Wellbore tool for fracturing hydrocarbon formations, and method for fracturing hydrocarbon formations using said tool

Abstract

A wellbore tool for adapted for insertion into a wellbore extending into a hydrocarbon-containing formation, for fracturing said formation, comprising an elongate, substantially cylindrical tubular member. The tubular member has at a first end external thread means adapted for threadable connection to internal thread means disposed on an end of a wellbore piping member, and at an opposite end having internal thread means. At least a pair of longitudinally-spaced apart radially-outwardly protruding annular rib members are located on an exterior periphery of said tubular member, each of an outer diameter greater than an outer diameter of said wellbore piping member to which said tool is adapted to be threadably coupled. A method for fracturing a hydrocarbon formation using such wellbore tool is further disclosed.

1 . A wellbore tool for insertion in a wellbore and use in fracturing a hydrocarbon-containing formation into which said wellbore extends, comprising:
 (i) an elongate, substantially cylindrical tubular member, having at a first end thereof first thread means adapted for threadable connection to thread means disposed on an end of wellbore piping extending into said wellbore, and at an opposite end having second thread means; and   (ii) a pair of longitudinally-spaced apart radially-outwardly protruding annular rib members located on an exterior periphery of said tubular member intermediate said thread means, each rib member of an outer diameter less than said wellbore but greater than said outer diameter of said wellbore piping.   
     
     
         2 . A wellbore tool as claimed in  claim 1 , wherein said outer diameter of said annular rib members is at least 24% greater than said outer diameter of said piping. 
     
     
         3 . A wellbore tool as claimed in  claim 1 , wherein said wellbore tool when situated in said wellbore is adapted to provide a cross-sectional clearance area between at least one of said annular ring members and an inner diameter of said wellbore that is at least 80 percent less than an inner cross-sectional area of said tubular member of said wellbore tool. 
     
     
         4 . A wellbore tool as claimed in  claim 1 , having at least three longitudinally-spaced apart radially-outwardly protruding annular rib members located on an exterior periphery of said tubular member. 
     
     
         5 . A wellbore tool as claimed in  claim 4 , wherein a longitudinal distance separating a second of said at least three annular rib members from a first of said at least three annular rib members is less than a distance separating a third of said at least three annular rib members from said second annular ring member. 
     
     
         6 . A wellbore tool as claimed in  claim 5 , wherein longitudinally spaced apart distances between each of said annular ring members follows and is proportional to a Fibonacci sequence. 
     
     
         7 . A wellbore tool as claimed in  claim 1 , wherein said opposite end is adapted for threaded connection to a threaded distal end of another wellbore piping. 
     
     
         8 . A wellbore tool as claimed in  claim 2  wherein said opposite end is adapted for threaded connection to a threaded distal end of another wellbore piping. 
     
     
         9 . A wellbore tool as claimed in  claim 3  wherein said opposite end is adapted for threaded connection to a threaded distal end of another wellbore piping. 
     
     
         10 . A wellbore tool as claimed in  claim 1  further having a plurality of radially-outwardly extending but longitudinally-aligned centralizers members placed in uniform circumferentially-spaced intervals around the exterior periphery of the wellbore tool to allow centralization of the tool within said wellbore. 
     
     
         11 . A wellbore tool as claimed in  claim 2  further having a plurality of radially-outwardly extending but longitudinally-aligned centralizers members placed in uniform circumferentially-spaced intervals around the exterior periphery of the wellbore tool to allow centralization of the tool within said wellbore. 
     
     
         12 . A wellbore tool as claimed in  claim 3  further having a plurality of radially-outwardly extending but longitudinally-aligned centralizers members placed in uniform circumferentially-spaced intervals around the exterior periphery of the wellbore tool to allow centralization of the tool within said wellbore. 
     
     
         13 . A wellbore tool as claimed in  claim 2  wherein said opposite end is adapted for threaded connection to a threaded distal end of another wellbore tool. 
     
     
         14 . A wellbore tool as claimed in  claim 2  having a length ranging from at least a nominal outer diameter of said tool to a length approximately 7 times said nominal outer diameter. 
     
     
         15 . A wellbore tool as claimed in  claim 3  having a length ranging from at least a nominal outer diameter of said tool to a length approximately 7 times said nominal outer diameter. 
     
     
         16 . A frac'ing tool for insertion in a wellbore and adapted for use in fracturing a hydrocarbon-containing formation, adapted to be coupled at each end thereof to respectively first and second wellbore piping members, comprising:
 (i) an elongate, substantially cylindrical tubular member;   (ii) external/internal thread means at a first end thereof adapted for threadable connection to mating thread means disposed on an end of said first wellbore piping member, and at an opposite end thereof having external/internal thread means adapted for threadable connection to thread means disposed on an end of said second wellbore piping member;   (iii) at least one pair of longitudinally-spaced apart radially-outwardly protruding annular rib members, each respectively located on an exterior periphery of said tubular member proximate at respectively opposite ends thereof, each of said rib members of a diameter greater than a nominal outer diameter of said first and second wellbore piping members; and   (iii) each of said at least one pair of longitudinally-spaced apart radially-outwardly protruding annular rib members separated by an intermediate distance; and   (iv) aperture means situated in said periphery and located within said intermediate distance, to allow pressurized fluid egress from an interior of said tubular member to an exterior of said tubular member.   
     
     
         17 . The frac'ing tool as claimed in  claim 16 , each of said rib members of a diameter at least 24% greater than a nominal outer diameter of said first and second wellbore piping members. 
     
     
         18 . A frac'ing tool as claimed in  claim 16 , said frac'ing tool when situated in said wellbore adapted to provide a radial cross-sectional clearance area between said annular ring members and an inner diameter of said wellbore that is at least 80 percent less than an inner cross-sectional area of said tubular member of said frac'ing tool. 
     
     
         19 . A method for fracturing a hydrocarbon formation through which extends a vertical, inclined, or horizontal wellbore, comprising the steps of:
 (i) threadably coupling one end of each of a pair of wellbore tools as claimed in  claim 1 ,  2  or  3  to respectively opposite ends of a tubular member so as to situate said tubular member between said two tools;   (ii) coupling a second end of one of said tools to a wellbore piping member and inserting said pair of tools and intermediate tubular member downhole in said wellbore; and   (iii) fracturing said hydrocarbon formation downhole by pumping fracturing fluid downhole under pressure and causing said fracturing fluid to flow into said formation via an aperture created in said tubular member situated between said pair of wellbore tools.   
     
     
         20 . A method for fracturing a hydrocarbon formation through which extends a vertical, inclined, or horizontal wellbore, comprising the steps of:
 (i) threadably coupling an end of a frac'ing tool as claimed in  claim 16 ,  17 , or  18  to a wellbore piping member, and further coupling said wellbore piping member to further wellbore piping members, and inserting said tool and connected wellbore piping members downhole in said wellbore; and   (ii) fracturing said hydrocarbon formation downhole by pumping fracturing fluid downhole under pressure and causing such fracturing fluid to flow into said formation via said aperture means.