Culzean is an ultra high-pressure/high-temperature (uHP/HT) field discovered in 2008 in block 22/25, with the reservoir at 4,300 m (14,107 ft) below sea level. It is one of the UK’s largest discoveries of recent years. If the project goes forward, first gas could follow in 2019, with plateau production of 400-500 MMcf/d (11-14 MMcm/d).
This means the field could eventually supply around 5% of the UK’s total gas needs, Maersk says.
The proposed offshore facilities, to be installed in 88 m (289 ft) of water, would comprise a 12-slot wellhead platform (WHP), a central processing facility, and utilities/living quarters, with accommodation for more than 100 people. Total investment could be more than $4.7 billion.
KBR London has been appointed front-end engineering design contractor, and Hercules Offshore’s new heavy duty jackup will drill the wells starting in 2016.
Due to the uHP/HT conditions Maersk plans to place equipment contracts for the rig now and for the WHP jacket later this year.
Subject to a final investment decision in 2015, a phased installation of the facilities would start in 2016.
Culzean should benefit from the UK government’s consultation on an extended uHP/HT allowance, announced in the Chancellor’s March 2014 budget statement. This is designed to exempt a portion of a company’s profits from the supplementary tax charge: the amount exempt will likely to be equivalent to at least 62.5% of the capex incurred on qualifying projects, although this remains to be confirmed.
Maersk Oil UK operates Culzean with a 49.99% interest, in partnership with JX Nippon (34.01%), and Britoil (BP) (16%).