Expandable Sand Screen: Three New World Records in the Brigantine Field

摘要

Between October 2000 and March 2001, Shell Expro, operating in the UKsector of the North Sea on behalf of Shell UK Limited and ExxonMobil UKLimited set three new world records in the application of expandable tubulartechnology, in 6” horizontal hole. Firstly, deployment and expansion of 4000ft of 4” Expandable Sand Screens [ESS] in Brigantine B; surpassing theprevious record tenfold. Secondly, deployment of 7000 ft of 4” ESS inBrigantine A and fully expanding 4920 ft of this screen. Thirdly, using themodified Compliant Rotary Expansion System [CRES] for full primaryexpansion of 60 ft of the 2150 ft ESS as Proof of Concept deployed inBrigantine C.Brigantine is a small offshore gas field located some 100 miles northeast ofthe Bacton Gas Terminal in the UK Southern North Sea. The field containsthree small hydrocarbon-bearing blocks, deemed individually uneconomicalsince their discovery in 1986. However, Deliver the Limit [DtL] concept,teamwork and application of three new technologies imporoved theeconomics of these accumulations and hence another success story forShell Expro. The three new technologies are listed below: -1). The Brigantine Wells were drilled from two minimum facility TridentPlatforms, which had won international recognition for their revolutionarydesign.2). Geo-steering Technology was chosen to drill the long 6” horizontalsections to maximize reservoir connectivity and overcome the risk ofcompartmentalisation within the structures.3). An integrated sand study carried out confirmed the need for downholesand exclusion. The selected option was the Expandable Sand Screen. Thisnovel approach, developed by Shell Technology with WeatherfordCompletion Systems (WCS) having a licence, was preferred to conventionalmethods, such as ‘Gravelpack’, due primarily to the larger bore it provides tomaximise deliverability and the high potential to eliminate annular flow whenfully expanded against the wellbore. However, ESS Technology was in itsinfancy and classified internally as ‘new unproven technology’.The three wells were completed 32 days ahead of plan, achieved initialproduction of between 23% and 40% above expectation with total ESS addedvalue of ￡13.5 million.The following paper documents the decision to choose ESS as the preferredSand Exclusion Technology, and the ESS delivery process from ‘unproventechnology’ to deployment and expansion in the Brigantine Wells.Brigantine Project OverviewThe Brigantine Project produces gas from three small Rotliegend gasreservoirs to the Shell ExproTerminal at Bacton.The first discovery, Brigantine A, was made in 1986 but was too small tojustify development. 3D seismic shot in 1992 lead to the discovery of twomore fields, B and C in 1997 and 1998 respectively, making the totaldevelopment economically viable.