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Fiscal Year 1998 Well Installation, Plugging and Abandonment, and Redevelopment summary report Y-12 Plant, Oak Ridge, Tennessee

Description: This report summarizes the well installation, plugging and abandonment, and redevelopment activities conducted during the federal fiscal year (FY) 1998 at the Y-12 Plant, Oak Ridge, Tennessee. Five new groundwater monitoring wells were installed at the Y-12 Plant under the FY 1998 drilling program. Two of the wells are located in west Bear Creek Valley, one is in the eastern Y-12 Plant area near Lake Reality, and two are located near the Oil Landfarm Waste Management Area, which were installed by Bechtel Jacobs Company LLC (Bechtel Jacobs) as part of a site characterization activity for the Oak Ridge Reservation (ORR) Disposal Cell. Also, two existing wells were upgraded and nine temporary piezometers were installed to characterize hydrogeologic conditions at the Disposal Cell site. In addition, 40 temporary piezometers were installed in the Boneyard/Bumyard area of Bear Creek Valley by Bechtel Jacobs as part of the accelerated remedial actions conducted by the Environmental Restoration Program. Ten monitoring wells at the Y-12 Plant were decommissioned in FY 1998. Two existing monitoring wells were redeveloped during FY 1998 (of these, GW-732 was redeveloped tsvice). All well installation and development (including redevelopment) was conducted following industry-standard methods and approved procedures from the Environmental Surveillance Procedures Quality Control Program (Energy Systems 1988); the Resource Conservation and Recovery Act (RCRA) Groundwater Monitoring Technical Enforcement Guidance Document (EPA 1992); and the Monitoring Well Installation Plan for the Department of Energy Y-12 Plant, Oak Ridge, Tennessee (Energy Systems 1997a). Well installation and development of the non-Y-12 Plant GWPP oversight installation projects were conducted using procedures/guidance defined in the following documents: Work Plan for Support to Upper East Fork Poplar Creek East End Volatile Organic Compound Plumes Well Installation Project, Oak Ridge Y-12 Plant, Oak Ridge, Tennessee (SAIC 1998a); Sampling and Analysis Plan for the Oil Landfarm Soils Containment ...
Date: December 1, 1998
Partner: UNT Libraries Government Documents Department

Oil Well Remediation in Clay and Wayne Counties, IL

Description: This is the second progress and final technical report of the remediation of abandoned wells in Clay and Wayne Counties in Illinois. The wells will be identified as the Routt No.3 and No.4 and the Bates Hosselton 1 and 2. Both sites have met all legal, financial and environmental requirements to drill and/or pump oil on both leases. We have also obtained all available information about both leases. All steps were taken to improve access roads, dig the necessary pits, and build the necessary firewalls. This progress and final technical report will address the remediation efforts as well as our results and conclusions.
Date: July 9, 2003
Creator: Dakuras, Peter L.; Stieber, Larry & Young, Dick
Partner: UNT Libraries Government Documents Department

Fiscal Year 1993 Well Plugging and Abandonment Program Summary Report Y-12 Plant, Oak Ridge, Tennessee

Description: This report is a synopsis of the progress of the well plugging and abandonment program at the Y-12 Plant, Oak Ridge, Tennessee, from October 1993 through August 1994. A total of 57 wells and borings were plugged and abandoned during the period of time covered in this report. All wells and borings were plugged and abandoned in accordance with the Monitoring Well Plugging and Abandonment Plan for the U.S. Department of Energy, Y-12 Plant, Oak Ridge, Tennessee.
Date: September 1, 1994
Partner: UNT Libraries Government Documents Department

Final sitewide environmental assessment for preparation for transfer of ownership of Naval Petroleum Reserve No. 3 (NPR-3), Natrona County, Wyoming

