On December 4 , 2015 SoCal Gas started drilling a relief well to the caprock , 8,000 feet down , with the help of Boots & Coots , a subsidiary of Halliburton . The relief well is " similar to the relief well BP ’s engineers drilled to stop oil flowing into the Gulf of Mexico in 2010 after the Deepwater Horizon disaster " . The plan was to pump liquid and cement into the main well once the relief well could vent the gas safely . SoCal Gas estimated the first relief well would be completed by February 24 , 2016 . SoCal Gas planned to drill a secondary relief well , estimating the leak repair to take up until the end of March 2016
Deepwater Horizon
Deepwater Horizon oil spill
Aliso Canyon gas leak