摘要
针对连续管钻井过程中水平段岩屑运移困难、管柱摩阻大影响连续管钻井水平延伸能力的问题,提出了连续管水平段旋转管柱钻井系统,该系统由不旋转连续管和部分旋转管柱组成。建立了连续管水平段环空三维流体域模型,并进行数值计算,研究了管柱旋转速度、旋转管柱直径及管柱偏心度等参数对水平段环空流动及岩屑运移的影响。研究结果表明:水平段设置旋转管柱可使连续管钻井水平段环空流体产生旋转流动,岩屑分布均匀,环空压降减小;转速越大,岩屑切向速度也越大,旋转管柱直径增大能提高环空岩屑切向速度;在偏心状态下岩屑更容易在环空底部堆积,但管柱旋转不仅提高了旋转部分岩屑的切向速度,也提高了非旋转部分环空岩屑的切向运动能力;随着管柱旋转速度的增加,水平环空非旋转部分岩屑体积分数逐渐减小,提高了水平环空的清洁程度。研究结果可为合理设计连续管水平井段部分旋转管柱钻井系统提供理论依据。
To address the horizontal extension of coiled tubing drilling caused by difficult cutting transportation and large drilling string friction,a coiled tubing drilling system with rotary drillpipe for horizontal section is proposed.The system consists of a non-rotating coiled tubing and a rotating string.The three-dimensional fluid domain model of the horizontal section of the coiled tubing was established,and the numerical calculation was carried out to study the effects of parameters such as the string rotation speed,the diameter of the rotating string and the eccentricity of the string on the annulus flow and cutting movement in the horizontal section.The results show that the rotating string in the horizontal section can make the annular fluid run a rotating flow.The cuttings are evenly distributed,and the annular pressure drop is reduced.The increase in string diameter can increase the tangential velocity of annulus cuttings.In the eccentric state,the cuttings are more likely to accumulate at the bottom of the annulus.The rotation of the string not only increases the tangential velocity of the rotating part of the cuttings,but also improves tangential movement ability of the annulus cuttings in the non-rotating part.As the rotation speed of the string increases,the volume fraction of the non-rotating part of the horizontal annulus gradually decreases,which improves the cleanliness of the horizontal annulus.The research results can provide a theoretical basis for the rational design of the coiled tubing rotary drillpipe drilling system.
作者
汪皖
马卫国
王晓蒙
Wang Wan;Ma Weiguo;Wang Xiaomeng(School of Mechanical Engineering,Yangtze University;Qinghai Drilling Company of CNPC Xibu Drilling Engineering Company Limited)
出处
《石油机械》
北大核心
2019年第5期38-43,共6页
China Petroleum Machinery
基金
国家科技重大专项“连续管装备与应用技术”(2011ZX05036-006)
长江大学青年基金项目“不压井闸板防喷器胶芯的动密封仿真及优化”(2016cqn29)
长江青年科技创新团队基金项目“油气高效钻井工具技术研究”(2016cqt02)
关键词
连续管
旋转管柱
钻井系统
岩屑运移
环空压降
coiled tubing
rotary drillpipe
drilling system
cuttings transportation
annular pressure drop
