裂缝性气藏气井产能计算新方法

A New Method for Calculating Gas Well Productivity in Fractured Gas Reservoir

裂缝性气藏储层中的裂缝是其气井产能的主要贡献者,裂缝的形态与位置对气井产能影响较大。传统裂缝性气藏气井产能模型多基于等效连续介质理论模型提出,未考虑储层裂缝的形态与位置。基于等值渗流阻力法,充分考虑裂缝性气藏裂缝形态与位置对气井产能的影响,利用裂缝微元段的径向渗透率表征裂缝对气井产能的贡献,推导了裂缝性气藏产能计算新方法。通过实例计算发现所提新方法能够较为准确地预测气井产能。裂缝性气藏的裂缝长度对气井产能的影响较小,而裂缝偏转角度、裂缝与气井距离对气井产能影响较大,随着裂缝偏转角度、裂缝与气井距离的逐渐增大,气井无阻流量逐渐减小,且减小幅度不断减小。

Fractures in fractured gas reservoirs are the main contributors to the gas well productivity,which is influenced greatly by the shape and location.The gas well productivity model of traditional fractured gas reservoirs is mostly based on the equivalent continuum theoretical model,and the shape and location of reservoir fractures are not considered.Based on the equivalent percolation resistance method,the influence of fracture shape and location on the productivity of gas wells is fully considered.Using the radial permeability of fracture microelement to characterize the contribution of fractures to gas well productivity,and finally a new method for calculating the productivity of fractured gas reservoirs is derived.Based on the example calculation,it is found that the new method can accurately predict the gas well productivity.The fracture length of the fractured gas reservoirs has little effect on the gas well productivity,but the fracture deflection angle,the distance between fracture and gas well have a great influence on it.With the fracture deflection angle,the distance between fracture and gas well gradually increasing,the absolute open flow potential of the gas well is gradually reduced,and the decreasing range is continuously reduced.