AndreaBozzo/ceres-open-data-index huggingface dataset:
Underground coal gasification. 1970-April 1980 (citations from the Engineering Index data base). Report for 1970-April 1980

The bibliography presents worldwide research pertaining to underground (in-situ) coal gasification. It includes environmental effects, the different processes and techniques that are used, gas removal, rock fracturing, costs, and economics. (This updated bibliography contains 269 citations, none of which are new entries to the previous edition.)

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Laboratory studies of gasification kinetics for western coals under conditions expected during in-situ combustion

Kinetics for the reaction of steam with western U.S. sub-bituminous chars are described for operating conditions characteristic of those expected during underground coal gasification (UCG). The mineral matter present in these coals has been found to have significant catalytic activity for the water gas shift reaction. Also, the inorganic constituents of brackish waters occurring naturally in western aquifers have been found to have little effect on the gasification rates. 10 refs.

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Brazil programs a 25,000-bbl/d unit for '85 and a twin for '88

Petrobras has started construction of a 25,000 bpd shale oil module, the first of 2 units to be supplied from a strip mine that will provide an eventual 112,000 metric tons/day of mine-run oil shale and an ultimate 54,000-bpd shale oil recovery. Scheduled for initial production in 1985, the first retorting train will produce shale oil only, the equivalent of heavy diesel. Downstream upgrading, hydrotreating, gas cleaning, and by-product recovery units will be built concurrently with the second module, which is scheduled for production in 1988. Petrobras has researched intensely and developed its oil-from-shale Petrosix process at a 2200 metric tons/day prototype mine and processing plant. The process has been continuously tested since 1972 and has provided valuable information on design criteria, engineering parameters, operating conditions, and capital and operating costs of a commercial oil shale mining and processing venture on the Irati shales of Parana State.

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Geologic evaluation and reservoir properties of the PR Spring tar sand deposit, Uintah and Grand Counties, Utah

In 1980, the Laramie Energy Technology Center completed a seven-corehole drilling program at the PR Spring tar sand deposit, southeastern Uinta Basin, Utah. The data from this project were integrated with other resource information to complete lithologic correlations, to evaluate general reservoir property trends for each major tar sand zone, and to identify areas of potential in situ processing. Five distinct arkoses (sandstones) of lacustrine origin (from uppermost to lowermost, zones E, D, C, B, A), found in the upper Douglas Creek Member and lower Parachute Creek Member of the Eocene Green River Formation, have definable areal extents and are variably saturated with bitumen. Two newly recognized zones (zones 1 and 2), stratigraphically lower than the other five, have tentatively been identified in one core from the southeast portion of the deposit. Core descriptions and analytical data were used to generate computerized maps to identify general areal trends in resource parameters for the five major zones. Two pairs of zones (D and C; B and A) exhibit similar areal trends, indicating similar depositional conditions. Insufficient data for zone E inhibited the identification of any resemblance to other zones. Overall direction of increase for some reservoir properties were noted for all zones: thickness - southeast, southwest; extracted porosity - east, southeast; oil saturation - east, northeast, southeast; and extracted bulk density - northeast, northwest. Large areas of zones D and C and smaller sections of zone B and A fulfill the minimum reservoir properties recommended for in situ combustion processing. Portions of all five zones are suitable for surface mining. 46 refs., 19 figs., 6 tabs.

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Mathematical modeling of oil shale retorting

In the horizontal retorting model, a scheme where there is an oil buildup and then at various times the oil is pushed down to account for the dripping, seems to be a better explanation than another scheme. In the optimization studies, the projected oil yield was considerably enhanced by increasing the heat input from the burner to about 10/sup 6/ Btu/h. Oil recovery as percent of Fischer assay could be increased to the 75 to 80% level, with the upper limit determined by the particle sizes used. Other factors, such as leaving the burner on for a longer time, did not change the yield as significantly as raising the burner rate. Run 17 was conducted with steam injection instead of gas recycle. The predicted oil yield was improved here also by the higher burner rate. Experimentally achieving higher burner rates is a problem with the current 150-ton retort configuration and burner arrangement. Higher firing rates result in a back pressure buildup and possible extinction of the flame, necessitating a costly reloading of the retort. Accordingly, a suggestion has been simulated in which the burner is stepped up at a prescribed rate until the 10/sup 6/ Btu/h rate is achieved. This approach may be possible experimentally. Calculations indicate in this case the oil yield does come up to the 75% of Fischer assay level.

