页岩气藏压裂数值模拟敏感参数分析

针对页岩气藏压裂形成复杂裂缝网络后，单一的裂缝描述方法不再适用的问题，采用Eclipse 软件中的页岩 气模型，建立了一种“等效方法”，将页岩气有效改造体积表征为“主裂缝+ 网络裂缝渗透率”，代替“主裂缝+ 次裂 缝”的模拟方法，两种方法产量和长期压力驱替是等效的，解决了手工划分网格工作量大、计算速度慢的问题。运用 Plackett-Burman 型线性试验设计方法，对水力裂缝参数和储层参数进行敏感性排序，结果表明：水力裂缝参数中，压裂 纵向改造程度、网络裂缝渗透率和有效改造体积对产量影响最敏感，储层参数对产量影响敏感程度由强到弱为：地层 压力系数、总含气量、储层有效厚度、吸附气比例、井底流压、基质渗透率。为页岩气压裂选井选层和压裂设计方案优 化提供了依据。

Analysis of Sensitive Parameter in Numerical Simulation of Shale Gas#br# Reservoir with Hydraulic Fractures

To settle the difficulty of describing the complicated fracture network of shale gas after hydraulic fracturing，by using the shale model in Eclipse software，we build an equivalent method to characterize the effective stimulated reservoir volume as primary fracture and permeability of fracture network，which is to replace the primary fracture and secondary fracture method. The two methods are equivalent in gas production and pressure drainage，but the proposed method can solve the problem of heavy workload to grid manually and slow running. In this paper，we analyze the influence of hydraulic fracture parameters and reservoir parameters on shale gas production after fracturing by using the equivalent method. Meanwhile， we use linear experiments of Plackett-Burman type to screen the sensitivity of hydraulic fracture parameters and reservoir parameters. Simulation results indicate that the hydraulic fracture height，fracture network permeability and ESRV are the three most sensitive parameters among hydraulic fracture parameters and the sensitivity of reservoir parameters is arranged from strong to weak as follows：reservoir pressure coefficient，total gas content，effective reservoir thickness，rate of adsorbed gas，bottom hole flowing pressure and permeability of matrix，This paper can provide theoretical basis for well and formation selection and hydraulic fracturing design optimization.