Hydraulic pumping system

A pumping apparatus for a well, comprising:

• a power fluid passage in fluid communication with a power fluid line;
• a product fluid passage in fluid communication with a product fluid line;
• a piston reciprocatingly mounted within the pumping apparatus, the piston defining a product fluid chamber in fluid communication with the product fluid passage and comprising a first check valve;
• a bottom block positioned at a bottom portion of the pumping apparatus, the bottom block comprising a well fluid inlet having a second check valve;
• a well fluid intake chamber positioned between the bottom block and the piston and configured to receive well fluid through the second check valve when the second check valve is open;
• one or more piston vent chambers, each of the one or more piston vent chambers in fluid communication with the product fluid chamber via one or more piston vent chamber vents, the one or more piston vent chambers comprising a first piston vent chamber and a second piston vent chamber positioned between the first piston vent chamber and the well fluid intake chamber;
• and
• one or more well vent chambers, each well vent chamber in fluid communication with well fluid external to the pumping apparatus via one or more well vent chamber vents, wherein each well vent chamber is defined at least partially by the piston, wherein the one or more well vent chambers comprise a first well vent chamber positioned between the first piston vent chamber and the second piston vent chamber and a second well vent chamber positioned between the second piston vent chamber and the well fluid intake chamber;
• wherein the product fluid chamber is configured to receive the well fluid from the well fluid intake chamber through the first check valve when the first check valve is open.