FREMGANGSMAATE FOR AA REDUSERE VAESKETAP VED FORTRENGNING AV HYDROKARBONER I UNDERJORDISKE FORMASJONER

摘要

Injectivity losses in alternate displacing fluid-aqueous fluid injections into an oil-bearing reservoir can be reduced through injection of a secondary displacing fluid in conjunction with the first displacing fluid injection cycle. The secondary displacing fluids reduce residual oil saturation near the injection wells to prevent adverse effects on relative permeability to aqueous fluid flow, which can occur. Fluids useful as the secondary displacing fluid of the invention include nitrogen, methane, ethane, propane, benzene, and refined oil.