Research On Reasonable Water Injection Scheme Reservoir In Shuang68 Fault Block

The development of fault blocks in Shuang 68 block of Daqing periphery is complex,with edge water,inconsistent oil-water interface between fault blocks and complex oil-water distribution.In the vertical direction,there are 12 small layers in the three sets of oil layers.The thickness of the small layers is large,the permeability coefficient of variation is high,the physical properties of the oil layers between the sedimentary facies are different in the plane,and the plane heterogeneity is strong.In order to determine a reasonable water injection scheme for complex heterogeneous reservoirs,this paper studies the reasonable water injection scheme.According to the geological characteristics of Class I,II and III reservoirs in the block,stratified water injection is implemented,and reasonable water injection intensity and production allocation scheme are given according to the reservoir type.Using Petrel geological model software,combined with the research results of sedimentary microfacies,the structural modeling and attribute modeling of Shuang 68 block are carried out.In view of the large saturation error interpreted by oil-water transition zone logging,the unreasonable oil-water distribution in the interpolation of fluid saturation attributes,and even the phenomenon of ’ high water and low oil ’,a J function correction method for logging interpretation of water saturation in the transition zone is proposed,supplemented by virtual wells to control the oil bottom and water top,and a fine geological model of complex oil-water interface is established.On this basis,Eclipse software was used for numerical simulation.The effects of different pressure levels on oil production rate,water content,recovery degree and recovery rate of I,II and III reservoirs were studied respectively.The mechanism of formation pressure affecting the development effect of reservoirs with different permeability was studied by analyzing the remaining oil saturation field.The reasonable pressure coefficients of I,II and III reservoirs were determined to be 0.9,1.0 and1.1,respectively.The current situation of injection-production balance of each injection-production unit and the current pressure level of various reservoirs in each fault block are studied by well group,and the gap between each fault block and reasonable pressure level is clarified.The influence of pressure recovery rate of various reservoirs on the development effect was studied,and the reasonable pressure recovery rates of Class I,II and III reservoirs were determined to be 0.18,0.2 and 0.24 MPa / a,respectively.The relationship between pressure recovery rate and injection-production ratio is established by using reservoir engineering method and considering the water capacity of surrounding rock and edge water energy.The pressure recovery period of each fault block and the reasonable injection-production ratio of various reservoirs are determined.According to the reasonable formation pressure level and flow pressure limit,the liquid production of each year is determined,and then the reasonable water injection volume and water injection intensity of various reservoirs are determined by reasonable injection-production ratio.Then,taking the oil well as the center,the reasonable production and injection allocation scheme of oil and water wells in the pressure recovery stage and pressure stability stage of Shuang 68 fault block reservoir is given by splitting method,which provides a basis for reasonable water injection development in Shuang 68 block.It provides a reference for formulating oilfield development planning and has certain guiding significance for field production and application.