围压对井内爆炸压裂损伤破坏尺度影响的数值模拟研究  

Numerical Simulation for the Influence of Confined Pressure on the Damage Scale of Explosive Fracturing Inside Wellbore

作　　者：王京印[1] 程远方[1] 刘芳[2] 温盛魁[3] 李庆华[4] 

机构地区：[1]中国石油大学(华东)石油工程学院,山东东营257061 [2]中国石油大学(华东)计算机与通信工程学院,山东东营257061 [3]中国石化胜利油田分公司采油工艺研究院,山东东营257000 [4]中国石化胜利油田分公司滨南采油厂,山东滨州256600

出　　处：《石油钻探技术》2011年第4期81-86,共6页Petroleum Drilling Techniques

基　　金：国家高技术研究发展计划("863"计划)项目"低渗低丰度油气田井内动载压裂开采新技术"(编号:2007AA06Z208)部分研究内容

摘　　要：针对当前因条件所限而无法通过开展大规模井内爆炸压裂试验来研究围压对井内爆炸压裂损伤破坏尺度的影响规律这一问题,借助LS-DYNA有限元分析模块,结合前期开展的室内爆炸压裂试验,建立了井内爆炸压裂数值计算模型。该模型主要由围岩损伤力学模型、炸药爆炸力学模型和耦合介质模型3部分构成。在对模型准确性进行验证的基础上,进行了爆炸压裂作用下围压对井壁围岩损伤破坏尺度的数值模拟,并通过岩石损伤力学理论,对模拟结果进行了分析。结果表明:在确保诸如炸药量、岩性和装药结构等其他条件不变的情况下,随着围压的增大,围岩损伤衰减速度加快,损伤破坏范围减小;对于围岩内部同一位置,其损伤破坏程度随固压增大而降低。Considering the current difficulty of using the field test method to analyze the influence of confining pressure on the damage and failure scale of explosive fracturing inside wells,a numerical model of explosive fracturing inside wellbore has been established based on the lab explosive fracturing test and the finite-element analysis module, LS-DYNA. The numerical model includes three components, the surrounding rock damage mechanical model, the explosion mechanical model and the coupling medium model. On the basis of the verification of model accuracy,the numerical simulations were conducted to determine the influence of explosive fracturing inside wellbore on the surrounding rock under the confining pressure. At last, the simulation result was analyzed using rock damage mechanics. The results showed that,with the increase of the confining pressure, the decay rate of rock damage accelerates and the damage area becomes smaller under the same condition of explosive amount, rock properties and the charging structure. For the same location inside the surrounding rock,the damage caused by the explosion decreases with the increase of confining pressure.

关 键 词：封闭压力 爆炸压裂 损伤尺度 数值模拟 数学模型 

分 类 号：TE357.3[石油与天然气工程—油气田开发工程]