DEVICE FOR CASING PIPE CEMENTING INSIDE WELL Russian patent published in 2007 - IPC E21B33/14 

FIELD: oil production, particularly methods or devices for cementing, for plugging holes, crevices, or the like.

SUBSTANCE: device comprises stop ring made as nipple with annular groove sealed from nipple bottom, supporting ring installed in lower coupling of casing pipe, which may telescopically cooperate with nipple, shear member and flushing pipe string connected with nipple. Lower part of casing pipe is provided with check valve. Nipple is fixedly connected to flushing pipe string and has annular extension located in top nipple part and with throttle channel arranged in lower part thereof. Supporting ring has disc valve formed in lower part thereof and breakable stop. The breakable stop maintains disc valve in opened position during casing pipe lowering in well. Central supporting ring orifice may be hermetically sealed with nipple. Disc valve and breakable stop may cooperate with nipple. Lower part of flushing string has radial channels. Bush is located inside flushing string over the radial channels and is fixed with shear member so that the bush may slide downwards in axial direction.

EFFECT: possibility of flushing pipe string pressure testing and prevention of grouting mortar ingress in casing pipe.

2 dwg