Abstract
The OTTER field is the first to use a 'dual ESP' completion in a subsea field, the project was developed by TOTAL and its partner's in the Brent sand reservoir, in the UK North Sea sector.
This development consists of three horizontal open hole oil producers and two cased hole water injectors, drilled from a combined drilling template and production manifold and tied-back to the EIDER host platform 21km away. Each oil producer can deliver up to 20,000 BOPD, the field has been on production since October 2002.
A risk of sand production during the life of the field was identified, therefore downhole sand control was deemed necessary.
Well longevity has a major impact on the global project economics. Achieving and maintaining sand free production through optimal completion design was therefore critical to the overall success of the development.
This paper describes the strategy adopted and the factors considered in the development of the sandface completion optimised for the field life. Decisions on the sand control technique decisions were made while drilling the well based on cuttings particle size analysis: too small would have lead to open hole gravel pack. By eosteering the horizontal drain to stay within the most competent a sand body it would be possible to use a Stand Alone Screen completion, which was considered as the best option (cost, risk, and efficiency). The operationnal experience gained and lessons learnt on the first well contributed to the design enhancements required for completion of the following horizontal wells.
