Integrated Well-Completion Strategies With CHOPS To Enhance Heavy-OilProduction: A Case Study in Fula Oilfield

摘要

Fula oil field is composed of unconsolidated sandstones,rnburied as deep as 3500ft, with high porosity (31%) andrnpermeability(2 Darcy), producing viscous oil with 19-21°APIrnon the south flank of Muglad Basin. It is well-known thatrnunder proper conditions formation flow characteristics can bernimproved by non-thermal massive sand production and foamyrnoil behavior, referred to CHOPS.rnIntegrated well completion strategies with CHOPS were usedrnto increase heavy oil production. Limited sand influx providesrna means for effective sand control while eliminating the needrnfor conventional sand control processes. The principle ofrnlimited sand flux is 'coarse sands controlled and finer sandsrnproduced', which is using the screen liner to inhibit 0.5mm orrnlarger sands flowing into the wellbore, in addition, the restrnsmaller solids can be produced to the surface by viscous oil.rnExperiments were conducted to study the capability of liftingrnsands by crude oil. It showed that the sand of 0.9mm can bernallowed to move up with heavy oil to the surface while 510rnmPa.s of viscous oil is lifted in 3 1/2 in tubing. Usingrnprogressing cavity pump deliberately initiated sand influx butrnonly 15% solids were controlled to form wormhole to improvernpermeability of the pay zone.rnThis paper describes initial field test results of the new systemrnthat 20 heavy oil wells were equipped with PCP which isrnhelpful for handling sanding effectively. The sand cuts rangernfrom 0.1 to 12% by volume. Average oil rate of each well isup to 580bopd from 175bopd before CHOPS. The best wellrncan produce as much as 1200 BOPD. Oil production hasrnreached to 2,450,000 bbl/y with attractive result.