Wellbore pumps in series, including device to separate gas from produced reservoir fluids

Abstract

A pump system for a wellbore includes a production tubing nested within a wellbore. At least two pumps are disposed in the production tubing and are axially spaced apart from each other. One of the pumps is removable from the production tubing while the production tubing remains in place. A fluid intake conduit is disposed outside the production. The fluid intake conduit is in fluid communication with an interior of the production tubing below a lower one of the pumps and at a position of an intake of an upper one of the pumps. At least one fluid discharge conduit is disposed outside the tubing and inside the wellbore. The at least one fluid discharge conduit is in fluid communication with the interior of the production tubing proximate a discharge of the lower one of the pumps and above the upper one of the pumps.

What is claimed is: 
     
         1 . A pump system for a wellbore, comprising:
 a production tubing disposed in a wellbore;   at least two pumps disposed in the production tubing and axially spaced apart from each other, at least one of the at least two pumps removable from the production tubing while the production tubing remains in place in the wellbore; and   at least one fluid intake conduit disposed outside the production tubing and inside the wellbore, the at least one fluid intake conduit in fluid communication with and providing a fluid transport path between an interior of the production tubing below a lower one of the at least two pumps and at a position of an intake of an upper one of the at least two pumps; and   at least one fluid discharge conduit disposed outside the tubing and inside the wellbore, the at least one fluid discharge conduit in fluid communication with and providing a fluid transport path between the interior of the production tubing at a discharge of the lower one of the at least two pumps and either at an intake of or above the upper one of the at least two pumps.   
     
     
         2 . The system of  claim 1  wherein at least the upper one of the at least two pumps is seated in a wet mateable electrical/mechanical connector disposed in the production tubing. 
     
     
         3 . The system of  claim 1  wherein both the upper one and the lower one of the at least two pumps is seated in a respective wet mateable electrical/mechanical connector disposed in the production tubing. 
     
     
         4 . The system of  claim 1  further comprising a gas separator disposed in the production tubing below the lower one of the at least two pumps, the gas separator having at least one gas discharge conduit disposed outside the tubing and inside the wellbore, the gas discharge conduits in fluid communication with the interior of the production tubing above the upper one of the at least two pumps. 
     
     
         5 . The system of  claim 4  further comprising a booster disposed above the upper one of the at least two pumps having an intake in fluid communication with the at least one gas discharge conduit, an outlet of the booster in fluid communication with an interior of the production tubing. 
     
     
         6 . The system of  claim 3  wherein the gas separator comprises an inner tube nested within an outer tube having fluid entry ports, the inner tube having fluid entry ports at an axial position below the fluid entry ports in the outer tube, a seal disposed between the inner tube and the outer tube disposed at a longitudinal position above the fluid entry ports in the outer tube, the seal having at least one gas discharge tube passing therethrough. 
     
     
         7 . The system of  claim 1  wherein at least the upper one of the at least two pumps is sealingly engaged to the interior of the production tubing so as to substantially prevent movement of fluid between an interior of the production tubing and an exterior of the at least the upper one of the at least two pumps. 
     
     
         8 . The system of  claim 1  wherein the at least two pumps comprise electrically submersible pumps. 
     
     
         9 . The system of  claim 1  further comprising an annular seal element disposed between the production tubing and a casing disposed in the wellbore, the annular seal element disposed at a position below the lower one of the at least two pumps. 
     
     
         10 . The system of  claim 1  wherein the lower one of the at least two pumps is coupled to the production tubing so as to require removal of the production tubing to remove the lower one of the at least two pumps from the wellbore. 
     
     
         11 . The system of  claim 1  further comprising a plurality of fluid flow conduits each being in fluid communication with an interior of the production tubing at longitudinal positions corresponding to fluid communication positions of the at least one fluid intake conduit. 
     
     
         12 . The system of  claim 1  further comprising a plurality of fluid flow conduits each being in fluid communication with an interior of the production tubing at longitudinal positions corresponding to fluid communication positions of the at least one fluid discharge conduit. 
     
