1982 THERMAL SHALLOW RESERVOIR TESTING (open access)

1982 THERMAL SHALLOW RESERVOIR TESTING

An extensive study of the Thermal Shallow Reservoir at The Geysers was performed in 1982 to improve our understanding of the source and flow patterns of steam in the shallow anomaly and how they relate to the Thermal 4 blowout. This project included gathering and analyzing pressure transient, enthalpy, tracer and chemical data and developing a reservoir model that was consistent with this data. Following the pressure transient testing and analysis, a convection-plume with lateral-flow model was proposed. Subsequent analysis of enthalpy, tracer and chemical data corroborated this model. The high flowrate wells--Thermal 4, Thermal 10, Thermal 11 and Magma 1--produce from the high-pressure, high-permeability upflow zone. The source of this upflow is a limited fracture system connecting the shallow anomaly with the underlying main reservoir. The outlying low-pressure, low-permeability wells are supplied by lateral flow of steam from the central area. The pressure gradient from the core to the periphery is caused by condensation in the flanks.
Date: January 22, 1985
Creator: Mogen, P.; Pittinger, L. & Magers, M.
Object Type: Article
System: The UNT Digital Library
ANALYSIS OF RECHARGE COOLDOWN AT THE WESTERN BOUNDARY OF CERRO PRIETO I GEOTHERMAL FIELD (open access)

ANALYSIS OF RECHARGE COOLDOWN AT THE WESTERN BOUNDARY OF CERRO PRIETO I GEOTHERMAL FIELD

Extensive study of the Cerro Prieto geothermal field has provided much geologic and thermodynamic data of its structurally-complex, liquid-dominated reservoir. Several of the studies investigated the resource characteristics of fluid and energy flow. An early report by Mercado (1975) showed that the heat source for the part of the reservoir under development, now called Cerro Prieto I (CPI), originated in the eastern part of the field. Subsequent studies confirmed the flow of hot water from the east. A summary of several experimental and numerical studies of fluid and energy transport in the field was given by Lippmann and Bodvarsson (1983). The hydrogeologic model of Halfman et al. (1982) shows hot-water flow from the east divided into a shallow (alpha) aquifer at about 120Om and a deeper (beta) aquifer at about 170Om depth. A cross section along an east-west direction shows a central upflow to the two aquifers and uncertain geology beyond the western border of the field near well M-9. It also shows a fault dividing the line of border wells at M-29 from the inner wells at M-25 to the east. The hydrogeology of the field was described by Sanchez and de la Pena (1981) as an alluvial unit …
Date: January 22, 1985
Creator: Kruger, P.; Lam, S.; Hunsbedt, A.; Esquer, C.; Marquez, R. & Hernandez, L. Cobo, J.
Object Type: Article
System: The UNT Digital Library
ASPECTS OF DOE'S CURRENT GEOTHERMAL PROGRAM (open access)

ASPECTS OF DOE'S CURRENT GEOTHERMAL PROGRAM

In bringing you up to date on DOE's geothermal R and D programs, they are going to emphasize first those elements that may be of special interest to a reservoir engineering audience, because the activities in support of an improved understanding of hydrothermal reservoirs deserve attention. Reservoir definition, brine injection, and reservoir stimulation technologies are major elements of the Hydrothermal Research Program, and in total they account for nearly 50% of the fiscal year (FY) 1985 hydrothermal research budget. These elements fall into the essential R and D category; that is, while some basic technologies have been borrowed from the petroleum industry for geothermal service, they are often ill-suited to geothermal requirements, and cannot be used without significant technological innovations. Into this category fall the current reservoir technology, brine injection, and reservoir stimulation projects that are listed in Table 1. The reservoir technology projects include: (1) development of methods for characterizing and mapping reservoir parameters, processes, and spatial dimensions; (2) development of methods to predict and monitor reservoir changes from fluid extraction; (3) evaluation of existing methods and development of new methods for predicting the location and mapping faults and fractures in geothermal reservoirs; and (4) testing of new analysis …
Date: January 22, 1985
Creator: Mock, J. E. & Marshall, J. R.
Object Type: Article
System: The UNT Digital Library
Booster RF Program for Heavy Ions (open access)

Booster RF Program for Heavy Ions

None
Date: August 22, 1985
Creator: G., Ruggiero A. & Young, G.
Object Type: Report
System: The UNT Digital Library
Common Mode Rejection of Stack Tail Kicker Hybrids (open access)

