元坝区块超深井钻井提速关键技术应用

元坝超深井提速受大尺寸井眼长、致密性硬地层多、同一裸眼井段压力体系多且差异大、深层地层高温、高压、高含硫等因素制约,机械钻速提高困难,钻井周期长。为此,对空气钻、个性化PDC钻头选型及井下工具、预弯曲钻具组合、钻井液体系等方面进行优化,形成了一套元坝区块超深井提速模板。现场应用表明,元坝701井通过空气钻和个性化PDC钻头实现陆相地层提速,在须家河组地层最高机械钻速达2.02 m/h。在易斜地层使用小度数螺杆的预弯曲钻具组合,相比常规钻具组合能更好释放钻压,在防斜和提速方面达到平衡。

Application of key technology for increasing drilling speed of ultra-deep wells in Yuanba block

The speed increase of Yuanba ultra deep well is restricted by many factors, such as large-scale borehole length, many dense hard formations, multiple and different pressure systems in the same open hole section, high temperature, high pressure and high sulfur content in deep formation, which makes it difficult to improve ROP and long drilling cycle. Therefore, air drilling, personalized PDC bit selection and downhole tools, pre bent BHA and drilling fluid system are optimized to form a set of ultra-deep well speed-up template in Yuanba block. Field application shows that well Yuanba 701 can increase the drilling speed of continental formation through air drilling and personalized PDC bit, and the maximum ROP in Xujiahe formation is 2.02 m/h. Compared with conventional BHA, pre bending BHA with small degree screw can release WOB better and achieve balance between deviation control and speed increase.