储层非均质性对水力压裂裂缝扩展的影响研究  

The Influence of Reservoir Heterogeneity on Hydraulic Fracture Propagation

作　　者：申峰 任相彦 周雷[2] 汤积仁[2] Shen Feng;Ren Xiangyan;Zhou Lei;Tang Jiren(Research Institute of Shaanxi Yanchang Petroleum(Group)Co.Ltd.,Xi'an 710075,P.R.China;State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,P.R.China)

机构地区：[1]陕西延长石油(集团)有限责任公司研究院,西安710075 [2]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044

出　　处：《地下空间与工程学报》2021年第5期1444-1456,共13页Chinese Journal of Underground Space and Engineering

基　　金：重庆市基础科学与前沿重点项目(CSTC,2017jcyjB0252);国家自然科学基金(51774056);科技部十三五重大专项(2017ZX05049-003-11)。

摘　　要：为了研究滤失和储层非均质性对水平井多簇射孔水力压裂裂缝扩展形态的影响,在前期建立的水力压裂流固耦合模型基础上,增加考虑多孔介质内流体流动,裂缝孔隙间的流体交换和射孔流量分配的物理过程,形成了用于多簇射孔水力压裂裂缝扩展的裂缝孔隙流固耦合模型,并数值模拟研究了致密砂岩气储层性质均质、非均质下水平井多簇射孔水力压裂裂缝扩展。研究发现:(1)滤失对中间簇射孔水力压裂裂缝扩展影响较大;(2)在储层均质情况下,多裂缝呈对称扩展,而在储层杨氏模量、抗拉强度、基质渗透率等非均质分布情况下,多裂缝呈非对称、非均匀扩展;(3)在储层复杂非均质情况下,四簇和三簇射孔水力压裂存在射孔簇过度改造、欠改造、甚至未起裂扩展的情况,尤其是在小间距条件下的四簇射孔。而两簇射孔水力压裂即使在间距较小时裂缝也能正常起裂扩展。因而,为了裂缝更多地有效扩展,在实际工程中,如果水力压裂密集施工,建议采取两簇射孔压裂;如果水力压裂不密集施工,兼顾施工成本建议采取三簇或四簇射孔压裂。In order to study the influence of the fluid leak-off and the reservoir heterogeneity on the fracture propagation patterns of multi-cluster perforation hydraulic fracturing in a horizontal well,a fracture-pore flow-solid model for multi-cluster perforation hydraulic fracturing was formed.On the basis of the fluid-solid coupling model of hydraulic fracturing established in the early research,the extra physical processes were considered in this model,including fluid flow in porous media,fluid exchange between fractures and pores and perforation flow distribution.By using this model,the fracture propagations of four cluster perforation hydraulic fracturing in a horizontal well in a tight sandstone reservoir in the condition of the different cluster spacing and the horizontal stress difference were numerically simulated.This work aimed to study and compare the fracture propagation patterns in the homogeneous reservoir and that in the heterogeneous reservoir.The study found that fluid leak-off has a great influence on intermedia fracture propagation of multi-cluster perforation hydraulic fracturing.And Multi-fracture propagation patterns are symmetrical in the homogeneous reservoir,while is asymmetrical and non-uniform in the heterogeneous reservoir with Young’s modulus,tensile strength or matrix permeability,respectively.In addition,in the complex heterogeneous reservoir,there are some ineffective propagated fractures for four cluster and three cluster perforation hydraulic fracturing,while both fractures propagate effectively for two cluster perforation hydraulic fracturing,even for that with small cluster spacing.For the site hydraulic fracturing operation,perforation should be designed to make multi fractures propagated more effectively.Therefore,it is suggested to adopt two cluster perforation for the intensive operation,while to adopt three cluster or four cluster perforation for non-intensive operation with the consideration of the operation cost.

关 键 词：多簇射孔水力压裂 非均质性 滤失 数值仿真 裂缝-孔隙流固耦合 

分 类 号：TE343[石油与天然气工程—油气田开发工程]