莫深1井Φ444.5 mm大尺寸井眼钻井技术

莫深1井位于新疆准噶尔盆地中央坳陷莫索湾凸起莫索湾背斜，设计井深7 380 m，其中Φ444.5 mm井眼钻达4 436 m，为当前国内最深的大尺寸井眼。根据莫深1井的实际情况优化水力参数，采用合适的钻头选型技术、个性化的PDC钻头设计及应用技术、有效地防斜打快技术、大尺寸螺杆复合钻井技术以及大排量、高泵压的强化水力参数技术，大幅度地提高了大尺寸井眼钻井速度。在确保井身质量和井下安全的情况下，莫深1井Φ444.5 mm井段平均机械钻速达到5.49 m/h，最大井斜角仅为1.1°。与这一区块邻井相比，在井眼尺寸大一级的情况下，莫深1井Φ444.5 mm井眼的钻井速度仍高于邻井相同井段。其实践经验对于提高深井、超深井钻井速度具有重要的意义。

DRILLING TECHNOLOGY IN Φ444.5 mm LARGE WELLBORE OF THE WELL MOSHEN 1

The well Moshen 1 is located at Mosuowan anticline of the Junggar basin Central Depression in Xinjiang, with the designed depth of 7380 m and Φ444.5 mm wellbore drilled till the depth of 4436 m. It is now the deepest large size wellbore in China. The ROP on the well Moshen 1 was greatly improved through a series of measures, such as optimizing hydraulic parameters according to the field data, selecting proper bits, specially designed characteristic PDC bit and application, effective well deviation control during fast drilling, compound drilling with large size PDM, adoption of high flow rate and high pump pressure, etc. The average ROP obtained during drilling through Φ444.5 mm  wellbore of the well Moshen 1 reached 5.49 mm/h, the maximum deviation angle was 1.1°, in addition to high wellbore quality and downhole safety ensured. The comparison with offset wells drilled in the same block shows the ROP at Φ444.5 mm section of the well Moshen 1 is even higher than those obtained at the same well interval of other wells with smaller boreholes. This field practice is significant for ROP improvement on deep and ultra deep wells.