High Temperature Downhole Reservoir Monitoring System

Abstract

Sandia has developed a downhole monitoring system
that can operate continuously at temperatures up to
240ì?Í?î©C. The developed monitoring system can be
used to measure small changing reservoir conditions,
thereby providing information on the condition of the
Geothermal reservoir. This information can help
engineers develop strategies to extend the life of
Geothermal reservoirs. The monitoring system
utilizes SOI (Silicon-on-Insulator) technology, which
is known for its inherent reliability at elevated
temperatures. The present monitoring system
measures wellbore temperatures and pressures but
other sensors such as accelerometers and strain-gage
type sensors could easily be added. By utilizing a
precision quartz pressure sensor such as the
Quartzdyne pressure sensor, pressure changes less
than .008 psi and temperature changes less than
.008ì?Í?î©C can be made. This capability enables the
monitoring system to detect earth tidal pressure
effects and earthquake-induced pressure changes. To
date, three systems have been successfully deployed.