Sourcebook on high-temperature electronics and instrumentation

This sourcebook summarizes the high-temperature characteristics of a number of commercially available electronic components and materials required in geothermal well-logging instruments that must operate to 275/sup 0/C. The sourcebook is written to provide a starting place for instrument designers, who need to know the high-temperature electronic products that are available and the design and performance limitations of these products. The electronic component information given includes the standard repertoire of passive devices such as resistors, capacitors, and magnetics; the active devices and integrated circuits sections emphasize silicon semiconductor JFETs and CMOS circuits; and, to complete the electronics, interconnections and packaging of hybrid microelectronics are described. Thermal insulation and refrigeration alternatives are also presented in the sourcebook. Finally, instrument housing materials and high-temperature cables and cablehead connectors are listed. This information was compiled as part of the Geothermal Logging Instrumentation Development Program that Sandia National Laboratories conducted for the US Department of Energy's Divison of Geothermal Energy from 1976 to 1981

Pressure measurements in low permeability formations

This paper examines the performance requirements and identifies candidate hardware implementations for pressure instrumentation that is needed to provide well test data in low permeability formations. Low permeability values are typically defined to be less than 1 microdarcy and are usually encountered in hard rock formations, such as granite, that are of interest in hot dry rock geothermal, deep exploration drilling, and fluid waste disposal. Groundwater flow in these tight formations has been shown to be dominated by flow-through fractures rather than through the formation's intrinsic permeability. In these cases, we cannot use Darcy's law or the usual dimensionless coefficients to estimate the expected scale factors and dynamic responses necessary to properly select and setup the wellbore pressure instrument. This paper shows that the expected instrument responses can be estimated using some recent work by Wang, Narasimhan, and Witherspoon. This paper further describes the minimum electronic capability that the downhole pressure instrument must have in order to provide the required measurement resolution, dynamic range, and transient response. Three specific hardware implementations are presented based on the following transducers: a quartz resonator, a capacitance gauge, and a resistance strain gauge

Geothermal Logging Instrumentation Development Program Plan (U)

This Geothermal Logging Instrumentation Development Program Plan outlines a nine-year, industry-based program to develop and apply high temperature instrumentation technology which is needed by the borehole logging industry to serve the rapidly expanding geothermal market. Specifically, this program will upgrade existing materials and sondes to improve their high-temperature reliability. To achieve this goal specialized equipment such as high temperature electronics, cables and devices for measuring formation temperature, flow rate, downhole pressure, and fractures will be developed. In order to satisfy critical existing needs, the near-term (FY80) goal is for operation at or above 275/sup 0/C in pressures up to 48.3 MPa (7,000 psi). The long-term (FY84) goal is for operation up to 350/sup 0/C and 138 MPa (20,000 psi). This program plan has been prepared for the Department of Energy's Division of Geothermal Energy (DGE) and is a portion of the DGE long-range Geothermal Well Technology Program

Development of a high resolution downhole pressure instrument for high temperature applications

As part of the Geothermal Logging Instrumentation Development Program being conducted by Sandia Laboratories for the Department of Energy's Division of Geothermal Energy, high resolution, quartz crystal based, downhole pressure instruments are being developed. Under a joint no-cost contract, Sandia and Paroscientific, Inc., of Redmond, Washington, are working to upgrade a Paroscientific transducer for operation at 275/sup 0/C. In addition, Sandia Laboratories has been investigating various design configurations and fabrication techniques for high temperature quartz resonators and their associated electronic circuits. The goal of these efforts is to achieve a resolution of 0.01 psi in a 0 to 7000 psi range and in temperatures up to 275/sup 0/C. The progress and plans for this project will be reviewed and hardware samples will be displayed

High temperature electronics and instrumentation seminar proceedings

This seminar was tailored to address the needs of the borehole logging industry and to stimulate the development and application of this technology, for logging geothermal, hot oil and gas, and steam injection wells. The technical sessions covered the following topics: hybrid circuits, electronic devices, transducers, cables and connectors, materials, mechanical tools and thermal protection. Thirty-eight papers are included. Separate entries were prepared for each one. (MHR