Description: The Secretary of Energy is authorized to produce the Naval Petroleum Reserves No. 3 (NPR-3) at its maximum efficient rate (MER) consistent with sound engineering practices, for a period extending to April 5, 2000 subject to extension. Production at NPR-3 peaked in 1981 and has declined since until it has become a mature stripper field, with the average well yielding less than 2 barrels per day. The Department of Energy (DOE) has decided to discontinue Federal operation of NPR-3 at the end of its life as an economically viable oilfield currently estimated to be 2003. Although changes in oil and gas markets or shifts in national policy could alter the economic limit of NPR-3, it productive life will be determined largely by a small and declining reserve base. DOE is proposing certain activities over the next six years in anticipation of the possible transfer of NPR-3 out of Federal operation. These activities would include the accelerated plugging and abandoning of uneconomic wells, complete reclamation and restoration of abandoned sites including dismantling surface facilities, batteries, roads, test satellites, electrical distribution systems and associated power poles, when they are no longer needed for production, and the continued development of the Rocky Mountain Oilfield Testing Center (RMOTC). DOE has prepared this environmental assessment that analyzes the proposed plugging and abandonment of wells, field restoration and development of RMOTC. Based on the analysis in the EA, the DOE finds that the proposed action is not a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act of 1969 (NEPA). The preparation of an environmental impact statement is not required, and DOE is issuing this Finding of No Significant Impact (FONSI).
Date: April 1, 1998
Partner: UNT Libraries Government Documents Department

Numerical Modeling Studies of The Dissolution-Diffusion-Convection ProcessDuring CO2 Storage in Saline Aquifers

Description: For purposes of geologic storage, CO2 would be injected into saline formations at supercritical temperature and pressure conditions, and would form a separate phase that is immiscible with the aqueous phase (brine). At typical subsurface temperature and pressure conditions, supercritical CO2 (scCO2) has lower density than the aqueous phase and would experience an upward buoyancy force. Accordingly, the CO2 is expected to accumulate beneath the caprock at the top of the permeable interval, and could escape from the storage formation wherever (sub-)vertical pathways are available, such as fractures or faults through the caprock, or improperly abandoned wells. Over time, an increasing fraction of CO2 may dissolve in the aqueous phase, and eventually some of the aqueous CO2 may react with rock minerals to form poorly soluble carbonates. Dissolution into the aqueous phase and eventual sequestration as carbonates are highly desirable processes as they would increase permanence and security of storage. Dissolution of CO2 will establish phase equilibrium locally between the overlying CO2 plume and the aqueous phase beneath. If the aqueous phase were immobile, CO2 dissolution would be limited by the rate at which molecular diffusion can remove dissolved CO2 from the interface between CO2-rich and aqueous phases. This is a slow process. However, dissolution of CO2 is accompanied by a small increase in the density of the aqueous phase, creating a negative buoyancy force that can give rise to downward convection of CO2-rich brine, which in turn can greatly accelerate CO2 dissolution. This study explores the process of dissolution-diffusion-convection (DDC), using high-resolution numerical simulation. We find that geometric features of convection patterns are very sensitive to small changes in problem specifications, reflecting self-enhancing feedbacks and the chaotic nature of the process. Total CO2 dissolution rates on the other hand are found to be quite robust against modest changes in ...
Date: November 17, 2008
Creator: Pruess, Karsten & Zhang, Keni
Partner: UNT Libraries Government Documents Department

A Comparative Review of Hydrologic Issues Involved in Geologic Storage of CO2 and Injection Disposal of Liquid Waste

Description: The paper presents a comparison of hydrologic issues and technical approaches used in deep-well injection and disposal of liquid wastes, and those issues and approaches associated with injection and storage of CO{sub 2} in deep brine formations. These comparisons have been discussed in nine areas: (1) Injection well integrity; (2) Abandoned well problems; (3) Buoyancy effects; (4) Multiphase flow effects; (5) Heterogeneity and flow channeling; (6) Multilayer isolation effects; (7) Caprock effectiveness and hydrogeomechanics; (8) Site characterization and monitoring; and (9) Effects of CO{sub 2} storage on groundwater resources There are considerable similarities, as well as significant differences. Scientifically and technically, these two fields can learn much from each other. The discussions presented in this paper should help to focus on the key scientific issues facing deep injection of fluids. A substantial but by no means exhaustive reference list has been provided for further studies into the subject.
Date: April 15, 2008
Creator: Tsang, C.-F.; Birkholzer, J. & Rutqvist, J.
Partner: UNT Libraries Government Documents Department

