1,221 Matching Results

Search Results

Advanced search parameters have been applied.

In-situ borehole seismic monitoring of injected CO2 at the FrioSite

Description: The U.S. Dept. of Energy funded Frio Brine Pilot provided an opportunity to test borehole seismic monitoring techniques in a saline formation in southeast Texas. A relatively small amount of CO{sub 2} was injected (about 1600 tons) into a thin injection interval (about 6 m thick at 1500 m depth). Designed tests included time-lapse vertical seismic profile (VSP) and crosswell surveys which investigated the detectability of CO{sub 2} with surface-to-borehole and borehole-to-borehole measurement.
Date: June 1, 2006
Creator: Daley, Thomas M. & Korneev, Valeri A.
Partner: UNT Libraries Government Documents Department

Characterization of Mixed Wettability at Different Scales and Its Impact on Oil Recovery Efficiency

Description: The objectives of the this research project were to: (1) Quantify the pore scale mechanisms that determine the wettability state of a reservoir; (2) Study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states; (3) Clarify the effect of mixed-wettability on oil displacement efficiency in waterfloods; and (4) Develop a new tracer technique to measure wettability, fluid distributions, residual saturations and relative permeabilities.
Date: September 1, 2003
Creator: Sharma, Mukul M. & Hirasaki, George J.
Partner: UNT Libraries Government Documents Department

Intercomparison of numerical simulation codes for geologic disposal of CO2

Description: Numerical simulation codes were exercised on a suite of eight test problems that address CO2 disposal into geologic storage reservoirs, including depleted oil and gas reservoirs, and brine aquifers. Processes investigated include single- and multi-phase flow, gas diffusion, partitioning of CO2 into aqueous and oil phases, chemical interactions of CO2 with aqueous fluids and rock minerals, and mechanical changes due to changes in fluid pressures. Representation of fluid properties was also examined. In most cases results obtained from different simulation codes were in satisfactory agreement, providing confidence in the ability of current numerical simulation approaches to handle the physical and chemical processes that would be induced by CO2 disposal in geologic reservoirs. Some discrepancies were also identified and can be traced to differences in fluid property correlations, and space and time discretization.
Date: November 27, 2002
Creator: Pruess, Karsten; Garcia, Julio; Kovscek, Tony; Oldenburg, Curt; Rutqvist, Jonny; Steefel, Carl et al.
Partner: UNT Libraries Government Documents Department

Characterization of Mixed Wettablility at Different Scales and Its Impact on Oil Recovery Efficiency

Description: The objectives of the this research project were to: (1) Quantify the pore scale mechanisms that determine the wettability state of a reservoir; (2) Study the effect of crude oil, brine and mineral compositions in the establishment of mixed wet states; (3) Clarify the effect of mixed-wettability on oil displacement efficiency in waterfloods; and (4) Develop a new tracer technique to measure wettability, fluid distributions, residual saturations and relative permeabilities.
Date: August 31, 2003
Creator: Sharma, Mukul M. & Hirasaki, George J.
Partner: UNT Libraries Government Documents Department

A Feasibility Study of Non-Seismic Geophysical Methods forMonitoring Geologic CO2 Sequestration

Description: Because of their wide application within the petroleumindustry it is natural to consider geophysical techniques for monitoringof CO2 movement within hydrocarbon reservoirs, whether the CO2 isintroduced for enhanced oil/gas recovery or for geologic sequestration.Among the available approaches to monitoring, seismic methods are by farthe most highly developed and applied. Due to cost considerations, lessexpensive techniques have recently been considered. In this article, therelative merits of gravity and electromagnetic (EM) methods as monitoringtools for geological CO2 sequestration are examined for two syntheticmodeling scenarios. The first scenario represents combined CO2 enhancedoil recovery (EOR) and sequestration in a producing oil field, theSchrader Bluff field on the north slope of Alaska, USA. The secondscenario is a simplified model of a brine formation at a depth of 1,900m.
Date: July 1, 2006
Creator: Gasperikova, Erika & Hoversten, G. Michael
Partner: UNT Libraries Government Documents Department

A method for quick assessment of CO2 storage capacity in closedand semi-closed saline formations

