Geothermal brines at 600 F which contain metallic salts, H{sub 2}S, and hydrocarbons quickly degrade conventional hydrocarbon elastomers, and hydrolyse crosslinks. Carbon-carbon and carbon-fluorine bonds are expected to be superior, but no such elastomer is now commercially available. We have prepared crosslinked, perfluorocarbon elastomers by radiation crosslinking VDFHFP and TFEP (alternating) copolymers in film and sheet form, and then converting C-H bonds to C-F bonds with elemental Fluorine gas. EPLM elastomers became brittle on fluorination. The best products exceeded 100 days survival at 300 C in simulated geothermal brine. Tensile, elongation, solvent swelling, and TCA methods were used to study the products.

Rankine cycle power plants operate on a closed cycle in which heat is transferred from a high temperature reservoir to a low temperature sink while performing useful work. leaks in this cycle cause the loss of working fluid and/or corrosion of the power plant. Both of these constitute a loss of capital assets. A severe leak can reduce the efficiency of the cycle to the extent of creating an operating loss. PNL is undertaking the development of continuous monitoring techniques to protect rankine cycle plants from such losses. The location of these continuous monitors on an organic rankine cycle is described and shown schematically.

The most important difference between traditional steam systems and those that utilize geothermal fluids is the potential for corrosion of metals. The recently developed sourcebook ''Materials Selection Guidelines for Geothermal Energy Utilization Systems'' is expected to facilitate corrosion engineering decision making and reduce the cost of geothermal systems where new resources are similar to those presented by the corrosivity classification system.

In response to the need for tapping national energy resources, an improved high temperature sealing material has been developed through the sponsorship of the Department of Energy. Parker Seal was selected as one of the technology transferees from L'Garde Inc. and has optimized this transferred technology for further improved performance capabilities and acceptable plant processing. This paper summarizes Parker Seal's testing and evaluation efforts on L'Garde's Y267 transferred technology for a new geothermal and stream service material. This new product, Parker's E962-85 is described in this paper.

The authors must have accurate knowledge of the geothermal fluid chemistry at operating temperature if they are to optimize operation, prevent corrosion, increase equipment service life and maximize profit and use. Available electrochemical sensors do not survive at the temperatures encountered in geothermal fluids; and new developments in this area are required. In order to fill this gap in technology, the Pacific Northwest Laboratory (PNL) is developing chemical control and monitoring instruments for measuring in situ characteristics of geothermal fluids. Progress in the development of electrochemical sensors to measure pH, carbonate and sulfide-sulfur is discussed.

This paper addresses how designers can take into account, the necessary chemical and materials precautions that other geothermal power plants have learned. Current worldwide geothermal power plant capacity is presented as well as a comparison of steam composition from seven different geothermal resources throughout the world. The similarities of corrosion impacts to areas of the power plants are discussed and include the turbines, gas extraction system, heat rejection system, electrical/electronic systems, and structures. Materials problems and solutions in these corrosion impact areas are identified and discussed. A geothermal power plant design team organization is identified and the efficacy of a new corrosion/materials engineering position is proposed.

The results of an investigation conducted to determine the corrosion characteristics of a number of alloys in a high saline environment are discussed. The ferritic stainless steels and several copper/nickel alloys exhibited good corrosion resistance in these high saline geothermal environments.

The California Division of Mines and Geology (CDMG) selected the San Bernardino area for detailed geothermal resource investigation because the area was known to contain promising geothermal resource sites, the area contained a large population center, and the City of San Bernardino had expressed serious interest in developing the area's geothermal resource. Ninety-seven geothermal wells and springs were identified and plotted on a compiled geologic map of the 40-square-mile study area. These wells and springs were concentrated in three distinguishable resource areas: Arrowhead Hot Springs, South San Bernardino, and Harlem Hot Springs--in each of which detailed geophysical, geochemical, and geological surveys were conducted. The Arrowhead Hot Springs geothermal area lies just north of the City of San Bernardino in the San Bernardino Mountains astride a shear zone (offshoot of the San Andreas fault) in pre-Cambrian gneiss and schist. The Harlem Hot Springs geothermal area, on the east side of the City, and the South San Bernardino geothermal area, on the south side, have geothermal reservoirs in Quaternary alluvial material which overlies a moderately deep sedimentary basin bound on the southwest by the San Jacinto fault (a ground water barrier). Geothermometry calculations suggest that the Arrowhead Hot Springs geothermal area, with …

Data relative to aquifer locations, temperature, and water quality for Pleistocene aquifers has been collected and preliminary interpretations of this data are presented here.

High performance elastomers were developed for hostile geothermal environments which clearly advance the state-of-the-art. The Y267 EPDM compound is eminently successful and has accumulated broad laboratory and field test experience. Over 15 separate tests are reviewed with about 95% performed independently by other organizations. The tests include a broad spectrum of environments with temperatures in excess of 320 C (608 F), differential pressures up to 138 MPa (20,000 psi) and in fluids including brine, oils, isobutane, and others.

