基于有限元软件的煤层气水平井井壁稳定数值模拟  

Numerical Simulation of Wellbore Stability for CBM Horizontal Well by Finite Element Software

作　　者：张丹丹[1] 冯雨实[1] 李永臣 任小庆 康海涛 吴辽 ZHANG Dandan1, FENG Yushi1, LI Yongchen2, REN Xiaoqing3, KANG Haitao4, WU Liao5(1.Department of Civil Engineering, Chongqing Energy College, Chongqing 402260, China;2.Xinzhou Branch of Petrochina Coalbed Methane Company Limited, Taiyuan 030000, China;3.Sinopec Green Energy Geothermal Development Co., Ltd., Xianyang 712000, China;4.Southwest Drilling Branch, Sinopec Zhongyuan Petroleum Engineering Co., Ltd., Nanchong 637001, China; 5.Xiaobaoding Coal Mine, Panmei Coal（Group） Co.,Ltd., Panzhihua 617013, China)

机构地区：[1]重庆能源职业学院土木工程系,重庆402260 [2]中石油煤层气有限责任公司忻州分公司,山西太原030000 [3]中石化绿源地热能开发有限公公司,陕西咸阳712000 [4]中石化中原石油工程有限公司西南钻井分公司,四川南充637001 [5]攀枝花煤业(集团)有限责任公司小宝鼎矿,四川攀枝花617013

出　　处：《煤矿安全》2018年第3期144-147,共4页Safety in Coal Mines

基　　金：重庆市教委2017年度科学技术研究资助项目(KJ1754490)

摘　　要：以山西宁武盆地的石炭系上统太原组9~#煤层为地质背景,该煤层煤岩力学性质为依托,运用COMSOL Multiphysics软件模拟分析了在欠平衡钻井中3种钻井液液柱压力下井周围岩的应力和变形情况。研究发现:研究区块水平井在垂向应力方向井周围岩所承受的应力最大,变形最为严重;井周围岩处存在应力突变点,该点处容易产生拉剪裂纹,导致井周围岩破裂或失稳;井周围岩应力分布及变形情况与钻井液液柱压力有关,液柱压力与储层压力差值越小,井周相对越稳定。In this article, the No.9 coal seam of the Carboniferous upper Taiyuan formation is taken as geological background, the stress and deformation of the surrounding rock under three kinds of drilling fluid column pressure in under-balanced drilling was analyzed by using the finite element software COMSOL Multiphysics. The study shows that the stress and deformation of surrounding rock in the horizontal wells in vertical direction of the study block is the most severe. There is a sudden change of stress in the surrounding rock, which is easy to produce tensile and sheared crackles and lead to fracture or instability of the surrounding rock. The stress distribution and deformation of the surrounding rock are related to the drilling fluid column pressure,the smaller difference between the liquid column pressure and the reservoir pressure is, the more stability of the wellbore will.

关 键 词：煤层气 欠平衡钻井 数值模拟 井壁稳定 水平井 液柱压力 

分 类 号：TD713[矿业工程—矿井通风与安全]