Common Mode Rejection of Stack Tail Kicker Hybrids

The betatron heating of the core is commonly agreed to be due to a undesired difference mode in the kickers. This could be due to tolerances and mistakes in the kickers or in the hydrids which ideally drive the kickers in the sum mode. The purpose of this note is to estimate the effect of the latter. The hydrids, by the nature of their construction, have systematic errors. These errors appear to be larger than the errors which come from construction tolerances.
Date: November 22, 1985
Creator: Marriner, J.
Object Type: Report
System: The UNT Digital Library
CORRELATIONS BETWEEN VAPOR SATURATION, FLUID COMPOSITION, AND WELL DECLINE IN LARDERELLO (open access)

CORRELATIONS BETWEEN VAPOR SATURATION, FLUID COMPOSITION, AND WELL DECLINE IN LARDERELLO

A large body of field data from Larderello shows striking temporal correlations between decline of well flow-rate, produced gas/steam ratio, chloride concentration and produced vapor fraction. The latter is inferred from measured concentrations of non-condensible gases in samples of well fluid, using chemical phase equilibrium principles. Observed temporal changes in the vapor fractions can be interpreted in term of a ''multiple source'' model, as suggested by D'Amore and Truesdell (1979). This provides clues to the dynamics of reservoir depletion, and to the evaluation of well productivity and longevity.
Date: January 22, 1985
Creator: D'Amore, F. & Pruess, K.
Object Type: Article
System: The UNT Digital Library
Cryogenic structural materials for superconducting magnets (open access)

Cryogenic structural materials for superconducting magnets

This paper reviews research in the United States and Japan on structural materials for high-field superconducting magnets. Superconducting magnets are used for magnetic fusion energy devices and for accelerators that are used in particle-physics research. The cryogenic structural materials that we review are used for magnet cases and support structures. We expect increased materials requirements in the future.
Date: February 22, 1985
Creator: Dalder, E.N.C. & Morris, J.W. Jr.
Object Type: Article
System: The UNT Digital Library
Decline Curve Analysis for Infinite Double-Porosity Systems Without Wellbore Skin (open access)

Decline Curve Analysis for Infinite Double-Porosity Systems Without Wellbore Skin

This paper presents a transient pressure analysis method for analyzing the rate decline of a constant pressure well producing in an infinite double-porosity reservoir, without wellbore skin. This analysis method may be used to interpret well test rate data, and to compute the rate behavior of an infinitely acting reservoir that is being produced at constant pressure. The development of the pseudo steady state log-log type curve Is presented along with a hypothetical example of its use. This type curve allows the estimation of the two controlling parameters in double-porosity systems: {lambda} and {omega}. The first parameter, {lambda}, describes the interporosity flow, and the second parameter, {omega} describes the relative fracture storativity. This paper considers the estimation of these two parameters. The estimations of permeabilities and storativities have been described in the past, hence, are not considered. In a double-porosity system, with pseudo steady state interporosity flow, the initial infinite acting rate decline, representing only the fracture system, is followed by a constant rate flow period. The length of this constant rate flow period is controlled by the parameter {omega}. The beginning of this period is controlled by the interporosity flow parameter, {lambda}. Following this constant rate period, the rate …
Date: January 22, 1985
Creator: Sageev, A.; Da Prat, G. & Ramey, H. J., Jr.
Object Type: Article
System: The UNT Digital Library
DEVELOPMENT OF THE THERMAL SHALLOW RESERVOIR (open access)

DEVELOPMENT OF THE THERMAL SHALLOW RESERVOIR

The Geysers was discovered in 1847, and its therapeutic mineral baths were widely recognized by 1880. It was not until 1921, however, that the first steam well at The Geysers was drilled. Between 1922 and 1925, eight additional wells were drilled and tested as reported by Allen and Day. Development activity ceased until 1955 when Magma Power Company drilled the first ''commercial'' well. This success led to additional drilling in the Thermal Shallow Reservoir and the commissioning of a 12 MW power plant in September 1960, followed by a 14 MW power plant in February, 1963. This completed the commercial development of the Thermal shallow Reservoir.
Date: January 22, 1985
Creator: Raasch, G.D.
Object Type: Article
System: The UNT Digital Library
DISCUSSIONS ON A TYPE OF RESERVOIR CELL BOUNDARY IN THE GEYSERS STEAM FIELD (open access)

