Corporation Tax Act 2010 section 355A

Large deep water oil field

Section 355A defines what constitutes a "large deep water oil field" for the purposes of the ring fence expenditure supplement rules, as introduced by Finance Act 2015.

• A large deep water oil field is an oil field where the water depth and the expected reserves meet specified qualifying thresholds.
• The field must have a water depth of at least 200 metres, measured from the surface of the sea to the seabed at the relevant point within the licensed area.
• The field must also have expected total reserves of at least 25 million tonnes of oil equivalent at the time the development decision is made.
• This definition is relevant because companies operating large deep water oil fields may qualify for an enhanced rate of ring fence expenditure supplement, reflecting the higher costs and risks associated with deep water extraction.