Patent ID: 6089832
Filing Date: 2000-07-18
Classification: E21B,F04C,F04D

Abstract:
A pump system for lifting formation fluids from a production zone in a wellbore, said system comprising:a production tubing string adapted to extend from said production zone to the surface and having a landing nipple therein adjacent said production zone;an electric motor fixed to the bottom of said tubing;an electrical cable connected to said motor and extending along the outside of said production tubing; anda pump unit releasably positioned within said nipple and releasably connected to said motor, said pump unit being retrievable and installable through said tubing without removing said production tubing, said motor, or said electrical cable from said wellbore, said pump unit comprising:a housing having an upper and a lower end;an outlet conduit extending upward from said upper end of said housing; anda slip-joint slidably mounted on said upper end of said housing, said slip-joint having means for releasably latching said housing in said nipple; said slip-joint further comprising:a first member slidably mounted on said outlet conduit;a second member slidably mounted on said first member and carrying said means for releasably latching said housing in said nipple whereby said first member and said second member are in a first position in relation to each other as said pump unit is being installed and retrieved and in a second position with respect to each other when said pump unit is latched in said nipple; andopenings in said outlet conduit, said first member, and said second member which align with each other to thereby provide a fluid passage for equalizing pressures in said production tubing above and below said pump unit when said slip-joint is in said first position.