空气锤钻井技术在哈深201井火成岩地层的应用

Application of air hammer drilling technology in the igneous strata of Well Hashen 201

准噶尔盆地火成岩地层岩石坚硬、研磨性强、可钻性差,钻进过程中井斜问题突出、机械钻速低、钻井周期长,严重影响了火成岩目的层的勘探开发进程。首先分析了牙轮钻头气体钻井技术难点,通过开展火成岩岩石力学特性实验,分析空气锤破岩机理及其在火成岩中的适应性,结合KQC型空气锤主要结构、技术性能特点,提出空气锤钻井低钻压、低转速、高频率冲击的破岩方式,在实现山前带火成岩防斜打快的同时,能有效避免钻具磨损、疲劳断裂等情况发生。在准噶尔盆地哈深201井火成岩中进行了现场应用,在保证井斜始终控制在2°以内情况下,平均机械钻速和单趟钻进尺较牙轮钻头气体钻井同比分别提高了2.45倍和6.42倍以上,哈山区块?444.5 mm井眼单趟钻机械钻速14.29 m/h,?311.2 mm井眼单趟钻进尺470.62 m,取得了显著的防斜打快应用效果,为今后火成岩地层优快钻井探索出了一种有效的技术手段。

The igneous strata in the Junggar Basin is competent with strong abrasivity and poor drillability, so it is usually suffered from well deviation, low rate of penetration （ROP） and long drilling cycle in the process of drilling. And consequently, the exploration and development progress in the target of igneous strata is impacted. In this paper, the technical diffculties of cone-bit gas drilling were investigated, and the rock breaking mechanisms of air hammer and its adaptability in igneous rocks were analyzed by means of igneous rock mechanics experiment. Then, based on the main structures and technical characteristics of KQC air hammer, the rock breaking mode of air hammer drilling with low weight on bit and rotation speed and high frequency percussion was put forward to prevent effec-tively the drilling tools from abrading and fatigue fracturing while achieving the deviation control and fast drilling of igneous rocks in piedmont zones. It was for the frst time, applied on site in the igneous rocks of Well Hashen 201 in the Junggar Basin. Compared with cone-bite gas drilling, its average ROP and single-trip drilling footage are 2.45 times and 6.42 times higher when the well deviation is controlled below 2°. In Hashan block, remarkable deviation control and fast drilling is achieved with the single-trip drilling ROP of 14.29 m/h in the hole of ？444.5 mm and the single-trip drilling footage of 470.62 m in the hole of ？311.2 mm. It provides one effective technology for the optimized fast drilling in igneous strata.