A weekly newspaper from Mineral Wells, Texas that included local, state, and national news along with advertising.

Drill cuttings from geothermal and mineral exploration boreholes, by contrast with those from most petroleum wells, commonly are derived highly fractured and faulted, hydrothermally altered igneous and metamorphic rock sequences, and are likely to be severely contaminated. Characterization of a subsurface resource from cuttings thus requires not only especially careful sample collection, preparation, storage and examination, but also a thorough knowledge of drilling technology, local geology and the full range of potential borehole contaminants. Accurate identification of lithology from cuttings is critical for recognition and correlation of rock types likely to selectively host the desired commodity. However, many of the rocks encountered in geothermal and mineral exploration boreholes (such as gneisses and granitic rocks) can resemble one another closely as cuttings even though dissimilar in outcrop or core. In such cases, the actual rock type(s) in a cuttings sample generally can be determined by comparison with simulated cuttings of representative surface rocks, and with various geophysical and other well logs. Many other clues in cuttings, such as diagnostic metamorphic mineralogy, or sedimentary rounding and sorting, may help identify subsurface lithologies. Faults and fractures commonly are the dominant physical controls on geothermal and mineral resources. Faults occasionally can be recognized directly …

Weekly newspaper from Alto, Texas that includes local, state, and national news along with extensive advertising.

Good-quality geothermal reservoirs displaying secondary porosity exist on the upper Texas coast (Brazoria County), site of the Pleasant Bayou No. 1 and No. 2 wells, and are attributed to a moderately stable mineral assemblage, normal geothermal gradients, and low in situ pH. Major authigenic minerals are calcite, quartz, and kaolinite. Detrital feldspar has been extensively albitized at depth. Major diagenetic events overlapped, occurring in the general order-precipitation of calcite, formation of quartz overgrowths, albitization, leaching of calcite to form secondary porosity, and precipitation of kaolinite. Seventeen Brazoria County water analyses including two from the Pleasant Bayou No. 2 well were thermodynamically tested. Predictions based on equilibrium thermodynamics add new insight on mineral stabilities and are consistent with the paragenetic sequence developed from petrographic data. Early precipitation of calcite at shallow depths of burial is predicted. Low temperture and low in situ pH explain the general absence of chlorite. The use of solution-mineral equilibria as a predictor of reservoir quality is inconclusive, but well-defined clustering of waters indicates that identification of regional trends will probably be possible. Shallow waters may be the key to predicting reservoir quality at depth.

This paper summarizes the testing of five hot, geopressured aquifers in different geologic environments in Texas and Louisiana by Eaton Operating Company for the US Department of Energy. The results were encouraging. Natural gas-to-brine content ranged from 33.0 to 55.0 SCF/bbl. Gas production rates ranged from 93 to 600 MCFD. Sustained water production rates ranged from 1950 to 15,000 BWPD. Bottom-hole temperatures ranged from 260 to 327/sup 0/F. Reservoir pressures ranged from 6627 psia to 13,203 psia. A test near Beaumont resulted in discovery of oil and gas.

The thermal springs of Oregon range in composition from dilute NaHCO/sub 3/ waters to moderately saline CO/sub 2/-charged NaCl-NaHCO/sub 3/ waters. Most of the thermal springs are located in southeastern or southcentral Oregon, with a few in northeastern Oregon and near the contact of the Western Cascades with the High Cascades. Thermal springs in the central and northern parts of the Cascades generally issue moderately saline NaCl waters. Farther south in the Cascades, the thermal waters are high in CO/sub 2/ as well as chloride. Most thermal springs in northeastern Oregon issue dilute NaHCO/sub 3/ waters of high pH (>8.5). These waters are similar to the thermal waters which issue from the Idaho batholith, farther east. Most of the remaining thermal waters are Na mixed-anion waters. Based on the chemical geothermometers, Mickey Srpings, Hot Borax Lake, Alvord Hot Springs, Neal Hot Springs, Vale Hot Springs, Crump Well, Hunters (Lakeview) Hot Springs, and perhaps some of the springs in the Cascades are associated with the highest temperature systems (>150/sup 0/C).

