Apparatus and Method for Cleaning a Well

Abstract

The present invention relates to apparatus and a method for cleaning a well. In an embodiment, the apparatus ( 10 ) includes a well cleaning tool ( 12 ) coupled to a support string 26 , which may be located in well tubing ( 14 ) to permit cleaning of the well tubing ( 14 ). The cleaning tool ( 10 ) may restrict fluid flow past the tool, for example, in an annular space between the tool ( 12 ) and the well tubing ( 14 ). Further, the tool ( 12 ) can be translated relative to the well tubing ( 14 ) to displace fluid along the well tubing ( 14 ) and thus clean the well.

1 . A well cleaning tool for location in well tubing to be cleaned on an associated support string, the cleaning tool adapted to be configured to restrict fluid flow past the tool and to be translated relative to the well tubing to displace fluid along the well tubing and thereby clean the well. 
   
   
       2 . A well cleaning tool as claimed in  claim 1 , wherein the tool is adapted to be configured such that fluid flow past the tool is substantially prevented. 
   
   
       3 . A well cleaning tool as claimed in  claim 1 , wherein the tool is adapted to be configured to restrict fluid flow past the tool along an annulus defined between the well tubing and the support string. 
   
   
       4 . A well cleaning tool as claimed in  claim 1 , wherein the cleaning tool is movable between a first configuration where fluid flow past the cleaning tool is permitted, and a second configuration where fluid flow past the cleaning tool is substantially prevented. 
   
   
       5 . A well cleaning tool as claimed in  claim 4  wherein the first configuration is a deactivated, running configuration, and the second configuration is an activated, cleaning configuration. 
   
   
       6 . A well cleaning tool as claimed in  claim 1 , wherein the cleaning tool is adapted to permit fluid flow in one direction past the tool, and to restrict fluid flow past the tool in an opposite direction. 
   
   
       7 . A well cleaning tool as claimed in  claim 1 , wherein the cleaning tool is arranged such that the tool automatically restricts fluid flow when the tool is translated in one direction along the well tubing, but permits fluid flow when the tool is translated in an opposite direction. 
   
   
       8 . A well cleaning tool as claimed in  claim 1 , wherein the cleaning tool is adapted to abut a wall of the well tubing in order to restrict fluid flow. 
   
   
       9 . A well cleaning tool as claimed in  claim 1 , wherein the cleaning tool is coupled to tubing of the support string. 
   
   
       10 . A well cleaning tool as claimed in  claim 9 , wherein the tubing of the support string is adapted to permit flow of completion fluid therethrough and into the well. 
   
   
       11 . A well cleaning tool as claimed in  claim 1 , wherein the cleaning tool comprises at least one abutting element for abutting the wall of the well tubing, the element serving for permitting and restricting fluid flow past the tool. 
   
   
       12 . A well cleaning tool as claimed in  claim 11 , wherein the abutting element is movable between a deactivated configuration and an activated configuration, which corresponds to deactivated and activated configurations of the tool, for selectively engaging an internal surface of the tubing. 
   
   
       13 . A well cleaning tool as claimed in  claim 10 , wherein the abutting element is adapted to be biased into abutment with the well tubing wall. 
   
   
       14 . A well cleaning tool as claimed in  claim 4 , wherein the tool comprises an actuating mechanism for moving the tool between the deactivated and activated configurations. 
   
   
       15 . A well cleaning tool as claimed in  claim 14 , wherein the actuating mechanism is adapted to exert a radial actuating force on the abutting element. 
   
   
       16 . A well cleaning tool as claimed in  claim 10 , wherein the abutting element defines a cleaning surface for cleaning an internal wall of the well tubing during translation of the cleaning tool through the tubing. 
   
   
       17 . A well cleaning tool as claimed in  claim 16 , wherein the cleaning tool is adapted to be movably mounted relative to the support string, and comprises a body mounted for movement relative to the support string along a length thereof. 
   
   
       18 . Apparatus for cleaning a well, the apparatus comprising:
 a support string adapted to be located in well tubing to be cleaned;   at least one well cleaning tool coupled to the support string, the well cleaning tool adapted to be configured to restrict fluid flow past the tool and to be translated relative to the well tubing to displace fluid along the well tubing and thereby clean the well.   
   
   
       19 . Apparatus as claimed in  claim 18 , wherein the apparatus comprises a plurality of cleaning tools, and comprises a first cleaning tool adapted to define a first cleaning diameter for cleaning a first section of well tubing of a corresponding first diameter and a second cleaning tool adapted to define a second cleaning diameter for cleaning a second section of well tubing of a corresponding second diameter. 
   
   
       20 . Apparatus as claimed in  claim 19 , wherein at least one of the cleaning tools is adapted to be movably mounted relative to the support string, and comprises a body mounted for movement relative to the support string along a length thereof. 
   
   
       21 . Apparatus as claimed in  claim 19 , wherein at least one of the cleaning tools is movable relative to at least one other cleaning tool. 
   
   
       22 . Apparatus as claimed in  claim 19 , wherein a lower cleaning tool is secured against movement relative to the support string, and an upper cleaning tool is movably mounted relative to the support string. 
   
   
       23 . Apparatus as claimed in  claim 19 , wherein upper cleaning tool is adapted to initially be provided in a deactivated configuration permitting fluid flow past the tool, lower cleaning tool is adapted to be provided in an activated configuration, restricting fluid flow past the tool so as to urge fluid along the well tubing and past the upper tool during movement of the lower cleaning tool. 
   
   
       24 . Apparatus as claimed in  claim 18 , wherein the support string is adapted to permit fluid to be pumped therethrough and into the well to facilitate cleaning the wellbore. 
   
   
       25 . Apparatus as claimed in  claim 18 , wherein the apparatus comprises a flow restrictor, the restrictor adapted to be located within the support string, to define a barrier between fluid within the string above the restrictor and fluid below the restrictor. 
   
   
       26 . Apparatus as claimed in  claim 25 , wherein the flow restrictor is adapted to be pumped down the support string using completion fluid for defining a barrier between the completion fluid and fluid present in the well and in the string below the restrictor. 
   
   
       27 . A method of cleaning a well, the method comprising the steps of:
 locating a well cleaning tool in well tubing to be cleaned on an associated support string;   configuring the well cleaning tool to prevent fluid flow past the tool; and   translating the well cleaning tool relative to the well tubing to displace fluid along the well tubing to thereby clean the well.   
   
   
       28 . A method as claimed in  claim 27 , wherein the cleaning tool is translated along the support string relative to the well tubing in a direction from surface to a downhole location, to displace fluid in the well tubing and up the support string to surface. 
   
   
       29 . A method as claimed in  claim 27 , wherein the cleaning tool is secured relative to the support string and translated relative to the well tubing in a direction towards the surface, to displace fluid in the well tubing along the tubing to surface, by translating the support string along the well tubing. 
   
   
       30 . A method as claimed in  claim 27 , wherein the method comprises the step of defining a barrier between fluid in the well tubing and replacement fluid pumped into the well tubing.