On December 4, 2015 SoCal Gas started drilling a relief well to the caprock, down, with the help of Boots &amp; 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.