小井眼长水平段水平井摩阻扭矩控制技术

Friction and Torque Control Technology For Slim and Long Horizontal Well

小井眼长水平段水平井+分段压裂的开发方式在大牛地气田的开发中取得了理想效果,然而仍然存在一系列的问题,尤其是水平段后期的摩阻扭矩控制问题。以理论分析和实钻工程特征为基础,建立了摩阻扭矩分段计算模型,并对水平段长度、轨迹剖面、钻具组合和钻井液流变性等影响规律进行了分析,结果表明:随着水平段长度的增加,钻进和起钻的摩阻扭矩均在增加,当摩阻扭矩不再增加时,此时便是水平段的极限长度;随着单增剖面靶前位移的增加,摩阻扭矩增加;采用组合钻杆(φ1 01.6 mm/φ114.3 mm+φ88.9 mm)既有利于水平段和大斜度井段携岩,同时又能有效地控制摩阻扭矩;钻井液屈服值和塑性黏度越低,摩阻扭矩越小。将摩阻扭矩综合控制技术应用于DPH7井,水平段轨迹平稳,平均全角变化率1.79。/30 m。

The development mode of Slim-and-long-section horizontal well with staged fracturing approach in Daniudi Gas Field has achieved the desired effect,however,there are still a series of problems,especially friction torque control problems for the later part of the horizontal section.In this paper,based on theoretical analysis and practical drilling engineering features,segmented calculation model for drag and torque is established,and influencing rules are analyzed,such as horizontal section length,trajectory profile,BHA and drilling fluid rheology,etc.The results show that with the increase of horizontal section length,friction and torque of drilling or POOH increases.When the friction torque does not increase,the length of the horizontal section reaches limitation.With increase of before A target displacement,friction and torque also increase.In addition,using combinations of drill pipe（101.6 mm/114.3 mm＋88.9 mm） is not only conducive to carry rocks for high deviation angle and horizontal section,but also available to effectively control the friction and torque at the same time.The lower the yield value and plastic viscosity of drilling fluid,the lower friction and torque.Applying friction torque control technology to DPH7,horizontal section trajectory is smooth,and the average dogleg is 1.79730 m.