On January 24, 2016, staff from South Coast AQMD and the California Department of Gas and Geothermal Resources (DOGGR) performed survey measurements of remote wells at the SoCalGas Aliso Canyon site, including 14 wells previously unavailable for inspection. This activity was prompted by flyover observations which suggested two other sources of methane emissions in the area in addition to the leaking SS-25 well.
DOGGR staff assisted in identifying a potential emissions source on the side of the hill, within 100 meters west of the SS-25 well, and South Coast AQMD staff took survey measurements as follows:
A likely source of these emissions, though not verified, may be underground natural gas migration from the leak in the SS-25 well.
A second emission source was identified from a pressure relief pipe approximately three quarters of a mile northeast of the SS-25 well and within 100 meters of another well. The area was too remote to perform mobile LI-COR methane measurements, and H2S measurements again fell below the detection limit of the Jerome H2S analyzer. But the FLIR camera showed emissions venting from one specific area, and a canister sample (1602609) was collected at this location. The pressure relief pipe was traced to an active oil production well operated by the Termo Company at its Del Aliso Lease in Aliso Canyon [1].
Following the discovery of the leaking well, Termo shut in all their casing gas across the oil fields and closed the upstream valves to this venting pipe. No further emissions were observed with the FLIR camera.
Staff will continue to monitor these wells to ensure that no excess emissions are allowed to escape.
[1] Termo company operates a total of 16 active oil production wells as its Del Aliso Lease, a Title V facility (South Coast AQMD Facility ID# 83508) and at Oat Mountain, a RECLAIM facility (South Coast AQMD Facility ID# 97081)