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Development of a Mine Rescue Drilling System (MRDS)

Knudsen, Steven D.; Broome, Scott T.; Su, Jiann-Cherng S.; Blankenship, Douglas A.

Sandia National Laboratories (Sandia) has a long history in developing compact, mobile, very high-speed drilling systems and this technology could be applied to increasing the rate at which boreholes are drilled during a mine accident response. The present study reviews current technical approaches, primarily based on technology developed under other programs, analyzes mine rescue specific requirements to develop a conceptual mine rescue drilling approach, and finally, proposes development of a phased mine rescue drilling system (MRDS) that accomplishes (1) development of rapid drilling MRDS equipment; (2) structuring improved web communication through the Mine Safety & Health Administration (MSHA) web site; (3) development of an improved protocol for employment of existing drilling technology in emergencies; (4) deployment of advanced technologies to complement mine rescue drilling operations during emergency events; and (5) preliminary discussion of potential future technology development of specialized MRDS equipment. This phased approach allows for rapid fielding of a basic system for improved rescue drilling, with the ability to improve the system over time at a reasonable cost.

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Compaction behavior of surrogate degraded emplaced WIPP waste

Broome, Scott T.; Kuthakun, Souvanny K.; Herrick, Courtney G.; Pfeifle, Tom P.

The present study results are focused on laboratory testing of surrogate waste materials. The surrogate wastes correspond to a conservative estimate of degraded Waste Isolation Pilot Plant (WIPP) containers and TRU waste materials at the end of the 10,000 year regulatory period. Testing consists of hydrostatic, triaxial, and uniaxial strain tests performed on surrogate waste recipes that were previously developed by Hansen et al. (1997). These recipes can be divided into materials that simulate 50% and 100% degraded waste by weight. The percent degradation indicates the anticipated amount of iron corrosion, as well as the decomposition of cellulosics, plastics, and rubbers (CPR). Axial, lateral, and volumetric strain and axial, lateral, and pore stress measurements were made. Two unique testing techniques were developed during the course of the experimental program. The first involves the use of dilatometry to measure sample volumetric strain under a hydrostatic condition. Bulk moduli of the samples measured using this technique were consistent with those measured using more conventional methods. The second technique involved performing triaxial tests under lateral strain control. By limiting the lateral strain to zero by controlling the applied confining pressure while loading the specimen axially in compression, one can maintain a right-circular cylindrical geometry even under large deformations. This technique is preferred over standard triaxial testing methods which result in inhomogeneous deformation or (3z(Bbarreling(3y. (BManifestations of the inhomogeneous deformation included non-uniform stress states, as well as unrealistic Poisson<U+2019>s ratios (> 0.5) or those that vary significantly along the length of the specimen. Zero lateral strain controlled tests yield a more uniform stress state, and admissible and uniform values of Poisson<U+2019>s ratio.

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Geomechanical testing of Bayou Choctaw 102B core for SPR analysis

Ingraham, Mathew D.; Bauer, Stephen J.; Broome, Scott T.; Flint, Gregory M.; Barrow, Perry C.

A laboratory testing program was developed to examine the short-term mechanical and time-dependent (creep) behavior of salt from the Bayou Choctaw Salt Dome. This report documents the test methodologies, and constitutive properties inferred from tests performed. These are used to extend our understanding of the mechanical behavior of the Bayou Choctaw domal salt and provide a data set for numerical analyses. The resulting information will be used to support numerical analyses of the current state of the Bayou Choctaw Dome as it relates to its crude oil storage function as part of the US Strategic Petroleum Reserve. Core obtained from Drill Hole BC-102B was tested under creep and quasi-static constant mean stress axisymmetric compression, and constant mean stress axisymmetric extension conditions. Creep tests were performed at 100 degrees Fahrenheit, and the axisymmetric tests were performed at ambient temperatures (72-78 degrees Fahrenheit). The testing performed indicates that the dilation criterion is pressure and stress state dependent. It was found that as the mean stress increases, the shear stress required to cause dilation increases. The results for this salt are reasonably consistent with those observed for other domal salts. Also it was observed that tests performed under extensile conditions required consistently lower shear stress to cause dilation for the same mean stress, which is consistent with other domal salts. Young's moduli ranged from 3.95 x 106 to 8.51 x 106 psi with an average of 6.44 x 106 psi, with Poisson's ratios ranging from 0.10 to 0.43 with an average of 0.30. Creep testing indicates that the BC salt is intermediate in creep resistance when compared with other bedded and domal salt steady-state behavior.

