Downhole pump with bypass around plunger

A downhole pump, comprising:

• a) a barrel having a first section and a second section coupled together in an end-to-end manner, the first section having a first one-way valve therein, each of the first and second sections having a respective inside diameter, the inside diameter of the first section being less than the inside diameter of the second section;
• b) a plunger having a second one-way valve therein, the plunger having an outside diameter that is slightly less than the first section inside diameter such that the plunger can reciprocate within the first section and pump fluid while so reciprocating;
• c) the plunger having an end that is closest to the first one-way valve, the plunger having an opening therethrough located between the plunger end and the second one-way valve, the opening communicating with an annulus between the barrel second section and the plunger when the opening is within the barrel second section.

A method of venting gas or equalizing pressure in a downhole pump comprising a barrel with a first one-way valve and a plunger with a second one-way valve, there being a chamber located between the first and second one-way valves, comprising the steps of:

• a) reciprocating the plunger with respect to the barrel so as to expand and contract the chamber between the first and second one-way valves;
• b) as the chamber nears an end of its expansion, opening a channel between the plunger and the barrel and around the plunger, wherein any gas present in the chamber can be vented out of the chamber and/or pressure can be equalized across the second one-way valve;
• c) closing the channel as the chamber contracts.