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SoCalGas Prepares Second Relief Well at Aliso Canyon Gas Storage Leak Site

Under a second order from the state’s oil and natural gas supervisor, Sempra Energy's Southern California Gas Co. (SoCalGas) began this week preparing to drill a second relief well at the 86 Bcf-capacity Aliso Canyon underground storage field 40 miles northwest of downtown Los Angeles.

An acknowledgement of the added work on Tuesday by the nation's largest gas-only utility and officials from seven state agencies underscored the growing impatience and uneasiness around the leak, which experts said is a first for similar gas storage facilities. The leak, initially thought to be a routine incident, has continued unabated for nearly two months (see Daily GPI, Dec. 11; Nov. 12).

The chiefs of the seven state agencies held a conference call Tuesday and said a combination of worker safety concerns and the challenging task of drilling relief wells are the major reasons SoCalGas has estimated it may take up to three more months to plug and fully abandon the storage well. The well is one of more than 100 on the 3,600-acre, 3,000-foot elevation site in the Santa Susana Mountains.

Steve Bohlen, the outgoing head of the California Department of Conservation's Division of Oil, Gas and Geothermal Resources (DOGGR), told NGI on Monday that the well could be finished sooner, but there is no assurance of that, given the complexity of the topography and the 8,500-foot depth of the storage well where any relief well would need to intersect.

"It could go relatively quickly, and it could go much faster than three months, but I don't want to speculate on how quickly that might be," said Bohlen. DOGGR has had its most experienced field engineers at the site on a rotating 24/7 basis since the leak was discovered and reported to the state Oct. 23.

As to how long drilling the well could take, Bohlen said, "you won't know until you actually do it. And that's why it is a fairly common practice to have two relief wells."

SoCalGas engineers at the site said the second well is an insurance policy against the first well failing to hit its target, which Bohlen called a "bullseye less than 12 inches in diameter, 8,500 feet below the surface."

State-of-the-art technology is being used by SoCalGas's contract drilling crews, but the relief well drillbit must move about 1,000 feet diagonally, wrap around the existing small-diameter casing, and penetrate it at precisely a 2-degree downward angle.

Separately, SoCalGas is assessing proposals from outside contractors for the design, installation and operation of a gas capture system that would be fabricated specifically for the assignment. The system could take weeks, but it is expected to help reduce the volumes of emissions said to be irritating nearby residents. SoCalGas officials have not speculated about what percentage of emissions may be captured with a revamped system.

As the time to fix the well lengthens and the plugging work, which now involves up to 200 contractors, becomes more complex, SoCalGas officials have felt increased pressure from local elected officials and nearby residents.

In the Porter Ranch community, more than 2,000 families have requested help relocating temporarily or installing in-home air filtration systems to avoid the ill effects from the odorant mercaptan in the gas emissions. Although state and other officials emphasize there is no public health or safety risk to residents, the Los Angeles city attorney earlier this month filed a complaint in state Superior Court, alleging SoCalGas has been negligent (see Daily GPI, Dec. 6).

On the conference call Tuesday, California Public Utilities Commission President Mike Picker said there is no indication of health or safety problems from the storage field site. But he acknowledged that "there are always risks associated with drilling operations and gas leaks, and the levels at which the gas leaks are occurring seem manageable. And on the question of whether the utility has acted properly, we rely on DOGGR."

Bohlen described the situation at the leaking well site as an "omnipresent ignition risk," meaning care has to be taken to eliminate any ignition sources, ranging from cellphones to engines used on heavy equipment. As for the utility's culpability, "on the surface, subject to future investigation, it does not appear that SoCalGas is guilty of any violations,” he said.

SoCalGas officials said Tuesday that there have been no accidents or injuries to workers, and they are moving with care to maintain a spotless safety record.

SocCalGas on Wednesday opened a temporary community resource center in Porter Ranch to offer relocation at the utility's expense to residents seeking it. Updates for the community are also being posted on a website.

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