414 Matching Results

Search Results

Advanced search parameters have been applied.

Estimation of Retained Crude Oil Associated with Crushed Salt and Salt Cores in the Presence of Near-Saturated Brine

Description: This paper describes three experiments whose purpose is to determine the amount of retained oil on massive salt surfaces and in crushed salt in the presence of water and brine. These experiments have application to the decommissioning process for the Weeks Island mine. In the first experiment, oil-coated salt cores were immersed in either fresh water or in 85% brine. In the case of both fluids, the oil was completely removed from the cores within several hours. In the second experiment, oil-coated salt pieces were suspended in air and the oil was allowed to drain. The weight of retained oil clinging to the salt was determined. This experiment was used to estimate the total amount of oil clinging to the roofs of the mine. The total amount of oil clinging to the roofs of the mine is estimated to be between 240 and 400 m3 (1500 and 2500 BBL). In the third experiment, a pan of oil-soaked crushed salt was immersed in 85% brine, and oil removal from the salt was monitored as a function of time. At the start of the experiment, prior to immersion, 16% of the bulk volume of the crushed salt was determined to be interstitial oil. After the pan of crushed salt was immersed in 85% brine, 80% of the oil, which had been in the interstitial spaces of the crushed salt, immediately floated to the surface of the brine. This oil was not bound and was immediately released. During the next 380 hours, oil continued to separate from the salt and the rate of transfer was governed by a mass-transfer rate limitation.
Date: February 1, 1999
Creator: Grasser, T.W.; Hinkebein, T.E. & O'Hern, T.J.
Partner: UNT Libraries Government Documents Department

SALT DAMAGE CRITERION PROOF-OF-CONCEPT RESEARCH

Description: The purpose of this study was to conduct a field-scale application demonstrating the use of continuum damage mechanics to determine the minimum allowable operating pressure of compressed natural gas storage caverns in salt formations. A geomechanical study was performed of two natural gas storage caverns (one existing and one planned) utilizing state-of-the-art salt mechanics to assess the potential for cavern instability and collapse. The geomechanical study consisted primarily of laboratory testing, theoretical development, and analytical/numerical tasks. A total of 50 laboratory tests was performed on salt specimens to aid in the development and definition of the material model used to predict the behavior of rock salt. Material model refinement was performed that improved the predictive capability of modeling salt during damage healing, recovery of work-hardened salt, and the behavior of salt at stress states other than triaxial compression. Results of this study showed that the working gas capacity of the existing cavern could be increased by 18 percent and the planned cavern could be increased by 8 percent using the proposed method compared to a conventional stress-based method. Further refinement of the continuum damage model is recommended to account for known behavior of salt at stress conditions other than triaxial compression that is not characterized accurately by the existing model.
Date: November 2002
Creator: DeVries, Kerry L.; Mellegard, Kirby D. & Callahan, Gary D.
Partner: UNT Libraries Government Documents Department

Characterizing the Weeks Island Salt Dome drilling of and seismic measurements from boreholes

Description: A sinkhole 36 ft across, 30 ft deep was first observed in the alluvium over the Weeks Island Salt Dome (salt mine converted for oil storage by US Strategic Petroleum Reserve) May 1992. Four vertical, two slanted boreholes were drilled for diagnostics. Crosswell seismic data were generated; the velocity images suggest that the sinkhole collapse is complicated, not a simple vertical structure. The coring operation was moderately difficult; limited core was obtained through the alluvium, and the quality of the salt core from the first two vertical wells was poor. Core quality improved with better bit selection, mud, and drilling method. The drilling fluid program provided fairly stable holes allowing open hole logs to be run. All holes were cemented successfully (although it took 3 attempts in one case).
Date: October 1, 1996
Creator: Sattler, A.R.; Harding, R.S.; Jacobson, R.D.; Finger, J.T.; Keefe, R. & Neal, J.T.
Partner: UNT Libraries Government Documents Department

Mine-induced sinkholes over the U.S. Strategic Petroleum Reserve (SPR) Storage Facility at Weeks Island, Louisiana: geological mitigation and environmental monitoring

