Emerging Techniques in Gravel Packing Open-Hole Horizontal Completions in High-Performance Wells

摘要

Gravel-packing of open-hole highly-deviated or horizontalrnwells is increasingly becoming a common practice, especiallyrnin deep water and sub-sea completion environments wherernproduction rates may reach up to 50,000 BOPD or 250rnMMSCFD. In these wells, reliability of the sand facerncompletion, in addition to other factors, is of utmostrnimportance due to the prohibitively high cost of interventionrnor side-tracking and the very high hydrocarbon recoveriesrnrequired per well. To date the norm in gravel-packing suchrnwells is water-packing or shunt-packing with water-basedrnfluids. With both techniques, filter-cake removal treatmentsrnare conventionally done through coiled tubing after gravelrnpacking, pulling out of the hole with the service tool andrnrunning in with the production/injection tubing. Furthermore,rnbecause conventional gravel-pack carrier fluids are water-basedrn(brine or viscous fluids), water-based drilling fluids arerntraditionally used to drill the reservoir section to ensurerncompatibility and improve wellbore cleanup, even if the upperrnhole is drilled with a synthetic/oil-based drilling fluid.rnIn this paper, we discuss several novel techniques that canrnsubstantially improve return on investment in gravel packingrnof open-hole horizontal completions, through reduced cost andrnprocess time, improved fluid management practices, increasedrnproductivity and/or reduced risk of future interventions, sornmitigating against the risk of sand face completion failure orrnunder-performance. The proposed techniques include:rn· Simultaneous gravel-packing and filter-cake removal withrnwater-based carrier fluids when the reservoir is drilledrnwith a water-based drilling fluid: laboratory data relevantrnto gravel-packing are given and field case histories arerndiscussed in detail.rn· Simultaneous gravel-packing and cake cleanup with eitherrnwater or a synthetic/oil-based carrier fluid when thernreservoir is drilled with a synthetic/oil-based drillingrnfluid: laboratory data on cake removal while gravelrnpacking are presented for both water-based and oil-basedrncarrier fluids along with data on kinetics of cake removal.rn· a new service tool that utilizes wash-pipe as continuousrntubing and thus allows spotting of breaker treatmentsrnimmediately after gravel packing: detailed description ofrnthe tool and its operation is given.rn· Gravel-packing of highly-deviated or horizontal wellsrnabove fracturing pressure.rnBenefits offered by each of the proposed techniques arerndiscussed in detail along with their current limitations.