塔河油田TH12328CH长靶前位移中短半径水平井钻探实践

塔河油田常规中短半径水平井靶前位移为40~50 m,造斜率控制在(1°~1.5°)/m。TH12328CH侧钻水平井为避开一个溢漏并存的定容体腔,靶前位移长达395 m。针对该井井身轨迹控制难度大,测量仪器性能要求高,钻压传递困难,极易发生出新眼及钻具疲劳断裂等事故难点,介绍了该井井身剖面设计、开窗试钻、井身轨迹控制、优快钻井技术等方面措施。钻探实践表明:3°单弯螺杆是塔河油田中短半径侧钻水平井的理想选择;短无磁测斜工艺可提高井底轨迹预测精度;采用柔性倒装钻具组合、优选仪器、下钻分段循环降温、下钻遇阻摆原工具面位置进行划眼等措施,保证了施工安全。

Drilling practice of the medium-short radius horizontal well TH12328 CH with a long displacement before the target in Tahe oilfield

For conventional medium -short radius horizontal wells in Tahe oilfield ,the displacement before the target is 40 to 50 m,and the build-up rate is 1 to 1.5 degree per meter.To evade a cavity in which overflow and lost -circulation occured at the same time ,the well TH12328 has a long displacement of 395 m.Aiming at a series of difficulties such as difficultly controlling well trajectory ,difficultly conveying WOB ,easily making a new borehole ,drilling string fatigue ,high requirements for survey tools ,etc.,this article introduces some methods adopted in well profile design ,casing sidetrack ,traj-ectory control ,and high performance drilling .The drilling practice showed that 3°motor is the best choice for the medium-short horizontal well in Tahe oilfield;the short-collar survey technology can improve prediction accuracy of well trajec-tory;some measures can guarantee drilling safety ,which include using flexible inverted BHA ,optimizing survey tools ,re-ducing temperature by circulation while trip in ,reaming located by old tool face ,etc.