不同裂缝倾角诱导井底岩爆动态演化数值模拟  

Numerical Simulation of Rock Burst Dynamic Evolution at Bottom Hole Induced by Different Fracture Dips

作　　者：罗成波 何龙[3] 蒋祖军[1] 李皋[2] 欧彪[1] 孟英峰[2] 肖国益 严焱诚[1] 王希勇[1] 贾红军[4] LUO Cheng-bo;HE Long;JIANG Zu-jun;LI Gao;OU Biao;MENG Ying-feng;XIAO Guo-yi;YAN Yan-cheng;WANG Xi-yong;JIA Hong-jun(Petroleum Engineering Technology Research Institute,Southwest Oil&Gas Branch,SINOPEC,Deyang 618000,China;State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu 610599,China;SINOPEC Southwest Oil&Gas Branch,Chengdu 610041,China;China Petroleum Tarim Oilfield Company,Kuerle 841000,China)

机构地区：[1]中国石化西南油气分公司石油工程技术研究院,德阳618000 [2]西南石油大学国家重点实验室,成都610599 [3]中国石化西南油气分公司,成都610041 [4]中国石油塔里木油田公司,库尔勒841000

出　　处：《科学技术与工程》2021年第4期1305-1311,共7页Science Technology and Engineering

基　　金：国家科技重大专项(2016ZX05021-004)。

摘　　要：氮气钻井钻遇致密砂岩裂缝圈闭导致井底岩爆是QL1井恶性井喷事故的根本诱因,针对岩爆的动态演化过程进行系统分析并形成正确认识是恢复氮气钻井技术良性发展的紧迫需要。应用多物理场耦合分析软件COMSOL Multiphysics 4.3,建立井底逐渐接近裂缝的数值模型,以致密砂岩岩体内部微裂缝起裂时对应的等效塑性应变为判断标准,分别应用CWFS-DP(cohesion weakening and frictional strengthening-Drucker-Prager)强度准则、DP(Drucker-Prager)强度准则及MC(Mohr-Coulomb)强度准则进行平行数值计算,得到不同裂缝倾角诱导井底岩爆的动态演化过程。研究成果系统地解释了DX1井随钻监测参数的异常变化,不仅可为岩爆的防治提供理论基础,而且在石油工程领域可为深部岩体动力学失稳研究提供一个新的视角。Bottom hole rockburst caused by tight sandstone fracture trap during nitrogen drilling was the main cause of malignant blowout accident in the QL1 well.It is urgent to systematically analyze the dynamic evolution process of the rockburst for good understanding in order to improve nitrogen drilling technology.COMSOL Multiphysics 4.3 was applied to analyze the problem,and the numerical model of bottom hole gradually approaching to the fracture was established.The equivalent plastic strain corresponding to the initiation of micro-cracks in tight sandstone rock mass was used as the judgment criterion.Meanwhile,criteria of the CWFS-DP(cohesion weakening and frictional strengthening-Drucker-Prager)strength,DP(Drucker-Prager)strength,and MC(Mohr-Coulomb)strength were adopted for parallel numerical calculation,from which the dynamic evolution process of the bottom-hole rockburst induced by different fracture dips was interpreted.This study shows that the larger the fracture inclination,the larger the critical distance of instability and the volume of rock burst debris.The dynamic evolution process analysis explained the abnormal change of logging monitoring parameters in the DX1 well,which provided the theoretical basis for the prevention and control of rock burst with a new tool for petroleum engineering for deep rock dynamic instability in the field.

关 键 词：氮气钻井 井底岩爆 裂缝圈闭 动态演化 数值模拟 

分 类 号：TD235.38[矿业工程—矿井建设]