High temperature electronics for geothermal energy

Instrumentation for geothermal borehole measurements is being expanded beyond today's limited capabilities. Prototype logging tools have been successfully field-tested to 275°C; a high-resolution quartz pressure transducer and a gallium phosphide diode have been successfully tested. Near-term goals of current programs are to develop instrumentation for use at 275° in pressures up to 48.3 MPa (7000 psi).