Productivity Prediction Of Multi-stage Hydraulically Fractured Horizontal Wells In Tight Oil Sandstone Reservoirs

The tight sandstone reservoirs in China are rich in resources and have broad prospects for exploration and development.Its basic characteristics are the large oil-bearing coverage area,strong heterogeneity,low natural production capacity,and difficult development.In the development process,with the reduction of formation pressure,it shows strong stress sensitivity.At present,the horizontal well volume fracturing technology is the main mining method,and the reasonable prediction of the fracturing productivity of horizontal wells is crucial for the optimal design and long-term efficient development of fracture parameters in tight sandstone reservoirs.Therefore,this paper firstly conducts stress sensitivity laboratory tests in Daqing Oilfield,and obtains the law of permeability reduction of different formation pressure coefficients,and studies the variation law of the starting gradient of tight sandstone reservoirs;secondly,the hydraulic fracturing productivity prediction model for horizontal wells considering the pressure sensitivity of permeability was established;On this basis,the number of fracture segments,fracture spacing,fracture length,and diversion was considered under the consideration of pressure sensitivity and pressure sensitivity.The change of the optimal capacity determines the main optimization objective of the horizontal well volume fracturing considering both the initial volumetric fracturing production and the long-term cumulative production after taking into account the pressure sensitivity.Finally,the initial stage and cumulative production verification of actual tight oil horizontal wells proved that after considering the pressure sensitivity,the production model can accurately reflect the production characteristics of the horizontal wells of tight oil in Daqing,and it is the main attack on the production prediction of the horizontal wells of tight oil horizontal wells in Daqing Oilfield.The research direction has certain application and reference value.