The Study On Development Method Of Injection And Production In Single Multi-stage Fracturing Horizontal Well In Tight Oil Reservoir

At present,the development of tight oil reservoir is often carried out by failure or conventional well pattern waterflooding,but the effect is not ideal.Therefore,how to determine the reasonable development method becomes the key to the efficient development of tight reservoirs in China.This paper analyzes the water injection development of horizontal well in the tight oil reservoir of the Changqing Oilfield,and finds that the well between the production wells and the injection wells is poor,the effect by water injection is not obvious,and the output is in accordance with the exponential decline law.In this paper,the law of oil-water seepage and pressure propagation between fractures of injection and production in single multi-stage fracturing horizontal well in tight oil reservoir is analyzed,the reservoir engineering and the numerical simulation method are comprehensive used to analyze the influence of different factors on the development effect by asynchronous injection and production in single well,which includereservoirpermeability,heterogeneity,thresholdpressureandstress sensitivity,and fracture network pattern,fracture half length,spacing and conductivity.then,the effects of the water injection intensity,close time and liquid rate on the development by asynchronous injection and production in single well were analyzed.The results show that the better scheme is the length of the horizontal section is 800m,all fracture half length is 180m,fracture spacing is 100m and fracture conductivity is 60×10^-3μm²·m.In this situation,the cyclic injection-water is 5400m³,close time is 60d,and the liquid rate is 24 m³/d,the cumulative oil production is79769.47t,the recovery degree is 22.34%.Compared with the simultaneous injection and production in single well,five-point wells pattern water injection development water injection huff-puff and failure development,,the degree of improvement were increased by 4.13%、7.57%、10.65%and 13.22%.The numerical simulation results show that the asynchronous injection and production in single multi-stage fracturing horizontal well is suitable for the development of tight reservoirs,which can effectively solve the problem that the water effects is not obvious,and the range of water injection is small.It can exert the infiltration of the medium and the matrix suction effect,improve the water injection effect.The work of this paper provides an important technical reserve for the effective development of tight reservoir.