WELL PREOPERATIONAL CLEAN-UP DEVICE Russian patent published in 2014 - IPC E21B37/00 

FIELD: oil and gas industry.

SUBSTANCE: invention is related to oil producing industry and may be used for preoperation clean-up of the well from heavy borehole fluid. The device comprises an electric-centrifugal pump mounted at the flow string thus forming annular space with the well bore, a starting clutch coupling the pump with the flow string with an aerator is installed in the wall of the latter, a hollow shutoff valve, a rope controlled from the wellhead. The valve is made as a break pin installed to the aerator so that it may be broken under weight of the load thrown to the string from the wellhead, and a connection of the stubs with annular space of the well bore. In the starting clutch above the aerator there is a hollow bushing equipped with a plug on top, which is fixed by a shear tie. The bushing is designed to destroy the shear tie and to move axially downwards to the thrust into inner circular panel under excess pressure developed in the string upon throwing of the shutoff device and its placing at the plug with fixation of the bushing and sealed coverage by the aerator bushing from inside. The shutoff device is made as a semiball with a rod rigidly fixed at the top and equipped with a centralizer, at that the upper end of the rod is equipped with a fishing head.

EFFECT: increase of the device operation reliability and efficiency.

3 dwg