Abstract: A rod pump plunger is so constructed to collect oil from a produced fluid from an oil well and use it to lubricate the plunger inside of a pump barrel. The plunger has a first sealing structure, a second sealing structure, and penetrating ports in between the sealing structures. A fluid trap which captures oil from the produced fluid flowing through the plunger is formed interior to the body of the plunger and is connected to the port. The trap is connected to a penetrating port such that the trapped oil will flow into the first and second sealing structures. The trap is sized to capture sufficient oil to exceed oil slippage from a pump during each stroke. The oil lubricates the plunger to increase pump efficiency and run life.

Abstract: A housing unit installed within a tubing string of a oil well, water well, or gas dewatering well contains at least one reciprocating plunger which utilizes the hydraulic head of the fluid in the tubing to modify the loading in a subsurface pump actuation string, such as a string of sucker rods. The device can be used to either reduce observed polished rod loads at the surface to reduce the required counterbalance, or the device can be used to provide additional loading in the pump actuation string above the pump to reduce buckling. The device is used in a method for modifying the loading in a subsurface pump actuation string.