Technique of Water Control and Oil Recovery Based on Water Plugging Combined with Fracturing in Low Permeability and High Water Cut Oilfield

Abstract

Abstract In low permeability oilfield, normally fracturing is applied for production and the water injecting pressure is quite high. As most of the major oil reservoirs are flooded by water after fractured, the production rate is very low. With the oilfields further developed, the number of high water cut wells increased. How to further tap the remaining oil and enhance the oil recovery is becoming a big challenge to us currently. In Daqing low permeability oilfield, a pilot test of pressure plugging, water control and oil recovery of high water cut wells was conducted and achieved a good result. The test was including: 1) Further verified the understanding of well and reservoir selection and established the selection standard of the pressure block, water control and oil recovery technique for fractured reservoirs in low permeability oilfield. 2) Optimized field operation process of pressure block, water control and oil recovery. Compensator + K341-114 packer + fixed pressure valve + K341-114packer + ball seat was designed as the plugging string. Small diameter string was studied to repair casing damaged wells. 3) Optimized the chemical plugging agent and developed the fracturing technique of plugging the water cracks through compound water plugging. Production enhancement and water drop were observed through large scale field application.