煤储层中巷道型水平井井周应力分布特征的数值模拟研究——以晋城矿区胡底矿为例  

Numerical simulation study on stress distribution around the roadway-type horizontal wells in coal reservoirs:A case study of Hudi coal mine of Jincheng mining area

作　　者：张小东[1,2] 孙飞扬 张斌 衡帅 李贤忠[1] ZHANG Xiaodong;SUN Feiyang;ZHANG Bin;HENG Shuai;LI Xianzhong(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China;Henan Province Collab orative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region,Jiaozuo 454000,Henan,China;CBM and Gas Storage Business Department of Huabei Oilfield Company,PetroChina,Renqiu 062552,Hebei,China)

机构地区：[1]河南理工大学能源科学与工程学院,河南焦作454000 [2]中原经济区煤层(页岩)气河南省协同创新中心,河南焦作454000 [3]中国石油华北油田分公司煤层气与储气库事业部,河北任丘062552

出　　处：《河南理工大学学报（自然科学版）》2022年第2期1-9,共9页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金资助项目(41372162,51804100)。

摘　　要：为了研究煤储层中巷道型水平井井周应力分布特征,以晋城矿区胡底矿为例,基于煤储层及其顶底板的岩石力学性质,利用ABAQUS数值模拟软件,建立在煤储层和顶底板耦合作用下巷道型水平井开挖过程井周应力场计算模型,探讨不同断面形状、尺寸、开挖方向时井周应力分布特征,结果表明:(1)顶底板明显改变了竖直应力分布,促进了分界面处的应力集中,有利于巷道型水平井开挖;(2)圆形和矩形巷道型水平井井周应力影响范围基本相同,但圆形巷道型水平井应力释放更剧烈,易造成井壁破裂和失稳,利于扩大井径;(3)对于圆形巷道型水平井,随着断面尺寸增加,应力剧烈释放区和应力影响区范围增大,且后者增加更为明显;(4)巷道型水平井无论沿最大水平主应力方向还是沿最小水平主应力方向开挖,均在竖直方向出现应力集中,而水平方向表现为应力释放。研究结果认为,相比于矩形巷道型水平井,圆形巷道型水平井井径扩展更为显著,且断面尺寸越大,应力影响区范围越大,在开挖方向上沿最小水平主应力方向开挖优于沿最大水平主应力方向开挖。To clarify the stress distribution of a large-diameter roadway-type horizontal well drilled in coal reservoirs, Hudi coal mine in Jincheng mining area was taken as a case study.Based on the reservoir conditions and rock mechanics properties of coal seam and its roof and floor, a calculation model of stress field around the roadway-type horizontal wells during excavation was established by the numerical simulation software ABAQUS,and the stress distribution characteristics around the wells under different conditions of wellbore shapes, sizes and excavation directions were discussed.The results showed that:(1)The existence of roof and floor obviously changed the stress distribution in the vertical direction, which made the stress discontinuous and incongruous, and increase the stress concentration at the interface to a certain extent.The stress concentration at the interface was more conducive to the excavation of horizontal wells;(2)Circular and rectangular roadway-type horizontal wells had the same range of stress influence zone.But the severe stress release of circular roadway-type horizontal wells was easy to cause wellbore instability and breakdown, thus it was conducive to enlarging wellbore diameter;(3)The range of the stress releasing zone and the stress influence zone around circular roadway-type horizontal wells increased with the increase of the wellbore size, and the range of the stress influence zone increased more obviously;(4)The roadway-type horizontal wells showed stress concentration in the vertical direction and stress release in the horizontal direction, whether the horizontal wells were excavated along the direction of the maximum horizontal principal stress or the minimum horizontal principal stress.By contrast, the stress release was more severe when the roadway-type horizontal well was excavated along the direction of the minimum horizontal principal stress.On the other hand, compared with the rectangular roadway-type horizontal wells, the circular roadway-type horizontal wells had more sign

关 键 词：胡底矿 煤储层 巷道型水平井 井孔几何尺寸 井周应力分布 

分 类 号：P618.13[天文地球—矿床学]