COMPONENT OF DRILL STRING ASSEMBLY Russian patent published in 1997 - IPC

FIELD: well drilling. SUBSTANCE: component of drill string assembly includes drill pipe with displaced center of gravity of cross-section, for instance, displacement of axis of external cylindrical surface of pipe body. Installed on pipe ends are supporting-centering members for connection with members of drill string. Installed on side surface of supporting-centering members within the central angle of 90 deg of pipe cross-section are rolling contact bearings so that the contact with well wall during drilling is effected by rolling-contact bearings. Angle equalling 90 deg is measured from diametrical plane of pipe cross-section running through the cross-section center of gravity. In this case, rolling-contact bearings are located within the above-mentioned angle opposite to direction of drill string rotation. The component is incorporated into the drill string, either, above the rock cutting tool, or between common drill pipes at a definite spacing over the entire interval of the compression part of the drill string. EFFECT: higher efficiency. 7 dwg