One-third of Aliso Canyon wells pass initial test

OREANDA-NEWS. April 21, 2016.  California regulators have approved one-third of the injection wells at the shut Aliso Canyon natural gas storage field near Los Angeles, allowing them to undergo further well-integrity tests that may lead to an eventual return to service.

State regulators, the California grid operator and electric utilities are working to address gas and power grid reliability issues ahead of rising summer and winter demand after SoCal Gas halted a major gas leak at its 86 Bcf (2.4bn m?) Aliso Canyon storage site in February.

SoCal officials have said they hope to complete well testing needed to gain state approval to bring the Aliso Canyon storage field back into partial operation by late summer to avoid potential rolling blackouts across southern California.

The field has about 15 Bcf of working gas available. If the field returns to service, operation will likely be limited.

In its latest filing with the Division of Oil, Gas, and Geothermal Resources (DOGGR) within the California Department of Conservation, SoCal said 86, or 75pc, of the 114 active wells have completed phase one temperature and noise testing to determine if gas is leaking from the well casing.

DOGGR has approved test results from 39 wells, up from 16 wells in the company's previous filing made two weeks earlier. Wells must pass the initial tests to advance to more complex well degradation testing or be taken off-line and isolated from the underground gas reservoir. Some of the additional testing requires that a rig be placed at the well site.

Once all testing and remediation work is complete or wells are taken off line and plugged, DOGGR will determine if Aliso Canyon can return to operation.

Only six wells have been through some of the additional testing, about the same number SoCal reported two weeks earlier. Of those wells, two have been taken out of service.

SoCal has already taken 22 Aliso Canyon wells, or 20pc of the wells, out of service, according to the status report.

More than 20 DOGGR staff members are working with SoCal on the Aliso Canyon testing.

Aliso Canyon plays a critical role in supplying gas to 17 power plants, oil refineries and large agricultural processing plants in the Los Angeles basin. Gas from Aliso Canyon is especially important during the afternoon power ramp period when generators must pull gas from storage to quickly increase electric output as solar generation wanes.

Without Aliso Canyon, gas supply problems could interrupt electric service on 14 or more days this summer for millions of southern California residents, a report from four state agencies has warned. The situation would likely worsen during the winter when additional gas is needed to heat homes as well as to generate power.

The California ISO is working with stakeholders to look at tools the grid agency might use to mitigate the risks of the change in gas storage capacity and from SoCal's proposed daily-balancing rule. A final strawman proposal is expected to be posted on 25 April.

PUC and other agencies are warning residents to be prepared to curb electric use on days when temperatures rise and air conditioning use could strain the gas supply to power plants.