Particulate separator for production wells

Abstract

Disclosed in a particulate separator for use with a petroleum production well that produces a fluid mixture including particulate matter. The separator includes an outer casing and an inner pipe disposed within the outer casing. The outer casing includes fluid intake slots extending through its sidewall near is upper end. Fluid entering the outer casing flows downward along a flow path between the outer casing and a lower open end of the inner pipe. A fin on a lower portion of the inner pipe imparts a radial motion to the downwardly flowing fluid, which forces particulates toward the inside surface of the outer casing. In an arrangement, the outer casing has an upper portion and a lower portion that overlaps the fin. In an arrangement, a sidewall thickness of the lower portion of the casing is greater than a sidewall thickness of the upper portion of the outer casing.

What is claimed is: 
     
         1 . A particulate separator for disposition within a well casing of a petroleum production well producing a fluid mixture including particulate matter, the separator comprising:
 an outer casing including intake apertures, proximate an upper end of the outer casing, allowing the fluid mixture to enter the outer casing;   an inner pipe disposed within the outer casing, wherein an upper outlet of the inner pipe exits through the upper end of the separator and a lower end of the inner pipe is disposed proximate to a lower end of the outer casing;   a fin disposed on a lower portion of the inner pipe, wherein fluid flows downward between the interior of the outer casing and an exterior of the inner pipe, wherein the fin imparts a radial path to the fluid as it moves toward a pump intake defined by the lower end of the inner pipe,   wherein, a lower portion of the outer casing that encases the fin on the lower portion of the inner pipe has at least a first material property that is different than a material property of an upper portion of the outer casing that encases an upper portion of the inner pipe that free of the fin.   
     
     
         2 . The separator of  claim 1 , wherein the material property comprises one of:
 a sidewall thickness;   a hardness; and   a material type.   
     
     
         3 . The separator of  claim 1 , wherein a sidewall thickness of the outer casing varies over its length. 
     
     
         4 . The separator of  claim 3 , wherein the sidewall thickness of the lower portion of the outer casing is greater than a sidewall thickness of the upper portion of the outer casing. 
     
     
         5 . The separator of  claim 3 , wherein the outer casing comprises:
 an upper barrel forming the upper portion of the outer casing; and   a lower barrel forming the lower portion of the outer casing.   
     
     
         6 . The separator of  claim 5 , wherein the lower barrel and the upper barrel are threadedly connected. 
     
     
         7 . The separator of  claim 1 , further comprising:
 an elongated hollow connector having:
 a first set of threads configured to connect to mating threads on an upper end of the inner pipe; and 
 a second set of threads configured to connect to mating threads on an upper end of the outer casing. 
   
     
     
         8 . The separator of  claim 7 , wherein the first set of threads and the second set of threads are disposed on a first end of the elongated hollow connector, the elongated hollow connector further comprising:
 a third set of threads disposed on a second end of the elongated hollow connector.   
     
     
         9 . The separator of  claim 1 , further comprising:
 a hollow bottom fitting having:
 a first set of threads on a first end of the hollow bottom fitting configured to connect to mating threads on a lower end of the outer casing; and 
 a second set of threads on a second end of the hollow bottom fitting. 
   
     
     
         10 . The separator of  claim 9 , internal periphery of the upper interior end of the hollow bottom fitting comprises a chamfered surface. 
     
     
         11 . A particulate separator for disposition within a well casing of a petroleum production well producing a fluid mixture including particulate matter, the separator comprising:
 an outer casing having:
 an upper barrel having at least a first intake aperture disposed through a sidewall of the upper barrel proximate an upper end of the upper barrel; 
 a lower barrel having an upper end attached to a lower end of the upper barrel, wherein hollow interiors of the upper barrel and lower barrel are aligned to define a hollow interior the outer casing; 
   an inner pipe disposed within the hollow interior of the outer casing, the inner pipe extending from an upper end disposed proximate to an upper end of the outer barrel to an open lower end disposed within a lower portion of the lower barrel, wherein a space between the inside surface of the outer casing and an outside surface of the inner pipe defines a flow path between the intake aperture and the open lower end of the inner pipe; and   a fin disposed on a lower portion of the inner pipe, wherein the fin imparts a radial path to the fluid as it moves along the flow path toward the open end of the inner pipe, wherein the lower barrel overlaps the lower portion of the inner pipe and the fin.   
     
     
         12 . The separator of  claim 11 , wherein a sidewall thickness of the lower barrel is greater than a sidewall thickness of the upper barrel. 
     
     
         13 . The separator of  claim 12 , wherein an inside diameter of the upper barrel is substantially equal to an inside diameter of the lower barrel. 
     
     
         14 . The separator of  claim 11 , wherein the lower barrel is formed from a first material and the upper barrel is formed form a second material, wherein the first and second materials are different. 
     
     
         15 . The separator of  claim 11 , further comprising:
 an elongated hollow connector having:
 a first set of threads configured to connect to mating threads on an upper end of the inner pipe; and 
 a second set of threads configured to connect to mating threads on an upper end of the upper barrel of the outer casing. 
   
     
     
         16 . The separator of  claim 17 , wherein the first set of threads and the second set of threads are disposed on a first end of the elongated hollow connector, the elongated hollow connector further comprising:
 a third set of threads disposed on a second end of the elongated hollow connector.   
     
     
         17 . The separator of  claim 1 , further comprising:
 a hollow bottom fitting having:
 a first set of threads on a first end of the hollow bottom fitting configured to connect to mating threads on a lower end of the lower barrel of the outer casing; and 
 a second set of threads on a second end of the hollow bottom fitting. 
   
     
     
         18 . The separator of  claim 17 , internal periphery of the upper interior end of the hollow bottom fitting comprises a chamfered surface. 
     
     
         19 . The separator of  claim 11 , wherein an upper outlet of the inner pipe exits through an upper end of the separator. 
     
     
         20 . The separator of  claim 11 , further comprising:
 a plurality of intake apertures disposed about a periphery of the sidewall of the upper barrel.