Patent ID: 6533033
Filing Date: 2003-03-18
Classification: E21B

Abstract:
A pump protection system for use with a well pump in which the well pump pumps a fluid from a production zone near the well pump from which fluid may be pumped to a discharge point; the well pump having an intake port through which the fluid enters the pump and a delivery pipe through which the fluid is pumped; and the well pump having a pumping mode in which fluid is pumped from the productions zone through the delivery pipe and having a back flush mode in which fluid flows from the delivery pipe into the production zone which comprises:(1) a shell which completely surrounds the well pump and through which any fluid must pass before it enters the intake port of the well pump and through which any fluid which flows from the delivery pipe into the production zone must pass prior to reaching the production zone; (2) a screen which makes up a portion of the shell; the screen being of sufficiently small mesh that most of any solid particles within the fluid within the production zone are stopped from entering said shell by said screen when the well pump is in pumping mode; and (3) a valve interposed between the delivery pipe and the well pump intake port inside said shell; the valve allowing flow of fluid from the well pump through the delivery pipe when the well pump is in pumping mode; the valve preventing flow of fluid from the delivery pipe from entering the well pump; and said valve directing the flow of fluid from the delivery pipe into the interior of said shell and through said screen into the production zone such that this flow flushes solid particles caught by said screen into the production zone when the well pump is in back flush mode; whereby a well pump may be surrounded by said shell including said screenâ€”such that any solid particles in the fluid to be pumped are trapped in the screen and do not enter the intake port of the well pump and solid particles trapped in said screen may be flushed away from said screen by back flushing fluid from the delivery pipe through said screen.