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Petrologic and petrophysical evaluation of the Dallas Center Structure, Iowa, for compressed air energy storage in the Mount Simon Sandstone

Heath, Jason; Bauer, Stephen J.; Broome, Scott T.; Dewers, Thomas D.; Rodriguez, Marko A.

The Iowa Stored Energy Plant Agency selected a geologic structure at Dallas Center, Iowa, for evaluation of subsurface compressed air energy storage. The site was rejected due to lower-than-expected and heterogeneous permeability of the target reservoir, lower-than-desired porosity, and small reservoir volume. In an initial feasibility study, permeability and porosity distributions of flow units for the nearby Redfield gas storage field were applied as analogue values for numerical modeling of the Dallas Center Structure. These reservoir data, coupled with an optimistic reservoir volume, produced favorable results. However, it was determined that the Dallas Center Structure cannot be simplified to four zones of high, uniform permeabilities. Updated modeling using field and core data for the site provided unfavorable results for air fill-up. This report presents Sandia National Laboratories petrologic and petrophysical analysis of the Dallas Center Structure that aids in understanding why the site was not suitable for gas storage.

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Temperature-dependent mechanical property testing of nitrate thermal storage salts

Broome, Scott T.

Three salt compositions for potential use in trough-based solar collectors were tested to determine their mechanical properties as a function of temperature. The mechanical properties determined were unconfined compressive strength, Young's modulus, Poisson's ratio, and indirect tensile strength. Seventeen uniaxial compression and indirect tension tests were completed. It was found that as test temperature increases, unconfined compressive strength and Young's modulus decreased for all salt types. Empirical relationships were developed quantifying the aforementioned behaviors. Poisson's ratio tends to increase with increasing temperature except for one salt type where there is no obvious trend. The variability in measured indirect tensile strength is large, but not atypical for this index test. The average tensile strength for all salt types tested is substantially higher than the upper range of tensile strengths for naturally occurring rock salts. Interest in raising the operating temperature of concentrating solar technologies and the incorporation of thermal storage has motivated studies on the implementation of molten salt as the system working fluid. Recently, salt has been considered for use in trough-based solar collectors and has been shown to offer a reduction in levelized cost of energy as well as increasing availability (Kearney et al., 2003). Concerns regarding the use of molten salt are often related to issues with salt solidification and recovery from freeze events. Differences among salts used for convective heat transfer and storage are typically designated by a comparison of thermal properties. However, the potential for a freeze event necessitates an understanding of salt mechanical properties in order to characterize and mitigate possible detrimental effects. This includes stress imparted by the expanding salt. Samples of solar salt, HITEC salt (Coastal Chemical Co.), and a low melting point quaternary salt were cast for characterization tests to determine unconfined compressive strength, indirect tensile strength, coefficient of thermal expansion (CTE), Young's modulus, and Poisson's ratio. Experiments were conducted at multiple temperatures below the melting point to determine temperature dependence.

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Hydrostatic compaction of Microtherm HT

Broome, Scott T.

