体积压裂水平井复合流动模型

Compound flow model of volume fractured horizontal well

基于体积压裂水平井复杂裂缝改造特点及流动特征,构建了耦合双重介质复合流动模型,应用Laplace变换和Stehfest数值反演,得到了定产和定压条件下封闭边界裂缝的井底压力和水平井产量半解析解。在模型正确性验证的基础上,结合陇东致密油储层特征参数着重研究了体积压裂缝网参数对产量的影响。模型研究结果表明:缝网改造带宽越大,体积压裂水平井单井产能越高,缝网区域渗透率对初期产量影响较大;水平井体积压裂优化设计应同时兼顾单条裂缝改造体积和裂缝条数的关系。实例计算结果表明压裂改造带宽不宜过大,采用多裂缝、小带宽的压裂方案增产效果最好。该研究结果对致密储层水平井体积压裂设计具有一定的指导意义。

Based on reconstrcution characteristics and flow feature of fracture network of volume hydraulic fracture horizontal well,this paper establishs compound flow model coupling double porosity model,applying Laplace transform and Stehfest numerical inversion,and obtains the formulas of bottom hole pressure and horizontal well production under the constant output and pressure for the single fracture in closed boundary.On the basis of model validation,this paper researchs the influence of parameters of fracture network on production.It is shown that the longer of band width,the higher the cumulative oil production and the permeability of fracture network has a great influence on production.Interference between fractures number and single fracture stimulate volume should be considered when optimizing design for horizontal well and the analysis results shows that the plan with more fracture numbers is better.The results of the study supplies striking influences for the plan of fracture network in the tight oil reservoir.