Abstract: A pump can include a plunger and a barrel, at one stroke extent flow being substantially restricted between the plunger and the barrel at spaced apart positions and a plunger interior passage in filtered communication with a fluid chamber between the positions, and at an opposite stroke extent the fluid chamber being in communication with the standing valve. A method can include displacing a plunger in one direction, thereby receiving filtered liquid into a fluid chamber, and b) displacing the plunger in an opposite direction, thereby transferring the liquid to a barrel interior passage. A system can include an actuator that reciprocates a rod string, and a pump including a plunger with a traveling valve, a barrel with a standing valve, and a filter that filters liquid which flows from a tubing string to a compression chamber disposed between the traveling valve and the standing valve.

Abstract: An artificial lift system for a well has a surface unit and a subsurface pump. The surface unit reciprocates a rod in the well, and the pump disposed in a tubular in the well is actuated by the rod. A barrel of the pump has a standing valve restricting fluid passage out of the barrel. The plunger is reciprocally disposed in the barrel and has seals with the barrel. A traveling valve of the plunger uses a sleeve and a bob. The sleeve is movable relative to the bob to restrict fluid out of the plunger's interior through a variable gap relative to the bob and the sleeve. The filter is disposed on the plunger between the seals and separates the plunger's interior from an annulus between the plunger and the barrel. The filter restricts particulate in the interior from passing into the annulus.

Abstract: A pump can include a plunger and a barrel, at one stroke extent flow being substantially restricted between the plunger and the barrel at spaced apart positions and a plunger interior passage in filtered communication with a fluid chamber between the positions, and at an opposite stroke extent the fluid chamber being in communication with the standing valve. A method can include displacing a plunger in one direction, thereby receiving filtered liquid into a fluid chamber, and b) displacing the plunger in an opposite direction, thereby transferring the liquid to a barrel interior passage. A system can include an actuator that reciprocates a rod string, and a pump including a plunger with a traveling valve, a barrel with a standing valve, and a filter that filters liquid which flows from a tubing string to a compression chamber disposed between the traveling valve and the standing valve.

Abstract: A pump can include a plunger and a barrel, at one stroke extent flow being substantially restricted between the plunger and the barrel at spaced apart positions and a plunger interior passage in filtered communication with a fluid chamber between the positions, and at an opposite stroke extent the fluid chamber being in communication with the standing valve. A method can include displacing a plunger in one direction, thereby receiving filtered liquid into a fluid chamber, and b) displacing the plunger in an opposite direction, thereby transferring the liquid to a barrel interior passage. A system can include an actuator that reciprocates a rod string, and a pump including a plunger with a traveling valve, a barrel with a standing valve, and a filter that filters liquid which flows from a tubing string to a compression chamber disposed between the traveling valve and the standing valve.

Abstract: An artificial lift system for a well has a surface unit and a subsurface pump. The surface unit reciprocates a rod in the well, and the pump disposed in a tubular in the well is actuated by the rod. A barrel of the pump has a standing valve restricting fluid passage out of the barrel. The plunger is reciprocally disposed in the barrel and has seals with the barrel. A traveling valve of the plunger uses a sleeve and a bob. The sleeve is movable relative to the bob to restrict fluid out of the plunger's interior through a variable gap relative to the bob and the sleeve. The filter is disposed on the plunger between the seals and separates the plunger's interior from an annulus between the plunger and the barrel. The filter permitting fluid passage between the interior and the annulus and restricts particulate in the interior from passing into the annulus.

Abstract: A pump can include a plunger and a barrel, at one stroke extent flow being substantially restricted between the plunger and the barrel at spaced apart positions and a plunger interior passage in filtered communication with a fluid chamber between the positions, and at an opposite stroke extent the fluid chamber being in communication with the standing valve. A method can include displacing a plunger in one direction, thereby receiving filtered liquid into a fluid chamber, and b) displacing the plunger in an opposite direction, thereby transferring the liquid to a barrel interior passage. A system can include an actuator that reciprocates a rod string, and a pump including a plunger with a traveling valve, a barrel with a standing valve, and a filter that filters liquid which flows from a tubing string to a compression chamber disposed between the traveling valve and the standing valve.