PUMP-VACUUM DEVICE FOR WELL CLEANING OF SAND PLUG Russian patent published in 2008 - IPC E21B37/00 

FIELD: oil well operation and repair, particularly to clean well of sand plugs and mud with the use of coiled tubing in the case of abnormally low reservoir pressures.

SUBSTANCE: device comprises jet pump, separation unit and damage unit. The separation unit comprises connection pipe coaxially arranged in body and defining annular sucking channel, as well as upper and lower packing members connected to body. Jet pump is located over separation unit and has sucking annular cavity. Central and lower connection pipe ends, as well as upper and central body parts have radial circulation orifices. Central parts of the tubes are connected with each other by means of intermediate support nut. Tubes of connection pipe and upper and lower body parts are connected through upper and lower support nuts correspondingly. The nuts have radial orifices formed so that radial orifice of upper support nut is inclined upwards and that of lower support nut is directed downwards relatively device axis. Upper support bush is installed in sleeve so that annular space is defined in-between. Upper and lower packing members are spring-loaded and installed over intermediate and lower support nuts correspondingly. Jet pump and separation unit have common sucking vacuum line.

EFFECT: increased efficiency of sand plug breakage and removal with the use of coiled tubing.

3 cl, 3 dwg