PREPARATION OF PRODUCED WATER FOR PRESSURE MAINTENANCE SYSTEM IN LOW PERMEABLE OIL RESERVOIR

Abstract

Oil production in Russia is mainly with maintaining reservoir pressure by injection of bottom water. Based on the experience of exploitation of oil fields at the late stage, it is concluded that the depth of cleaning produced water is insufficient. This leads, on the one hand, to colmatation of the reservoir and reduce the oil recovery factor, on the other hand, water pollution by oil, heavy metals, hydrogen sulfide. Sampling of bottom water after cleaning a pipe separator showed that they contained more than 1000 mg/l film of oil, about 100 mg/l of emulsified oil, up to 7 mg/l of iron, which is extremely unsatisfactory for subsequent injection of water into oil-containing reservoirs. Performed technological research on the purification of produced water by the method of sedimentation using coagulant and alkalizing reagent and water purification innovative electrochemical filters with active mineral download. The purified produced water oil concentration does not exceed 3 mg/l, suspended solids of 2 mg/l iron 0.3 mg/l. The technological scheme of preparation of produced water for use in the formation pressure maintenance system.