The Southern California Gas Company is facing major new hurdles before it can restart the crippled Aliso Canyon Storage Facility, the site of the worst methane leak in U.S. history.
The gas company has been barred from injecting gas into the massive underground reservoir since late last year, soon after a well, SS-25, began leaking uncontrollably. That leak took nearly four months to stop, sent more than 100,000 tons of methane into the atmosphere, and drove thousands of Porter Ranch residents from their homes.
The entire field has been shut in — with no injections or withdrawals — since Jan. 21, according to Melissa Bailey, a company spokeswoman. The company is keeping some gas in the reservoir in case of an emergency, but for now all 115 wells at the facility are idle.
On Friday, the state Division of Oil, Gas and Geothermal Resources (DOGGR) issued a new order mandating several tests and upgrades before operations can resume at the facility.
The most significant order is that the gas company will be required to withdraw and inject gas through tubes placed inside the steel well casings, instead of through the casing. On many wells, including SS-25, the gas company was producing using the wider casing. That well design, first reported by the Weekly in January, meant that the company could pump much more gas in and out of the storage reservoir than if it were using the smaller tubes.
But the design also carried a risk. Had the company been pumping gas through the tube, a hole in the tube would not have been catastrophic, because the gas would have been contained by the casing. But pumping through the wider casing meant there was only one layer of steel between the high-pressure gas and the surrounding rock. Corrosion appears to have caused a hole in the SS-25 casing at a depth of about 470 feet, and the gas vented out through the rock formation and up into the air. (See update below.)
In December, a SoCalGas executive, Rodger Schwecke, told the Weekly that there was nothing inherently dangerous about producing through the casing. “There's no reason why producing out of the casing creates greater risk,” he said.
But DOGGR now seems to disagree. The regulator ordered Friday that “if and/or when” injection into the Aliso Canyon field is allowed to resume, “all injection and production shall be through tubing only.”
This is likely to have some effect on the amount of gas that Aliso Canyon can deliver to customers, including to power plants. Retrofitting old wells to allow for “tubing flow” also is likely to cost many millions of dollars.
SS-25 was plugged in February. The gas company used a relief well to cement the leaking well at its base, nearly a mile and a half underground. SS-25 will be permanently abandoned.
It will likely be several months, at least, before the facility will be put back into service, according to Don Drysdale, a DOGGR spokesman.
Save Porter Ranch, a residents group, has joined with environmentalists at Food & Water Watch to call for the permanent closure of Aliso Canyon. Company representatives have countered that the facility forms the backbone of its gas-delivery system, and without it the company would have a difficult time maintaining a reliable supply of gas to its 21 million customers and 14 power plants.
“The inability to use Aliso Canyon could have a direct effect on both natural gas service and electric grid reliability,” Bailey said in an email. “The electric generators currently served by Aliso are subject to possible natural gas curtailments in the event of insufficient natural gas supplies.”
Several state agencies are studying how the situation at Aliso Canyon will affect the natural gas system in the coming months.
“For now, the supply we are relying on is our traditional supply through pipelines,” said Linda Rappatoni, a spokeswoman for the California Energy Commission. “I don't believe there’s a concern about meeting demand for natural gas at the moment. It’s further into the summer that there’s some concerns.”
The California Independent System Operator, which is responsible for maintaining the reliability of the state's electric grid, also is studying the issue.
*Bailey, the SoCalGas spokeswoman, responds that the idea that corrosion caused the leak is “pure speculation.” “The cause of the leak is under investigation and has not yet been determined,” she says.