Drilling technology for the Beigou polymetallic mining area in Wangjiazhuang

Abstract:

In drilling at Beigou Molybdenum Polymetallic Mine, Wangjiazhuang, Chengde County, Hebei Province, the main rock encountered was chert strip dolomite and quartzite with strong drillability, and they were hard, brittle, broken and seriously slippery, leading to very low drilling efficiency. In order to improve drilling efficiency, the lithology was assayed through sampling the rock with the drill bit custom-made for the formation. A variety of methods were adopted to force exposure of the cutting elements, and different drilling parameters and drilling fluid systems were selected for the lithology over different sections of the borehole. This paper summarizes the drilling parameters suitable for the formation in this mining area, together with the drilling fluids of different performance for wall protection and leakage plugging, and higher drilling efficiency.

Key words:drilling technology; slipping formation; bit selection; drilling parameters; broken formation; wall protection; drilling fluid