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

Description: The field operator, Goldrus Producing Company, has been unable to secure funding needed to continue the field demonstration phase of the project. Accordingly, we have temporarily halted all project activities until necessary funding is obtained. Goldrus is confident that funds can be acquired by third quarter 2005 at which time it will be necessary to request a project extension to complete the originally designed study.
Date: March 31, 2005
Creator: Loucks, Robert & Ruppel, Stephen C.
Partner: UNT Libraries Government Documents Department

REVIVING ABANDONED RESERVOIRS WITH HIGH-PRESSURE AIR INJECTION: APPLICATION IN A FRACTURED AND KARSTED DOLOMITE RESERVOIR

Description: The field operator, Goldrus Producing Company, has been unable to secure funding needed to continue the field demonstration phase of the project. Accordingly, we have temporarily halted all project activities until necessary funding is obtained. Goldrus felt confident that funds could be acquired by third quarter 2005 at which time it would have been necessary to request a project extension to complete the originally designed study. A project extension was granted but it appears Goldrus will have difficulty securing funds. We Bureau of Economic Geology are investigating a new approach on how to fulfill our initial objectives of promoting high-pressure air injection of Ellenburger reservoirs.
Date: February 1, 2006
Creator: Loucks, Robert & Ruppel, Stephen C.
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. [Quarterly] technical progress report, April 1, 1995--June 30, 1995

Description: Advanced reservoir characterization techniques are being applied to selected reservoirs in the Frio Fluvial-Deltaic Sandstone (Vicksburg Fault Zone) trend of South Texas in order to maximize the economic producibility of resources in this mature oil play. More than half of the reservoirs in this depositionally complex 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 Frio fluvial-deltaic 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. The results of these studies will lead directly to the identification of specific opportunities to exploit these heterogeneous reservoirs for incremental recovery by recompletion and strategic infill drilling. Project work during the second quarter of 1995 consisted of (1) documentation of Phase II 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 (T-C-B) fields, as well as (2) tasks related to the transfer of the technologies to industry that aided in delineation. Text and figures have been prepared to support the geological-based compartment architecture and petrophysical analysis is being undertaken to provide a volumetric assessment of remaining resources and recoverable reserves. Petrophysical work during this period has focused on Rincon field reservoirs because of the availability of core material for special core analysis.
Date: June 30, 1995
Creator: Tyler, N. & Levey, R.A.
Partner: UNT Libraries Government Documents Department

ENVIRONMENTAL ASSESSMENT OF OKLAHOMA ABANDONED DRILLING AND PRODUCTION SITES AND ASSOCIATED PUBLIC EDUCATION/OUTREACH ACTIVITIES

Description: The U.S. Department of Energy has participated with the Oklahoma Energy Resource Board (OERB) since 1995 by providing grant funding for on-going work in both environmental assessment of abandoned oilfield exploration and production sites and associated public education/outreach activities. The OERB, a state agency created in 1993 by the Oklahoma legislature, administers programs funded by an assessment of one tenth of one percent on all oil and natural gas produced and sold in the state of Oklahoma. Approximately one half of the funds are used to assess and remediate abandoned oilfield sites and the other half are being used to educate about the importance of the oil and natural gas industry and OERB's environmental efforts. Financial participation through grant funding by the U.S. D.O.E. has been $200,000 annually which represents approximately 3 percent of OERB's private funding. Most of OERB's revenues come from an assessment of 1/10th of 1% on the sale of crude and natural gas in Oklahoma. The assessment is considered voluntary in that any interest owner may ask for a refund annually of their contributions to the fund. On average, 95% of the assessment dollars have remained with OERB, which shows tremendous support by the industry. This Final Report summarizes the progress of the three year grant. The purpose of this three-year project was to continue the progress of the OERB to accomplish its environmental and educational objectives and transfer information learned to other organizations and producing states in the industry.
Date: March 1, 2002
Creator: Terry, Mike
Partner: UNT Libraries Government Documents Department

