Abstract: A downhole pump has a barrel and a plunger which reciprocate with respect to each other. The plunger has a first portion with a first seal, a second portion and a third portion with a second seal. The second portion is intermediate the first and second portions. A balancing chamber is formed between the plunger second portion and the barrel. The balancing chamber communicates with the plunger interior by way of an opening. A sand snare chamber is provided with respect to the opening so as to prevent sand from contacting the seals in the balancing chamber.

Abstract: A reciprocating downhole pump has a gas separator located at its bottom end. The separator forms a chamber that is expanded and contracted when the pump is reciprocated. Expansion and contraction of the chamber occurs by either the plunger reciprocating in the chamber or a piston coupled to the plunger reciprocating in the chamber. The chamber has an orifice therein so that during reciprocation fluid flows in and out of the orifice. The orifice is sized so as to subject the fluid to a pressure drop, wherein gas in the fluid is separated from the liquid.

Abstract: A downhole pump for a well has a barrel and a plunger. The barrel has a passage extending along the length of the barrel, with the passage having an inside diameter. The plunger has an outside diameter and is received by the barrel passage for relative reciprocal movement. One of the barrel or the plunger is equipped with wear rings, with a wear ring at one or at each end. The wear rings are made of a material that is harder than the material of the respective plunger or barrel. The wear rings provide protection from abrasion, particularly in a sandy well.

Abstract: A stuffing box for a polished rod used with a downhole pump uses injectable packing to provide a seal around the polished rod. The stuffing box has a chamber for receiving the packing. The chamber has an opening to allow the addition of packing to the chamber. The packing is maintained in a compacted condition by either injecting additional packing through the opening or adjusting the volume of the chamber.