页岩水平井井眼轨迹方位与层理面产状的关系

Relationship between shale horizontal well track orientation and bedding plane occurrence

夏宏泉 史亚红 王瀚玮 赵昊 朱伟厚3

西南石油大学油气藏地质及开发工程国家重点实验室，四川 成都 610500 中国石油西南油气田公司蜀南气矿，四川 泸州 646000 中国石化中原油田分公司工程技术管理部，河南 濮阳 457001

State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China Shunan Gas Field, Southwest Oil & Gas Field Company, PetroChina, Luzhou 646000, China Engineering Management Department, Zhongyuan Oilfield Company, SINOPEC, Puyang 457001, China

准确掌握层理面产状对页岩水平井井眼轨迹方位选取的影响规律，能有效预防井壁坍塌，节约钻井成本。对长宁区块H1井龙马溪组岩心进行三轴压缩实验，依据页岩岩石强度单一弱面剪切破坏准则和页岩水平井井壁应力分布模型，建立了页岩水平井井壁坍塌压力计算模型。利用页岩水平井测井资料和岩石力学实验数据，采用数值模拟方法，得到层理面产状对页岩水平井井壁坍塌压力的影响规律。当页岩层理面倾向一定时，随层理面倾角的逐渐增大，页岩水平井井壁坍塌压力当量密度范围逐渐变宽。当层理面倾角小于45°时，井壁岩石发生层理面的剪切破坏；当层理面倾角大于45°时，井壁岩石发生本体破坏，且当井壁岩石发生本体破坏时，页岩水平井沿层理面倾向的相反方向钻进有利于井壁稳定。

It is effective to prevent the collapse of the borehole wall and save the drilling cost by accurately grasping the influence of the bedding surface on the selection of the well trajectory of the shale horizontal well. Triaxial compression experiment was carried out on the core of the Longmaxi Formation in the Changning Block, and the calculation method of collapse pressure of shale horizontal well was established based on the single weak shear failure criterion and the shale horizontal well wall stress distribution model. Based on the logging data of shale horizontal well and the experimental data of rock mechanics, the influence law of bedding plane occurrence on the collapse pressure of shale horizontal well borehole was obtained. It is found that when the shale bedding dip is constant, the collapse pressure equivalent density range of shale horizontal wall gradually broadens with the increase of bedding dip angle. When the dip angle of the bedding plane is less than 45°, shearing failure will occur on bedding plane of rock wall; when the dip angle of the bedding plane is more than 45°, the body of the rock will be destroyed; when the body of the rock is destroyed, the shale horizontal well is drilled in the opposite direction along the bedding plane, which is favorable for the wellbore stability.

10.6056/dkyqt201803021