There are over 192 wellheads off Summerland’s shore, some dating back to the early 1900s. Years ago, these wells were decommissioned and sealed, but not thoroughly enough. An unknown number of abandoned wellheads under the sand of the ocean floor are leaking today. Heavy rains and high tides put pressure on wellheads and cause more leakage, and finding the exact source of the leaks is a complicated and laborious process.
Marine researcher Harry Rabin and marine construction company InterAct, contracted by the State Lands Commission, have spent weeks collecting data to map the water column and pinpoint the origin of the oil leak that they believe is associated with the wellhead known as Treadwell. The team employs aerial surveys and under water multi-beam images (a technology similar to sonar) along with magnetometer testing, a device that is towed behind a boat, and detects metal composites in the water for an indication of whether or not a wellhead (made out of iron and steel) is nearby. If no wellhead is found, a large leak might be determined a natural seep, and natural seeps are unlikely to be sealed by contractors. According to Rabin, metal has been detected near where the team believes the Treadwell wellhead lies, which is a good sign that they are close to finding the precise location of a manmade leak. Next, divers will make a more-definite identification. All of the data will be compiled to create accurate maps of Summerland’s oil well field to help ongoing efforts to cap leaking wellheads.
After precise coordinates for Treadwell are mapped, plans are in place to cap the wellhead in February 2020. According to Rabin, the process requires various steps and heavy machinery but the result will be a completely sealed wellhead. A large copper tube, about 40 feet long, is installed around the wellhead. The tube is driven into the bedrock 30 feet below the ocean surface, providing access to seal the leak with cement, after which the copper tube is removed.
Mediating leaks on Summerland’s abandoned oil field has been a decades-long process, and will continue in the future. Most recently, the Becker wellhead was capped in June 2018. Next up, on July 3, at 3:30 a.m., divers will check on the integrity of the Olsson 805 wellhead.