| Popis: |
Abstract The Captain field in the North Sea UKCS is a highly viscous crude accumulation produced via waterflooding with extended reach horizontal wells. Captain's high oil-water mobility ratio and exceptional reservoir quality make it an ideal candidate for improved oil recovery by polymer augmented waterflooding. Polymer storage tanks and subsea polymer flowlines were included in the design and build of the Captain facilities to simplify future implementation of a polymer flood pilot. Offshore logistical considerations led to the selection of liquid hydrolyzed polyacrylamide (HPAM) as a basis for the polymer flood design. We report in this paper the methods and results obtained from a series of laboratory studies undertaken to identify HPAM's that could be used at Captain and to provide data for reservoir simulation input. This work, conducted by the Operator and two polymer vendors, included coreflood tests, scaled polymer mixing tests, and polymer shear degradation tests. Although good viscosity yield, low polymer retention, and good coreflood oil recoveries were obtained with HPAM's, the solutions caused face plugging of Captain cores. Using a membrane filtration method to quickly screen new products, both vendors developed improved HPAM's that were judged suitable for use in the Captain reservoir. Results of the shear degradation experiments indicated that shear degradation should be insignificant in tubulars at field design flowrates, but possibly substantial at the sandface. P. 385 |
