Patent ID: 9631472
Date: 2017-04-25
CPC Classifications: E21B,F04D

Claim:
1. A well pump assembly, comprising: a pump having a pump intake and a discharge above the pump intake for connection to a string of production tubing; a submersible motor operatively engaged with the pump below the pump for driving the pump; a shroud surrounding the pump intake and the motor, the shroud having an open upper end in fluid communication with the pump intake for drawing well fluid along an upper flow path down the shroud into the pump intake; a tubular member extending downward from a lower end of the shroud below the motor and having a smaller outer diameter than an outer diameter of the shroud, the tubular member being in fluid communication with a portion of the shroud surrounding the motor; a gas anchor sleeve surrounding the lower portion of the tubular member, the gas anchor sleeve having a closed lower end below the lower portion of the tubular member, and the gas anchor sleeve having an open upper end, requiring well fluid flowing up along a lower flow path to flow around the gas anchor sleeve then down between the gas anchor sleeve and the tubular member to reach the open lower portion of the tubular member; a debris chamber mounted to a lower end of the gas anchor sleeve for collecting debris from well fluid flowing in the upper end of the shroud and in the gas anchor sleeve; a drain port in the debris chamber; and a normally closed valve in the debris chamber for closing the drain port, the valve being operable to open the drain port while the pump and motor are being retrieved to drain the shroud.