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

Abstract:

There are the characteristics of dense lithology, strong abrasive and poor drillability in upper formaton in Jiaoshiba area of Chongqing, active shallow gas with sulfur in Changxin formation and long third spud horizontal section, high friction 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 efficient 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 unconventional shale gas horizontal well for Sinopec Group, and drilling speed is effectively improved.