     
         13 . The system of  claim 1  wherein each of the at least two pumps has a fluid pumping rate enabling lift of a full flow rate of fluid from the wellbore to the surface, whereby failure of one of the at least two pumps enables substitution of the other of the at least two pumps to maintain full fluid flow from the wellbore to the surface. 
     
     
         14 . The system of  claim 1  wherein the at least two pumps have an outer diameter and/or a length such that the at least two pumps are able to move through a point of maximum dog leg severity in the wellbore. 
     
     
         15 . The system of  claim 1  further comprising at least a third pump disposed in the production tubing intermediate the upper one of the at least two pumps and the lower one of the at least two pumps,
 the at least a third pump having at least one respective fluid intake conduit disposed outside the production tubing and inside the wellbore, the at least one respective fluid intake conduit in communication with the interior of the production tubing below the lower one of the at least two pumps and at a position of an intake of the at least a third pump, the at least a third pump having at least one respective fluid discharge conduit disposed outside the tubing and inside the wellbore, the at least one fluid discharge conduit in fluid communication with the interior of the production tubing proximate a discharge of the at least a third pump and either proximate the intake of or above the upper one of the at least two pumps. 
 
     
     
         16 . The system of  claim 15  wherein the at least a third pump is seated in a respective wet mateable electrical/mechanical connector disposed in the production tubing. 
     
     
         17 . The system of  claim 16  wherein the at least a third pump is removable from the production tubing without removing the production tubing from the wellbore. 
     
     
         18 . The system of  claim 15  wherein any combination of two of the upper one of the at least two pumps and the at least a third pump has a fluid pumping rate enabling lift of a full flow rate of fluid from the wellbore to the surface, whereby failure of any one of the at least two pumps and the at least a third pump enables substitution of the other of the at least two pumps to maintain full fluid flow from the wellbore to the surface. 
     
     
         19 . A method for pumping fluid from a wellbore, comprising:
 operating at least one of at least two pumps disposed in a production tubing disposed in the wellbore,   at least one of the at least two pumps removable from the production tubing while the production tubing remains in place in the wellbore, at least one fluid intake conduit disposed outside the production tubing and inside the wellbore, the at least one fluid intake conduit in fluid communication with and providing a fluid transport path between an interior of the production tubing below a lower one of the at least two pumps and at a position of an intake of an upper one of the at least two pumps,   at least one fluid discharge conduit disposed outside the tubing and inside the wellbore, the at least one fluid discharge conduit in fluid communication with and providing a fluid transport path between the interior of the production tubing at a discharge of the lower one of the at least two pumps and either at an intake of or above the upper one of the at least two pumps.   
     
     
         20 . The method of  claim 19  wherein each of the at least two pumps has a fluid pumping rate enabling lift of a full flow rate of fluid from the wellbore to the surface, whereby failure of one of the at least two pumps enables substitution of the other of the at least two pumps to maintain full fluid flow from the wellbore to the surface. 
     
     
         21 . The method of  claim 19  further comprising operating at least a third pump disposed in the production tubing intermediate the upper one of the at least two pumps and the lower one of the at least two pumps, the at least a third pump having at least one respective fluid intake conduit disposed outside the production tubing and inside the open wellbore, the at least one respective fluid intake conduit in communication with the interior of the production tubing below the lower one of the at least two pumps and at a position of an intake of the at least a third pump, the at least a third pump having at least one respective fluid discharge conduit disposed outside the tubing and inside the wellbore, the at least one fluid discharge conduit in fluid communication with the interior of the production tubing proximate a discharge of the at least a third pump and either proximate the intake of or above the upper one of the at least two pumps. 
     
     
         22 . The method of  claim 21  wherein any combination of two of the upper one of the at least two pumps and the at least a third pump has a fluid pumping rate enabling lift of a full flow rate of fluid from the wellbore to the surface, whereby failure of any one of the at least two pumps and the at least a third pump enables substitution of the other of the at least two pumps to maintain full fluid flow from the wellbore to the surface.