JM series of casing antifriction joint mainly consists of mandrel, upper stopper, bottom stopper, outside irrotational wearing bush and so on. Bearing friction pairs are equipped between mandrel and outside irrotational wearing bush, as well as between outside irrotational wearing bush and upper and bottom stopper. Working principle: in the process of drilling, choose the proper quantity and installation position according to the specific situation. Drill string and outside irrotational wearing bush can swirl. No high-speed rotation appears between outside irrotational wearing bush and casing. In this way, it will prevent swirling drill string abrading casing. Because of the low coefficient of friction of bearing friction pair, torque of drilling is lowered significantly. Technical characteristics The equipment adopts bearings of sintered carbide TC , and the drilling fluid is open with simple structure, long lifetime and less risk. The bottom stopper and mandrel is connected by rigid connection of high strength. The whole set of tools is made of alloy structure steel of high strength. It helps to solve the technical problems of casing wear and excessive high drilling torque in extended well, deep well, horizontal well, super deep well or highly-deviated well. It can also be applied in the sections with too high dog leg scale and the relative areas. Technique parameters model Total length(mm)OD(mm) water hole(mm)Withholding styleLubricating methodstrength gradeJM-240915Ø240Ø90.551/2”FH