DOWNHOLE PUMPING UNIT WITH BACKWASH CLEANING Russian patent published in 2023 - IPC E21B34/06 E21B43/02 F04B47/00 

FIELD: oil and gas industry.

SUBSTANCE: downhole pumping unit with backwash cleaning contains a downhole pump, a sand filter with an anchor, consisting of a branch pipe with a packer, a check valve located inside and a sand filter with a container attached from below. Anchor below the outlet, but above the packer, is provided with a plate on the outside for sedimentation of sand from the liquid above. Between the check valve above the packer and the pump inlet, there is a circulation impulse valve, consisting of a cylinder with a coaxial piston with an upper rod pressed by a spring into the upper transport position, which are equipped with a common axial channel for fluid inflow from the well underpacker space to the pump. The stem is equipped with at least one side hole. The cylinder is equipped with a stepped axial cylindrical through hole. The lower cylinder of large diameter is equipped on top with at least one radial hole located above the piston. The upper cylinder is made with the possibility of interacting with the rod, closing the side hole in the transport position and opening the hole when the piston with the rod moves to the lower working position with communication of the side and radial holes. The total cross-sectional area of both the side holes and the radial holes allows to create a pulsed fluid flow with an average speed higher than the rate of settling of destructible mechanical impurities and/or asphalt-hammer-paraffin deposits. The spring force is selected based on holding the piston and rod in the transport position when the lift pipes are filled to the annulus mouth with liquid when the pump is running and providing the necessary frequency of liquid pulsations during backwashing.

EFFECT: increasing the efficiency of backwash by providing a pulsed mode of passage of the flow of process flushing fluid through the downhole pump.

1 cl, 2 dwg