Description: Saline aquifers of high permeability bounded by overlying/underlying seals may be surrounded laterally by low-permeability zones, possibly caused by natural heterogeneity and/or faulting. Carbon dioxide (CO{sub 2}) injection into and storage in such 'closed' systems with impervious seals, or 'semi-closed' systems with nonideal (low-permeability) seals, is different from that in 'open' systems, from which the displaced brine can easily escape laterally. In closed or semi-closed systems, the pressure buildup caused by continuous industrial-scale CO{sub 2} injection may have a limiting effect on CO{sub 2} storage capacity, because geomechanical damage caused by overpressure needs to be avoided. In this research, a simple analytical method was developed for the quick assessment of the CO{sub 2} storage capacity in such closed and semi-closed systems. This quick-assessment method is based on the fact that native brine (of an equivalent volume) displaced by the cumulative injected CO{sub 2} occupies additional pore volume within the storage formation and the seals, provided by pore and brine compressibility in response to pressure buildup. With nonideal seals, brine may also leak through the seals into overlying/underlying formations. The quick-assessment method calculates these brine displacement contributions in response to an estimated average pressure buildup in the storage reservoir. The CO{sub 2} storage capacity and the transient domain-averaged pressure buildup estimated through the quick-assessment method were compared with the 'true' values obtained using detailed numerical simulations of CO{sub 2} and brine transport in a two-dimensional radial system. The good agreement indicates that the proposed method can produce reasonable approximations for storage-formation-seal systems of various geometric and hydrogeological properties.
Date: February 10, 2008
Creator: Zhou, Q.; Birkholzer, J.; Tsang, C.F. & Rutqvist, J.
Partner: UNT Libraries Government Documents Department

Modeling Hydrogeological and Geomenchanical Processes Related toCO2 Injection in a Faulted Multilayer System

Description: This paper presents a numerical study of coupled hydrological and geomechanical processes during a deep underground injection of supercritical CO{sub 2} in a hypothetical brine aquifer. We consider a multilayer system in which the injection zone is situated below a sequence of caprock and aquifer layers that are intersected by a vertical fault zone. The fault zone consists of highly fractured shale across the first caprock layers that are located just above the injection zone. Initially, the fractured shale zones are considered sealed with minerals, but we allow fractures (and the fractured zones) to open as a result of injection induced reductions in effective stresses. Our results indicate that even when assuming a very sensitive relationship between effective stress and fractured-zone permeability, the injection-induced changes in permeability across are only moderate with largest changes occurring in the first caprock layer, just above the injection zone. As a result, the upward leakage rate remains relatively small and therefore changes in fluid pressure and hydromechanical effects in overlying zones are also relatively small for the case studied in this paper.
Date: January 1, 2006
Creator: Rutqvist, Jonny; Birkholzer, Jens & Tsang, Chin-Fu
Partner: UNT Libraries Government Documents Department

Site Characterization for CO2 Geologic Storage and Vice Versa -The Frio Brine Pilot as a Case Study

Description: Careful site characterization is critical for successfulgeologic sequestration of CO2, especially for sequestration inbrine-bearing formations that have not been previously used for otherpurposes. Traditional site characterization techniques such asgeophysical imaging, well logging, core analyses, interference welltesting, and tracer testing are all valuable. However, the injection andmonitoring of CO2 itself provides a wealth of additional information.Rather than considering a rigid chronology in which CO2 sequestrationoccurs only after site characterization is complete, we recommend thatCO2 injection and monitoring be an integral part of thesite-characterization process. The advantages of this approach arenumerous. The obvious benefit of CO2 injection is to provide informationon multi-phase flow properties, which cannot be obtained from traditionalsitecharacterization techniques that examine single-phase conditions.Additionally, the low density and viscosity of CO2 compared to brinecauses the two components to flow through the subsurface differently,potentially revealing distinct features of the geology. Finally, tounderstand sequestered CO2 behavior in the subsurface, there is nosubstitute for studying the movement of CO2 directly. Making CO2injection part of site characterization has practical benefits as well.The infrastructure for surface handling of CO2 (compression, heating,local storage) can be developed, the CO2 injection process can bedebugged, and monitoring techniques can be field-tested. Prior to actualsequestration, small amounts of CO2 may be trucked in. Later, monitoringaccompanying the actual sequestration operations may be used tocontinually refine and improve understanding of CO2 behavior in thesubsurface.
Date: February 14, 2006
Creator: Doughty, Christine
Partner: UNT Libraries Government Documents Department

