超短半径水平井钻井轨迹优化设计及应用

Optimization Design and Application of Ultra-short Radius Horizontal Well Drilling Trajectory

超短半径水平井钻井技术是实现低产、低效井治理改造的有效措施。根据油藏适用性和工程可实施性,基于柔性钻具特性,对超短半径水平井井眼轨迹进行设计优化,开发了一套选井选层技术,实现了油藏与工程的结合,可以以较低的造斜率实现造斜着陆的角度,从而降低了摩阻扭矩和进一步提高水平段钻进长度。通过对柔性钻具进行优化设计,确定柔性钻具单节长度为0.15 m、最大弯转角度4.5°,与井眼间隙达19 mm(钻头直径为152 mm),确保了柔性钻具在井眼中的姿态稳定,减少了与井眼的摩擦。现场应用效果表明,该技术可实现井眼曲率半径3.6 m、孔眼直径152 mm、水平段长60 m,作业完成后,产能测试显示,该井从作业前的16.7 m^(3)/d增长至95.1m^(3)/d,比作业前产量提高了5.7倍,实现了经济高效开发。

The drilling technology of an ultra-short radius horizontal well is an effective measure to achieve the treatment and transformation of low production and low efficiency wells.According to reservoir applicability and engineering implementability,based on the characteristics of flexible drilling tools,the wellbore trajectory of ultra-short radius horizontal wells was designed and optimized,a set of well and layer selection methods was developed to realize the combination of reservoir and engineering and achieve the landing angle with a low dogleg,thus reducing the drag and torque and improving the horizontal drilling length.By optimizing the design of flexible drilling tools,it is determined that the single section length of flexible drilling tools is 0.15 m,the maximum bending angle is 4.5°,and the gap between the flexible drilling tools and the hole is 19 mm(the bit diameter is 152 mm),so as to ensure the stable attitude of the flexible drilling tools in the hole and reduce the friction with the hole.The on-site application results show that this technology can achieve a wellbore curvature radius of 3.6 m,a borehole diameter of 152 mm,and a horizontal section length of 60 m.Post-operation tests show that the production increases from 16.7 m^(3)/d to 95.1 m^(3)/d,which is 5.7 times higher than the pre-operation,realizing economic and efficient development.