复杂地层井眼轨迹控制方法研究

Study on Well Trajectory Control Method in Complex Formation

川西凹陷中江回龙构造地区地层压力系统复杂,气层多且薄,同时存在岩石可钻性差、砂泥岩互层频繁以及地层倾角大等因素,在直井段井斜和方位控制难度大,钻进效率低,斜井段着陆难度大,需要多次进行轨迹调整,使得该地区水平施工和井眼轨迹控制困难。根据该地区地质构造特征,结合井眼轨迹的影响因素,深入分析钻井施工和轨迹控制的问题和难点,从井下钻具组合优选、剖面优化设计、造斜段控制等方面进行井眼轨迹控制方法研究。通过在该区块施工的钻井,总结出具有可行性的井眼轨迹控制方法,为该区块水平评价井优、快钻进提供技术参考。

The Zhongjiang-Huilong structural area in the western depression of the Sichuan have are many difficult factors for drilling engineer,including complex formation pressure system,thin gas layers,poor rock drillability,frequent sand-shale interbeds,large formation inclination angle,and so on.In the vertical section,it is difficult to control the deviation and azimuth,and the drilling efficiency is low.Also it is difficult to land in horizontal section from the inclined shaft section with multiple trajectory adjustments.According to the geological structure characteristics and the wellbore trajectory influencing factors,the wellbore trajectory control method is studied from the aspects of bottom hole assembly,wellbore structure design.Through the well in this block,a feasible well trajectory control method is summarized,which provides technical reference for the optimal and fast drilling of horizontal evaluation wells in this block.