Tubing inserted balance pump with internal fluid passageway

A pump assembly for pumping a production fluid from a subsurface fluid reservoir, the pump assembly comprising:

• an upper barrel connected to a lower barrel, wherein the upper barrel is in fluid communication with a fluid conduit, wherein the fluid conduit extends from the upper barrel to a surface of a well, wherein the lower barrel is in fluid communication with the subsurface fluid reservoir;
• a plunger assembly movably disposed within the upper barrel and the lower barrel, wherein the plunger assembly comprises a fluid passageway extending therethrough;
• and
• a first fluid valve preventing the production fluid from flowing from the pump assembly to the fluid reservoir,
• wherein increasing a pressure of an actuating fluid within a tubing string moves the plunger assembly in a first direction to draw the production fluid into the lower barrel and to force the production fluid located in the upper barrel into the fluid conduit, wherein the actuating fluid and the production fluid are isolated from one another,
• wherein reducing the pressures of the actuating fluid against the plunger assembly enables the plunger assembly to move in a second direction, and wherein movement of the plunger assembly in the second direction moves the production fluid through the fluid passageway from the lower barrel to the upper barrel.

A pump assembly configured for insertion into a tubing string, the pump assembly comprising:

• an upper barrel fluidly connected to a lower barrel, wherein the upper barrel is fluidly connectable to a fluid conduit, and wherein the lower barrel is fluidly connectable to a fluid reservoir;
• a plunger assembly comprising an upper plunger movable within the upper barrel and a lower plunger movable within the lower barrel, wherein the upper plunger and the lower plunger are connected, wherein the plunger assembly comprises a fluid passageway extending therethrough,
• wherein the plunger assembly is movable in an upward direction to draw a production fluid from the fluid reservoir into the lower barrel,
• wherein the plunger assembly is movable in a downwell direction to force the production fluid from the lower barrel into the upper barrel through the fluid passageway, and
• wherein the plunger assembly is movable in the upward and downwell directions responsive to changes in pressure of an actuating fluid within the tubing string, the production fluid within the fluid conduit, or combinations thereof.

A method for pumping a production fluid from a fluid reservoir to the surface by using a pump assembly, comprising the steps of:

• pressurizing an actuating fluid within a tubing string, thereby:
• moving a plunger assembly in an upward direction,
• forcing the production fluid from an upper portion of the pump assembly into a fluid conduit, and
• drawing the production fluid from the fluid reservoir into a lower portion of the pump assembly;
• preventing the production fluid from flowing from the upper portion of the pump assembly into the lower portion of the pump assembly;
• depressurizing the production fluid within the tubing string, thereby:
• enabling the plunger assembly to move in a downwell direction, and
• forcing the production fluid from the lower portion of the pump assembly to the upper portion of the pump assembly through a fluid passageway extending through the plunger assembly;
• preventing the production fluid from flowing from the lower portion of the pump assembly into the fluid reservoir;
• and
• isolating the actuating fluid within the tubing string from the production fluid in the upper and lower portions of the pump assembly.