SoCalGas to Try Capturing Methane in Attempt to Address Porter Ranch Leak

As methane continues to billow out of the Aliso Canyon storage field in Los Angeles County, Southern California Gas (SoCalGas) is seeking permission to try to capture the leak and possibly incinerate it.

Workers detected the leak almost three months ago. Initial repairs failed.

SoCalGas shot a heavy, sticky fluid into the leak, a kind of mud crossed with chewing gum. But the high pressure of the leak blew this “well kill” right back out.

"To date the company has attempted seven separate attempts to plug the well directly in this standard manner, but none has worked,” says Bob Wyman, a lawyer with the firm Latham & Watkins, which is representing SoCalGas.

Now the company is drilling new wells to relieve pressure and reduce the flow of the leak, to enable another attempt to plug the well nearer to its source.

Meanwhile another kind of pressure is growing. Thousands of people living in nearby Porter Ranch, a community in the City of Los Angeles, have relocated away from the leak. Those who remain continue to complain of headaches, nausea and nosebleeds. Lawsuits are piling up.

SoCalGas says it has been developing a plan to capture fugitive natural gas since mid-November. Now the company has applied to the South Coast Air Quality Management District for permits to enact its plan.

"The company would use pipes," says the district’s Sam Atwood.

Big ones. Imagine a straw 3 feet wide hovering over the leak, sucking in methane and air. Rough estimates suggest the company could catch up to 90 percent of the methane as the leak slows.

"The gas would have to be piped to some distance from the wellhead for safety reasons,” Atwood says. “And then it would be either captured and, or, it would be incinerated."

One thing SoCalGas could do is bring in an adsorption system, equipment that could eliminate foul odors. Jen Wilcox, a professor of energy systems engineering at Stanford, says an activated carbon filter system could do for escaping natural gas what home purifiers do for water.

"It’s just a, you know, charcoal kind of material,” she says. “It’s porous. And what it’s doing is selectively removing contaminants from the air.”

The pores could capture problematic molecules in the chemical mercaptan, which is a stinky additive used to help identify when odorless, colorless methane is around.

But that methane remains a concern, because the state requires all utilities to cut contributions to global warming. So, under another scenario, the company may burn what it captures from the leak.

“That’s not an irrational thing to do. It’s just a difficult thing to do,” says Roger Aines, a geochemist at Lawrence Livermore National Laboratory.

Equipment often used by oil companies would allow SoCalGas to burn methane inside a ceramic chamber, or a sort of kiln. Once the methane was captured in pipes, it could pass over a very hot surface.

"It’s a hot screen, you know, or pile of screens” Aines says. “It’s hot enough that as you pass the mixture of gas and air over it, it burns but it doesn’t burn with a flame. It actually just combusts on that catalyst.”

SoCalGas emphasizes that safety is its top concern. But a fix this big has never been tried in California. If the company burns this methane, it would eventually create enough pollution to need the kind of permit required for big refineries.

All these unknowns make the gas field’s neighbors nervous -- including Matt Pakucko, a founder of Save Porter Ranch, a grass-roots group that wants to shut the gas field down.

“We are greatly concerned with the possible unintended consequences of that plan,” he told a hearing board for the AQMD. “This does not sound safe. Especially since SoCalGas has failed in all attempts to stop or mitigate their nuisance.”

Pakucko and other homeowners say they don’t trust SoCalGas. That’s why they’re pushing politicians to investigate not only why the leak happened but why a gas capture plan wasn’t in place sooner.