DISCUSSIONS ON A TYPE OF RESERVOIR CELL BOUNDARY IN THE GEYSERS STEAM FIELD

The boundaries of reservoir fluid convection cells are discreet and intricate zones, commonly sealed or reduced in permeabilities, which are often quite readily identifiable in many hydrothermal systems. Cell boundaries in the Geysers Steam Field are more vague; however, they are gradually being revealed by cumulative and extensive wellbore data. A profound example of a type of boundary has been revealed by drilling in one area of the steam field. A proposed model utilizes a sericitic alteration scheme to establish cell self-sealing. Mineralogical, permeability, and temperature properties all coincide so as to allow formation of a boundary model. This reinforces previously held views that the reservoir cell rock and hydrothermal system are greatly out of equilibrium. Such similar phenomena are suggested from drilling experiences in other parts of the steam field. Considerably, more work is required to better define and comprehend the nature and location of reservoir cell boundaries within the Geysers Steam Field.
Date: January 22, 1985
Creator: Hebein, J.L.
Object Type: Article
System: The UNT Digital Library
Electromagnetic ''Particle-in-Cell'' Plasma Simulation (open access)

Electromagnetic ''Particle-in-Cell'' Plasma Simulation

''PIC'' simulation tracks particles through electromagnetic fields calculated self-consistently from the charge and current densities of the particles themselves, external sources, and boundaries. Already used extensively in plasma physics, such simulations have become useful in the design of accelerators and their r.f. sources. 5 refs.
Date: April 22, 1985
Creator: Langdon, A. B.
Object Type: Article
System: The UNT Digital Library
Environmental radiological studies downstream from Rancho Seco Nuclear Power Generating Station (open access)

Environmental radiological studies downstream from Rancho Seco Nuclear Power Generating Station

This report summarizes the information compiled in 1984 while assessing the environmental impact of radionuclides in aquatic releases from the Rancho Seco Nuclear Power Generating Station. Gamma-emitting radionuclides discharged since 1981 are found in many of the dietary components derived from the creeks receiving the effluent wastewater. Some soils and crops are found to contain radionuclides that originate from the contaminated water that was transferred to land during the irrigation season. /sup 134/Cs and /sup 137/Cs are the primary gamma-emitting radionuclides detected in the edible flesh of fish from the creeks. Concentrations in the flesh of fish decreased exponentially with distance from the plant. No significant differences in the /sup 137/Cs activity were found between male and female fish of equal size, but concentrations may vary in fish of different size, with the season and diet. 21% of the total /sup 137/Cs and /sup 134/Cs discharged between 1981 and 1984 is associated with the creek sediments to a distance of 27 km from the plant. Fractions of the missing inventory have been transferred to land during the irrigation season or to downstream regions more distant than 27 km from the plant. The radiocesium content of the sediments in 1984 decreased …
Date: March 22, 1985
Creator: Noshkin, V. E.; Wong, K. M.; Eagle, R. J.; Dawson, J. W.; Brunk, J. L. & Jokela, T. A.
Object Type: Report
System: The UNT Digital Library
EVAULATION OF THE MAKUSHIN GEOTHERMAL RESERVOIR, UNALASKA ISLAND (open access)

EVAULATION OF THE MAKUSHIN GEOTHERMAL RESERVOIR, UNALASKA ISLAND

Analysis of an extended flow test of well ST-1 on the flanks of Makushin Volcano indicates an extensive, water-dominated, naturally fractured reservoir. The reservoir appears to be capable of delivering extremely large flows when tapped by full-size production wells. A productivity index in excess of 30,000 lb/hr/psi implies a phenomenal permeability-thickness product, in the range of 500,000 to 1,000,000 md-ft. The flowing bottomhole (1,949-foot) temperature of the fluid is 379 F, which is lower than the measured static temperature at that depth (395 F). This phenomenon, coupled with an observed static temperature gradient reversal from the maximum 399 F observed at 1,500 feet, indicates that the reservoir proper is located some distance from the well. presumably it is at a temperature slightly lower than 379 F and communicates with the wellbore via a high conductivity fracture system. A material balance calculation yields an estimate of reserves that are capable of sustaining all of the present power needs of the island (13 {+-} MW peak) with a geothermal power plant for several hundred years. Theoretically, a single large diameter well at the site of ST-1 could satisfy this requirement.
Date: January 22, 1985
Creator: Economides, Michael J.; Morris, Charles W. & Campbell, Don A.
Object Type: Article
System: The UNT Digital Library
EVIDENCE OF TWO EXTREME FLOW REGIMES OPERATING I N THE PRODUCTION ZONE OF DIFFERENT WELLS FROM LOS AZUFRES (open access)