Hanford well custodians. Revision 1

Description: The Hanford Site Groundwater Protection Management Program recognized the need to integrate monitoring well activities in a centralized manner. A key factor to Hanford Site well integration was the need to clearly identify a responsible party for each of the wells. WHC was asked to identify all wells on site, the program(s) using each well, and the program ultimately responsible for the well. This report lists the custodian and user(s) for each Hanford well and supplies a comprehensive list of all decommissioned and orphaned wells on the Hanford Site. This is the first update to the original report released in December 1993.
Date: February 2, 1995
Creator: Schatz, A.L. & Underwood, D.J.
Partner: UNT Libraries Government Documents Department

Reservoir class field demonstration. Publication and presentation bibliography

Description: The Reservoir Class Field Demonstration Program was initiated in FY92 in response to rapidly declining domestic production and the realization that huge volumes of oil are being abandoned in reservoirs because of uneconomic production techniques. This program is just one of the critical elements of the National Oil Program necessary to move Improved Oil Recovery (IOR) technology from the conceptual stage through research, pilot scale field experiments, and full-scale field demonstrations to industry acceptance and commercialization. Both the successful results and failures of the field demonstrations will provide focus to concurrent research programs. Elements of the field demonstrations that are suitable for broad industry application are being communicated to the industry through the oil program`s technology transfer effort. As part of the technology transfer effort, this listing of publications and presentations by the project operators has been compiled by the US Department of energy`s (DOE) National Petroleum Technology Office (NPTO). The bibliography contains 240 citations for publications and a similar number of citations for presentations.
Date: December 1997
Partner: UNT Libraries Government Documents Department

An Investigation of the Integrity of Cemented Casing Seals with Application to Salt Cavern Sealing and Abandonment

Description: This research project was pursued in three key areas. (1) Salt permeability testing under complex stress states; (2) Hydraulic and mechanical integrity investigations of the well casing shoe through benchscale testing; and (3) Geomechanical modeling of the fluid/salt hydraulic and mechanical interaction of a sealed cavern.
Date: April 19, 2001
Creator: Pfeifle, T.W.; Mellegard, K.D.; Skaug, N.T. & Bruno, M.S.
Partner: UNT Libraries Government Documents Department

Environmental Assessment of Oklahoma abandoned drilling and production sites and associated public education/outreach activities. Quarterly technical progress report, February 8, 1995--March 30, 1995. First quarter of 1995

Description: The purpose of this project was to conduct environmental assessments of abandoned oil and gas drilling sites where no responsible owner can be found and transfer environmental technology to oil and gas operators; and provide a comprehensive public education program concerned with the oil and gas industries.
Date: April 27, 1995
Creator: Terry, M.
Partner: UNT Libraries Government Documents Department

Assist in the recovery of bypassed oil from reservoirs in the Gulf of Mexico. Quarterly report, April 1, 1995--June 31, 1995

Description: Objective is to assist the recovery of remaining noncontacted oil from known reservoirs/abandoned offshore wells on the Outer Continental Shelf in the Gulf of Mexico. Progress continues for reducing the data to fit a simplified model and redescribing the resource to accommodate known production behavior and geologic assumptions. Final reports are currently being prepared.
Date: July 30, 1995
Creator: Schenewerk, P.A.
Partner: UNT Libraries Government Documents Department

Chemicals, metals, and pesticide pits waste unit low induction number electromagnetic survey

