ROTATION SPOOL Russian patent published in 2000 - IPC

FIELD: oil and gas production, geological prospecting. SUBSTANCE: invention is meant for rotation of string of drill pipes while well- head is sealed. Body of rotation spool can be split for axial rotation of outer and inner parts one relative to another. Body presents two branch pipe fitted with flanges and two bearing units mounted concentrically. Circular grooves in outer surface of inner branch pipe are used as inner races of bearing units. Circular groove in inner surface of outer branch pipe is employed as outer race of upper bearing and circular groove in body of adjustment nut is used as outer race of lower bearing. Outer branch pipe is provided with window intended for placement of balls into upper bearing unit. Window is closed with plug fixed by lockpin and recess matching circular groove in body of outer branch pipe used as outer race of upper bearing. Conduits, circular grooves in both branch pipes separated by seals installed in circular grooves are provided to feed hydraulic control, if necessary, to equipment mounted on upper flange. EFFECT: conducting of key technological operations when well-head is sealed and pressure in well is excessive without usage of special rotating counteroutburst equipment. 1 dwg