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Effect of coal thickness and structure and of coal quality on indices of the underground coal gasification process (according to operating data for gas generators of the Moscow Podzemgaz Station)

An analysis of the operation of the underground coal-gas generators at the USSR's Moscow Podzemgaz station reveals a definite relationship among the indexes of the underground-coal-gasification process: the degree of gasification of the coal and the calorific value of the gas depend on the coal seam's thickness and structure and on the coal's quality. The operating data obtained indicate that (1) although coal seams of any thickness can be gasified underground, a profitable operation requires a seam at least 4.3 ft thick, and the best process indexes are achieved with 7-13 ft thick seams, (2) the coal ash content should not exceed 40%, and (3) coal seams with complex structures, such as seams containing rock interbeds, are more difficult and expensive to gasify than simple-structure seams - a rock-interbed content of over 30% makes the seam noncommercial.

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Investigation of sorption interactions between oil shale principal mineral phases and organic compounds

The interactions between minerals representative of the bulk composition of oil shales and organic compounds that have been found in oil shale leachates were investigated. The method used to directly determine the type of interactions that could take place between organic compounds and oil shale mineral phases was Fourier transform infrared spectroscopy (FTIR) using several advanced detection methods, including diffuse reflectance (DRIFT) and photoacoustics (PAS). The minerals that were investigated include quartz, calcite, and dolomite, which are known to figure significantly in the composition of processed oil shales. The organic chemical compounds used were chosen from a list of compounds identified in spent oil shale leachates, and they include pyridine, phenol, p-cresol, and acetone. The sorption interactions for the study were prepared by exposing each of the minerals to the organic compounds by three different methods. These were vapor deposition, direct application, and immersion in an aqueous solution at pH 12. 41 refs., 3 figs., 4 tabs.

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Hydrophilic organic solutes associated with oil shale retort water

Hydrophilic organic solutes in oil shale retort waters are potential indicators of aqueous contaminants emanating from retorting operations. Monitoring these contaminants has been approached in a variety of ways. Studies at Western Research Institute (WRI) have involved the characterization of hydrophilic organic solutes in waters collected from (1) field samples with a low concentration of organic solutes from an in situ retort site (called RB-1 water) in the post-operational phase of study and (2) product water from run 17 of the WRI 150-ton simulated in situ retort (R-17 water) with a high concentration of organic solutes. The WRI studies comprised two phases of work. In the first, selected samples were screened by total organic carbon analysis, high-resolution mass spectrometry, reversed-phase liquid chromatography (RPLC), gas chromatography (GC) with mass spectrometric detection (GC/MS), GC with nitrogen- and phosphorus-specific detection, and GC with electron-capture detection. In the second phase of study the RB-1 THP and R-17 THP fractions were derivatized with heptafluorobutyrylimidazole and analyzed by GC/ECD. The RB-1 profile revealed no unique peaks. The profile of the R-17 THP showed several unique peaks, tentatively identified as hydroxypyridines and aminophenols. Further work is necessary to positively identify these compounds. 11 refs., 9 figs., 5 tabs.

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Determination of particle deterioration and collapse susceptibility of retorted oil shale piles caused by potential internal combustion. Final report

A significant concern in the disposal of retorted shales is the potential ignition and uncontrolled burning in disposal piles. At the Anvil Points Oil Shale Retort Facility, near Rifle, Colorado, high temperatures approaching 500/sup 0/C (900/sup 0/F) were discovered within a retorted oil shale pile and zones of a powdery, low density, ash-like material. These zones are primarily caused by the continuing degradation of the retorted shale particles, resulting from internal combustion of residual carbon within the pile. The purpose of this study is to make an initial investigation of the effects of high temperatures on retorted oil shale in order to guide further research in this area. The work addresses particle breakdown, combustion front migration, and collapse susceptibility of retorted shale piles. The effects of prolonged heating on individual particle size is estimated by subjecting retorted shale particles to high temperatures in an oxidized environment. The collapse susceptibility of loose retorted shale during and after combustion is predicted by loading a sample inside a tube furnace. The field combustion front velocities are estimated by monitoring changes in temperature in a retorted shale sample at various distances from a heat source. Conclusions drawn from this study are: a weight loss of up to 12% can occur from combustion of residual carbon and carbonate decomposition of retorted shale particles; retorted shale particles break down to a fine ashlike material after being subjected to high temperatures in an oxidizing environment; a significant increase in pH occurs due to the loss of residual carbon; a volume reduction occurs with the addition of heat to a loaded sample with only limited access to air; and a combustion front on the order of 10/sup -6/ ft/sec can move through retorted shale at temperatures of 150/sup 0/ to 250/sup 0/C. 9 refs., 11 figs., 1 tab.

