Fluid Permeation Characteristics And Capacity Prediction Of Horizontal Fracturing Wells In Tight Reservoirs

In recent years,with the development of oil and gas technology,the development of tight reservoirs has attracted more and more attention from many countries and scholars.In the course of conventional exploiting,due to compact lithology,small radius of the pore throat and large seepage resistance in tight oil reservoirs,the single well's natural production capacity is lower than the lowest limit of industrial production.The successful application of “horizontal well completion + volume fracturing” has improved the seepage flow path of fractures,increased the volume of reservoir reformation,and improved oil and gas production capacity in tight reservoirs.However,there is no detailed and in-depth study on the seepage characteristics,production capacity distribution,and the influence law of different fracture network parameters after the fracturing on the productivity of the fluid in the tight reservoir volume fracturing.This paper first summarizes the geological characteristics and formation mechanism offracture network of tight oil reservoirs.Based on this,a numerical model of a typical block in a tight reservoir is established.The fluid flow law in the reservoir is analyzed detailedly using streamline simulation methods to study different fractures.The impact of defferent network parameters on reservoir productivity,using numerical simulation techniques to predict the capacity changes of complex grid systems.By comparing the fluid flow law,production capacity distribution,and water cut of fluids in fractured series reservoirs of different fracture networks,the number of fracturing segments in a tight oil reservoir is selected to be 6 segments.The flow characteristics of fluids in three seepage stages are obtained,and the different position production are determined.The productivity and water cut in the middle fracture are better than those in the edge;the dual media prediction model of tight oil reservoirs is analyzed and compared,and the productivity characteristics of reservoirs under stage fracturing and volume fracturing are compared.The design of different well patterns,fracture network patterns,the spacing and number of fracture network,and the length of the main fracture were used to develop the effects of fracture network parameters on the development effect.The results show that the development effect of 5-well pattern is better than that of 7-point pattern;the shape of spindle-type fracture network is better than that of isometric-type,and the shape of single-spindle-type fracture network is the best;Designing 9 types of fracture network spacing and number,the optimal design is 70×8,that isthe spacing between fracture network is 70 m,and the number of fracturing stages is 8.In this model,when it uses 5-point well pattern,the field construction and economic factors are taken into consideration,finally determinethe lengths of the fractures are 61 m,116m,197 m,340m,340 m,197m,116 m,and 61 m,respectively.The research results have certain reference and guidance significance for the development of volume fracturing in tight reservoirs.