长斜井段氮气钻井高扭矩摩阻机理及减摩降扭技术研究  

Study on High Torque Mechanism and Reducing Friction Torque in Nitrogen Drilling in Long Deviated Section

作　　者：罗成波 严焱诚[1] 朱化蜀[1] 谭军 LUO Chengbo;YAN Yancheng;ZHU Huashu;TAN Jun(Southwest Oil&Gas Company of Sinopec,Deyang 618000,Sichuan,China;Guangdong University of Petrochemical Technology,Maoming 525000,Guangdong,China)

机构地区：[1]中国石化西南油气分公司石油工程技术研究院,四川德阳618000 [2]广东石油化工学院,广东茂名525000

出　　处：《科技和产业》2023年第22期281-288,共8页Science Technology and Industry

摘　　要：大邑105井二开造斜,斜井段长2422 m左右,水平位移1398 m,井斜角35°左右,三开采用氮气钻井。基于钻柱运动学与动力学理论,参考钻柱动力学室内实验结果,表明钻柱涡动是大邑105井氮气举升清水阶段、钻进阶段及钻头提离井底循环阶段扭矩呈现“锯齿形”波动的根本原因,较多的钻具接头及钻具本体与井底低边碰撞摩擦导致扭矩处于波峰点,同时斜井段形成的岩屑床及岩粉附着在钻具表面诱发的黏滞摩擦导致扭矩和摩阻值平均值增加;钻具提离井底定点循环阶段,钻具涡动诱发钻具接头与井壁碰摩形成键槽,当钻具接头处于键槽中时,此时上提钻具须克服键槽形成的机械阻力,导致摩阻增大。同时设计了氮气钻井用减摩降扭清砂接头,分析不同井斜角、造斜率、钻压和钻具组合对扭矩摩阻的影响。因此,为了氮气钻井安全快速建井,建议钻井设计进一步优化井眼轨迹,钻具组合中增加清砂接头,通过清除岩屑床到达减弱钻具涡动效应的目的。The second spud of well Dayi 105 has a deviation of about 2422 m,a horizontal displacement of 1398 m and a deviation angle of about 35°.The third spud is drilled with nitrogen.Based on the theory of drill string kinematics and dynamics and referring to the indoor experimental results of drill string dynamics,the drill string whirl was the fundamental reason for the“sawtooth”fluctuation of torque in the clean water stage of nitrogen lifting,drilling stage and bit lifting off the bottom hole circulation stage of well Dayi 105.More drill tool joints and drill tool body collide and rub with the low side of the bottom hole,resulting in the torque at the peak point,At the same time,the viscous friction caused by the cuttings bed formed in the inclined section and the rock powder adhering to the surface of the drilling tool leads to the increase of the average value of torque and friction resistance.In the fixed-point circulation stage when the drilling tool is lifted off the bottom hole,the whirl of the drilling tool induces the friction between the drilling tool joint and the well wall to form a keyway.When the drilling tool joint is in the keyway,the lifting of the drilling tool must overcome the mechanical resistance formed by the keyway,resulting in the increase of friction.At the same time,the friction reducing and torque reducing sand cleaning joint for nitrogen drilling is designed,and the effects of different well deviation angle,build-up slope,WOB and BHA on torque friction are analyzed.Therefore,in order to build the well safely and quickly in nitrogen drilling,it is recommended to further optimize the borehole trajectory in the drilling design,add sand cleaning joints in the BHA,and reduce the whirling effect of the drilling tool by removing the cuttings bed.

关 键 词：长斜井段 氮气钻井 扭矩摩阻 减摩降扭技术 

分 类 号：TE2[石油与天然气工程—油气井工程]