Description: A sinkhole formed over the former salt mine used for crude oil storage by the U.S. Strategic Petroleum Reserve at Weeks Island, Louisiana. This created a dilemma because in-mine grouting was not possible, and external grouting, although possible, was impractical. However, environmental protection during oil withdrawal and facility decommissioning was considered critical and alternative solutions were essential. Mitigation of, the sinkhole growth over the salt mine was accomplished by injecting saturated brine directly into the sinkhole throat, and by constructing a cylindrical freeze curtain around and into the dissolution orifice at the top of the salt dome. These measures vastly reduced the threat of major surface collapse around the sinkhole during oil transfer and subsequent brine backfill. The greater bulk of the crude oil was removed from the mine during 1995-6. Final skimming operations will remove residual oil trapped in low spots, concurrent with initiating backfill of the mine with saturated brine. Environmental monitoring during 1995-9 will assure that environmental surety is achieved.
Date: March 1, 1997
Creator: Neal, J.T.
Partner: UNT Libraries Government Documents Department

Summary of scientific investigations for the Waste Isolation Pilot Plant

Description: The scientific issues concerning disposal of radioactive wastes in salt formations have received 40 years of attention since the National Academy of Sciences (NAS) first addressed this issue in the mid-50s. For the last 21 years, Sandia National Laboratories (SNL) have directed site specific studies for the Waste Isolation Pilot Plant (WIPP). This paper will focus primarily on the WIPP scientific studies now in their concluding stages, the major scientific controversies regarding the site, and some of the surprises encountered during the course of these scientific investigations. The WIPP project`s present understanding of the scientific processes involved continues to support the site as a satisfactory, safe location for the disposal of defense-related transuranic waste and one which will be shown to be in compliance with Environmental Protection Agency (EPA) standards. Compliance will be evaluated by incorporating data from these experiments into Performance Assessment (PA) models developed to describe the physical and chemical processes that could occur at the WIPP during the next 10,000 years under a variety of scenarios. The resulting compliance document is scheduled to be presented to the EPA in October 1996 and all relevant information from scientific studies will be included in this application and the supporting analyses. Studies supporting this compliance application conclude the major period of scientific investigation for the WIPP. Further studies will be of a ``confirmatory`` and monitoring nature.
Date: February 1996
Creator: Weart, W. D.
Partner: UNT Libraries Government Documents Department

Evaluation of constitutive models for crushed salt

Description: Three constitutive models are recommended as candidates for describing the deformation of crushed salt. These models are generalized to three-dimensional states of stress to include the effects of mean and deviatoric stress and modified to include effects of temperature, grain size, and moisture content. A database including hydrostatic consolidation and shear consolidation tests conducted on Waste Isolation Pilot Plant (WIPP) and southeastern New Mexico salt is used to determine material parameters for the models. To evaluate the capability of the models, parameter values obtained from fitting the complete database are used to predict the individual tests. Finite element calculations of a WIPP shaft with emplaced crushed salt demonstrate the model predictions.
Date: May 1, 1996
Creator: Callahan, G.D.; Loken, M.C.; Hurtado, L.D. & Hansen, F.D.
Partner: UNT Libraries Government Documents Department

Sinkhole progression at the Weeks Island, Louisiana, Strategic Petroleum Reserve (SPR) site

Description: A sinkhole measuring 11 m (36 ft) across and 9 m (30 ft) deep was first observed in alluvium overlying the Weeks Island, Louisiana, salt dome in May 1992, but it was about a year old, based on initial surface appearance and subsequent reverse extrapolation of growth rates. A second and much smaller sinkhole was identified in early 1995, nearly three years later. Their position directly over the edges of the SPR oil storage chamber, a former room-and-pillar salt mine, caused apprehension. The association of sinkholes over mines is well established and this occurrence suggested that groundwater influx undoubtedly was causing salt dissolution at shallow depth, and associated collapse of soil at the surface. Leaks of groundwater into other salt mines in Louisiana and elsewhere led to flooding and eventual abandonment (Coates et al., 1981). Consequently, much attention has been and continues to be given to characterizing these sinkholes, and to mitigation. This paper summarizes current engineering geologic concepts, and briefly describes diagnostic and risk mitigation efforts being conducted by the US Department of Energy, operator of the Strategic Petroleum Reserve (Bauer et al., 1994).
Date: November 1, 1995
Creator: Neal, J.T.; Bauer, S.J. & Ehgartner, B.L.
Partner: UNT Libraries Government Documents Department