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Coupled thermo-mechanical and poro-mechanical response evaluations associated with underground coal conversion. Final report, June 1982-December 1985

Research investigations on hygrothermomechanical response modeling associated with underground coal conversion processes are reported. In particular, stress mediated cavity shapes and subsidence profiles for several field experiments are evaluated from the developed thermostructural models. These finite element codes utilize temperature dependent material properties with different constitutive characterizations, depending on the desired predictive capabilities and field applications. On the basis of the conducted thermo-elastic, thermo-elastoplastic, thermal consolidation, cavity spalling model, and parametric sensitivity simulations, criteria related to UCC site selection, cavity roof, and subsidence response prediction are identified and discussed. 15 refs., 11 figs.

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Effect of feed source in the hot water processing of Utah tar sand

The processing strategy for the effective separation of bitumen from low grade (< 10% by wt bitumen) Utah tar sands by a hot water process differs significantly from that used for the processing of high grade (> 10% by wt bitumen) Utah tar sands. Excellent separations (coefficient of separation = 0.9) can be achieved for high grade Utah tar sands by intense hot water digestion, followed by a modified froth flotation step. Such a technique is ineffective for low grade tar sands. In order to change the characteristics of the low grade tar sand, an attempt was made to enrich the bitumen content of the feed to < 10% by wt by recycle of bitumen concentration to the digestion stage. However, the quality of the separation was not improved under these circumstances. Similarly, feed enrichment by heat treating the low grade feed with recycled concentrate prior to digestion did not improve the separation. More successful separations of low grade Utah tar sands were finally achieved by modification of the viscosity of the low grade bitumen with controlled addition of diluent. 20 references.

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Beneficiation of oil shales by froth flotation and heavy media separation: Volume 2, Appendix A: Final Report

As a review, the hypothesis being tested in this program was that crushing to finer crush sizes liberates more high grade oil shale thereby allowing for increased oil recovery at higher grades. Heavy medium technology utilizing dynamic vessels can successfully upgrade properly sized oil shale. It should be stressed that the shale must be well screened to remove -28 mesh material to allow for successful plant operation. The fines if not removed an result in significant operating problems by increasing the viscosity of the medium being used. As a review, the medium mixes used for this study would suggest that, at necessary gravities of separation, a mixture between magnetite and ferrosilicon will be necessary in an operating plant. The pilot plant results suggest that some small advantage does exist in the grade recovery relationship as a function of top crush size. As the crust size decreases, a higher grade product can be recovered. For the 3/4''and 3/8''crust size, however, this product will not be better than 0.5 to 1.0 gallon per ton higher in grade as the crush size is decreased from 3/4''to 3/8''. Judging only on the heavy liquid results, here appears to be no great advantage to crushing beyond 3''for upgrading by heavy medium techniques. The true economic balance will be between final grade produced and the economics of retorting and handling of the tailings material. From the work presented herein it would appear as if no more than a two gallon per ton advantage will be achieved in the final product by crushing from say 1-1/2''to 3/8''. It is apparent that within the  28 mesh fraction, higher grade samples at internally higher recoveries can be achieved; however, when compared to the total oil feeding the plant, i.e., total ore, these recovery grade improvements are diminished. 11 figs., 16 tabs.

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Borehole-to-borehole seismic studies of an in situ coal gasification process. [Hannah II]

The Laramie Energy Research Center conducted the Second Hanna in situ coal gasification experiment in 1975-76. Sandia Laboratories fielded a significant amount of instrumentation of this test, including temperature, surface resistivity, and seismic arrays, specifically designed to provide diagnostic information as well as to develop remote monitoring methods for eventual use in a process control system. Seismic measurements made during his in situ coal gasification experiment indicate that a borehole to borehole procedure using transmission timing attenuation as well as reflection timing models in sufficient to characterize the extent of the area affected by gasification. Changes in the times of arrival as well as first peak amplitudes alone specific refracted ray path provide the partial correlation to the process. In addition, because of the relative placement of source receiver pair and the available seismic wavelengths, various reflected and refracted wave fronts overlap, requiring the use of a power spectrum technique which is based on the interference of the phases, with this technique, and visual scanning of the records, estimates of reflection times are obtained allowing the determination of a reflecting boundary which can be used to detect the vertical motion of the process. Spatial temperature profiles collected at the same time indicate that these results are consistent and provide the baseline correlation between the process and borehole to borehole technique.

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Fundamental investigations of underground coal gasification. Final report, March 1982-December 1986

This work presents several mathematical models of underground coal gasification processes. Through these models, a much better theoretical understanding of underground coal gasification becomes possible. Specific phenomena studied were the effects of high amplitude pressure oscillation, reverse combustion, spontaneous ignition at high pressures, an analytical model of reverse combustion channeling, an exploratory study of electrolinking, cavity growth behavior, and a technical evaluation of the Forestburg underground coal gasification field test at Forestburg, Alberta. This test is especially interesting because the site was escavated after completion of the experiment.

