The Alpha Fuels Environmental Test Facility (AFETF) impact gun is a unique tool for impact testing /sup 238/PuO/sub 2/-fueled heat sources of up to 178-mm dia at velocities to 300 m/s. An environmentally-sealed vacuum chamber at the muzzle of the gun allows preheating of the projectile to 1,000/sup 0/C. Immediately prior to impact, the heat source projectile is completely sealed in a vacuum-tight catching container to prevent escape of its radioactive contents should rupture occur. The impact velocity delivered by this gas-powered gun can be regulated to within +-2%.

Ultralow to low-frequency oscillatory phenomena of elastomechanical nature have been observed in a number of geothermal areas. These include pressure and water level oscillations in the tidal frequency range 10{sup -6} to 10{sup -4} Hz (White, 1968), flow oscillations at around 10{sup -3} Hz (Bodvarsson and Bjornsson, 1976) and ground noise in the range 10{sup -1} to 10 Hz (Douze and Sorrel, 1972). The presence of such oscillations conveys certain information on the underlying geothermal systems which is of both theoretical and practical interest. In the following, we will very briefly discuss a few aspects relating to the interpretation of oscillatory field data with the main emphasis on borehole tides. 3 figs., 4 refs.

Morgantown Energy Technology Center (METC) is planning to expand its in-house coal gasification R&D capabilities by installing a research facility that can address a number of concepts including entrained, fluid bed, and catalytic gasification and flash pyrolysis. This Advanced Gasification Concepts (AGC) facility design, as it currently stands, includes piping and instrumentation diagrams, vessel drawings and specifications, instrumentation lists and specifications, and equipment layout and isometric drawings. Before the design is finalized, a critique is needed to ensure that the intended flexibility and objectives can be met. The design approach was evaluated to determine whether the present design will meet the research objectives, including the need for flexibility. Heat and material balances, critical velocity requirements, vessel arrangements, potential operational problems, and instrumentation were reviewed. The mechanical design review included a critique of the drawings and specifications, adherence to standards and codes, materials of construction, vessels, piping, valves, heaters, and fittings. In addition, utilities requirements, heat transfer and particulate removal calculations, and pumping and heat exchanger requirements were checked. An evaluation of the equipment cost includes a critique of the reliability of the equipment cost breakdown, the areas of cost uncertainty, and the areas for potential cost savings. A safety analysis …

An investigation of the relative utility and performance of nine major household consumer products covered by the Energy Policy and Conservation Act is summarized. The objective was to define the terms utility and performance, to recommend methods for quantifying these two concepts, and to recommend an approach for dealing with utility and performance issues in the energy efficiency standards program. The definitions developed are: performance of a consumer product is the objective measure of how well, with the expected level of consumer input (following the manufacturer's instructions for installation and operation), the product does its intended job; and utility of a consumer product is a subjective measure, based on the consumer's perception, of the capability of the product to satisfy human needs. Quantification is based on test procedures and consumer survey methods which are largely already in use by industry. Utility and performance issues are important in product classification for prescribing energy efficiency standards. The recommended approach to utility and performance issues and classification is: prior to setting standards, evaluate utility and performance issues in the most quantitative way allowed by resources and schedules in order to develop classification guidelines. This approach requires no changes in existing Department of Energy …

The engineering necessity of achieving maximum cooling of the borehole during drilling and logging operations on geothermal wells prohibits the determination of equilibrium temperature in the sub-surface before virtual rebound from the drilling disturbance some months after operations cease. Clearly, substantial economic benefits would accrue, in many cases, if a reasonable prediction of equilibrium temperature can be made while the rig is still over the borehole. The purpose of this brief report is to provide an abbreviated explanation of the physical principles of temperature rebound and provide a convenient plotting method similar to the Horner plot in order to standardize temperature prediction in Geothermal Operations. It has the further purpose of outlining methods to determine an approximate thermal conductivity value for reservoir rocks and rebound times after drilling from the nature of the rebound curve. 2 refs., 2 figs.

