Southern California Gas Co. recently used innovative methane gas capture technology to empty natural gas from a permanently abandoned pipeline in Santa Clarita, Calif. The special process enables gas to be saved for later use while eliminating noise and emissions that occur in the traditional venting method. In total, approximately 390,000 cubic feet of natural gas was captured – about what 2,020 homes use each day on average in the U.S.
As part of the project, crews decommissioned a two-and-half-mile section of pipeline that was recently replaced by a new pipeline in a new location. The work required the pipe to be completely emptied of about 422,050 cubic feet of natural gas. Instead of following standard protocol of venting the gas, workers compressed most of it and then pumped it into two large tanks so it could be put back into the system and used by customers. Some gas along the two-and-half mile pipeline was vented to the atmosphere, but, because pressure was reduced from 220 psi to 31 psi, there was a significant reduction in the amount of gas lost to the atmosphere.
“We’re pleased to continue to use this groundbreaking innovation,” said Rick Phillips, senior director of SoCalGas’ Pipeline Safety Enhancement Plan. “Capturing the methane we would traditionally vent to atmosphere not only reduces noise or smells neighbors might notice, but also minimizes impacts to the environment. We hope to expand the use of this new innovation whenever its application may be suitable.”
SoCalGas has been utilizing methane capture technology for about nine months. To date, the company has captured and reinjected more than 900,000 cubic feet of natural gas back into its system. This is approximately equal to what 4,660 homes use each day on average in America. Prior to the use of methane capture technology, this natural gas would have been vented and lost to the atmosphere.
The methane capture technique is being used as part of SoCalGas’ Pipeline Safety Enhancement Plan, a multi-billion-dollar program that identifies various high pressure pipeline sections throughout SoCalGas’ system and schedules them to be pressure-tested or replaced. PSEP also includes provisions to upgrade, replace or retrofit hundreds of mainline valves in the system with technology that allows them to be opened or closed remotely by system operators from a central control location, or that automatically shuts off the flow of natural gas in the event of a large drop in pressure.
In 2017, the company plans to invest approximately $1.2 billion in improvements to distribution, transmission and storage systems and for pipeline safety.