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Reaction of Green River oil shale with radical-forming reagents: summary of experimental results

A rich Green River Formation oil shale and derived materials have been subjected to solvent swelling and to radical-forming reagents. Some of the reacted shales from these experiments have been studied using Carbon-13 Nuclear Magnetic Resonance Spectroscopy. Data from swelling experiments indicate the existence of a three-dimensional organic matrix. The reaction of the shale organic matter with radical-forming reagents occurs under certain conditions, but does not result in large increases of bitumen yield. NMR studies indicate that some carbon-heteroatom bonds in the shale may be preferentially attacked by radical-forming species. One reagent may suppress coke formation when heated with shales. The attack by radicals on chemical bonds at kerogen-mineral interfaces could not be confirmed by the experimental data from this preliminary study.

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Beneficiation of oil shales by froth flotation and heavy media separation: Volume 3, Appendix B: Final report

A study to evaluate physical beneficiation processes was undertaken to assess the efficiency of beneficiating oil shale, and to measure its impact on the economics of shale oil production. This study evaluated the effect of crusher types and degree of crushing on beneficiation of oil shales, the natural beneficiation that occurs due to particle size distribution, different beneficiation techniques (heavy liquid sink-float, heavy media cyclones, and froth flotation), and the costs associated with beneficiating low grade oil shales. Every effort was made to incorporate all test available in published reports for both the Green River and Eastern Oil Shales. Results of beneficiation tests show that within the scatter in data, there is no effect of shale particle size (between 45 microns to -3''), method of beneficiation, grade of feed material (13 to 3/GPT), or type of crusher used on oil recovery. The geochemical nature of the oil shale clearly shows that maximum separation of kerogen and inorganic materials occur at particle size below 20 microns. This was verified when the froth flotation technique was used on these fine particle sizes; the oil recovery increased dramatically with much lower oil losses. Analysis of the data shows that froth flotation is the preferred technique for beneficiating oil shales as opposed to heavy media separation. 17 refs., 31 figs., 42 tabs.

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Prototype underground demonstration mine in oil shale deposits. Open file report (final), July 1976-February 1979

This report contains a summary of designs, specifications, costs, and schedules developed for a prototype oil-shale demonstration mining program to be undertaken at the Horse Draw site in the Piceance Creek Basin, Rio Blanco County, Colo. The objective of the program is to assess the feasibility of extracting oil shale and associated saline minerals from deep, rich oil shale zones that occur within the central portion of the basin. Four mining systems were specified for demonstration. These include (1) chamber and pillar mining with backfill, (2) sublevel stoping with backfill, (3) sublevel stoping with full subsidence, and (4) block caving. The report also contains a detailed breakdown of projected capital and operating costs for the program.

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Remote electromagnetic sensing of underground coal burns. Final report, June 1976-July 1978

This research program developed an induction sounding system and estimator algorithm for remote determination of the location, shape and size of the reaction zone produced by Underground Coal Gasification. It was field tested in Wyoming at DOE/LETC sites Hanna II, Phase 1 and Hanna II, Phases 2 and 3. Estimates of the volumes of coal gasified compared favorably with that obtained formerly by chemical estimation. However, the burn may have deviated to the side of the gasification wells more than was predicted by chemical instrumentation. Measurements taken repeatedly over a one-year span on one traverse at Hanna II, Phases 2 and 3 show aging characteristics that demonstrate a migration of the conducting anomaly toward the surface. The final system employed horizontal loops with a fixed separation and 0 to 10 kHz bandwidth. Soundings were made in line across the burn site. Psuedo-noise/cross-correlation techniques were employed to effectively combat the noise. The magnitude response at 1 kHz was used in the final statistical fitting of field data to induction models. Wire grid induction models were used to simulate buried metal boxes, cylinders and spheres in a conducting overburden in order to efficiently compute model responses. Box and cylinder responses were shown to be insignificantly different at coal seam depths and spheres proved to be unlikely candidates for fitting field data. The air-earth interface effect was determined to be only of secondary importance. Adding vertical gasification pipes to models did not change responses significantly at coal seam depths. Horizontal gasification pipes were simulated in the field and showed no significant change in responses.

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Simulated in situ combustion retorting in fractures between large blocks of oil shale

True in situ combustion retorting of oil shale in fractures has been simulated in six experiments by igniting the common surfaces between two instrumented blocks of oil shale. Experimental details are given for all experiments although only one of the six experiments became self-sustaining. Three ignition systems were used involving heating the injected gas, heaters between the blocks and heaters in the blocks. The data obtained allow estimation of the heating rates of the oil shale at various places, the rate of combustion zone movement, the amount of shale retorted, and the width of the combustion front. The data show that the fracture between the blocks can be closed down by condensed or coked oil, shale swelling, shale spallation, and shale fusion. Results indicate that longer blocks would be desirable in further experimentation. 18 figures, 7 tables.

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