生产过程中裂缝内压力分布的模拟研究

STUDY ON PRESSURE DISTRIBUTION IN FRACTURE DURING PRODUCING PROCESS

根据压裂后油气渗流机理 ,考虑裂缝闭合压力和裂缝导流能力的变化 ,建立了生产过程中裂缝内压力分布模型 ,包括地层系统渗流模型、裂缝系统渗流模型、闭合压力方程和导流能力方程等 ,并以变步长网格 ,对地层系统渗流数学模型采用交替方向隐式格式、对裂缝系统渗流数学模型采用预测—校正格式 ,进行了迭代求解。在此基础上研制了裂缝内压力分布模拟软件 ,可准确预测和模拟裂缝内压力分布、裂缝闭合压力和裂缝导流能力的动态变化 ,用于指导并修正压裂设计及施工材料、施工参数的选取。

According to the mechanics of gas and oil flow in reservoir after fracturing, a pressure distribution model during producing process has been established, which consider the variation of closure pressure and fracture conductivity, and includes flow equations of formation system, flow equation of fracture system, closure pressure equation and conductivity equation. Meanwhile these equations have been iteratively solved by Alternating Direction Method and Prediction-Correction Method. Based on those work, a set of software simulating pressure distribution in fracture has been developed, which can be used to guide and emend the fracturing design, and selection of treatment material and parameters.