Abstract: A plunger apparatus, comprising: a plunger body able to travel within the tubular string; a flow channel through the plunger body; an actuatable external seal assembly operatively provided on or within an outer surface of the plunger body; and a plug mechanism mechanically integrated with the plunger body and reversibly moveable between a closed position and an open position with respect to the plunger body and flow channel, the open position configured to permit the passage of a continuous water slug past the plug mechanism and through the flow channel; and wherein the actuatable external seal assembly is actuated between the deployed position when the plug mechanism is operatively in the closed position and the retracted position when the plug mechanism is operatively in the open position.

Abstract: A method of removing a liquid from a wellbore with a plunger, comprising: flowing a wellbore fluid stream in contact with the plunger and in an uphole direction within the wellbore conduit, wherein the plunger is located within a downhole region of the wellbore conduit and includes an actuatable external seal assembly operable between a retracted position in a low fluid drag state and a deployed position in a high fluid drag state; maintaining the plunger in a low fluid drag state while a variable associated with the wellbore fluid stream is outside a threshold range to permit the plunger to remain within the target region of the wellbore conduit during the flowing; transitioning the external seal assembly to a high fluid drag state responsive to the variable associated with the wellbore fluid stream being within the threshold range and thereby conveying the plunger and liquid in the uphole direction.