Otter North Sea Subsea Field Development: Sand-Control Strategy and Implementation

摘要

The Otter field is the first "dual" electric submersible pump (ESP) completion in the U.K. sector of the North Sea in a subsea field development. This subsea development consists of three horizontal openhole oil producers and two cased-hole water injectors clustered around a production manifold and tieback, 21 km from the Eider host platform. Each oil producer has been able to deliver up to 20,000 BOPD since October 2002. Because a risk of sand production was identified during the life of the field, downhole sand control was deemed necessary. Well longevity has a major impact on the global-project economics. This meant that achieving and maintaining sand-free production through optimal completion design was 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 design for the field's life. The sand-control technique had to be decided upon while drilling the well, on the basis of the drill cuttings-particle-size analysis—oversmall particles would have lead to an openhole gravel pack. It appeared that correct geosteering was permitted to stay within a sand body that was adequate for standalone screen completion, which the authors consider the best option (i.e., in cost, risk, and efficiency) when applicable. The operational experience gained and lessons learned on the first well contributed to the design enhancements required for completion of the horizontal wells described in this paper.