Numerical simulation of leakage from a geologic disposal reservoirfor CO2, with transitions between super- and sub-criticalconditions

Description: The critical point of CO2 is at temperature and pressureconditions of Tcrit = 31.04oC, Pcrit = 73.82 bar. At lower (subcritical)temperatures and/or pressures, CO2 can exist in two different phases, aliquid and a gaseous state, as well as in two-phase mixtures of thesestates. Disposal of CO2 into brine formations would be made atsupercritical pressures. However, CO2 escaping from the storage reservoirmay migrate upwards towards regions with lower temperatures andpressures, where CO2 would be in subcritical conditions. An assessment ofthe fate of leaking CO2 requires a capability to model not onlysupercritical but also subcritical CO2, as well as phase changes betweenliquid and gaseous CO2 in sub-critical conditions. We have developed amethodology for numerically simulating the behavior of water-CO2 mixturesin permeable media under conditions that may include liquid, gaseous, andsupercritical CO2. This has been applied to simulations of leakage from adeep storage reservoir in which a rising CO2 plume undergoes transitionsfrom supercritical to subcritical conditions. We find strong coolingeffects when liquid CO2 rises to elevations where it begins to boil andevolve a gaseous CO2 phase. A three-phase zone forms (aqueous - liquid -gas), which over time becomes several hundred meters thick as decreasingtemperatures permit liquid CO2 to advance to shallower elevations. Fluidmobilities are reduced in the three-phase region from phase interferenceeffects. This impedes CO2 upflow, causes the plume to spread outlaterally, and gives rise to dispersed CO2 discharge at the land surface.Our simulations suggest that temperatures along a CO2 leakage path maydecline to levels low enough so that solid water ice and CO2 hydratephases may be formed.
Date: April 13, 2003
Creator: Pruess, Karsten
Partner: UNT Libraries Government Documents Department

Pleasant Bayou Operations Brazoria County, Texas

Description: This project will demonstrate the Hybrid Cycle Concept for electricity generation using geopressured-geothermal resources. The test is scheduled to be a minimum of one year, which may be extended. The majority of the equipment came from the DOE facility at East Mesa, CA. The hybrid cycle has been designed for 10,800 BPD brine and 220,000 SCFD of gas. The power output will be about one megawatt, which will be sold to Houston Lighting and Power Company. An important research objective is to determine the size and ultimate production capability of the geopressured-geothermal reservoir. The long-term deliverability of these type reservoirs is a significant factor in determining the ultimate economic capability of these systems.
Date: March 21, 1989
Creator: Eaton, B.A.; Featherston, C.R. & Meahl, T.E.
Partner: UNT Libraries Government Documents Department

JV Task 99-Integrated Risk Analysis and Contaminant Reduction, Watford City, North Dakota

Description: The Energy & Environmental Research Center (EERC) conducted a limited site investigation and risk analyses for hydrocarbon-contaminated soils and groundwater at a Construction Services, Inc., site in Watford City, North Dakota. Site investigation confirmed the presence of free product and high concentrations of residual gasoline-based contaminants in several wells, the presence of 1,2-dichloroethane, and extremely high levels of electrical conductivity indicative of brine residuals in the tank area south of the facility. The risk analysis was based on compilation of information from the site-specific geotechnical investigation, including multiphase extraction pilot test, laser induced fluorescence probing, evaluation of contaminant properties, receptor survey, capture zone analysis and evaluation of well head protection area for municipal well field. The project results indicate that the risks associated with contaminant occurrence at the Construction Services, Inc. site are low and, under current conditions, there is no direct or indirect exposure pathway between the contaminated groundwater and soils and potential receptors.
Date: May 31, 2007
Creator: Solc, Jaroslav & Botnen, Barry W.
Partner: UNT Libraries Government Documents Department

