DEVICE FOR WELL CEMENT BRIDGING Russian patent published in 2014 - IPC E21B33/134 

FIELD: oil-and-gas industry.

SUBSTANCE: proposed device comprises hollow cylindrical pipe and bottom separation plug with flow channel equipped with seat for top separation plug. Hollow cylindrical pipe in length larger than absorption zone is connected with pipe string and equipped with shoe at its bottom. Cylindrical pipe outside has several conical resilient collars with lower end rigidly locked and upper bell pressed against cylindrical pipe by shear pins. The latter are fitted in lateral holes arranged in rows over cylindrical pipe perimeter. Space between collar and pipe is filled with grouting mortar filler or chemical reagents for improvement of bridge quality. Bottom separation plug after fitting in seat of the top separation plug displaces downward to open lateral holes to straighten collar bells. Bottom separation plug has the edge made of material harder than that of branch pipe to interact with branch pipe and displace only downward. Lateral hole diameters allow fluid filter return from cement after fixation of separation plugs at bottom position and termination of fluid feed in pipe string.

EFFECT: higher quality of cement bridging, lower costs.

3 dwg