焦页非常规页岩气井优快钻井技术

Optimized and Fast Drilling for Construction of Jiaoye Unconventional Shale Gas Well

重庆涪陵焦石坝地区上部地层岩性致密、研磨性强、可钻性差,长兴组浅层气活跃且含硫,三开水平段长、摩阻大、泥质页岩层易垮塌。钻井面临的突出问题是机械钻速低、井控难度大、钻井周期长。针对上述气藏钻井难点,重点从钻井工艺、维持井壁稳定以及钻井液方面进行分析,优化钻具结构、优选钻头选型、抑制井壁失稳以加快焦石坝区块钻井速度。"油基螺杆+高效PDC钻头"配合优质钻井液,经过焦页12平台4口井的实践应用,大大缩短了钻井周期,焦页12-4HF井创下了中石化集团公司非常规页岩气水平井最长水平段记录,提速效果显著。

There are the characteristics of dense lithology, strong abrasive and poor drillability in upper formaton in Jiaoshi-ba area of Chongqing, active shallow gas with sulfur in Changxin formation and long third spud horizontal section, high fric-tion and being easy to collapse in clay shale.The prominent problems were low ROP, difficult well control and long drilling cycle.According to the above difficulties in gas reservoir drilling, the analysis was made mainly on the drilling technology, wellbore stability maintenance and drilling fluid;optimization of drilling tool structure, optimizing bit selection, inhibition of wellbore instability were carried out in order to speed up the drilling speed in Jiaoshiba area.“Screw drill ＋high effi-cient PDC bit” with high-quality drilling fluid were applied in 4 wells of the 12th drilling platform and the drilling cycle was greatly shortened.The construction of Jiaoye 12-4HF sets the record of the longest horizontal section in unconvention-al shale gas horizontal well for Sinopec Group, and drilling speed is effectively improved.