阿北1井垂直钻井工具应用分析

Analysis on Application of Vertical Drilling Tools in Well 1 of Abei Oilfield

为解决塔里木盆地两北地区二叠系地层底部—志留系地层采用常规钻具组合钻井时井斜严重及防斜与打快矛盾突出的难题,阿北1井进行了VTK垂直钻井系统防斜打快试验。VTK垂直钻井系统为一种闭环自动垂直钻井系统,在工作中可主动启动液压部件,通过1～2个肋板向井壁施加一定的作用力以对抗井斜趋势,以保持井眼按垂直方向钻进。现场试验结果表明:阿北1井应用VTK垂直钻井系统钻进深部易斜地层时,井斜角控制在0.14°～2.09°,大部分井段的井斜角小于1.00°;大部分试验井段(5 331.00～5 532.00和5 698.8～5 965.15m)机械钻速可达2.34～1.17m/h,与常规钟摆钻具组合相比,机械钻速提高17%～21%。这表明利用VTK垂直钻井系统基本可以解决塔里木盆地两北地区井斜控制困难及防斜与打快突出的难题,但为充分发挥VTK垂直钻井系统防斜打快的优势,需在钻头选型、钻井液性能优化及应对井下故障能力等方面进行进一步研究。

In the Two North exploration wildcats of the Tarim Basin,serious wellhole deviation and fierce conflict between anti-deviation and fast drilling occurred during the drilling from the bottom of the Permian to Silurian strata with conventional BHA.To resolve this problem,special VTK（VertiTrak） drilling system was tested in Well 1 of Abei Oilfield.As a closed loop automatic vertical drilling system,it can automatically activate the hydraulic parts,countering deviation by exerting a certain force against the borehole wall through one to two floor plates,and keeping the well vertical.The test results showed that,using the VTK vertical drilling system in the drilling of deep inclination prone strata in Well 1 of Abei Oilfield,the deviation angle of the well was controlled between 0.14° and 2.09°,for the majority of borehole,less than 1.00°;at the same time,the ROP increased up to 2.34-1.17 m/h for most of the well section（5 331.00-5 532.00 m,5 698.82-5 965.15 m）,which was 17%-21% higher than that of conventional pendulum drill assembly.This suggested that the VTK vertical drilling system could solve the problem mentioned above,but in order to give full play to anti-deviation and fast drilling speed of the VTK vertical drilling system,bit selection,drilling fluid performance optimization and dealing with the complex downhole conditions need to be studied further for the system.