A New Disc One-Cone Bit

摘要

With exploration moving into deeper waters, deserts andrnplateaus, the geological condition and natural environmentrnfaced with by the drilling operation get more complex andrnworse, so that the difficulty of exploration and development isrnincreasing and the more requirements are put forward torndrilling tools. Owing to the extensive application of slim-holerndrilling in the world, it is the one of the most importantrnresearches for rock bit suppliers and rock bit researchers torndevelop the efficient small diameter bit.rnAccording to analysis, the rock-breaking efficiency hasrnimportant relationship with tooth structure and arrangement ofrnteeth. However, owing to the lack of fundamental change onrnthe tooth surface structure of bits in the past tens of years, therndrilling speed has nearly not been raised in some specialrnformations. So the new structure of tooth surface must bernsought according to the new knowledge for rock-breakingrnmechanism so as to raise the drilling speed and drillingrnfootage under special environment and some specialrnformations. The disc bit is just the bit with brand-new toothrnstructure.rnAfter some researches on disc bit and one-cone bit havernbeen done, Southwest Petroleum University (SWPU) hasrndeveloped a new small size bit with high rotary speed, namedrndisc one-cone bit, which combines the advantages of both oneconernbit and disc bit. This new bit will have expansivernapplication prospect in deep drilling, ultradeep drilling andrnslim-hole drilling because of its less torsion, higher bottomholerncoverage coefficient and longer bearing life.rnIn this paper, the experimental study on rock-breakingrnmechanism of disc one-cone bit is introduced emphatically.