British oil company BP has pledged several US Gulf of Mexico assets as collateral for the $20bn Deepwater Horizon Oil Spill Trust, set up to pay legitimate claims arising from the oil spill disaster.

The pledged collateral consists of an overriding royalty interest in oil and gas production of BP’s Thunder Horse, Atlantis, Mad Dog, Great White and Mars, Ursa and Na Kika oil and gas assets in the Gulf of Mexico.

Since the Macondo well was finally confirmed sealed on 19 September, BP has been completing the process of plugging and abandoning the well, which includes removing portions of the casing and setting cement plugs.

BP has also started the process of dismantling and recovering containment equipment and decontaminating the vessels that were in position at the wellsite.

The cost of the response to 29 September amounts to approximately $11.2bn, including the cost of the spill response, containment, relief well drilling, static kill and cementing, grants to the Gulf states, claims paid and federal costs.

On 23 August, processing of claims from individuals and businesses related to the Deepwater Horizon incident was transferred to the Gulf Coast Claims Facility (GCCF).