山东莱州西岭勘查区ZK8819深孔同径造斜绕障工艺

Same diameter directional drilling for obstacle bypassing in ZK8819 deep hole in the Xiling gold exploration area of Shandong

山东莱州西岭勘查区ZK8819号钻孔设计孔深2500 m,2016年12月开孔,于孔深2034 m处发生烧钻事故,处理孔底钻具时再次发生烧钻事故,导致2套钻具及2套内管总成滞留孔底;2017年8月,受划定环境保护区的影响,中断施工,直至2020年3月恢复施工,继续处理孔内事故难度很大;经过多次论证,应用了深孔同径造斜绕障技术,包括设计了造斜偏心楔、造斜钻头以及研发了偏心楔固定技术等,成功绕过事故段,恢复钻进。

Borehole ZK8819 in the Xiling exploration area of Shandong Laizhou was designed with depth of 2500m,and drilling started in December 2016.Bit-burning happened at depth of 2034m,and it happened again when dealing with the downhole tool,resulting in two sets of drill tools and two sets of inner tube assemblies stuck at the bottom of the hole.In August 2017,drilling was forced to suspend due to the delineation of the environmental protection zone,and was resumed until March 2020.It was very difficult to continue to deal with the fish lost in the hole.Through feasibility study and verification,the self-developed deep-hole same-diameter directional drilling technology for obstacle bypassing,including design of the deflection wedge and deflection drill bit,and development of the deflection wedge placement technique,was applied and successfully bypassed the incident section,and drilling resumed.