Relative intensities for K x-rays and gamma rays emanating from /sup 99/Mo in equilibrium with its /sup 99/Tc* daughter have been measured using several Ge photon detectors. Combining these intensities with an evaluated set of electron-conversion coefficients has provided a set of absolute intensities for the observed gamma rays. The absolute intensity for the dominant 140.5-keV gamma ray in /sup 99/Tc was determined to be 90.7 +- 0.6/100 /sup 99/Mo disintegrations for /sup 99/Mo decay in equilibrium with decay of the /sup 99/Tc* daughter.

Flow tests and pressure measurements were made on a group of five wells in the Momotombo geothermal reservoir, Nicaragua. The purpose of these tests was to evaluate the hot water reservoir, to determine well interference effects, to determine reservoir boundary conditions and to obtain mass flow rates and enthalpy. Static bottom hoe pressures were measured on three wells and bottom hole flowing pressures and shut-in buildup pressures were measured on one of the wells. A Hewlett-Packard quartz crystal pressure gauge was used in connection with a Sperry Sun expandable chamber hung on steel capillary tubing to measure downhole pressure. Flow tests were made on all five wells. Four wells were flowed through a horizontal discharge pipe. One well was flowed through a vertical discharge pipe. 2 refs., 7 figs.

The code is primarily a manager of probabilistic data and deterministic mathematical models. The user determines the desired aggregation of the available models into a composite model of a physical system. MACRO1 then propagates the finite probability distributions of the inputs to the model to finite probability distributions over the outputs. MACRO1 has been applied to a sample analysis of a nuclear-waste repository, and its results compared satisfactorily with previously obtained Monte Carlo statistics.

Work during the period included analytic studies of vent clearing and jet-slug dynamics and computer simulations (HEMP and CHAMP codes) of pressure suppression experiments.

Plutonium is a man-made element whose behavior in the marine environment is inadequately known at present. It has been studied intensively in connection with production of weapons and power sources and has been characterized as an extremely toxic substance. Nevertheless, only a few dozen measurements have been made of concentrations in seawater and in the associated organisms and sediments. The first of these were as recent as 1964. There are reasons to believe its chemical behavior in the ocean is different from what has been observed on land, and that it will be difficult to predict how plutonium will distribute itself in the ocean. The consequences of increased environmental concentrations of Pu are discussed. (auth)

This paper is concerned with the optimal time to commence extraction of energy from a hot-water geothermal reservoir. The economic models that we have presented in the past have the common characteristics that the extraction program starts immediately (see References 1 and 2). Based on this assumption, we determined optimal extraction strategies and planning horizons such that the present values of total profits were maximized. In this study we relax the requirement that extraction be undertaken immediately, seeking instead the delay in starting time that along with the other decision variables maximizes the present value of total profits over the economic life of the reservoir. Of course, optimal starting time, economic life of the reservoir, optimal extraction rate, and optimal injection temperature are interrelated, and therefore, we analyze their effect on the overall planning strategy simultaneously. 4 refs.

Recent studies of liquid-dominated systems suggest that geothermal anomalies are intimately associated with specific patterns of faulting. One may infer from these studies that the East Mesa anomaly is intersected by a seismically active fault which acts as a conduit of heated water from depth. This paper describes such a model of the Mesa system. 28 refs.

White, Muffler, and Truesdell (1971) and Truesdell and White (1973) developed a conceptual model of transport in vapor-dominated geothermal zones. The main theme of the model is that coexisting liquid and vapor phases form a counterflowing convection system similar to that observed in a heat pipe (Dunn and Reay, 1976). It is hypothesized that water evaporates from a deep water table, passes upward through the formation, and condenses at an impermeable cap rock, effectively transferring the latent heat of boiling through the formation. The liquid water then percolates downward, completing the cycle. The physics involved in the flow system is illustrated in an analysis of an idealized one-dimensional, homogeneous, 2 km deep vapor-dominated zone which is bounded below by a water table which has a temperature of 236°C. Flow of water and steam in the system is assumed to be described by Darcy’s law for unsaturated porous materials. The liquid water potential, defined as the Gibbs free energy per unit volume of water, is used in place of the liquid pressure in the equation for water because flow in a highly unsaturated medium is to be considered. Comparison of figures 2 and 4 illustrates that the liquid saturation in a …

