Method for preparing a wellbore

Abstract

There is provided herein a method for preparing a wellbore comprising: positioning one or more sections of piping within the wellbore as part of a piping string by attaching the one or more sections to additional similar sections of piping, wherein at least a region of an external surface of the one or more sections of piping is shaped to include a pattern of indents and/or protrusions, and wherein the shaped region of the external surface is located so as to be exposed to a surrounding external environment when the section of piping is coupled to the additional similar sections of piping as part of the piping string. There is also provided herein a section of piping for use as part of a wellbore structure and a method for producing a section of piping for use as part of a wellbore structure.

1 . A method for preparing a wellbore comprising:
 positioning one or more sections of piping within the wellbore as part of a piping string by attaching the one or more sections to additional similar sections of piping, wherein   at least a region of an external surface of the one or more sections of piping is shaped to include a pattern of indents and/or protrusions, and wherein   the shaped region of the external surface is located so as to be exposed to a surrounding external environment when the section of piping is coupled to the additional similar sections of piping as part of the piping string.   
     
     
         2 . The method according to  claim 1 , wherein the at least one section of piping comprises coupling structures at either end for attachment to the additional similar sections of piping, and the external surface extends between these two coupling structures. 
     
     
         3 . The method according to  claim 1 , wherein at least a region of the external surface midway between the two ends of the one or more sections of piping is shaped to include a pattern of indents and/or protrusions. 
     
     
         4 . The method according to  claim 1 , comprising filling a region directly adjacent the shaped region of the external surface with a filler material so that the filler material fills one or more spaces formed by the indents and/or protrusions. 
     
     
         5 . The method according to  claim 1 , comprising modifying the region of the external surface of the one or more sections of piping. 
     
     
         6 . The method according to  claim 5 , wherein the modifying comprises positioning one or more conductive elements of a tool around the one or more sections of piping, connecting the piping to the tool, and connecting the conductive elements to a power source to remove parts of the external surface by a process of electrolysis. 
     
     
         7 . The method according to  claim 5 , comprising modifying the region of the external surface of the one or more sections of piping prior to inserting the one or more sections in the wellbore. 
     
     
         8 . The method according to  claim 1 ,
 wherein the section of piping is a section of wellbore casing or tubing.   
     
     
         9 . The method according to  claim 1 , wherein at least a region of the internal surface of the one or more sections of piping that is exposed to a surrounding external environment when the section of piping is coupled to additional similar sections of piping within a wellbore is also provided with a pattern of indents and/or protrusions. 
     
     
         10 . The method according to  claim 9 , wherein the pattern of indents and/or protrusions on the external and internal surfaces are different. 
     
     
         11 . The method according to  claim 10 , wherein the pattern of indents and/or protrusions on the external and internal surfaces comprise a plurality of radial grooves, slanting ringed grooves, or one or more helical grooves, and wherein the distance between adjacent grooves in a direction along the length of the one or more sections of piping is different for the internal and the external surfaces. 
     
     
         12 . The method according to  claim 9 , comprising modifying the region of the internal surface of the piping section. 
     
     
         13 . The method according to  claim 12 , wherein modifying the external and internal surfaces of the at least one section of piping comprises inserting the piping section into a tool comprising a first cathode internal to the inserted piping section and a second cathode external to the inserted piping section, coupling the cathodes and the piping section to a power source as part of the same circuit, and providing the patterns of indents and/or protrusions via a process of electrolysis. 
     
     
         14 . The method according to  claim 13 , wherein the tool comprises two separate fluid circulation systems for passing electrolytes around the first cathode and the second cathode respectively. 
     
     
         15 . The method according to  claim 1 , wherein substantially the whole of the external surface of the one or more sections of piping is provided with a pattern of indents and/or protrusions. 
     
     
         16 . A section of piping for use as part of a wellbore structure, wherein at least part of an external surface of the section of piping that is exposed to a surrounding external environment when the piping is coupled to additional sections of piping within a pipe string is provided with a pattern of indents and/or protrusions. 
     
     
         17 . A method for producing a section of piping for use as part of a wellbore structure, the method comprising:
 providing a pattern of indents and/or protrusions on at least a part of the external surface of the section of piping, wherein the at least a part of the external surface is located on the piping so as to be exposed to a surrounding external environment when the piping is coupled to similar piping sections as part of a piping string and positioned downhole.   
     
     
         18 . The method according to  claim 2 , wherein at least a region of the external surface midway between the two ends of the one or more sections of piping is shaped to include a pattern of indents and/or protrusions. 
     
     
         19 . The method according to  claim 2 , comprising filling a region directly adjacent the shaped region of the external surface with a filler material so that the filler material fills one or more spaces formed by the indents and/or protrusions. 
     
     
         20 . The method according to  claim 3 , comprising filling a region directly adjacent the shaped region of the external surface with a filler material so that the filler material fills one or more spaces formed by the indents and/or protrusions.