18th February 2020
The Culzean field is an Ultra-High Pressure/High Temperature (uHP/HT) lean gas condensate accumulation found within the sandstones of the Jurassic Pentland and the Triassic Skagerrak (Joanne Sandstone Member) Formations. The field was discovered in 2008 by Maersk Oil North Sea in block 22/25a of the UKCS, 233 km east of Aberdeen, Scotland and represents one of the largest UKCS hydrocarbon discoveries in the last 15 years.
The discovery well 22/25a-9z found more than 1500 ft of net hydrocarbon bearing reservoir in both the Joanne and the Pentland formations and led to the drilling of four subsequent appraisal wells. The appraisal campaign proved minimum economic production rates with DSTs, collected more than 1000ft of core material and provided full suites of log and pressure data that allowed a robust characterization of both the hydrocarbon and the water bearing intervals. A high-density Ocean Bottom Cable 3D seismic acquisition was acquired over the field in 2011 and was used for defining the reservoir models used for sanction and the field development plan (FDP) submission.
Project sanction and the FDP approval came in 2015 based on a 6 well development (5 producers and 1 water disposal well) from a stand-alone well head platform bridge-linked to a Central Processing Facility (CPF) and a Utilities Living Quarter platform. The CPF export capacity is 500 mmscfd gas along with 25k bopd condensate export. Gas export is via a new tie-back to the CATS pipeline and condensate export is via an FSO for the storage and offloading.
Development well drilling started in 2016 with first gas to facilities arriving on June 7th, 2019 and first gas export coming a month later. As of early 2020, four development wells are currently maintaining production at maximum CPF design rates with ongoing drilling operations continuing to deliver the remaining FDP wells. The Culzean field is capable of meeting around 5% of UK gas consumption and will be an important contributor to the UK energy supply for years to come.
The Culzean development is operated by Total E&P North Sea U.K. Ltd. along with co-venturers Britoil Ltd. and JX Nippon Exploration & Production (U.K.) Ltd.