水力压裂扩展的流固耦合数值模拟研究  

A simulation study of hydraulic fracturing propagation with a solid-fluid coupling model

作　　者：连志龙[1,2] 张劲[3] 吴恒安[1] 王秀喜[1] 薛炳[1] 

机构地区：[1]中国科学技术大学力学与机械工程系／中科院材料力学行为和设计重点实验室,合肥230027 [2]中国石油集团钻井工程技术研究院钻井工艺研究所,北京100195 [3]中国石油大学石油与天然气工程学院,北京102249

出　　处：《岩土力学》2008年第11期3021-3026,共6页Rock and Soil Mechanics

摘　　要：以临界应力作为裂纹扩展准则并采用流固耦合模型模拟了水力压裂扩展问题,推导出裂缝面内的压降方程表达式,并编写出用户子程序嵌入到ABAQUS中。建立的计算模型能够模拟地应力、岩石力学特性、压裂液流体特性等各种复杂因素对水力压裂扩展的影响。通过计算分析得到一些有益结论,采用有限元软件ABAQUS求解可渗透油藏水力压裂扩展过程问题是可行的;提出了临界宽度的概念,它可以作为判断裂缝是作为起渗透作用的孔隙通道还是作为起导流作用的裂缝的依据;其结论对于压裂作业优化具有参考价值。A model of coupling the stress equilibrium and fluid continuity equations is proposed and implemented to solve numerical simulation problem of the hydraulic fracturing propagations. The mechanism of critical stress criterion of crack propagation is also introduced. The pressure descent distribution function on the fracture face along the fracture length is deduced and the corresponding user subroutines are developed and also embedded into ABAQUS. The complex factors of geology such as in-situ stress distribution, mechanical properties, fracturing fluid properties etc. are included in the present model. Several conclusions are drawn from the simulation results. It is viable to solve problems of hydraulic fracturing propagations in the permeable reservoirs with the finite element analysis software（ABAQUS）, The concept of critical width is proposed; the critical width can be used to judge a hydraulic fracture is treated as a porous passage or as a fluid flow fracture passage. The obtained conclusions are of much significance for the perforation parameter optimization and design of hydraulic fracturing treatments.

关 键 词：水力压裂 流固耦合 射孔 数值模拟 有限元 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]