DEVICE FOR REGULATED DELIVERY OF DRILLING MUD OR CEMENT SLURRY Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: device is intended for strengthening of oil and gas wells, especially in lowering casing strings into wells. Device has body and rigidly secured to body is throttle valve which is made in the form of disk with peripheral holes covered by spring-biased strip. Installed in central passage of disk is spring-biased bush with axial passage and side openings, and dividing plug with lower end-face. Device is provided with spare member in the form of bush. This spare member is rigidly fastened to lower surface of strip and it closes side openings in bush. External surface of dividing plug has circular bores. Seated in these circular bores are sealing rings and spring-biased spare rings. Spring-biased bush has blind upper end-face. When dividing plug is in working position, locking ring is partially seated in circular bore. It is made in internal surface of body. Blind end-face of spring-biased bush is located so as to interact with lower end-face of separating plug. Application of aforesaid embodiment of device allows for higher reliability in self-filling of casing string during its lowering into well. EFFECT: higher efficiency. 2 cl, 2 dwg