Predicting the precipiation of amorphous silica from geothermal brines

Description: The voluminous gel-like deposits encountered at Cerro Prieto, Wairakei, and Niland consist of flocculated colloidal amorphous silica. The crumbly grey and white scales associated with the gel-like materials are cemented colloidal aggregates. This colloidal silica is produced by homogeneous nucleation in the liquid phase; i.e., nucleation by growth of polymers to critical nucleus size without the participation of some preexisting solid particle. With most substances heterogeneous nucleation is dominant, and homogeneous nucleation is very slow, rare in nature, and difficult to study in the laboratory. The precipitation of amorphous silica is an apparent exception to this because of the very low surface tension of the silica-water interface--between 35 and 50 ergs cm{sup -2} over the range of major practical interest. By comparison, the surface tension of the water-air interface is about 70-80 ergs cm{sup -2}. This means that enormous numbers of particles can be produced by homogeneous nucleation (on the order 10{sup 17} to 10{sup 18} per liter), and this completely swamps the effects of heterogeneous nucleation.
Date: January 1, 1978
Creator: Weres, Oleh; Yee, Andrew & Tsao, Leon
Partner: UNT Libraries Government Documents Department

DOE-DARPA High-Performance Corrosion-Resistant Materials (HPCRM), Annual HPCRM Team Meeting & Technical Review

Description: The overall goal is to develop high-performance corrosion-resistant iron-based amorphous-metal coatings for prolonged trouble-free use in very aggressive environments: seawater & hot geothermal brines. The specific technical objectives are: (1) Synthesize Fe-based amorphous-metal coating with corrosion resistance comparable/superior to Ni-based Alloy C-22; (2) Establish processing parameter windows for applying and controlling coating attributes (porosity, density, bonding); (3) Assess possible cost savings through substitution of Fe-based material for more expensive Ni-based Alloy C-22; (4) Demonstrate practical fabrication processes; (5) Produce quality materials and data with complete traceability for nuclear applications; and (6) Develop, validate and calibrate computational models to enable life prediction and process design.
Date: September 21, 2007
Creator: Farmer, J; Brown, B; Bayles, B; Lemieux, T; Choi, J; Ajdelsztajn, L et al.
Partner: UNT Libraries Government Documents Department

Interpretation Of Multifrequency Crosswell Electromagnetic Data With Frequency Dependent Core Data

Description: Interpretation of cross-borehole electromagnetic (EM) images acquired at enhanced oil recovery (EOR) sites has proven to be difficult due to the typically complex subsurface geology. Significant problems in image interpretation include correlation of specific electrical conductivity values with oil saturations, the time-dependent electrical variation of the subsurface during EOR, and the non-unique electrical conductivity relationship with subsurface conditions. In this study we perform laboratory electrical properties measurements of core samples from the EOR site to develop an interpretation approach that combines field images and petrophysical results. Cross-borehole EM images from the field indicate resistivity increases in EOR areas--behavior contrary to the intended waterflooding design. Laboratory measurements clearly show a decrease in resistivity with increasing effective pressure and are attributed to increased grain-to-grain contact enhancing a strong surface conductance. We also observe a resistivity increase for some samples during brine injection. These observations possibly explain the contrary behavior observed in the field images. Possible mechanisms for increasing the resistivity in the region include (1) increased oil content as injectate sweeps oil toward the plane of the observation wells; (2) lower conductance pore fluid displacing the high-conductivity brine; (3) degradation of grain-to-grain contacts of the initially conductive matrix; and (4) artifacts of the complicated resistivity/time history similar to that observed in the laboratory experiments.
Date: June 7, 2005
Creator: Kirkendall, B & Roberts, J
Partner: UNT Libraries Government Documents Department

Stabilization of Plutonium in Subsurface Environments via Microbial Reduction and Biofilm Formation

Description: Plutonium has a long half-life (2.4 x 104 years) and is of concern because of its chemical and radiological toxicity, high-energy alpha radioactive decay. A full understanding of its speciation and interactions with environmental processes is required in order to predict, contain, or remediate contaminated sites. Under aerobic conditions Pu is sparingly soluble, existing primarily in its tetravalent oxidation state. To the extent that pentavalent and hexavalent complexes and small colloidal species form they will increase the solubility and resultant mobility from contamination sources. There is evidence that in both marine environments and brines substantial fractions of the plutonium in solution is present as hexavalent plutonyl, PuO2 2+.
Date: April 19, 2007
Creator: Boukhalfa, Hakim; Icopini, Gary A.; Reilly, Sean D. & Neu, Mary P.
Partner: UNT Libraries Government Documents Department