Well specifications, drillers' logs, and temperature logs of geothermal test wells drilled at 7 sites near Mt. Hood, Oregon are presented.

This report contains tabulated oil and gas statistics compiled during 1980 in California. On-shore and off-shore oil production, gas production, reserves, drilling activity, enhanced recovery activity, unconventional heavy oil recovery, geothermal operations and financial data are reported. (DMC)

The Pauline Kraft Well No. 1 was originally drilled to a depth of 13,001 feet and abandoned as a dry hole. The well was re-entered in an effort to obtain a source of GEO/sup 2/ energy for a proposed gasohol manufacturing plant. The well was tested through a 5-inch by 2-3/8 inch annulus. The geological section tested was the Frio-Anderson sand of Mid-Oligocene age. The interval tested was from 12,750 to 12,860 feet. A saltwater disposal well was drilled on the site and completed in a Micocene sand section. The disposal interval was perforated from 4710 to 4770 feet and from 4500 to 4542 feet. The test well failed to produce water at substantial rates. Initial production was 34 BWPD. A large acid stimulation treatment increased productivity to 132 BWPD, which was still far from an acceptable rate. During the acid treatment, a failure of the 5-inch production casing occurred. The poor production rates are attributed to a reservoir with very low permeability and possible formation damage. The casing failure is related to increased tensile strain resulting from cooling of the casing by acid and from the high surface injection pressure. The location of the casing failure is now known …

Thirty-six shale samples ranging in depth from 1454 ft to 13,430 ft from Shell Oil Company No. 1 Dixie Mortgage Loan well and 33 shale samples ranging in depth from 2183 ft to 13,632 ft from Shell Oil/Delhi-Taylor Oil Corporation No. 3 A.A. McAllen well were examined by x-ray techniques to determine the mineralogical parameters of the geopressured zone in the Vicksburg Fairway. Both wells have the same weight-percent trends with depth for the mineralogy: quartz, calcite, total clay, and potassium feldspar are constant; plagioclase feldspar gradually increases; kaolinite increases; discrete illite decreases; total mixed-layer illite-smectite (I/S) decreases; illite in mixed-layer I/S increases; and smectite in mixed-layer I/S decreases. Chlorite is found only in the geopressured zone of each well.

To date, 71 geothermal wells have been drilled in Cerro Prieto. The activity has been divided into several stages, and, in each stage, attempts have been made to correct deficiencies that were gradually detected. Some of these problems have been solved; others, such as those pertaining to well casing, cement, and cementing jobs, have persisted. The procedures for well completion--the most important aspect for the success of a well--that were based on conventional oil well criteria have been improved to meet the conditions of the geothermal reservoir. Several technical aspects that have improved should be further optimized, even though the resolutions are considered to be reasonably satisfactory. Particular attention has been given to the development of a high-temperature drilling fluid capable of being used in drilling through lost circulation zones. Conventional oil well drilling techniques have been used except where hole-sloughing is a problem. Sulfonate lignitic mud systems have been used with good results. When temperatures exceed 300 C (572 F), it has been necessary to use an organic polymer to stabilize the mud properties.

Ninety-one sample splits of drill cuttings from approximately 6.1 m intervals in the 610 m hole that was completed in 1979 were provided for this study. An additional 225 sample splits (3.05 m intervals) from 536 m to the bottom of the drill hole at 1220 m were added to the study following the deepening of the drill hole. Stratigraphic and petrologic observations of the cuttings were made. Scanning electron microscope and x-ray diffractometer examinations were made of alteration minerals. The lithology and secondary mineralization are discussed.

