摘要
针对缝洞型碳酸盐岩水力裂缝转向问题,基于多孔介质流-固耦合基本方程和损伤力学基本理论,建立了缝洞型碳酸盐岩储层裂缝扩展的有限元模型并进行模拟分析。模拟发现:(1)水力裂缝遇到天然裂缝,逼近角越大,水力裂缝转向的极限水平主应力差越小;天然裂缝长度越长,极限水平主应力差越大。(2)水力裂缝遇到缝洞体,溶洞宽度越大,水力裂缝沿转向的极限水平主应力差越大;天然裂缝的逼近角越大,极限水平主应力差越小。(3)压裂裂缝遇到天然裂缝转向后,转向后的裂缝的宽度变小;水力裂缝遇到溶洞,裂缝总体宽度急剧下降。
In view of hydraulic fracture turning in fracture-cavity carbonate reservoirs,according to basic equations of fluid-solid coupling in porous medium and theory of damage mechanics,a finite element method model that is suit for hydraulic fracture in fracture-cavity carbonate reservoirs was built.A series of simulations were conducted.The results of stimulations as follow.（1） Hydraulic fracture encounter with natural fracture,the larger angle of intersection,the smaller the limit differential in-situ stresses.The longer natural fracture,the larger the limit differential horizontal in-situ stresses.（2） When hydraulic fracture encounter with fracture-cavity,angle of intersection increase,the limit differential horizontal in-situ stresses decrease.The width of cavity increase,the limit differential horizontal in-situ stresses increase.（3）The orientation of hydraulic fracture is turned,the width of turned fracture become small.The global width of hydraulic fracture decrease sharply when hydraulic fracture enter into cavity.
出处
《科学技术与工程》
北大核心
2012年第12期2816-2819,2824,共5页
Science Technology and Engineering
基金
国家重大专项(2008ZX05014-006)资助
关键词
流-固耦合
天然裂缝
溶洞
裂缝扩展
转向
fluid-solid coupling natural fracture cavity fracture propagation fracture turning
