24/7 monitoring of a large underground gas storage field
01 February 2023
When California-based utility company, Pacific Gas and Electric (PG&E) required a reliable system for monitoring a large underground gas storage (UGS) field, it partnered with Paulsson, Inc. to seek research funding from California Energy Commission (CEC) and develop a real-time 24/7 monitoring system. The CEC approved the proposal, resulting in a three-year research project, which started in mid-2020.
Paulsson’s solution was an acoustic and ultra-large aperture antenna, based on fibre-optic sensing technology, using distributed acoustic sensing (DAS) technology from Fotech, a bp Launchpad company.
Since installation, the system has achieved real-time gas flow detection and monitoring, both in the well and the formation, which is a world first for this type of application. It has also recorded numerous small and large earthquakes from nearby faults and those as far away as Japan and Peru, providing valuable information about the UGS formation properties.
A need for accurate monitoring
PG&E’s largest gas storage field is based at McDonald Island, California. It has a maximum capacity of 82 BCF and can provide 25 percent of Northern California’s winter peak-day gas demand. There are 87 total wells, 81 of which operate for injection and withdrawal; the other six operate as observation wells.
When gas demand is low, gas is injected into underground storage facilities, and when demand is highest during winter months, dry hydro-drought years, and a hot summer’s AC peak, gas is withdrawn to generate electric power.
Monitoring gas storage fields is vital to ensure the safety of the local community and environment, optimise operations and diversify gas resources, and protect shareholders and ratepayers from the high cost of disruptions and accidents.
Read the full article in DPA's February issue