苏丹水平井优快钻井技术研究与应用

苏丹市场老油区加密井增多,单井产量下滑,由于上产需要,甲方对水平井数量的需求大增.但因其独特、复杂的地质情况,导致钻井存在诸多难点,如起下钻阻卡、托压、塌卡等复杂和事故频发.对此,开展苏丹水平井优快钻井技术研究,通过实施井身结构优化技术、井眼轨迹控制技术、水平井钻井提速技术以及钻井液技术,有效解决了水平井施工难点,实现了优质、安全、快速钻井:钻头优选后,全面提升了钻井速度,减少了井下复杂;KCl/硅酸盐钻井液体系、Drilling-in钻井液体系有效保证了各项工序的顺利实施,在抑制页岩坍塌、稳定井壁、减少托压方面效果明显；水力震荡器的使用,可以解决长半径水平井摩阻大、造斜慢、加压困难的难题.研究成果一年内共成功实施20口水平井,平均钻井周期从2010年前的44d缩短至23.67d,缩短46.2％;平均建井周期为36.42d,比设计周期提前5～14d;机械钻速从原来的平均10.81m/h提高到12.41m/h,提高14.8％；事故和复杂现象由原来的3.7％降至1.8％.

Research and Application of Optimized and Fast Drilling Techniques for Horizontal Wells in Sultan

The single well production declined in old oil wells of Sultan with the infill wells increasing.So the demands of horizontal well increase greatly for the production need.But there are some difficulties because of the unique and complex geological conditions,such as complex situations of touch sticking in tripping,backing pressure,falling sticking and frequent occurrence of the accident.So the optimized and fast drilling technologies for the horizontal wells in Sultan are researched.After he technologies of hole structure optimization,well track control,horizontal well drilling speed boost and drilling fluid are applied,operation difficulty is solved effectively,and high-quality,safe and quick drilling may be realized.After bore bit optimization,drilling speed is enhanced with less downhole complexity.KCl/silicate drilling fluid system and Drilling-in drilling fluid system effectively ensure successful operation of each procedure,and it brings obvious result on shale collapse control,borehole wall stabilization and lower backing pressure.The application of hydraulic oscillator solves the difficulties of great friction,slow buildup and difficult loading in long-radius horizontal wells.Twenty horizontal wells are successfully drilled according to the research results in one year,and average drilling cycle cut down 46.2% from 44d before 2010 to 23.67d,average well construction cycle was 36.42d that moved up 5-14 days than designed cycle,ROP increased by 14.8% from the average value of 10.81m/h to 12.41m/h,and accidents and complexity decreased from 3.7% to 1.8%.