元坝地区超深井钻井提速难点与技术对策

Difficulties of Improving Rate of Penetration and Its Technical Solutions in Yuanba Area

元坝地区是中国石化天然气增储上产的一个重要勘探开发区域。前期钻探实践表明,元坝地区超深井钻井机械钻速低、钻井周期长,为了加快该地区的勘探开发进程,开展了钻井提速技术研究。对前期完钻的12口井进行了统计分析,指出元坝地区钻进过程中,有3个重点井段存在提速难点,重点介绍了针对该难点所采取的技术对策,以及应用这些技术对策所取得的提速效果。采用泡沫钻井技术后,上部大尺寸井眼的机械钻速提高4倍以上;采用控压钻井、孕镶金刚石钻头+高速涡轮、扭力冲击发生器等钻井新技术后,提高了下部陆相地层的机械钻速;采用优化井身结构以及"PDC钻头+螺杆"复合钻井技术后,解决了超深小井眼机械钻速低的难题。

Yuanba Area is one of key exploration areas to increase natural gas reserves for Sinopec.The previous drilling practices showed that the ROP was low and the drilling cycle was long,therefore the research to improve drilling speed was conducted to accelerate the exploration and development in Yuanba Area.On the basis of statistical analysis of 12 previous drilled wells in this area,three sections in Yuanba Area restricting the rate of penetration were identified.This paper introduced the technical solutions and applications results.The application of foam drilling technology improved the large-size hole ROP by 4 times in upper formation.The ROP in deeper continental strata was improved by using the manage pressure drilling technique,impregnated diamond bit with high speed turbine,torsion and percussion generator,etc.The low ROP in the ultra-deep and slim hole was solved by using the optimized casing program and PDM with PDC bit compound drilling technology.