EVIDENCE OF TWO EXTREME FLOW REGIMES OPERATING I N THE PRODUCTION ZONE OF DIFFERENT WELLS FROM LOS AZUFRES

A published method for calculating excess steam is modified in order to make it applicable to the case of a well producing fluid with a high non-condensable gas content. The method is applied to data from a number of wells from Los Azufres. The results show the expected linear relation between excess steam and the molar fraction of CO{sub 2} in the total discharge. The modified method also provides an estimate for the molar fraction of CO{sub 2} in the liquid phase of the reservoir. It is found that this concentration is relatively homogeneous in the southern section of the field, and seems to be slightly smaller in the deeper zones of the northern section. The calculated values of excess steam agree qualitatively, but not quantitatively, with values of steam quality in the undisturbed reservoir calculated by other authors. The calculation of excess steam tends to overestimate steam quality in cases where steam saturation in the reservoir is low, and has the opposite tendency when the steam quality in the reservoir is high. The first type of deviation is explained in terms of the effects of higher mobility of steam in the two-phase zone induced by pressure drawdown. The second …
Date: January 22, 1985
Creator: Nieva, D.; Gonzales, J. & Garfias, A.
Object Type: Article
System: The UNT Digital Library
Experimental Determination of Tracer Dispersivity in Fractures (open access)

Experimental Determination of Tracer Dispersivity in Fractures

Reinjection of waste hot water is commonly practiced in most geothermal fields, primarily as a means of disposal. Surface discharge of these waste waters is usually unacceptable due to the resulting thermal and chemical pollution. Although reinjection can help to main reservoir pressure and fluid volume, in some cases a decrease in reservoir productivity has been observed. This is caused by rapid flow of the reinjected water through fractures connecting the injector and producers. As a result, the water is not sufficiently heated by the reservoir rock, and a reduction in enthalpy of the produced fluids is seen. Tracer tests have proven to be valuable to reservoir engineers for the design of a successful reinjection program. By injecting a slug of tracer and studying the discharge of surrounding producing wells, an understanding of the fracture network within a reservoir can be provided. In order to quantify the results of a tracer test, a model that accurately describes the mechanisms of tracer transport is necessary. One such mechanism, dispersion, is like a smearing out of a tracer concentration due to the velocity gradients over the cross section of flow. If a dispersion coefficient can be determined from tracer test data, the …
Date: January 22, 1985
Creator: Gilardi, J. & Horns, R.N.
Object Type: Article
System: The UNT Digital Library
Experiments And Detectors For High Energy Heavy Ion Colliders (open access)

Experiments And Detectors For High Energy Heavy Ion Colliders

None
Date: October 22, 1985
Creator: T., Ludlam
Object Type: Report
System: The UNT Digital Library
FIELD DEVELOPMENT AND POWER GENERATION IN KIZILDERE, TURKEY (open access)

FIELD DEVELOPMENT AND POWER GENERATION IN KIZILDERE, TURKEY

Turkey is classified among countries which have high geothermal energy potential. Geological and geophysical explorations are continuing in promising areas. However primary emphasis was given to Western Anatolia during the last decade. As a result of these efforts Kizildere field was developed and power plant was put into operation in February 14, 1984. This paper summarizes the power plant, production problems encountered in wells during the last nine months and future field development plans.
Date: January 22, 1985
Creator: Okandan, E, & Polat, T.
Object Type: Article
System: The UNT Digital Library
The first multiwell, multitracer test in the Los Azufres geothermal field (open access)

The first multiwell, multitracer test in the Los Azufres geothermal field

None
Date: January 22, 1985
Creator: Iglesias, E.R.; Garfias, A.; Nieva, D.; Miranda, C.; Verma, S.; Corona, A. et al.
Object Type: Article
System: The UNT Digital Library
FRACSL CODE DEVELOPMENT AND CORRELATION OF EAST MESA TEST RESULTS (open access)

FRACSL CODE DEVELOPMENT AND CORRELATION OF EAST MESA TEST RESULTS

The FRACSL flow and transport code is under development as part of an effort to improve reservoir characterization techniques. The present version simulates a two-dimensional, isothermal reservoir composed of a global fracture network imbedded in a porous media. FRACSL simulates the hydraulic response of a reservoir to injection or backflow. The code simulates the movement of injected tracers within the reservoir by adding advective and random dispersive motions of discrete particles. FRACSL has been benchmarked against theoretical flow and transport responses in simple systems. It has been used to simulate a benchscale physical model and to correlate flow and dispersion data from the East Mesa Hydrothermal Injection Test Program. Correlation of East Mesa data has provided an estimate of an anisotropic hydraulic conductivity, a natural drift in the reservoir, and dispersivity.
Date: January 22, 1985
Creator: Clemo, T.M.
Object Type: Article
System: The UNT Digital Library
Geologic and Geochemical Investigations of the Meager Creek Geothermal System, British Columbia, Canada (open access)