The P.R. Girouard No. 1 Well, located approximately 10 miles southeast of Lafayette, Louisiana, was the fourth successful test of a geopressured-geothermal aquifer under the Wells of Opportunity program. The well was tested through 3-1/2 inch tubing set on a packer at 14,570 feet without major problems. The geological section tested was the Oligocene Marginulina Texana No. 1 sand of upper Frio age. The interval tested was from 14,744 to 14,819 feet. Produced water was piped down a disposal well perforated from 2870 to 3000 feet in a Miocene saltwater sand. Four flow tests were conducted for sustained production rates of approximately 4000 BWPD to approximately 15,000 BWPD. The highest achieved, during a fifth short test, was 18,460 BWPD. The test equipment was capable of handling higher rates. The gas-to-water ratio was relatively uniform at approximately 40 SCF/bbl. The heating value of the gas is 970 Btu/SCF. The reservoir tests show that is is doubtful that this well would sustain production rates over 10,000 BWPD for any lengthy period from the sand zone in which it was completed. This limited flow capacity is due to the well's poor location in the reservoir and is not a result of any production …

Oxygen isotopic compositions have been measured in drill cuttings and core samples from more than 40 wells ranging in depth to more than 3.5 km in the Cerro Prieto geothermal field. Oxygen isotopic profiles of pore-filling calcites in sandstones appear to be a reliable measure of the recent equilibrium temperature distribution in the field before production began. From these data, a detailed, three-dimensional map has been developed, showing the equilibrium temperatures in the geothermal field. A mass balance calculation has been performed using measured /sup 18/O enrichment of the geothermal brine. This calculation implies an overall water; rock volume ratio of approximately 3:1 during the history of the Cerro Prieto system. Paleotemperatures different from the present thermal regime have been studied by examining coexisting mineral systems which exchanged their oxygen with the geothermal brines at different rates.

Separate abstracts were prepared for the thirty papers included in this proceedings.

Low to moderate temperature (< 150/sup 0/C) geothermal fluids are being developed in the southern Raft River Valley of Idaho. Five deep geothermal wells ranging in depth from 4911 feet to 6543 feet (1490 to 1980 meters) and two intermediate depth (3858 feet or 1170 meters) injection wells have been drilled within the Raft River KGRA. Several shallower (1423-500 feet or 430-150 meters) wells have also been constructed to monitor the environmental effects of geothermal development of the shallower aquifer systems. Sampling of water from wells within the KGRA has been conducted since the onset of the project in 1974. Five analytical laboratories have conducted analyses on waters from the KGRA. Charge-balance error calculations conducted on the data produced from these laboratories indicated that data from three laboratories were reliable while two were not. A method of equating all data was established by using linear regression analyses on sets of paired data from various laboratories. The chemical data collected from the deep geothermal wells indicates that a two reservoir system exists within the Raft River KGRA. Each reservoir is associated with a major structural feature. These features are known as the Bridge Fault System (BFS) and the Narrows Structure (NS).

Geothermal well completion criteria have evolved from 1964 to this date. The evolution started with the common techniques used in oil-well completion and gradually changed to accommodate the parameters directly related to the mineralogic characteristics of the geothermal fluids. While acceptable completions can now be achieved, research techniques and data collection should be improved to optimize the procedures.

The detailed technical specifications for the production well, the lithologic sample analysis, and a suite of geophysical logs, consisting of electrical resistivity, spontaneous potential, gamma ray and neutron, are presented. (MHR)

Wireline well logs have three general uses in geothermal exploration and reservoir evaluation: reservoir parameter analysis, lithologic column determination, and reservoir size resolution. Reservoir flow testing data are acquired to understand the flow rate, life, and production potential of the geothermal reservoir. These data are a coarse subsurface measurement of the geothermal prospect. Wireline logs acquired from wells in a geothermal prospect are used to define in detail, or estimate the reservoir parameters of temperature, thickness, lateral size, amount of fracture and intergranular pore space, and the quantity and quality of fluid that might be produced. Laboratory measurements can be made on core samples and drill cuttings samples to define the intrinsic behavior of the materials and fluid that compose the geotheraml reservoir. Wireline log measurements are needed to correlate and link the reservoir testing and core analysis, reduce the amount of time needed for flow testing, and predict the production life (amount of heat and fluid available) in a geothermal field.