Description: An electromagnetic survey was conducted at the Chemicals, Metals, and Pesticide Waste Unit to identify any buried metallic objects that may be present in the materials used to fill and cover the pits after removal of pit debris. The survey was conducted with a Geonics EM-31 Terrain Conductivity Meter along north - south oriented traverses with 5-ft station intervals to produce a 5-ft by 5-ft square grid node pattern. Both conductivity and in-phase components were measured at each station for vertical dipole orientation with the common axis of the dipoles in the north - south and east - west orientations. The conductivity data clearly show elevated conductivities (2.1 to 7.0 mS/m) associated with the material over the pits, as compared with the surrounding area that is characterized by lower conductivities (1 to 2 mS/m). This is probably the result of the higher clay content of the fill material relative to the surrounding area, which has a higher sand to clay ratio and the presence of a plastic cover beneath the fill that has probably trapped water. Many metal objects are present in the survey area including manhole covers, monitoring well heads, metal, signs, drain culverts, abandoned wells, and BP waste unit marker balls. AU of these exhibit associated conductivity and in-phase anomalies of various magnitude. In addition to these anomalies that can be definitely associated with surface sources, conductivity and in-phase anomalies are also present with no obvious surface source. These anomalies are probably indicative of subsurface buried metallic objects. A high concentration of these objects appears to be present in the southwest corner of the survey area.
Date: June 1, 1995
Creator: Cumbest, R.J. & Mohon, D.
Partner: UNT Libraries Government Documents Department

Multiphase Flow and Cavern Abandonment in Salt

Description: This report will explore the hypothesis that an underground cavity in gassy salt will eventually be gas filled as is observed on a small scale in some naturally occurring salt inclusions. First, a summary is presented on what is known about gas occurrences, flow mechanisms, and cavern behavior after abandonment. Then, background information is synthesized into theory on how gas can fill a cavern and simultaneously displace cavern fluids into the surrounding salt. Lastly, two-phase (gas and brine) flow visualization experiments are presented that demonstrate some of the associated flow mechanisms and support the theory and hypothesis that a cavity in salt can become gas filled after plugging and abandonment
Date: February 13, 2001
Creator: Ehgartner, Brian & Tidwell, Vince
Partner: UNT Libraries Government Documents Department

An evaluation of known remaining oil resources in the state of Kansas: Project on advanced oil recovery and the states. Volume 4

Description: The Interstate Oil and Gas Compact Commission (IOGCC) has conducted a series of studies to evaluate the known, remaining oil resource in twenty-three (23) states. The primary objective of die IOGCC`s effort is to examine the potential impact of an aggressive and focused program of research, development, and demonstration (RD&D) and technology transfer on future oil recovery in the United States. As part of a larger effort by the IOGCC, this report focuses on the potential economic benefits of improved oil recovery in the state of Kansas. Individual reports for seven other oil producing states and a national report have been separately published by the IOGCC. Several major technical insights for state and Federal policymakers and regulators can be reached from this analysis. Overall, well abandonments and more stringent environmental regulations could limit economic access to the nation`s known, remaining oil resource. The high risk of near-term abandonment and the significant benefits of future application of improved oil recovery technoloy, clearly point to a need for more aggressive transfer of currently available technologies to domestic oil producers. Development and application of advanced oil recovery technologies could leave even greater benefits to the nation. A collaborative, focused RD&D effort, integrating the resources and expertise of industry, state and local governments, and the Federal government, is clearly warranted. With effective RD&D and a program of aggressive technology transfer to widely disseminate its results, Kansas oil production could be maximized. The resulting increase in production rates, employment, operator profits, state and Federal tax revenues, energy security will benefit the state of Kansas and the nation as a whole.
Date: November 1, 1993
Partner: UNT Libraries Government Documents Department

Revitalizing a mature oil play: Strategies for finding and producing unrecovered oil in Frio Fluvial-Deltaic Sandstone Reservoirs of South Texas

