Water hammer mitigating flow control structure and method

Abstract

A water hammer mitigating flow control structure for a downhole completion including a tubular member configured for the downhole environment. A valve member in operable communication with the tubular member and positionable with respect to the tubular member to allow or prevent fluid movement through the tubular member. An absorber in operable communication with the valve member and configured to allow movement of the valve member the movement absorbing a pressure rise against the valve member in use. Also included is a method for mitigating water hammer in a flow control structure for a downhole completion

1 . A water hammer mitigating flow control structure for a downhole completion comprising:
 a tubular member configured for the downhole environment;   a valve member in operable communication with the tubular member and positionable with respect to the tubular member to allow or prevent fluid movement through the tubular member; and   an absorber in operable communication with the valve member and configured to allow movement of the valve member the movement absorbing a pressure rise against the valve member in use.   
     
     
         2 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the valve member is a flapper valve. 
     
     
         3 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the valve member is a ball valve. 
     
     
         4 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber is of constant rate. 
     
     
         5 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber is of variable rate. 
     
     
         6 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber is positioned downstream of fluid flow relative to the valve member. 
     
     
         7 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber is positioned both upstream and downstream of the valve member. 
     
     
         8 . A water hammer mitigating flow control structure as claimed in  claim 7  wherein the absorber is two absorbers with one positioned upstream and one positioned downstream of the valve member. 
     
     
         9 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber is a spring. 
     
     
         10 . A water hammer mitigating flow control structure as claimed in  claim 9  wherein the spring is a coil spring. 
     
     
         11 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber is a gas charged chamber. 
     
     
         12 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the absorber further includes a dash pot. 
     
     
         13 . A water hammer mitigating flow control structure as claimed in  claim 12  wherein the dash pot is single acting. 
     
     
         14 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the structure further includes a housing radially adjacent the tubular member having one or more openings therein that are covered until the tubular member is moved following a pressure rise against the valve member in use. 
     
     
         15 . A water hammer mitigating flow control structure as claimed in  claim 14  wherein the one or more openings absorb pressure when exposed to fluid pressure subsequent to the valve member experiencing a pressure rise in use. 
     
     
         16 . A water hammer mitigating flow control structure as claimed in  claim 1  wherein the pressure rise is an origination or a reflection of a tube wave. 
     
     
         17 . A method for mitigating water hammer in a flow control structure for a downhole completion comprising:
 allowing a valve member to move relative to a tubular member with which the valve member is operable to allow or prevent fluid movement through the tubular member;   absorbing a pressure rise against the valve member with the movement.   
     
     
         18 . A method for mitigating water hammer in a flow control structure as claimed in  claim 17  wherein the absorbing includes deforming a spring. 
     
     
         19 . A method for mitigating water hammer in a flow control structure as claimed in  claim 17  wherein the deforming includes deforming a spring at a downstream position relative to the valve member. 
     
     
         20 . A method for mitigating water hammer in a flow control structure as claimed in  claim 17  wherein the deforming includes deforming a spring at both downstream and upstream positions relative to the valve member. 
     
     
         21 . A method for mitigating water hammer in a flow control structure as claimed in  claim 17  wherein upon deforming the spring in the downstream position, one or more openings in a housing of the structure are uncovered. 
     
     
         22 . A method for mitigating water hammer in a flow control structure as claimed in  claim 17  wherein the absorbing includes a rebound and the rebound is slowed.