California methane leak finally halted

After two months of drilling, SoCalGas had finally established a relief well to plug its massive Porter Ranch methane gas leak, where a ruptured well in the Aliso Canyon storage field has been releasing thousands of tons of gas into the Porter Ranch section of Los Angeles since October 2015. The relief well intersects the base of the leaking well, which has allowed workers to pump in heavy fluids and mud to cap the leak, thereby bringing the problem under control. According to an Incident Update report released by SoCalGas, control is the first of three major milestones to stopping the leak, referred to as the “three C’s.”

The next steps include cementing and confirmation. Cementing is the process of pouring cement down the relief well to permanently separate the leaking well from the reservoir of gas. Confirmation that the well is permanently sealed will come from the Division of Oil, Gas and Geothermal Resources, who will carry out their own inspection process to ensure that the well will not reopen.

SoCalGas remains on schedule to stop the leak by the end of February, at the latest.

According to the San Francisco Chronicle, the total amount of methane released from the Aliso Canyon well ranges from 80,000 to 95,000 metric tons, or 2 to 2.38 million tons of carbon dioxide equivalent. The methane leak served as the single largest source of greenhouse gas emission in the State of California for over 3 months.

The incident, that forced more than 4000 houseolds to relocate, raised attention on the issue of methane leaks in the US state.


(Image: Aliso Canyon facility, December 14, 2015. Photo credit: Scott L/Flickr)