Underground methane gas storage increases well pressure and risks
Underground gas storage (UGS) in wells helps ensure the availability of
gas in the event of an interruption in the supply. The wells used are sometimes
located in depleted gas reservoirs into which gas from other sites has been
injected, and they may cross multiple hydrocarbon zones. They must tolerate
high injection pressures, high production rates, and frequent changes in
pressure and temperature, yet still deliver gas fast enough to meet peaks in
demand. Meeting the increasing demands for natural gas requires better
management of the existing gas reservoirs and storage facilities.
An operator needed to increase the maximum methane gas storage capacity
in an existing reservoir in a Mediterranean country, mainly through an increase
in storage pressure. The country's law allows methane gas to be stored at
pressures higher than the original reservoir pressure only if a microseismic
monitoring system is permanently installed in the field and is continuously
monitored to prevent leaks and other damage to the storage system. The raw data
must also be available for governmental agencies at any time.
