Deepwater Horizon litigation

The civil and criminal proceedings stemming from the explosion of Deepwater Horizon and the resulting massive oil spill in the Gulf of Mexico began shortly after the April 20, 2010 incident and have continued since then. They have included an extensive claims settlement process for a guilty plea to criminal charges by BP, and an ongoing Clean Water Act lawsuit brought by the U.S. Department of Justice and other parties.

A federal judge, ruling on the Clean Water Act suit in September 2014, found that BP was primarily responsible for the oil spill as a result of its deliberate misconduct and gross negligence. The finding means that the company may be subject to $18 billion in penalties in addition to the $28 billion already paid out in claims and cleanup costs. In July 2015 BP settled the case and carries some extra penalties.

Litigation commenced almost immediately after the explosion and oil spill. By May 27, 2010, Transocean, which owned the Deepwater Horizon, said in testimony before the U.S. House Judiciary Committee that it was defendant in 120 lawsuits, of which more than 80 were class actions seeking payment for financial losses covered by the Oil Spill Pollution Act. The company said that most of these early plaintiffs were "fishermen, hotel operators, landowners, rental companies, restaurants and seafood processors, who claim a current or potential future loss of business in the aftermath of the oil spill."

At the same time UK media reported that over 130 lawsuits relating to the spill had been filed against one or more of BP, Transocean, Cameron International Corporation, and Halliburton Energy Services, although it was considered likely by observers that these would be combined into one court as a multidistrict litigation. Because the spill had been largely lingering offshore, the plaintiffs who claimed damages at that time were mostly out-of-work fishermen and tourist resorts that were receiving cancellations. BP and Transocean wanted the cases to be heard in Houston, seen as friendly to the oil business, but the plaintiffs requested the case be heard in Louisiana, Mississippi or Florida. Five New Orleans judges recused themselves from hearing oil spill cases because of stock ownership in companies involved or other conflicts of interest. BP has retained law firm Kirkland & Ellis to defend most of the lawsuits arising from the oil spill.

BP, which largely self-insures through its own Jupiter Insurance Ltd, was also the subject of early litigation from multiple Lloyd's of London underwriting syndicates and other underwriters seeking a declaration that they were not liable to BP under Transocean's US $700 million insurance policy.

In June 2010, Hornbeck Offshore Services, joined by several dozen corporations with offshore interests, filed suit in U.S. District Court seeking to enjoin the U.S. Department of the Interior from imposing a ban on deep water drilling.

In July 2010, news reports claimed that BP had been attempting to hire prominent scientists from public universities around the Gulf Coast to aid its defense against the lawsuit that the federal government will bring as a result of the spill. BP attempted to hire the entire marine sciences department at one university, but the university declined because of confidentiality restrictions, however several other universities have accepted. In developing its case, the government will draw on the large amount of scientific research conducted by academic institutions along the Gulf, and many scientists being hired by BP serve at those same institutions. The contract prohibits the scientists from publishing their research, sharing it with other scientists or speaking about the data that they collect for at least the next three years, and it requires scientists to agree to withhold data even in the face of a court order if BP decides to fight the order. It stipulates that scientists will be paid only for research approved by BP. Robert Wiygul, who specializes in environmental law, said that he sees ethical questions regarding the use of publicly owned laboratories and research vessels to conduct confidential work on behalf of a private company. "This is not an agreement to do research for BP. This is an agreement to join BP's legal team. You agree to communicate with BP through their attorneys and to take orders from their attorneys." The contracts have the added impact of limiting the number of scientists who are able to work with federal agencies.

In August 2010, 77 cases, including those brought by state governments, individuals, and companies, in the U.S. District Court for the Eastern District of Louisiana under Multi-District Litigation docket MDL No. 2179, captioned In re: Oil Spill by the Oil Rig "Deepwater Horizon" in the Gulf of Mexico, on April 20, 2010, presided over by U.S. District Judge Carl Barbier. Judge Barbier is trying the case without a jury, as is normal in United States admiralty law.