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The exploitation of geothermal resources often requires that naturally heated subterranean brines be pumped to the surface from depths of up to 6000 feet underground while minimizing heat losses and maintaining sufficient fluid pressure to prevent boiling. To accomplish this requires the use of downhole brine pumps capable of months of uninterrupted operation. Significant problems have occurred with pump lineshaft bearings in the geothermal wells. The objective of this research program was to determine the nature of the problems associated with commonly reported premature failures of downhole lineshaft pump bearings. Using the information gathered, a series of bearing endurance tests was performed on a variety of candidate bearing materials. These tests were accomplished using test rigs specially developed to simulate actual geothermal field conditions and to isolate specific bearing wear problems.

A specific polymer concrete formulation was applied as a steel pipe liner in response to a need for durable, economical materials for use in contact with high temperature geothermal brine. Compressive strengths of up to 165.8 MPa and splitting tensile strengths of 23.5 MPa were measured at ambient temperature. Compressive strengths of 24 MPa and splitting tensile strengths of 2.5 MPa were measured at about 150 C. Cost of piping a geothermal plant with PC and PC-lined steel pipe is calculated to be $1.21 million, which compares favorably with a similar plant piped with alloy steel piping at a cost of $1.33 million. Life-cycle cost analysis indicates that the cost of PC-lined steel pipe would be 82% of that of carbon steel pipe over a 20-year plant operating life.

The exploration techniques employed during the study included: (1) Temperature survey of selected wells and springs; (2) Chemical analysis of fluids from selected wells and springs; and (3) Temperature-depth measurements of selected holes of opportunity.

Chairman William Ogle said the overall purpose of the meeting was to consider how the US government, and the Division of Geothermal Energy in particular, might apply its geothermal effort more effectively. Given the present situation, how does Uncle Sam make the best possible effort? On this theme, there are 4 main subquestions: (1) what government support is needed? (2) how can we improve cooperation between industry, the national laboratories, universities, and industries, and does it matter? (3) how do we transfer technology to industry? (4) What should the technical aims be for the next year or so?

A semi-analytical model for studies of cold water injectioninto naturally fractured reservoirs has been developed. The model can beused to design the flow rates and location of injection wells in suchsystems. The results obtained using the model show that initially thecold water will move very rapidly through the fracture system away fromthe well. Later on, conductive heat transfer from the rock matrix blockswill retard the advancement of the cold water front, and eventuallyuniform energy sweep conditions will prevail. Where uniform energy sweepconditions are reached the cold waer movement away from the injectionwell will be identical to that in a porous medium; consequently maximumenergy recovery from the rock matrix will be attained. The time ofuniform energy sweep and the radial distance from the injection wellwhere it occurs are greatly dependent upon the fracture spacing, butindependent of the fracture aperture.

A semi-analytical model for studies of cold water injectioninto naturally fractured reservoirs has been developed. The model can beused to design the flow rates and location of injection wells in suchsystems. The results obtained using the model show that initially thecold water will move very rapidly through the fracture system away fromthe well. Later on, conductive heat transfer from the rock matrix blockswill retard the advancement of the cold water front, and eventuallyuniform energy sweep conditions will prevail. Where uniform energy sweepconditions are reached the cold waer movement away from the injectionwell will be identical to that in a porous medium; consequently maximumenergy recovery from the rock matrix will be attained. The time ofuniform energy sweep and the radial distance from the injection wellwhere it occurs are greatly dependent upon the fracture spacing, butindependent of the fracture aperture.

The density oscillations of warm particle bunches is investigated theoretically. Two different mathematical approaches are employed to derive the basic equation describing density oscillations; one is a fluid approach and the second is a more general Green1s function formulation. The motion is analyzed in first order perturbation theory where it is shown, under the assumption of no degeneracy, that there are only stable oscillations. Second order perturbation theory gives damping of the motion. The perturbation theory is examined and a criterion is exhibited for its proper use. Thus, when the resistivity is small enough (but nonzero) then the motion is stable, but when the resistivity is large then the motion is essentially unstable with a growth rate which is that of an unbunched beam. The criterion is approximately evaluated using a model for a bunched beam.

The Aquatic Species Program (ASP) is concerned with how plant biomass that naturally occurs in wetland or submerged areas is utilized. Processes are being developed in this program to make use of those aquatic species, capitalizing on their inherent capacity for rapid growth as well as on their extraordinary chemical compositions.

This paper discusses the strong resemblance of near-death experiences (NDEs) to complex hallucinations associated with limbic lobe dysfunction. The paper presents the hypothesis that neurohormones with the capacity to influence hippocampal activity may also cause characteristics of NDE limbic lobe syndrome.

This paper describes deep near-death experiences (NDEs). Personal flashforwards (PFFs) and prophetic visions (PVs) involve seeing events subsequent to the NDE, and seeing planetary-wide events, respectively. The paper describes PVs that depict major global changes.

This paper describes Emanuel Swedenborg and his out-of-body experiences that have been documented. It also describes Swedenborg's ceasing of his work in the natural sciences and commencing with the publishing of spiritual books.

This paper assesses the reliability of The Life, Death, and Transition Workshop conducted by Elisabeth Kubler-Ross with the Alexander Spirituality Change Survey. "Significant positive change in spirituality by attendees was reported and appeared to be sustained over time" (abstract).

This paper discusses the positive implications of experiencing NDEs. "The available evidence shows, in decreasing order of saliency: greatly increased concern for others; lessened fear of death and increased belief in an afterlife; increased religious interest and feeling, both non-institutionalized and institutionalized; and lessened desires for material success and approval of others" (abstract). "NDErs might be harbingers of a more humane future" (abstract).