合川地区丛式定向井钻井技术实践

Drilling Technology of Cluster Directional Wells in Hechuan Area

针对合川地区丛式定向井钻井周期长、地层岩性不均、可钻性差、井漏、井塌等钻井技术难点,采取了优化井身结构、井眼轨迹设计及控制、优选钻头类型和钻具组合、优化钻井参数等技术措施,降低了井下复杂事故发生的机率,提高了机械钻速。认为在斜井段施工中针对不同的地层优选PDC钻头,增加单趟钻的钻井进尺,能减少起下钻次数,从而实现安全、快速钻井。

During drilling cluster directional wells in Hechuan area,there are many difficulties of long drilling cycle,uneven lithological distribution,poor drillability,lost circulation and hole collapse. So,in this study,some countermeasures are made to not only reduce a probability of downhole accident but also increase a penetration rate,such as optimizing the casing program and drilling parameter,designing and controlling the well trajectory,and selecting the bit type and bottomhole assembly.It is considered that during some deviated wells,PDC bit should be optimized for different strata,and drilling footage should increase in single journey in order to decrease tripping times.As a result,a safety and fast drilling may be fulfilled.