渝东北田坝背斜页岩气地质调查田页1井钻井技术

Drilling technology of Well Tianye⁃1 of anticline shale gas Geological Survey in Tianba,northeast Chongqing

田页1井是部署于重庆南大巴山弧形褶皱带南部田坝背斜核部的一口页岩气地质调查井,设计目的为完成南方海相页岩地区页岩气有利目标区优选及新层系探索工作,采集矿权区内页岩的基础地质数据。施工中针对该井开孔岩层陡倾致设计倾角变更、页岩水敏性强产生井壁剥落失稳、井内地层高压和H_(2)S、CO气侵腐蚀、诱发井喷等问题,通过高密度钻井液技术与CHD127 mm绳索取心技术应用配合,采用陀螺测斜仪结合偏心锲稳斜定向,增加了钻杆接头壁厚以提高钻杆强度,较好地解决了高压溢流、钻杆折断、H_(2)S与CO气侵等安全隐患,很好的控制了井斜,顺利完成该井地质调查取心任务。该井施工的技术经验可供同类型工程参考。

Tianye‑1 well is a geological survey well for shale gas,which deployed in the southern Tianba anticlinal core of the South Daba Mountain curved fold belt,Chongqing.The design purpose is to complete the selection of shale gas favorable target areas in the southern Marine shale area,explore new strata,and collect the basic geological data of shale in the mineral area.In view of the probleums of the design dip angle of the opening rock is changed due to steep dip,the wall spalling instability caused by the strong water sensitivity of shale,the high pressure and H_(2)S and CO gas penetration corrosion in the inner well,and the induced blowout.Technologies are adopted such as the high density drilling fluid technology,CHD127mm wireline coring technology and gyro inclinometer combined with eccentric wedge orientation to increase the thickness of drill pipe joint to improve the strength of drill pipe.The safety hazards such as high pressure overflow,drill pipe fracture,H_(2)S and CO gas penetration,etc.are well solved,the well inclination is controlled,and the geological survey coring task of the well is successfully completed.This paper summarizes some technical experience and problems exist in the drilling process,and provides reference experience for similar projects.