Sensitivity study of CO2 storage capacity in brine aquifers withclosed boundaries: Dependence on hydrogeologic properties

Description: In large-scale geologic storage projects, the injected volumes of CO{sub 2} will displace huge volumes of native brine. If the designated storage formation is a closed system, e.g., a geologic unit that is compartmentalized by (almost) impermeable sealing units and/or sealing faults, the native brine cannot (easily) escape from the target reservoir. Thus the amount of supercritical CO{sub 2} that can be stored in such a system depends ultimately on how much pore space can be made available for the added fluid owing to the compressibility of the pore structure and the fluids. To evaluate storage capacity in such closed systems, we have conducted a modeling study simulating CO{sub 2} injection into idealized deep saline aquifers that have no (or limited) interaction with overlying, underlying, and/or adjacent units. Our focus is to evaluate the storage capacity of closed systems as a function of various reservoir parameters, hydraulic properties, compressibilities, depth, boundaries, etc. Accounting for multi-phase flow effects including dissolution of CO{sub 2} in numerical simulations, the goal is to develop simple analytical expressions that provide estimates for storage capacity and pressure buildup in such closed systems.
Date: February 7, 2007
Creator: Zhou, Q.; Birkholzer, J.; Rutqvist, J. & Tsang, C-F.
Partner: UNT Libraries Government Documents Department

Progress Report Processing of Hypersaline Brine

Description: There are several known areas in the Imperial Valley of California where geothermal brines having probable commercial value exist. The main ones being considered today are the Niland area, Heber area, East Mesa, and North Brawley. The bottom-hole temperatures and salinity of the brines from the different areas show wide variation. The highest bottom-hole temperatures and highest salinity so far known are found in the Niland area. This area covers the largest areas of proven ground so far known in this vicinity. This is the area considered as producing the Hypersaline Brines.
Date: January 1, 1976
Creator: Hutchinson, A.J.L.
Partner: UNT Libraries Government Documents Department

Sequestration of CO2 in Mixtures of Bauxite and Saline Waste Water

Description: Batch and semi-batch experiments were conducted to assess feasibility of utilizing mixtures of caustic bauxite residue slurry and produced brine from the Oriskany sandstone formation to sequester CO2 • Bauxite residue/brine mixture of 90/10 by volume sequestered 9.5 g of CO2 per liter of mixture (100 psig of CO2 at 20 ºC) • Carbon trapping is accomplished primarily through solubilization • Solution of the product mixture was neutralized following carbonation • Flow-through carbonation at 25 ºC and 1 atm. demonstrates that carbonation rates are acceptable for proposed process applications
Date: May 1, 2007
Creator: Dilmore, R.M.; Soong, Y.; Griffith, C.; Allen, D.E.; Hedges, S.W.; Frommell, E.A. et al.
Partner: UNT Libraries Government Documents Department


Description: This technical progress report describes work performed from June 20 through December 19, 2001, for the project, ''Conformance Improvement Using Gels''. Interest has increased in some new polymeric products that purport to substantially reduce permeability to water while causing minimum permeability reduction to oil. In view of this interest, we are currently studying BJ's Aqua Con. Results from six corefloods revealed that the Aqua Con gelant consistently reduced permeability to water more than that to oil. However, the magnitude of the disproportionate permeability reduction varied significantly for the various experiments. Thus, as with most materials tested to date, the issue of reproducibility and control of the disproportionate permeability remains to be resolved. Concern exists about the ability of gels to resist washout after placement in fractures. We examined whether a width constriction in the middle of a fracture would cause different gel washout behavior upstream versus downstream of the constriction. Tests were performed using a formed Cr(III)-acetate-HPAM gel in a 48-in.-long fracture with three sections of equal length, but with widths of 0.08-, 0.02-, and 0.08-in., respectively. The pressure gradients during gel extrusion (i.e., placement) were similar in the two 0.08-in.-wide fracture sections, even though they were separated by a 0.02-in.-wide fracture section. The constriction associated with the middle fracture section may have inhibited gel washout during the first pulse of brine injection after gel placement. However, during subsequent phases of brine injection, the constriction did not inhibit washout in the upstream fracture section any more than in the downstream section.
Date: February 28, 2002
Creator: Seright, Randall S.
Partner: UNT Libraries Government Documents Department