莫深1井φ444.5mm大尺寸井眼钻井技术

DRILLING TECHNOLOGY IN φ444.5 mm LARGE WELLBORE OF THE WELL MOSHEN-1

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7380m,其中φ444.5mm井眼钻达4436m,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φ444.5mm井段平均机械钻速达到5.49m/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φ444.5mm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。

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.