考虑天然裂缝的页岩储层体积压裂数值模拟  

Numerical simulation on volumetric fracturing for shale gas reservoir considering natural fractures

作　　者：陈旭日 张公社[1,2] 杨康 许冬进[1,2] CHEN Xuri;ZHANG Gongshe;YANG Kang;XU Dongjin(Hubei Cooperative Innovation Center of Unconventional Oil and Gas,Yangtze University,Wuhan 430100,China;Key Laboratoryof Oil and Gas Drilling Engineering of Hubei Province,Yangtze University,Wuhan 430100,China;Oil Production Technology Research Institute of Huabei Oilfield(CNPC),Renqiu,Heibei 062552,China)

机构地区：[1]长江大学非常规油气湖北省协同创新中心,武汉430100 [2]长江大学油气钻采工程湖北省重点实验室,武汉430100 [3]中国石油华北油田采油工程研究院,河北任丘062552

出　　处：《中国科技论文》2018年第3期286-290,共5页China Sciencepaper

基　　金：国家自然科学基金资助项目(51504038);湖北省自然科学基金资助项目(2015CFC857)

摘　　要：为了更真实地模拟页岩储层水平井体积压裂,采用擅长处理非连续结构问题的离散元方法,利用三维离散元程序(three dimension distinct element code,3DEC)及其内嵌fish语言建立表征天然裂缝的离散裂缝网络(discrete fractal network,DFN),并考虑流固藕合建立水力裂缝与复杂DFN相互作用的页岩水平井体积压裂数值计算模型。利用该模型计算分析了水力裂缝在存在DFN情况下的行为、同段多簇同时压裂裂缝形态和簇间距对裂缝网络形态以及破裂模式的影响。结果表明,水力裂缝会沟通天然裂缝产生分支缝;分簇数越多,改造所波及的范围越大,且由于簇间裂缝诱导应力互相干扰,同一段内的压裂簇所形成的裂缝形态可能相差较大;一定范围内,簇间距小沟通DFN彻底,簇间距大剪切滑移多,裂缝网络体积大,但不利铺砂。模拟结果可为进一步认识页岩储层体积压裂裂缝行为研究提供指导。To simulate the volumetric fracturing of horizontal wells for shale reservoirs more accurately,a model with discrete fractal network(DFN)is established by using three dimension distinct element code(3DEC)and its embedded fish coding language,which is good at dealing with discontinuous structure problem.The fluid-solid coupling is considered in the numerical model.Using this model,the behavior of hydraulic fractures in the presence of DFN is calculated and analyzed.The influence of clusters and the spacing of the clusters on the shapes of fractures are discussed.The results show that the hydraulic fractures will propagate the natural fractures to produce branch joints.The more the number of clusters is,the bigger volume of reservoir is stimulated,and the shape of fractures in one cluster can be different due to the induced stress.Within a certain range,the small cluster spacing can cause a better connection with DFN,and with bigger spacing,there will be more shear slippages and the stimulated reservoir volume will be bigger,but it is not convenient to transmiting the proppant.The simulation results provide guidance for further understanding the fracturing behavior of shale reservoir fractures.

关 键 词：页岩储层 水力压裂 离散元 体积压裂 

分 类 号：TE357.11[石油与天然气工程—油气田开发工程]