STUDY AND TEST FOR A NEW IMPACT AND PRESS IN TYPE OF ZUBLIN SIMPLEX BIT
Huang Wanzhi(Southwest Petroleum Institute)Марков O.A.(Moscow University of Oil and Gas Science and Technology)and Wu Hua (East Sichuan Drilling Co.of Sichuan Petroleum Administration).NATUR.GAS IND.v.20 no.2,pp.45～48,3/25/2000.(ISSN 1000 0976;In
In this paper,a new small sized bit is introduced.The bit is mainly composed of a biassed polyconic cutter,a cylindric roller and two bit legs.The operating principle of the bit is different to that of spherical zublin simplex bit,but is identical with that of three cone bit,namely it breaks rocks mainly through impact and press in by the cutter teeth and then the borehole wall is repaired by a cylindric roller and two injecting nozzles close to the bottom hole.The new bit′s cone and bearing are much larger than those of the three cone bit with the same size,therefore the new bit can bear a greater WOB,thus,the life of the bearing and cone can be prolonged and then the penetration rate can be raised and the length of bit run prolonged.In this paper,the situation and data in the test on testing table are presented,which are compared with those of three cone bit,obtaining an important result in applying this kind of bit.