Downhole apparatus and method

Abstract

A downhole apparatus comprising a body configured to be coupled to a production tubular and an upper opening and a lower opening. First and second flow paths are provided between the upper opening and the lower opening in the body, and a flow diverter is arranged to direct downward flow through the body towards the second flow path and away from the first flow path. A filter device in the second flow path filters or collects solid particles in the second flow path from passing out of the lower opening of the apparatus. The apparatus has particular application to artificial lift hydrocarbon production systems, and may be installed above a downhole pump in a production tubing to prevent solids from settling on the pump during pump shutdown. Embodiments for use with ESPs and PCPs are described.

1 . A downhole production apparatus comprising:
 an outer tubular having an upper opening and lower opening, the outer tubular configured to be assembled into a production string above a downhole production pump;   an inner tubular extending at least partially along the inside of the outer tubular, the inner tubular having a wall with at least one passageway; and   annular space separating at least part of the outer tubular and at least part of the wall of the inner tubular, wherein the annular space is arranged to collect downward moving solid particles that have been directed away from the inner tubular and toward the annular space;   wherein an upper portion of the apparatus is configured to direct downward moving solid particles toward the annular space and away from the inner tubular; and   wherein the at least one passageway extends from an inside of the inner tubular to the annular space such that fluid flowing upwardly into the inner tubular flows through the wall of the inner tubular and into the annular space, thereby causing solid particles that have been collected to be carried out of the annular space.   
     
     
         2 . The apparatus of  claim 1 , further comprising at least one opening, wherein the at least one opening permits fluid flowing upwardly in the inner tubular to reach the upper opening of the outer tubular even if upward flowing fluid cannot flow through the at least one passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
         3 . The apparatus of  claim 1 , wherein the at least one passageway comprises multiple passageways in the wall of the inner tubular, the multiple passageways arranged such that fluid flowing upwardly into the inner tubular flows out the multiple passageways and into the annular space, thereby causing solid particles that have been collected to be progressively carried out of the annular space. 
     
     
         4 . The apparatus of  claim 1 , wherein the at least one passageway comprises a first passageway and a second passageway in the wall of the inner tubular, the first passage way positioned adjacent a first end of the wall and the second passageway positioned adjacent an end opposite of the first end such that the second passageway permits fluid flowing upwardly in the inner tubular to reach the upper opening in the outer tubular even if fluid cannot flow through the first passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
         5 . The apparatus of  claim 1 , further comprising one or more holes arranged between a main flow path through the apparatus and a lower part of the annular space, the one or more holes arranged to receive upward flow of fluid from the main flow path and to stimulate upward flow at a bottom of the annular space, further assisting with carrying collected solids away from the lower part of the annular space. 
     
     
         6 . The apparatus of  claim 1 , wherein the at least one passageway comprises a slot. 
     
     
         7 . The apparatus of  claim 6 , wherein the slot has a dimension of approximately 0.5 millimeters. 
     
     
         8 . The apparatus of  claim 1 , wherein the at least one passageway comprises two or more slots having different orientations. 
     
     
         9 . The apparatus of  claim 1 , further comprising a mesh or screen disposed over the at least one passageway. 
     
     
         10 . The apparatus of  claim 1 , further comprising a downhole production pump, wherein the downhole production pump is an electric submersible pump (ESP) or progressive cavity pump (PCP) coupled beneath the lower opening of the tubular housing. 
     
     
         11 . The apparatus of  claim 1 , further comprising a flow diverter at the upper portion of the apparatus configured to direct downward moving solid particles toward the annular space and away from the inner tubular. 
     
     
         12 . The apparatus of  claim 11 , wherein the flow diverter comprises a valve. 
     
     
         13 . A downhole apparatus for a production tubing, the apparatus comprising:
 a tubular with an interior defining a first flow region, the tubular configured to be assembled into a body having an upper opening and a lower opening, the body forming part of a production string above a downhole production pump such that when the tubular is assembled into the body a second flow region is formed in a space between the first flow region and a wall of the body, the second flow region being arranged to collect downward moving solid particles;   wherein an upper end of the tubular is configured to direct solid particles moving downwardly in the body away from the first flow region and into the second flow region;   and one or more passageways extending through a wall of the tubular, the one or more passageways arranged such that when the tubular is assembled into the body upward flowing fluid through the first flow region causes upward fluid flow in the second flow region, which carries collected solid particles out of the second flow region.   
     
     
         14 . The apparatus of  claim 13 , wherein the one or more passageways comprises a first passageway and a second passageway in the wall of the tubular, the first passageway positioned adjacent a lower end of the wall and the second passageway positioned adjacent an upper end of the wall such that the second passageway permits fluid flowing upwardly in the inner tubular to escape the inner tubular even if fluid is unable to flow through the first passageway in the wall of the inner tubular due to an accumulation of collected solid particles. 
     
     
         15 . The apparatus of  claim 13 , wherein the one or more passageways comprises a slot. 
     
     
         16 . The apparatus of  claim 15 , wherein the slot has a dimension of approximately 0.5 millimeters. 
     
     
         17 . The apparatus of  claim 13 , wherein the one or more passageways comprises two or more slots having different orientations. 
     
     
         18 . The apparatus of  claim 13 , further comprising a mesh or screen disposed over the one or more passageways. 
     
     
         19 . The apparatus of  claim 13 , further comprising a downhole production pump, wherein the downhole production pump is an electric submersible pump (ESP) or progressive cavity pump (PCP) coupled beneath the lower opening of the body. 
     
     
         20 . The apparatus of  claim 13  wherein an upper end of the tubular comprises a flow diverter configured to direct downward moving solid particles toward the second flow region and away from the first flow region. 
     
     
         21 . The apparatus of  claim 20 , wherein the flow diverter comprises a valve. 
     
     
         22 . The apparatus of  claim 13 , wherein the tubular is assembled into the body in the production string above the downhole production pump. 
     
     
         23 . A method of forming a hydrocarbon production system, the method comprising;
 assembling a downhole apparatus according to  claim 13  into a production tubing above a downhole production pump.   
     
     
         24 . A method for washing away collected solid particles from a downhole apparatus, the method comprising:
 operating a downhole production pump, thereby causing fluid to flow upwardly into an inner tubular of the downhole apparatus and induce fluid flow in an annular space of the downhole apparatus via at least one passageway extending through a wall of the inner tubular separating the interior of the inner tubular from the annular space, the induced flow further causing collected solid particles that were directed toward the annular space and away from the inner tubular when the downhole production pump was shutdown to move upwardly, thereby washing collected solid particles from the downhole apparatus.   
     
     
         25 . The method of  claim 24 , wherein the solid particles were directed toward the annular space and away from the inner tubular by a flow diverter. 
     
     
         26 . The method of  claim 25 , wherein the flow diverter comprises a valve. 
     
     
         27 . The method of  claim 24 , wherein the at least one passageway comprises two or more passageways and the induced flow causes the collected solid particles to be progressively washed from the annular space. 
     
     
         28 . The method of  claim 24 , wherein the downhole production pump is an electrical submersible pump (ESP) or progressive cavity pump (PCP). 
     
     
         29 . The method of  claim 24 , wherein the at least one passageway comprises a plurality of slots along the inner tubular wall. 
     
     
         30 . The method of  claim 29 , wherein at least one of the plurality of slots has a dimension of approximately 0.5 millimeters. 
     
     
         31 . The method of  claim 29 , wherein at least two of the plurality of slots have a different orientation.