Utilize the input text as a context reference, choose the right relationship between Transocean and Deepwater Horizon from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

BP also settled with Transocean Ltd (RIGN.VX), which owned the Deepwater Horizon drilling rig, and Halliburton Co (HAL.N), which worked on the Macondo well.

Answer: owner_of