鄂尔多斯盆地本溪组8#煤煤岩气井壁稳定性影响因素研究  

Study on Factors Affecting Wellbore Stability in Benxi Formation No.8 Coalbed Methane Reservoir,Ordos Basin

作　　者：张小平[1,2] 丁磊 张存旺[3] 黄珺 王京光 陈磊 赵海锋[1,2] ZHANG Xiaoping;DING Lei;ZHANG Cunwang;HUANG Jun;WANG Jingguang;CHEN Lei;ZHAO Haifeng(National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields,Xi′an 710018,China;Drilling and Production Engineering Technology Research Institute,PetroChina Chuanqing Drilling Engineering Company,Xi′an 710018,China;Exploration Division of PetroChina Changqing Oilfield Company,Xi′an 710018,China;Engineering Technical Supervision Center of PetroChina Changqing Oilfield Company,Xi′an 710018,China)

机构地区：[1]低渗透油气田勘探开发国家工程实验室,西安710018 [2]中国石油川庆钻探工程公司钻采工程技术研究院,西安710018 [3]中国石油长庆油田公司勘探事业部,西安710018 [4]中国石油长庆油田公司工程技术监督中心,西安710018

出　　处：《煤炭技术》2025年第4期119-124,共6页Coal Technology

基　　金：中国石油集团川庆钻探工程有限公司科研项目(CQ2023B-15-2-3)。

摘　　要：以本溪组8^(#)煤为研究对象,测试了煤的工业分析与矿物组成,结果表明,煤中有机成分占比近90%,矿物成分中石英与黏土含量较高,对井壁稳定性具有一定影响。煤中的水溶盐含量及阳离子交换量均不高,但应注意Ca^(2+)、Mg^(2+)对泥浆性能的负面作用。采用了扫描电镜及压汞测试分析了煤的孔隙结构,煤中割理较发育,具有微米级孔隙,煤样浸水后单轴压缩强度显著降低,钻进过程中应尽量降低泥浆的失水量。对不同钻井方位下的水平井井壁变形进行了数值模拟,结果表明,其方位角与最小地应力平行时,井壁围岩的稳定性最好,不易发生井壁坍塌的问题。Focusing on the No.8 coal seam of Benxi formation,the industrial analysis and mineral composition of the coal were tested.The results showed that organic components made up nearly 90%of the coal,with high contents of quartz and clay among the minerals,affecting wellbore stability.Although the water-soluble salt content and cation exchange capacity are low,the negative effects of Ca^(2+)and Mg^(2+)on drilling fluid should be considered.Scanning electron microscopy and mercury intrusion porosimetry revealed that the coal has well-developed joints and micron-sized pores,and its uniaxial compressive strength significantly decreases after water immersion.Thus,it is important to minimize the water loss of drilling fluid during drilling.Numerical simulations indicated that when the drilling direction is parallel to the minimum in-situ stress,the stability of the wellbore is best,reducing the risk of collapse.

关 键 词：煤岩气 井壁稳定 矿物成分 孔隙结构 抗压强度 钻井方位 

分 类 号：TE28[石油与天然气工程—油气井工程]