BZ13-1-XX井大尺寸套管长段锻铣技术

Techniques of long milling operation on large sized casing at BZ13-1-XX Well

BZ13-1-XX井是渤中13-1油田一口废弃井,为了挖掘剩余产能,对其339.7 mm大尺寸套管实施了长达222 m的锻铣作业,然后侧钻成一口新井。分析了XX井浅层侧钻选取的原因,结合XX井锻铣施工,对锻铣工具使用特点、操作要点、锻铣的工艺技术、锻铣过程中遇到的难点进行了总结。最后指出,针对浅层锻铣套管,在钻具上加双向减震器可降低设备故障率;锻铣到设计深度后应使用侧钻井眼同尺寸的钻头进行通井,然后再进行后续打水泥塞侧钻作业;采用高黏、高切的坂土浆进行扫塞,同时提高排量,可达到较好的铁屑携带效果;每锻铣3 m要保持大排量上下大幅度活动钻具两次,防止严重堆积造成卡钻。

BZ131-XX Well is an abandoned well in Bozhong 13-1 Oilfield.To tap into its remaining reservoir,a milling operation of 222 m is conducted on its 339.7 mm casing to drill the well into a new one by sidetracking.This paper analyzes the reasons for shallow sidetracking selection at the XX Well.Based on the experiences of XX Well milling operations,the paper summarizes the operation specialty of milling tools,operating points,milling technology,and challenges in the milling process.It is indicated in the paper that,for shallow milling casing,the equipment failure rate can be reduced if the drilling tool is equipped with a bidirectional shock absorber.After milling to the design depth,a bit of the same size as the sidetracked wellbore should be used for drifting before subsequent cement plug sidetracking operation.Soil slurry with high viscosity and high gel strength should be used for plugging.The displacement rate should be as high as possible to achieve effective iron filing carrying.In every 3 m of milling,the drilling string should be moved twice up and down at a high displacement rate in large amplitude to prevent drill pipe sticking caused by severe cutting accumulation.