Two samples of jacketed Microtherm{reg_sign}HT were hydrostatically pressurized to maximum pressures of 29,000 psi to evaluate both pressure-volume response and change in bulk modulus as a function of density. During testing, each of the two samples exhibited large irreversible compactive volumetric strains with only small increases in pressure; however at volumetric strains of approximately 50%, the Microtherm{reg_sign}HT stiffened noticeably at ever increasing rates. At the maximum pressure of 29,000 psi, the volumetric strains for both samples were approximately 70%. Bulk modulus, as determined from hydrostatic unload/reload loops, increased by more than two-orders of magnitude (from about 4500 psi to over 500,000 psi) from an initial material density of {approx}0.3 g/cc to a final density of {approx}1.1 g/cc. An empirical fit to the density vs. bulk modulus data is K = 492769{rho}{sup 4.6548}, where K is the bulk modulus in psi, and {rho} is the material density in g/cm{sup 3}. The porosity decreased from 88% to {approx}20% indicating that much higher pressures would be required to compact the material fully.

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Temperature dependent mechanical property testing of nitrate thermal storage salts

Broome, Scott T.; Siegel, Nathan P.

Three salt compositions for potential use in trough-based solar collectors were tested to determine their mechanical properties as a function of temperature. The mechanical properties determined were unconfined compressive strength, Young's modulus, Poisson's ratio, and indirect tensile strength. Seventeen uniaxial compression and indirect tension tests were completed. It was found that as test temperature increases, unconfined compressive strength and Young's modulus decreased for all salt types. Empirical relationships were developed quantifying the aforementioned behaviors. Poisson's ratio tends to increase with increasing temperature except for one salt type where there is no obvious trend. The variability in measured indirect tensile strength is large, but not atypical for this index test. The average tensile strength for all salt types tested is substantially higher than the upper range of tensile strengths for naturally occurring rock salts.

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Phase transformation of PZST-86/14-5-2Nb ceramic under quasi-static loading conditions

Broome, Scott T.; Bauer, Stephen J.; Montgomery, Stephen M.; Scofield, Timothy W.; Hofer, John H.

Specimens of poled and unpoled PZST ceramic were tested under hydrostatic loading conditions at temperatures of -55, 25, and 75 C. The objective of this experimental study was to obtain the electro-mechanical properties of the ceramic and the criteria of FE (Ferroelectric) to AFE (Antiferroelectric) phase transformations of the PZST ceramic to aid grain-scale modeling efforts in developing and testing realistic response models for use in simulation codes. As seen in previous studies, the poled ceramic from PZST undergoes anisotropic deformation during the transition from a FE to an AFE phase at -55 C. Warmer temperature tests exhibit anisotropic deformation in both the FE and AFE phase. The phase transformation is permanent at -55 C for all ceramics tests, whereas the transformation can be completely reversed at 25 and 75 C. The change in the phase transformation pressures at different temperatures were practically identical for both unpoled and poled PZST specimens. Bulk modulus for both poled and unpoled material was lowest in the FE phase, intermediate in the transition phase, and highest in the AFE phase. Additionally, bulk modulus varies with temperature in that PZST is stiffer as temperature decreases. Results from one poled-biased test for PZST and four poled-biased tests from PNZT 95/5-2Nb are presented. A bias of 1kV did not show noticeable differences in phase transformation pressure for the PZST material. However, with PNZT 95/5-2Nb phase transformation pressure increased with increasing voltage bias up to 4.5kV.

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Revised results for geomechanical testing of MRIG-9 core for the potential SPR siting at the Richton Salt Dome

Bauer, Stephen J.; Broome, Scott T.

