FLOW ROTATION MECHANISM FOR CASING STRING Russian patent published in 2003 - IPC

FIELD: oil and gas producing industry, particularly, well flushing, casing cementing, rotation of fluid flow and well cleaning. SUBSTANCE: flow rotation mechanism includes body in form of two rings with through holes for fastening members, flexible spiral strips with blades from flexible rubberized-fabric material. Strips are secured to rings. Nominal inner diameter of strips in cross-section is equal to inner diameter of rings. Blade diameter in cross-section exceeds nominal diameter of wellbore. Flow rotation mechanism is run into well and secured by bolts in ring holes. Flow of displacement fluid is given rotary motion between blades. Twisted fluid entraps drilling mud in well wall caverns. EFFECT: higher efficiency of cleaning of cavernous sections of well wells. 2 cl, 3 dwg