Stability of plutonium(VI) in WIPP brine

Description: The redox stability of plutonium (VI) in WIPP brine was investigated by monitoring the oxidation state as a function of time using a combination of absorption spectrometry, radiochemical counting and filtration. Studies were performed with Pu-239 and Pu-238 in four WIPP brines at concentrations between 10{sup {minus}3} and 10{sup {minus}8} M for durations as long as two years. Two synthetic brines, Brine A and ERDA-6, and two underground collected brines, DH-36 and G-Seep, were used. The stability of Pu(VI) depended on the brine composition and the speciation of the plutonium in that brine. When carbonate was present, a Pu(VI)-carbonate complex was observed that was stable. In the absence of carbonate, Pu(VI) hydrolytic species predominated which had a wide range of stability in the brines investigated. The results reported will help define the speciation of plutonium in WIPP brine and hence its potential for migration.
Date: December 1, 1993
Creator: Reed, D.T. & Okajima, S.
Partner: UNT Libraries Government Documents Department

Strongly coupled single-phase flow problems: Effects of density variation, hydrodynamic dispersion, and first order decay

Description: We have developed TOUGH2 modules for strongly coupled flow and transport that include full hydrodynamic dispersion. T2DM models two-dimensional flow and transport in systems with variable salinity, while T2DMR includes radionuclide transport with firstorder decay of a parent-daughter chain of radionuclide components in variable salinity systems. T2DM has been applied to a variety of coupled flow problems including the pure solutal convection problem of Elder and the mixed free and forced convection salt-dome flow problem. In the Elder and salt-dome flow problems, density changes of up to 20% caused by brine concentration variations lead to strong coupling between the velocity and brine concentration fields. T2DM efficiently calculates flow and transport for these problems. We have applied T2DMR to the dispersive transport and decay of radionuclide tracers in flow fields with permeability heterogeneities and recirculating flows. Coupling in th ese problems occurs by velocity-dependent hydrodynamic dispersion. Our results show that the maximum daughter species concentration may occur fully within a recirculating or low-velocity region. In all of the problems, we observe very efficient handling of the strongly coupled flow and transport processes.
Date: March 1, 1995
Creator: Oldenburg, C.M. & Pruess, K.
Partner: UNT Libraries Government Documents Department

Simulation of ionic surfaces from an absolutely convergent solution of the Madelung problem

Description: The classic Madelung problem is cast into an absolutely convergent form that is readily evaluated by direct lattice summation, revealing a net r{sup {minus}5} range of the net Coulomb potential in ionic crystals and liquids. The realization that Coulomb interactions in condensed systems can actually be rather short ranged (provided the system is overall neutral) leads to the prediction, verified by computer simulations for rocksalt-structure surfaces, that all surfaces in predominantly ionic crystals should be fundamentally reconstructed. The work also provides a conceptual framework for the theoretical treatment of polar surfaces, as demonstrated for the case of the (111) surfaces of NaCl and MgO.
Date: April 1, 1995
Creator: Wolf, D.
Partner: UNT Libraries Government Documents Department

Origin, diagnostics, and mitigation of a salt dissolution sinkhole at the US Strategic Petroleum Reserve storage site, Weeks Island, Louisiana

Description: A sinkhole was first observed in May 1992 over the edge of the two-level former salt mine that was converted for oil storage by the US Strategic Petroleum Reserve (SPR). Diagnostic studies that included geophysical, geochemical, drilling, and hydrological methods suggest a direct connection exists between the surface collapse area and the underground mine as shown by correlative measurements of sediment slump rates and brine influx into the mine. The dissolution of salt below the sinkhole that initiated the leak into the mine was likely caused by several confluent geologic processes, and exacerbated by mining-induced stresses that created fractures which served as hydrologic flowpaths. Modeling studies of mine stresses show that years may be required before tensional cracking begins to occur, but once begun can continue to develop, and relieve the stress in that specific regime. The crack regime creates the avenue for incursion of groundwater, very slowly initially, but gradually enlarging as undersaturated groundwater dissolves salt on the sides of the crack. Mitigation measures include increasing the mine pressurization, slowing the dissolution by injecting brine into the sinkhole throat, and freeze grouting to restrict hydrologic flowpaths.
Date: January 27, 1995
Creator: Neal, J.T. & Myers, R.E.
Partner: UNT Libraries Government Documents Department

