Electric submersible pump dual gas and sand separator

Abstract

An electric submersible pump (ESP) dual gas and sand separator is described. An ESP system includes a dual gas and sand separator having a fluid flow pathway including an upward turn and a downward turn, the upward turn separating solids from a fluid flowing through the pathway and the downward turn separating gas from the fluid, the dual separator including a sand sump below the fluid flow pathway. The separator includes tubing that extends below the ESP assembly, at least a portion of the tubing including two concentric pipes. A dual gas and sand separating method includes causing pumped fluid to turn from upwards to downwards and then upwards again in a tortious pathway below the ESP assembly before the fluid travels into a centrifugal pump intake, and collecting solids that separate out of the multiphase fluid in a solid sump coupled below the tortious pathway.

1 . An electric submersible pump (ESP) assembly comprising:
 a tubular shroud separating a housing of the ESP assembly from a well casing, the tubular shroud extending between a base of a centrifugal pump and a location below the ESP assembly, the tubular shroud sealed from well fluid ingress at the centrifugal pump base;   a stinger hanging below the tubular shroud, the stinger comprising:
 an annular jacket, the annular jacket comprising a plurality of inlet openings and coupled to a sand sump below the annular jacket, 
 a pipe inwards of the annular jacket, the pipe open at a top end and a bottom end of the pipe, 
 a space above the inlet openings and between an inner diameter of the annular jacket and an outer diameter of the pipe sealed from upward fluid flow, and 
   an inside of the pipe fluidly coupled to an inner diameter of the tubular shroud.   
     
     
         2 . The ESP assembly of  claim 1 , wherein the tubular shroud and stinger define a production fluid pathway that extends through the plurality of inlet openings in the stinger, continues downward between the inner diameter of the annular jacket and the outer diameter of the pipe, turns at the bottom end of the pipe and flows upward through the inside of the pipe, continues upward through the inner diameter of the tubular shroud, enters the pump intake and then continues into the centrifugal pump. 
     
     
         3 . The ESP assembly of  claim 2 , wherein the ESP assembly comprises an induction motor encased in a motor housing, wherein the production fluid flows between an outside of the motor housing and the inner diameter of the tubular shroud as the production fluid continues upward through the inner diameter of the tubular shroud on the way to the pump intake. 
     
     
         4 . The ESP assembly of  claim 2 , wherein gas separates out of the production fluid when the production fluid continues downward between the inner diameter of the annular jacket and the outer diameter of the pipe. 
     
     
         5 . The ESP assembly of  claim 4 , wherein the gas exits the stinger and enters a casing annulus through a top row of the plurality of inlet openings. 
     
     
         6 . The ESP assembly of  claim 2 , wherein sand separates out of the production fluid when the production fluid turns at the bottom end of the pipe, and the sand collects in the sand sump. 
     
     
         7 . The ESP assembly of  claim 1 , wherein the bottom end of the pipe is chamfered. 
     
     
         8 . The ESP assembly of  claim 1 , wherein the plurality of openings comprise two offset rows of slots. 
     
     
         9 . An electric submersible pump (ESP) system comprising:
 a dual gas and sand separator, the dual gas and sand separator hanging below a downhole ESP assembly from a shroud;
 the shroud surrounding an inlet section of a centrifugal pump of the ESP assembly; 
 the dual gas and sand separator comprising a stinger, the stinger comprising a plurality of concentric pipes and a sand sump hanging below an outer pipe of the plurality of concentric pipes. 
   
     
     
         10 . The ESP system of  claim 9 , wherein the outer pipe of the plurality of concentric pipes comprises at least one inlet opening extending through a wall of the outer pipe. 
     
     
         11 . The ESP system of  claim 10 , wherein the at least one inlet opening comprises two rows of offset slots. 
     
     
         12 . The ESP system of  claim 10 , wherein the dual gas and sand separator is configured such that fluid flows through the at least one opening and downwards towards the sand sump, turns at the bottom of an inner pipe of plurality of concentric pipes and flows upward through the inside of the inner pipe. 
     
     
         13 . The ESP system of  claim 12 , further comprising multiphase fluid flowing through the dual gas and sand separator, and wherein gas separates from the multiphase fluid as it flows downward towards the sand sump and sand separates from the multiphase fluid as the fluid turns upwards at the bottom of the inner pipe. 
     
     
         14 . The ESP system of  claim 13 , wherein the sand collects in the sand sump. 
     
     
         15 . The ESP system of  claim 9 , wherein an inside of an inner pipe of the plurality of concentric pipes is fluidly coupled to an inlet of a centrifugal pump in a downstream direction from the inside of the inner pipe towards the inlet of the centrifugal pump. 
     
     
         16 . An electric submersible pump (ESP) system comprising a dual gas and sand separator suspended below an ESP assembly, the dual gas and sand separator having portions defining a fluid flow pathway comprising a 180° upward turn and a 180° downward turn, the 180° upward turn configured to separate solids from a fluid flowing through the pathway and the 180° downward turn configured to separate gas from the fluid flowing through the pathway, the dual gas and sand separator comprising a solid collection sump below the portions defining the fluid flow pathway. 
     
     
         17 . The ESP system of  claim 16 , wherein the dual gas and sand separator comprises an inner tube fluidly coupled to an intake of a centrifugal pump of the ESP assembly. 
     
     
         18 . The ESP system of  claim 16 , wherein the solid collection sump extends between twenty and five hundred feet in length. 
     
     
         19 . The ESP system of  claim 16 , wherein the dual gas and sand separator comprises a shroud, a stinger secured below the shroud and the solid collection sump secured below the stinger. 
     
     
         20 . An electric submersible pump (ESP) dual gas and sand separation method comprises:
 pumping a multiphase fluid downhole in a well to bring the multiphase fluid to a well surface;   causing the fluid to make a turn from upwards to downwards and a subsequent turn from downwards to upwards in a tortious pathway below the ESP assembly before the multiphase fluid travels into a centrifugal pump intake; and   collecting solids that separate out of the multiphase fluid in a collection receptacle below the tortious pathway.   
     
     
         21 . The ESP dual gas and sand separating method of  claim 20 , wherein the turn from upwards to downwards separates gas from the multiphase fluid, and wherein the subsequent turn from downwards to upwards separates the solids from the multiphase fluid.