Geologic and Geochemical Investigations of the Meager Creek Geothermal System, British Columbia, Canada

Meager Creek is perhaps the most intensely explored geothermal system occurring in the Cascade and Garibaldi Volcanic Belts. This paper describes the results of new lithologic, petrographic, X-ray, isotopic, and geochemical investigations of core and cuttings from the Meager Creek wells. The data demonstrate that alteration related to the present geothermal system is superimposed on basement rocks which were metamorphosed and intruded by dioritic stocks prior to the onset of volcanism. The geothermal alteration developed mainly after emplacement of hypabyssal dikes associated with Meager Mountain volcanism and is characterized by mineral assemblages consisting primarily of sheet silicates, quartz, carbonate, hematite, iron oxides, pyrite, and minor epidote, potassium feldspar, actinolite and biotite. Permeabilities within the upper portions of the reservoir are low, reflecting filling of the fracture systems by carbonate. Petrographic observations suggest that sealing of the fractures accompanied hydrothermal brecciation and boiling of the fluids.
Date: January 22, 1985
Creator: Moore, J. N.; Adams, M. C. & Stauder, J. J.
Object Type: Article
System: The UNT Digital Library
Harmonic generation of ion waves due to Brillouin backscattering (open access)

Harmonic generation of ion waves due to Brillouin backscattering

We report results of simulations of stimulated Brillouin backscatter in which we see the second spatial harmonic of the ion density fluctuation and compare with linear, fluid theory. We also describe examples of the competition between Raman and Brillouin backscatter. 21 refs., 3 figs.
Date: May 22, 1985
Creator: Estabrook, K.; Kruer, W. L. & Haines, M. G.
Object Type: Article
System: The UNT Digital Library
The Hohi Geothermal Area, Kyushu, Japan (open access)

The Hohi Geothermal Area, Kyushu, Japan

Geophysical data from surface measurements and downhole pressure/temperature data in northern Kyushu centered around Mount Waita are examined. The study area includes the geothermal fields supplying steam for the Hatchobaru and Ohtake power stations, but also extends a considerable distance to the northwest. Evidence from drilling logs, magnetotelluric surveys, lost-circulation horizons, downhole temperature surveys, and thermal and chemical properties of surface hot-spring discharge suggests the presence of a large geothermal reservoir north of the towns of Takenoyu and Hagenoyu.
Date: January 22, 1985
Creator: Pritchett, J. W.; Garg, S. K.; Farrell, W. E.; Ishido, T.; Yoshimurs, T.; Murakami, K. et al.
Object Type: Article
System: The UNT Digital Library
HYDROGEOLOGY OF THE THERMAL LANDSLIDE (open access)

HYDROGEOLOGY OF THE THERMAL LANDSLIDE

The large Thermal Landslide overlies the initial area of geothermal development at The Geysers. The landslide is waterbearing while the underlying Franciscan formation bedrock units are essentially non-waterbearing except where affected by hydrothermal alteration. Perched ground water moving through the landslide is heated prior to discharge as spring flow.
Date: January 22, 1985
Creator: Vantine, J.
Object Type: Article
System: The UNT Digital Library
Initial Chemical and Reservoir Conditions at Los Azufres Wellhead Power Plant Startup (open access)

Initial Chemical and Reservoir Conditions at Los Azufres Wellhead Power Plant Startup

One of the major concerns of electric utilities in installing geothermal power plants is not only the longevity of the steam supply, but also the potential for changes in thermodynamic properties of the resource that might reduce the conversion efficiency of the design plant equipment. Production was initiated at Los Azufres geothermal field with wellhead generators not only to obtain electric energy at a relatively early date, but also to acquire needed information about the resource so that plans for large central power plants could be finalized. Commercial electric energy production started at Los Azufres during the summer of 1982 with five 5-MWe wellhead turbine-generator units. The wells associated with these units had undergone extensive testing and have since been essentially in constant production. The Los Azufres geothermal reservoir is a complex structural and thermodynamic system, intersected by at least 4 major parallel faults and producing geothermal fluids from almost all water to all steam. The five wellhead generators are associated with wells of about 30%, 60%, and 100% steam fraction. A study to compile existing data on the chemical and reservoir conditions during the first two years of operation has been completed. Data have been compiled on mean values …
Date: January 22, 1985
Creator: Kruger, P.; Semprini, L.; Verma, S.; Barragan, R.; Molinar, R.; Aragon, A. et al.
Object Type: Article
System: The UNT Digital Library