Multinational firms often use complicated corporate structures and arcane provisions of the tax code to minimize or eliminate their global tax payments. Arcane changes in tax rules can give rise to big losses in tax revenues to country treasuries, as happened in the 2017 tax law passed under the Trump Administration, to the great benefit of oil and gas firms. Under this law, companies that extract oil and gas overseas enjoy special exemptions within the Global Intangible Low-Tax (GILTI) regime covering Foreign Oil and Gas Extraction Income (FOGEI).
The two largest offshore drilling companies in the world, Transocation and Noble Corporation, are in reality headquartered in the Houston area but moved their legal domiciles first to the Cayman Islands and then to Switzerland to avoid U.S. tax. Calculations shown below indicate that those maneuvers have reduced their tax bills by more than $2 billion.
Transocean owned and operated the floating, dynamically positioned rig that exploded on April 20, leading to a loss of 11 lives and spilling hundreds of thousands of gallons of crude oil into the Gulf of Mexico.