DEVICE FOR CEMENTING OF CASING STRINGS Russian patent published in 1994 - IPC

FIELD: well drilling. SUBSTANCE: device has hollow body with upper and lower stops on its inner surface. Stops have circulation holes. Arranged inside body are permanent periphery magnets which form circulation channel for fluid flow. Installed over body axis are additional permanent magnets rigidly connected with upper and lower stops. Arranged between body inner surface and peripheral magnets are magnetic circuits having conjugating surface with periphery magnets which is inclined to body axis. It ensures reduced section of circulation channel over body length in direction of fluid flow. Periphery and additional permanent magnets are made in form of strip set with alternating polarity. They are installed across body axis and oriented to each other with opposite polarities. Besides, inner surface of periphery magnets and outer surface of central magnets have teeth square to axis of circulation channel. EFFECT: higher efficiency. 1 dwg