Description: The Frio Fluvial-Deltaic Sandstone Play of South Texas is one example of a mature play where reservoirs are being abandoned at high rates, potentially leaving behind significant unrecovered resources in untapped and incompletely drained reservoirs. Nearly 1 billion barrels of oil have been produced from Frio reservoirs since the 1940`s, yet more than 1.6 BSTB of unrecovered mobile oil is estimated to remain in the play. Frio reservoirs of the South Texas Gulf Coast are being studied to better characterize interwell stratigraphic heterogeneity in fluvial-deltaic depositional systems and determine controls on locations and volumes of unrecovered oil. Engineering data from fields throughout the play trend were evaluated to characterize variability exhibited by these heterogeneous reservoirs and were used as the basis for resource calculations to demonstrate a large additional oil potential remaining within the play. Study areas within two separate fields have been selected in which to apply advanced reservoir characterization techniques. Stratigraphic log correlations, reservoir mapping, core analyses, and evaluation of production data from each field study area have been used to characterize reservoir variability present within a single field. Differences in sandstone depositional styles and production behavior were assessed to identify zones with significant stratigraphic heterogeneity and a high potential for containing unproduced oil. Detailed studies of selected reservoir zones within these two fields are currently in progress.
Date: July 1, 1995
Creator: McRae, L.E.; Holtz, M.H. & Knox, P.R.
Partner: UNT Libraries Government Documents Department

An evaluation of known remaining oil resources in the state of Louisiana: Project on advanced oil recovery and the states. Volume 5

Description: The Interstate Oil and Gas Compact Commission (IOGCC) has conducted a series of studies to evaluate the known, remaining oil resource in twenty-three (23) states. The primary objective of die IOGCC`s effort is to examine the potential impact of an aggressive and focused program of research, development, and demonstration (RD&D) and technology transfer on future oil recovery in the United States. As part of a larger effort by the IOGCC, this report focuses on the potential economic benefits of improved oil recovery in the state of Louisiana. Individual reports for seven other oil producing states and a national report have been separately published by the IOGCC. Several major technical insights for state and Federal policymakers and regulators can be reached from this analysis. Overall, well abandonments and more stringent environmental regulations could limit economic access to the nation`s known, remaining oil resource. The high risk of near-term abandonment and the significant benefits of future application of improved oil recovery technoloy, clearly point to a need for more aggressive transfer of currently available technologies to domestic oil producers. Development and application of advanced oil recovery technologies could leave even greater benefits to the nation. A collaborative, focused RD&D effort, integrating the resources and expertise of industry, state and local governments, and the Federal government, is clearly warranted. With effective RD&D and a program of aggressive technology transfer to widely disseminate its results, Louisiana oil production could be maximized. The resulting increase and improvement in production rates, employment, operator profits, state and Federal tax revenues, energy security will benefit both the state of Louisiana and the nation as a whole.
Date: November 1, 1993
Partner: UNT Libraries Government Documents Department

An evaluation of known remaining oil resources in the state of New Mexico: Project on advanced oil recovery and the states. Volume 6

Description: The Interstate Oil and Gas Compact Commission (IOGCC) has conducted a series of studies to evaluate the known, remaining oil resource in twenty-three (23) states. The primary objective of die IOGCC`s effort is to examine the potential impact of an aggressive and focused program of research, development, and demonstration (RD&D) and technology transfer on future oil recovery in the United States. As part of a larger effort by the IOGCC, this report focuses on the potential economic benefits of improved oil recovery in the state of New Mexico. Individual reports for seven other oil producing states and a national report have been separately published by the IOGCC. Several major technical insights for state and Federal policymakers and regulators can be reached from this analysis. Overall, well abandonments and more stringent environmental regulations could limit economic access to New Mexico`s known, remaining oil resource. The high risk of near-term abandonment and the significant benefits of future application of improved oil recovery technoloy, clearly point to a need for more aggressive transfer of currently available technologies to domestic oil producers. Development and application of advanced oil recovery technologies could leave even greater benefits to the nation. A collaborative, focused RD&D effort, integrating the resources and expertise of industry, state and local governments, and the Federal government, is clearly warranted. With effective RD&D and a program of aggressive technology transfer to widely disseminate its results, New Mexico oil production could be maximized. The resulting increase and improvement in production rates, employment, operator profits, state and Federal tax revenues, energy security will benefit both the state of New Mexico and the nation as a whole.
Date: November 1, 1993
Partner: UNT Libraries Government Documents Department