Japan is scarce in domestic natural resources. In fact, the degree of dependence on imports of basic raw materials is quite high. This paper describes primary energy supply as a background to the status of geothermal energy developments, and geophysical well logging in geothermal wells. 3 refs., 5 tabs., 5 figs.

The emphasis of the smaller scale laboratory of the Stanford Geothermal Program is on improving the understanding of the physics of flow through porous materials in a geothermal environment. Three major investigations are in progress: (1) examination of the phenomenon of vapor pressure lowering in porous media, (2) determination of the temperature dependence of absolute and relative permeabilities of steam and water in sandstones under high confining pressures, and (3) observation of steady and unsteady, single- and two-phase flows of water or brine through permeable cores. In addition, development continues on the dielectric constant liquid content detector—a device which would prove extremely useful in these and subsequent experiments. 10 refs., 4 figs.

The Reservoir Engineering Management Program being conducted at Lawrence Berkeley Laboratory includes two major tasks: 1) the continuation of support to geothermal reservoir engineering related work, started under the NSF-RANN program and transferred to ERDA at the time of its formation; 2) the development and subsequent implementation of a broad plan for support of research in topics related to the exploitation of geothermal reservoirs. This plan is now known as the GREMP plan. Both the NSF-RANN legacies and GREMP are in direct support of the DOE/DGE mission in general and the goals of the Resource and Technology/Resource Exploitation and Assessment Branch in particular. These goals are to determine the magnitude and distribution of geothermal resources and reduce risk in their exploitation through improved understanding of generically different reservoir types. These goals are to be accomplished by: 1) the creation of a large data base about geothermal reservoirs, 2) improved tools and methods for gathering data on geothermal reservoirs, and 3) modeling of reservoirs and utilization options. The NSF legacies are more research and training oriented, and the GREMP is geared primarily to the practical development of the geothermal reservoirs. 2 tabs., 3 figs.

Experiments are being conducted in the Stanford Geothermal Program (SGP) large geothermal reservoir model utilizing rock systems with several characteristics resembling high permeability, fracture-stimulated systems. The broad objective of these experiments is to evaluate nonisothermal fluid production and heat transfer processes and to analytically model these for such rock systems. Three nonisothermal energy extraction and production processes, referred to here as in-place boiling, sweep, and steam-drive, were considered during the early phases of this study. The results showed that all three processes are feasible in the experimental systems considered. However, the effectiveness of the processes varied widely. The simple analytic models developed for the model reservoir and for the heat transfer from the rock successfully predicted the experimental results as long as the assumptions inherent in the models were not seriously violated. However, it was recognized that more detailed experimental and analytic studies of the heat transfer aspects were required, and such studies have since been performed by Iregui [Reference 4]. The final report of these results is in preparation and the highlights are given below. 2 tabs., 5 refs., 4 figs.

Precision gravity methods provide new information regarding geothermal reservoir mechanisms and depletion. This paper discusses the principles of present interpretations and early conclusions from two producing geothermal fields, Wairakei, in New Zealand, and The Geysers, California. 4 refs., 4 figs.

