弹塑性中深地热储层暂堵转向压裂裂缝扩展数值模拟  

Numerical Simulation of Fracturing Fracture Propagation inElastic-plastic Medium-deep Geothermal Reservoirs

作　　者：王秋艳 汪道兵 郑臣 孙东亮[1] 宇波 WANG Qiuyan;WANG Daobing;ZHENG Chen;SUN Dongliang;YU Bo(Beijing Institute of Petrochemical Technology,School of Mechanical Engineering,Beijing 102617,China;Yangtze University,College of Petroleum Engineering,Hubei Wuhan 434023,China)

机构地区：[1]北京石油化工学院机械工程学院,北京102617 [2]长江大学石油工程学院,湖北武汉434023

出　　处：《北京石油化工学院学报》2024年第4期38-47,共10页Journal of Beijing Institute of Petrochemical Technology

摘　　要：为探究弹塑性中深地层暂堵转向压裂裂缝扩展机理,采用摩尔-库伦塑性准则和粘聚力单元牵引-分离定律,建立了中深地层渗流-应力全耦合有限元模型,对暂堵转向压裂过程中的暂堵剂强度、暂堵带长度、地层塑性参数、注入排量等多个影响因素开展一系列数值模拟研究,探究各因素与突破暂堵带所需压力和裂缝宽度变化。数值模拟结果表明:随着暂堵带长度、暂堵强度的增加,压裂突破暂堵带所需压力也越大;适当增加注入排量有利于形成憋压,提高裂缝宽度;改变地层岩石的弹塑性参数内摩擦角和黏聚强度,结果发现黏聚强度越低内摩擦角越小,塑性变形程度越大,裂缝扩展压力越高,裂缝宽度越宽。In order to explore the propagation mechanism of fracturing fractures in elastoplastic medium-deep formations,a fully coupled finite element model of seepage-stress in medium-deep formations was established by using the Moore-Coulomb plasticity criterion and the traction-separation law of cohesive units,and a series of numerical simulation studies were carried out on the strength of the temporary plugging agent,the length of the temporary plugging zone,the plastic parameters of the formation,the injection displacement and other influencing factors in the process of temporary plugging and fracturing,and the changes of each factor and the pressure and fracture width required to break through the temporary plugging zone were explored.The numerical simulation results show that with the increase of the length and strength of the temporary plugging zone,the pressure required for fracturing to break through the temporary plugging zone is also greater.Appropriately increasing the injection displacement is conducive to the formation of pressure holding and increasing the crack width.The results show that the lower the cohesion strength,the smaller the internal friction angle,the greater the plastic deformation,the higher the fracture propagation pressure,and the wider the crack width.

关 键 词：暂堵压裂 弹塑性 有限元 裂缝扩展 

分 类 号：TE375[石油与天然气工程—油气田开发工程]