This report is a revision of SAND2009-0852. SAND2009-0852 was revised because it was discovered that a gage used in the original testing was mis-calibrated. Following the recalibration, all affected raw data were recalculated and re-presented. Most revised data is similar to, but slightly different than, the original data. Following the data re-analysis, none of the inferences or conclusions about the data or site relative to the SAND2009-0852 data have been changed. A laboratory testing program was developed to examine the mechanical behavior of salt from the Richton salt dome. The resulting information is intended for use in design and evaluation of a proposed Strategic Petroleum Reserve storage facility in that dome. Core obtained from the drill hole MRIG-9 was obtained from the Texas Bureau of Economic Geology. Mechanical properties testing included: (1) acoustic velocity wave measurements; (2) indirect tensile strength tests; (3) unconfined compressive strength tests; (4) ambient temperature quasi-static triaxial compression tests to evaluate dilational stress states at confining pressures of 725, 1450, 2175, and 2900 psi; and (5) confined triaxial creep experiments to evaluate the time-dependent behavior of the salt at axial stress differences of 4000 psi, 3500 psi, 3000 psi, 2175 psi and 2000 psi at 55 C and 4000 psi at 35 C, all at a constant confining pressure of 4000 psi. All comments, inferences, discussions of the Richton characterization and analysis are caveated by the small number of tests. Additional core and testing from a deeper well located at the proposed site is planned. The Richton rock salt is generally inhomogeneous as expressed by the density and velocity measurements with depth. In fact, we treated the salt as two populations, one clean and relatively pure (> 98% halite), the other salt with abundant (at times) anhydrite. The density has been related to the insoluble content. The limited mechanical testing completed has allowed us to conclude that the dilatational criteria are distinct for the halite-rich and other salts, and that the dilation criteria are pressure dependent. The indirect tensile strengths and unconfined compressive strengths determined are consistently lower than other coastal domal salts. The steady-state-only creep model being developed suggests that Richton salt is intermediate in creep resistance when compared to other domal and bedded salts. The results of the study provide only limited information for structural modeling needed to evaluate the integrity and safety of the proposed cavern field. This study should be augmented with more extensive testing. This report documents a series of test methods, philosophies, and empirical relationships, etc., that are used to define and extend our understanding of the mechanical behavior of the Richton salt. This understanding could be used in conjunction with planned further studies or on its own for initial assessments.

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Geomechanical testing of MRIG-9 core for the potential SPR siting at the Richton salt dome

Broome, Scott T.; Bauer, Stephen J.; Hofer, John H.; Bronowski, David R.

A laboratory testing program was developed to examine the mechanical behavior of salt from the Richton salt dome. The resulting information is intended for use in design and evaluation of a proposed Strategic Petroleum Reserve storage facility in that dome. Core obtained from the drill hole MRIG-9 was obtained from the Texas Bureau of Economic Geology. Mechanical properties testing included: (1) acoustic velocity wave measurements; (2) indirect tensile strength tests; (3) unconfined compressive strength tests; (4) ambient temperature quasi-static triaxial compression tests to evaluate dilational stress states at confining pressures of 725, 1450, 2175, and 2900 psi; and (5) confined triaxial creep experiments to evaluate the time-dependent behavior of the salt at axial stress differences of 4000 psi, 3500 psi, 3000 psi, 2175 psi and 2000 psi at 55 C and 4000 psi at 35 C, all at a constant confining pressure of 4000 psi. All comments, inferences, discussions of the Richton characterization and analysis are caveated by the small number of tests. Additional core and testing from a deeper well located at the proposed site is planned. The Richton rock salt is generally inhomogeneous as expressed by the density and velocity measurements with depth. In fact, we treated the salt as two populations, one clean and relatively pure (> 98% halite), the other salt with abundant (at times) anhydrite. The density has been related to the insoluble content. The limited mechanical testing completed has allowed us to conclude that the dilatational criteria are distinct for the halite-rich and other salts, and that the dilation criteria are pressure dependent. The indirect tensile strengths and unconfined compressive strengths determined are consistently lower than other coastal domal salts. The steady-state-only creep model being developed suggests that Richton salt is intermediate in creep resistance when compared to other domal and bedded salts. The results of the study provide only limited information for structural modeling needed to evaluate the integrity and safety of the proposed cavern field. This study should be augmented with more extensive testing. This report documents a series of test methods, philosophies, and empirical relationships, etc., that are used to define and extend our understanding of the mechanical behavior of the Richton salt. This understanding could be used in conjunction with planned further studies or on its own for initial assessments.

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Results 51–78 of 78
Results 51–78 of 78