Brine Sampling and Evaluation Program 1992--1993 report and summary of BSEP data since 1982

Description: This report is the last one that is currently scheduled in the sequence of reports of new data, and therefore, also includes summary comments referencing important data obtained by BSEP since 1983. These BSEP activities document and investigate the origins, hydraulic characteristics, extent, and composition of brine occurrences in the Permian Salado Formation and seepage of that brine into the excavations at the (WIPP) Waste Isolation Pilot Plant. A project concern is that enough brine might be present after sealing and closure to generate large quantities of hydrogen gas by corroding the metal in the waste drums and waste inventory. This report describes progress made during the calendar years 1992 and 1993 and focuses on four major areas: (1) monitoring of brine inflow, e.g., measuring brines recovered from holes drilled downward from the underground drifts (downholes), upward from the underground drifts (upholes), and from subhorizontal holes from the underground drifts; (2) observations of weeps in the Air Intake Shaft (AIS); (3) further characterization of brine geochemistry; and (4) additional characterization of the hydrologic conditions in the fractured zone beneath the excavations.
Date: April 1, 1995
Creator: Deal, D.E.; Abitz, R.J. & Belski, D.S.
Partner: UNT Libraries Government Documents Department

Characteristics of seismic waves from Soviet peaceful nuclear explosions in salt

Description: The report is carried out by the Institute for Dynamics of the Geospheres, Russian Academy of Sciences under contract NB280344 with Lawrence Livermore National Laboratory, University of California. The work includes investigation of seismic waves generation and propagation from Soviet peaceful underground nuclear explosions in salt based on the data from temporary and permanent seismic stations. The explosions were conducted at the sites Azgir and Vega within the territory of the Caspian depression of the Russian platform. The data used were obtained in the following conditions of conduction: epicentral distance range from 0 to 60 degrees, yields from 1 to 65 kt and depths of burial from 160 to 1500 m.
Date: April 1, 1995
Creator: Adushkin, V.V.; Kaazik, P.B.; Kostyuchenko, V.N.; Kuznetsov, O.P.; Nedoshivin, N.I.; Rubinshtein, K.D. et al.
Partner: UNT Libraries Government Documents Department

Resource Assessment of the In-Place and Potentially Recoverable Deep Natural Gas Resource of the Onshore Interior Salt Basins, North Central and Northeastern Gulf of Mexico

Description: The objectives of the study were: (1) to perform resource assessment of the thermogenic gas resources in deeply buried (>15,000 ft) natural gas reservoirs of the onshore interior salt basins of the north central and northeastern Gulf of Mexico areas through petroleum system identification, characterization and modeling; and (2) to use the petroleum system based resource assessment to estimate the volume of the deep thermogenic gas resource that is available for potential recovery and to identify those areas in the interior salt basins with high potential for this thermogenic gas resource. Petroleum source rock analysis and petroleum system characterization and modeling, including thermal maturation and hydrocarbon expulsion modeling, have shown that the Upper Jurassic Smackover Formation served as the regional petroleum source rock in the North Louisiana Salt Basin, Mississippi Interior Salt Basin, Manila Subbasin and Conecuh Subbasin. Thus, the estimates of the total hydrocarbons, oil, and gas generated and expelled are based on the assumption that the Smackover Formation is the main petroleum source rock in these basins and subbasins. The estimate of the total hydrocarbons generated for the North Louisiana Salt Basin in this study using a petroleum system approach compares favorably with the total volume of hydrocarbons generated published by Zimmermann (1999). In this study, the estimate is 2,870 billion barrels of total hydrocarbons generated using the method of Schmoker (1994), and the estimate is 2,640 billion barrels of total hydrocarbons generated using the Platte River software application. The estimate of Zimmermann (1999) is 2,000 to 2,500 billion barrels of total hydrocarbons generated. The estimate of gas generated for this basin is 6,400 TCF using the Platte River software application, and 12,800 TCF using the method of Schmoker (1994). Barnaby (2006) estimated that the total gas volume generated for this basin ranges from 4,000 to 8,000 TCF. ...
Date: September 30, 2006
Creator: Mancini, Ernest A.
Partner: UNT Libraries Government Documents Department