The BP Operated Foinaven, Schiehallion and Loyal fields, located West of Shetland (WoS) in the UKCS, are a highly challenging environment to work in. The three deepwater fields are drilled and completed utilising 4th generation semi-submersible rigs and the harsh marine environment can severely impact operations.
Although standalone screen completions have been used successfully in the majority of the wells, premature sanding problems have been experienced, potentially jeopardizing project economics due to prohibitively high cost of remediation. To improve this situation, alternative means of sand control completions have therefore been sought. There are now four Open Hole Gavel Pack (OHGP) completions in the fields, all of which are performing well with high productivities and no sand production.
In this paper, we present a case history on the application of the circulating water pack in the Foinaven field. The P11 sidetrack is the third gravel pack completion in this deepwater environment, and the first to be completed with a water pack. The subject well is the longest OHGP in BP's North Sea portfolio with a 3,345 ft open hole, penetrating through two sand bodies and multiple shale and mudstone packages.
The well was designed with a long horizontal open hole section to cost-effectively access multiple sand bodies and maximise productivity while minimising drawdown across the sandface. Baker Oil Tools BetaBreaker technology was utilised for the completion to maintain the treatment pressure below the reservoir fracture gradient during the gravel pack. The well was completed with a +110% packing efficiency, has an early time mechanical skin of +2 based on pressure buildup testing and was delivered safely 5 days ahead of target at P(10) production expectations.