Buoyancy effects on upward brine displacement caused by CO2 injection

Description: Upward displacement of brine from deep reservoirs driven by pressure increases resulting from CO{sub 2} injection for geologic carbon sequestration may occur through improperly sealed abandoned wells, through permeable faults, or through permeable channels between pinch-outs of shale formations. The concern about upward brine flow is that, upon intrusion into aquifers containing groundwater resources, the brine may degrade groundwater. Because both salinity and temperature increase with depth in sedimentary basins, upward displacement of brine involves lifting fluid that is saline but also warm into shallower regions that contain fresher, cooler water. We have carried out dynamic simulations using TOUGH2/EOS7 of upward displacement of warm, salty water into cooler, fresher aquifers in a highly idealized two-dimensional model consisting of a vertical conduit (representing a well or permeable fault) connecting a deep and a shallow reservoir. Our simulations show that for small pressure increases and/or high-salinity-gradient cases, brine is pushed up the conduit to a new static steady-state equilibrium. On the other hand, if the pressure rise is large enough that brine is pushed up the conduit and into the overlying upper aquifer, flow may be sustained if the dense brine is allowed to spread laterally. In this scenario, dense brine only contacts the lower-most region of the upper aquifer. In a hypothetical case in which strong cooling of the dense brine occurs in the upper reservoir, the brine becomes sufficiently dense that it flows back down into the deeper reservoir from where it came. The brine then heats again in the lower aquifer and moves back up the conduit to repeat the cycle. Parameter studies delineate steady-state (static) and oscillatory solutions and reveal the character and period of oscillatory solutions. Such oscillatory solutions are mostly a curiosity rather than an expected natural phenomenon because in nature the geothermal gradient prevents the ...
Date: January 15, 2010
Creator: Oldenburg, C.M. & Rinaldi, A.
Partner: UNT Libraries Government Documents Department

On CO2 Behavior in the Subsurface, Following Leakage from aGeologic Storage Reservoir

Description: The amounts of CO2 that would need to be injected intogeologic storage reservoirs to achieve a significant reduction ofatmospheric emissions are very large. A 1000 MWe coal-fired power plantemits approximately 30,000 tonnes of CO2 per day, 10 Mt per year(Hitchon, 1996). When injected underground over a typical lifetime of 30years of such a plant, the CO2 plume may occupy a large area of order 100km2 or more, and fluid pressure increase in excess of 1 bar(corresponding to 10 m water head) may extend over an area of more than2,500 km2 (Pruess, et al., 2003). The large areal extent expected for CO2plumes makes it likely that caprock imperfections will be encountered,such as fault zones or fractures, which may allow some CO2 to escape fromthe primary storage reservoir. Under most subsurface conditions oftemperature and pressure, CO2 is buoyant relative to groundwaters. If(sub-)vertical pathways are available, CO2 will tend to flow upward and,depending on geologic conditions, may eventually reach potablegroundwater aquifers or even the land surface. Leakage of CO2 could alsooccur along wellbores, including pre-existing and improperly abandonedwells, or wells drilled in connection with the CO2 storage operations.The pressure increases accompanying CO2 injection will give rise tochanges in effective stress that could cause movement along faults,increasing permeability and potential for leakage.Escape of CO2 from aprimary geologic storage reservoir and potential hazards associated withits discharge at the land surface raise a number of concerns, including(1) acidification of groundwater resources, (2) asphyxiation hazard whenleaking CO2 is discharged at the land surface, (3) increase inatmospheric concentrations of CO2, and (4) damage from a high-energy,eruptive discharge (if such discharge is physically possible). In orderto gain public acceptance for geologic storage as a viable technology forreducing atmospheric emissions of CO2, it is necessary to address theseissues and demonstrate that CO2 can be injected and stored safely ingeologic formations. ...
Date: February 9, 2006
Creator: Pruess, Karsten
Partner: UNT Libraries Government Documents Department