California regulators on Friday ordered Sempra Energy's Southern California Gas Co. (SoCalGas) to apply six separate tests to each of the 114 storage wells at its now shuttered 86 Bcf-capacity Aliso Canyon underground natural gas storage field on the far northern fringe of Los Angeles. All the tests need to be completed before injections can resume at the state's largest gas storage facility.
At the site of a four-month-long storage well leak that was closed last month (see Daily GPI, Feb. 18), SoCalGas crews are in the midst of trying to implement provisions the state Division of Oil, Gas and Geothermal Resources (DOGGR) developed in consultation with the Lawrence Livermore and Berkeley National Laboratories.
No resumption of injections into the 3,600-acre field will be allowed before all of the testing is completed, which will take months, according to estimates from DOGGR and the utility.
"Test results are submitted by SoCalGas, reviewed by DOGGR staff, and subsequently posted on a special website pagethat will be updated frequently," a DOGGR spokesperson told NGI. "Wells must pass all tests within one year or be permanently sealed."
The spokesperson said that some wells may be temporarily plugged and taken out of service, but eventually they must be either remediated or permanently plugged and abandoned within a year's time.
Temperature and noise log tests can be done with wireline tools, but the other four tests require tubing to be removed from wells, and this requires more complicated workover rigs, according to the spokesperson. SoCalGas reportedly is in the process of prioritizing the wells.
"Any abnormal findings in this first two sets of tests are required to be addressed immediately," the spokesperson said. "For example, if a temperature decrease is noted on a temperature log and further investigation reveals a leak in the external well casing, the repair of the casing must take place immediately."
After the tests are completed and the remediation work done, SoCalGas will be required either to conduct a battery of additional tests to gain approval for resuming injection, or to remove the well from operation and isolate it from the underground storage reservoir.
'The company may opt to take some wells out of service, at least temporarily," the DOGGR spokesperson said.
While SoCalGas may have a different timeline, DOGGR initially is assuming the first two tests for all of the Aliso wells will consume at least a month's time, and for the wells subjected to the additional testing in lieu of being temporarily plugged several more months are likely to be required.
SoCalGas had not responded to a request for comment by presstime.