I think so, upstream taxation: The UK Continental Shelf Tax Regime

• Ring Fence Corporation Tax
  With some important modifications (e.g. relating to capital allowances and losses), this is the standard corporation tax applicable to all companies, with the addition of a "ring fence" and 100% first year allowances for almost all capital expenditure. The ring fence prevents taxable profits from oil and gas extraction in the UK and UKCS being reduced by losses from other activities or by excessive interest payments by treating ring fenced activities as a separate trade. The current rate of corporation tax is 30%.
• Supplementary Charge
  This is an additional charge of 20% (10% prior to 1 January 2006) on a company's ring fence profits excluding finance costs. The supplementary charge was introduced from 17 April 2002.
• Petroleum Revenue Tax (PRT)
  This is a special tax on oil and gas production from the UK and UKCS. It is a field based tax charged on profits arising from individual oil fields. The current rate of PRT is 50%. PRT was abolished for all fields given development consent on or after on 16 March 1993. PRT is deductible as an expense against corporation tax and the supplementary charge.