Exploration on Pressure Increase Water Flooding Test with Skid-Mounted Pump in Low Permeability Reservoirs

The water absorption capacity of injection wells is unfavorable in some blocks of Daqing Oilfield due to the limit form the border wells being shielded by faults, reservoir physical properties and system pressure, etc. In order to explore effective ways to stimulate the hard recovery reservoirs with low permeability and to quickly replenish the formation energy, a pilot on pressure increase water flooding test with skid-mounted pump was carried out in Hailar main production blocks of Daqing Oilfield. The selection of well and its formations was carried out after considering geological factors. The injection volume and liquid property were optimized according to sand body development level, effective thickness of reservoirs and effective porosity. The downhole long-term & high-pressure injection pipe string has been developed with bearing the temperature of 120 °C and pressure of 70 MPa, which will meet the requirements of high pressure, large displacement and long-time injection. A selected pilot well was injected continuously for 9 days with the cumulative water injection of 4277 m3. Four connected production oil wells around the pilot injection well had different effects, whose daily liquid production all increased significantly. The technology has been carried out in the Type III thin & poor reservoirs of Daqing Oilfield, which will provide technical support for improving oil recovery further. It will have good prospects for popularization.