The Deepwater Horizon oil spill (also referred to as the BP oil spill, the BP oil disaster, the Gulf of Mexico oil spill, and the Macondo blowout) was an oil spill in the Gulf of Mexico on the BP -operated Macondo Prospect , considered the largest accidental marine oil spill in the history of the petroleum industry, estimated to be between 8% and 31% larger in volume than the earlier Ixtoc I oil spill .