SUBMERSIBLE SUCKER-ROD PUMP Russian patent published in 2002 - IPC

FIELD: pulse bed stimulation in oil recovery. SUBSTANCE: submersible sucker-rod pump which is run into well in tubing string has housing with suction valve and plunger with discharge valve. Shut-down fitted above suction valve is used for periodic pulse bed stimulation; this shut-down has seat and cylindrical gate pressed by spring; this gate has bypass passage and tappet. On surface of gate there is program slot which receives lock secured in housing. While getting at point "A" and "B", lock holds gate in two positions: OPEN and CLOSED. To shift to pulse mode of operation, plunger is lowered below point of working stroke forcing tappet downward, thus shut-down is thrown to CLOSED position. After pulse bed stimulation, tappet is acted on by plunger to shift to pump mode of operation and shut-down is thrown to OPEN position. EFFECT: considerable simplification of construction. 3 dwg