Study Of Water Channeling Mechanism In Water Flooding Development Of Low Permeability Reservoirs With Fractured Horizontal Fractures

The porosity and permeability of low permeability reservoirs are very low,and the natural energy is too low,fracturing and injecting water are necessary for the exploitation of low permeability reservoirs.The fracture morphology of shallow reservoir is generally horizontal.The seepage characteristics and water channeling characteristics of horizontal fractures and vertical fractures are different.However,there are few studies on the mechanism of water channeling in low permeability reservoirs with fractured horizontal fractures.In this paper,the mechanism of water channeling in water injection development of fractured horizontal fractures in low permeability reservoirs is studied.By using reservoir simulation,water injection development characteristics of low permeability reservoirs under the condition of non fracturing,vertical fracture and horizontal seam are compared,and horizontal fractures are more likely to lead to water channeling than vertical fractures.The influence of different fracturing and water injection parameters on water breakthrough is studied through the ideal model.The time of water channeling is identified by the water content curve.The water channeling coefficient is used to quantitatively characterize the intensity of water channeling and the aggravation speed of water channeling.Collecting the data of S block to establish geological model and doing historical fitting.The influence of different parameters on water channeling in water injection development of S block with fractured horizontal cracks is studied.The conclusion is basically consistent with the conclusion of the ideal model.Through the simulation water injection development in S block,and comparing the characteristics of water channeling in different well groups,then the water channeling characteristics of water injection in low oil saturation reservoirs which similar to S block are analyzed.From the angle of controlling the water channeling and improving the recovery rate,make the optimization of fracturing and water injection parameters in S block.It is suggested that during the development of S block,the production well can be fractured in a small scale,the injecting wells should not be fractured,keeping the consistency of the injection and production layers,lower water injection intensity should be adopted and keeping the balance of injection rate and production rate.It is also suggested to change the working system by using periodic water injection to alleviate the water channeling.