Almost a year after a major gas leak was plugged, California regulators said the region's gas supplies may not recover in time to prevent shortages even if the Aliso Canyon underground gas storage field reopens soon.
Southern California Gas Co.'s Aliso Canyon needs to have a 29.7-Bcf gas inventory to maintain reliability, the California Public Utilities Commission said in a report released Jan. 17. Given that the field has just under 15 Bcf and only 34 of its 114 wells have passed the requisite tests as of Jan. 17, the CPUC said that inventory level will not be possible for much — if any — of the winter.
If SoCalGas were injecting through 31 wells, it would take eight weeks to raise the inventory from 14.9 Bcf to 29.7 Bcf, the CPUC estimated. "[T]he current number of wells available, even assuming optimistic production rates, is not sufficient to assure reliability in the short term," the report said.
The field has not been open for injections since the multi-month leak, sealed in February 2016, and state regulators have not yet decided whether, let alone when, the facility might be brought back online.
Sempra Energy subsidiary SoCalGas has been putting the field's wells through state-mandated analyses, and the company requested in November 2016 to resume injections. State regulators, including the CPUC and a division of the California Department of Conservation, announced Jan. 17 that they had finished reviewing the work SoCalGas had done so far, but the agencies will hold public consultations before making a decision about Aliso Canyon's future.
Should the facility come back online, it will be with somewhat reduced injection and withdrawal abilities. New standards require that storage operators move gas only from the inner tubing of each well, not also through the casing as was done before, which will limit the amount of gas that can be pulled or injected at a time. The CPUC said it was unclear how much of an impact that would have, though.
"[T]here is significant uncertainty concerning both injection and withdrawal capacity and the amount of inventory achievable over the short term at Aliso," the report said. "[W]ells not yet brought into service may not perform at the same level estimated for wells included in current plans."
Should Aliso Canyon manage to get its inventory back up to the recommended 29.7 Bcf, the commission estimated, the field would need 66 wells producing at expected withdrawal levels to be able to meet summer or winter peak-day needs. At the rate the well testing and review process are going, though, 66 wells may not be available until the last quarter of 2017, well after most of the year's seasonal demand peaks have come and gone.
If SoCalGas cannot supply enough gas to the region, power generators could face curtailments, potentially curtailing electric supplies, too, according to the report.
In 2017, the CPUC will be making a decision about whether and how the storage facility will be used long-term, as well. A state law passed after the Aliso Canyon leak was discovered requires the commission to start that process by July 1.