Hot water geothermal fields discharge steam-water mixtures, which have proved difficult to measure compared with the dry steam from fields like The Geysers and Lardarello. Hot water geothermal fields discharge steam-water mixtures, which have proved difficult to measure compared with the dry steam from fields like The Geysers and Lardarello. With the development of the lip pressure method, however (James 1962), an accurate method was derived which could measure the flow when a geothermal well discharges to the atmosphere at sonic velocity. Fortunately most discharges from wells do in fact attain such velocities, and as long as the enthalpy of the mixture is known, the flow can be determined. Where the enthalpy is unknown some other measurement has also to be made in order to solve the two factors of flow and enthalpy. By discharging the whole mixture into a silencer, the water portion can be estimated by means of a weir, and this provides the second measurement (described in James 1966) required to solve both unknowns. With the hoped-for commercial success of the total energy turbine in the near future, it will be necessary to have a means of measuring the steam-water flow into the machine. As long as …

Recent syntheses of geophysical work at The Geysers (Chapman 1975, Isherwood 1975) have provided useful insights into regional structure in this complex and chaotic area. Regional studies of this type, however, are of limited value to reservoir investigations and it may be that the more detailed temperature gradient/heat flow studies (Frye 1976) can supply more useful information. This paper describes results of a study carried out on the Rorabaugh lease in the southwest sector of The Geysers geothermal field. The success of this survey in a comparatively simple situation suggests that it may be developed to handle more complex areas with shallow hot water zones, variable lithology and variable microclimates. If this can be done, it may provide a useful link between geothermal exploration and reservoir engineering. 5 refs., 1 fig.

The experimental well, HGP-A, drilled under the auspices of the Hawaii Geothermal Project, is located on the island of Hawaii near the eastern rift of Kilauea volcano. Drilling was completed to a depth of 6450 feet in April 1976. The well is cased to 2230 feet below the surface, which is 600 feet above sea level, with a slotted liner running from the end of the casing to bottomhole. Cuttings and core samples obtained during drilling indicate that the region is composed of volcanic basalt with a profile that contains a zone of open fractures (3300-4500 feet) and a zone of partially sealed fractures (4500-6450 feet) as shown in Figure 1. Conclusions from preliminary test results and analyses: the Kapho Geothermal Reservoir is liquid-dominated, with permeability thickness of ~ 1000 md-ft, very high temperatures ~ 350°C, high formation pressure ~ 2000 psi, slightly brackish water, and high silica content, and is potentially large; the HGP-A Geothermal Well borehole contains steam and water at saturation during flash; flashing occurs in formation; the well has high wellhead pressures ~ 160 psi at 50 Klb/hr steam, probably has severe skin damage, and potential power output ~ 3.5 MWe; the well’s producing regions are …

Since the last conference, a fourth well has been drilled to an intermediate depth and tested as a production well, with plans to use this well in the long term for injection of fluids into the strata above the production strata. The third, triple legged well has been fully pump tested, and the recovery of the second well from an injection well back to production status has revealed very interesting data on the reservoir conditions around that well. Both interference testing and geochemistry analysis shows that the third well is producing from a different aquifer than that supplying the No. 2 well. There is an effective barrier, yet unidentified as to structure, making pressure communication between these aquifers quite negligible. These results have led to significantly different models for the aquifer system than those previously believed to apply. 3 figs., 1 tab., 3 refs.

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The producing characteristics of vapor-dominated geothermal steam reservoirs bear some strong resemblances to those observed in hydrocarbon natural gas reservoirs. Consequently, many geothermal steam well tests are commonly analyzed using flow theory developed for the isothermal flow of hydrocarbon natural gases. Such analysis is most often made using the idealization of perfect gas fluid flow behavior in the reservoir. This study investigated the real gas flow characteristics of geothermal steam over the ranges of pressure, temperature, and noncondensable gas content commonly found in vapor dominated geothermal systems. Details of this study are available elsewhere (Mannon, 1977). These results will allow the reservoir engineer to more accurately analyze transient flow of superheated geothermal steams. Geothermal steam wells have traditionally been analyzed using the ideal gas flow model, described by Eq. 1, without quantitative justification. The results of this study will allow for quantitative justification of the ideal gas flow assumption, where possible. Alternatively, they will facilitate use of the more correct pseudo-pressure function when analyzing geothermal steam wells. 5 refs., 2 tabs., 2 figs.