Same diameter directional drilling for obstacle bypassingin ZK88-19 deep hole in the Xiling gold exploration area of Shandong

Abstract:

Borehole ZK88-19 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.