During fiscal year 1981, activities of the Hot Dry Rock Geothermal Energy Development Program were concentrated in four principal areas: (1) data collection to permit improved estimates of the hot dry rock geothermal energy resource base of various regions of the United States and of the United States as a whole, combined with detailed investigations of several areas that appear particularly promising either for further energy extraction experiments or for future commercial development; (2) successful completion of a 9-month, continuous, closed-loop, recirculating flow test in the enlarged Phase I System at Fenton Hill, New Mexico - a pressurized-water heat-extraction loop developed in low-permeability granitic rock by hydraulic fracturing; (3) successful completion at a depth of 4084 m (13,933 ft) of well EE-3, the production well of a larger, deeper, and hotter, Phase II System at Fenton Hill. Well EE-3 was directionally drilled with control of both azimuth and inclination. Its inclined section is about 380 m (1250 ft) vertically above the injection well, EE-2, which was completed in FY80; and (4) supporting activities included new developments in downhole instrumentation and equipment, geochemical and geophysical studies, rock-mechanics and fluid-mechanics investigations, computer analyses and modeling, and overall system design. Under an International …

Sixty-five papers are included. Eleven papers were entered into the data base previously. Separate abstracts were prepared for fifty-four. (MHR)

The duration of heating in the Cerro Prieto reservoir was estimated by relating the fading of spontaneous fission tracks in detrital apatite to observed temperatures. The rate of fading is a function of both time and temperature. The apparent fission track age of the detrital apatites then, is a function of both their source age and their time-temperature history. Data from laboratory experiments and geologic fading studies were compiled from published sources to produce lines of iso-annealing for apatite in time-temperature space. Fission track ages were calculated for samples from two wells at Cerro Prieto, one with an apparently simple and one with an apparently complex thermal history. Temperatures were estimated by empirical vitrinite reflectance geothermometry, fluid inclusion homogenization and oxygen isotope equilibrium. These estimates were compared with logs of measured borehole temperatures. The temperature in well T-366, where complete annealing first occurs, was estimated to be between 160 and 180{sup 0}C. Complete annealing at these temperatures requires 10{sup 4} and 10{sup 3} years, respectively. Well M-94 has an apparently complex thermal history. Geothermometers in this well indicate temperatures some 50 to 100{sup 0}C higher than those measured directly in the borehole. Fission tracks are partially preserved in M-94 where …

As part of its effort to more accurately describe the nations geothrmal resource potential, the US Department of Energy/Division of Geothermal Energy contracted with the Colorado Geological survey to appraise the hydrothermal (hot water) geothermal resources of Colorado. Part of this effort required that the amount of energy that could possibly be contained in the various hydrothermal systems in Colorado be estimated. The findings of that assessment are presented. To make these estimates the geothermometer reservoir temperatures estimated by Barrett and Pearl (1978) were used. In addition, the possible reservoir size and extent were estimated and used. This assessment shows that the total energy content of the thermal systems in Colorado could range from 4.872 x 10{sup 15} BTU's to 13.2386 x 10{sup 15} BTU's.

The State Highway Department Buildings in Glenwood Springs have been evaluated in this appraisal for the use of geothermal energy in state-owned buildings. Glenwood Springs is the location of surface hot springs and has been assessed by various parties for several geothermal applications. The Glenwood Highway Department Buildings consist of an office building and a maintenance garage. These two building140 gpm. currently use an array of natural gas forced air furnaces and electric heaters for space/heating purpose; a propane unit is used for one water heater. Retrofit engineering for geothermal heating is based upon a central plate-in-frame heat exchanger coupled to several fan coil heaters and unit heaters. Design heating can be accomplished with 150/sup 0/F geothermal water at 140 gpm. The geothermal energy economics are evaluated for a single deep well, with and without a proration of the total production well cost for the required 140 gpm out of the 1000 gpm production capacity. Only the prorated well cost option provides an economically feasible geothermal system. The feasibility, therefore, depends on the use of the excess geothermal water by private or municipal facilities. The principal institutional/environmental issue for a geothermal heating sytem for the Highway Department Buildings is the …