill drilling. The third phase of the project consists of documentation of Phase 2 results, technology transfer, and the extrapolation of specific results from reservoirs in this study to other heterogeneous fluvial-deltaic reservoirs within and beyond the Frio play in South Texas. Project work during this quarter consisted of (1) documentation of Phase 2 tasks associated with the delineation of untapped and incompletely drained reservoir compartments and new pool reservoirs in selected Frio fluvial-deltaic sandstone intervals in Rincon and Tijerina-Canales-Blucher fields, as well as (2) Phase 3 tasks related to the transfer of the technologies to industry that aided in delineation.
Date: October 10, 1995
Creator: Tyler, N. & Levey, R.A.
Partner: UNT Libraries Government Documents Department

Productivity and injectivity of horizontal wells. Annual report, March 10, 1993--March 9, 1994

Description: In this report, the investigators review a range of reservoir scenarios in which horizontal wells can be advantageous and discuss some of the modeling problems associated with calculating well connection factors, productivity indices, coning behavior and well two-phase pressure drops. We show illustrative coning calculations and the implications of the well model on distribution of post-breakthrough gas saturations. Such calculations then open up the possibility of determining optimal recompletion strategies and/or additional hydraulic fracturing.
Date: October 1, 1994
Creator: Fayers, F. J.; Aziz, K.; Hewett, T. A. & Arbabi, S.
Partner: UNT Libraries Government Documents Department

Well log evaluation of natural gas hydrates

Description: Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question linking gas hydrate resource and hazard issues is: What is the volume of gas hydrates and included gas within a given gas hydrate occurrence? Most published gas hydrate resource estimates have, of necessity, been made by broad extrapolation of only general knowledge of local geologic conditions. Gas volumes that may be attributed to gas hydrates are dependent on a number of reservoir parameters, including the areal extent ofthe gas-hydrate occurrence, reservoir thickness, hydrate number, reservoir porosity, and the degree of gas-hydrate saturation. Two of the most difficult reservoir parameters to determine are porosity and degreeof gas hydrate saturation. Well logs often serve as a source of porosity and hydrocarbon saturation data; however, well-log calculations within gas-hydrate-bearing intervals are subject to error. The primary reason for this difficulty is the lack of quantitative laboratory and field studies. The primary purpose of this paper is to review the response of well logs to the presence of gas hydrates.
Date: October 1, 1992
Creator: Collett, T. S.
Partner: UNT Libraries Government Documents Department