Method of Manufacturing and Using Rod-Shaped Proppants and Anti-Flowback Additives

Abstract

A sintered rod-shaped proppant and anti-flowback agent possesses high strength and high conductivity. The sintered rods comprise between about 0.2% by weight and about 4% by weight aluminum titanate. In some embodiments, the sintered rods are made by mixing bauxitic and non-bauxitic sources of alumina that may also contain several so-called impurities (such as TiO 2 ), extruding the mixture, and sintering it. The starting material may optionally be milled to achieve better compacity and crush resistance in the final sintered rod. A fracturing fluid may comprise the sintered rods alone or in combination with a proppant, preferably a proppant of a different shape.

1 - 154 . (canceled) 
     
     
         155 . A method for making a proppant or anti-flowback additive, the method comprising:
 mixing an alumina containing material comprising bauxite with at least one binding agent to form an extrudable mixture;   extruding the extrudable mixture to form a plurality of extruded rods; and   sintering the extruded rods to obtain the proppant or anti-flowback additive,   wherein the proppant or anti-flowback additive has an average diameter ranging from about 0.5 mm to about 2 mm and an average length ranging from about 1 mm to about 5 mm.   
     
     
         156 . The method of  claim 155 , wherein the bauxite has a TiO 2  content ranging from about 0.15 wt % to 3.5 wt %. 
     
     
         157 . The method of  claim 155 , wherein the bauxite has an SiO 2  content of less than about 2 wt %. 
     
     
         158 . The method of  claim 155 , wherein the bauxite has an Fe 2 O 3  content of less than about 10 wt %. 
     
     
         159 . The method of  claim 155 , wherein the bauxite has an Al 2 O 3  content of greater than about 80 wt %, a TiO 2  content ranging from about 0.15 wt % to 3.5 wt %, and an SiO 2  content of less than about 2 wt %. 
     
     
         160 . The method of  claim 155 , wherein the bauxite has an Al 2 O 3  content of greater than about 80 wt %, a TiO 2  content ranging from about 0.15 wt % to 3.5 wt %, and an Fe 2 O 3  content of less than about 10 wt %. 
     
     
         161 . The method of  claim 155 , wherein the bauxite has an Al 2 O 3  content of greater than about 80 wt %, a TiO 2  content ranging from about 0.15 wt % to 3.5 wt %, an SiO 2  content of less than about 2 wt %, and an Fe 2 O 3  content of less than about 10 wt %. 
     
     
         162 . The method of  claim 155 , wherein the proppant or anti-flowback additive has an average diameter ranging from about 0.5 mm to about 1.5 mm. 
     
     
         163 . The method of  claim 155 , wherein the proppant or anti-flowback additive has an average length ranging from about 2 mm to about 4 mm. 
     
     
         164 . The method of  claim 155 , wherein the proppant or anti-flowback additive has an average length to width ratio ranging from about 1.5:1 to about 7:1. 
     
     
         165 . The method of  claim 155 , wherein the proppant or anti-flowback additive has an average length to width ratio ranging from about 2:1 to about 4:1. 
     
     
         166 . The method of  claim 155 , further including reducing the average length of the extruded rods to a desired length range. 
     
     
         167 . The method of  claim 166 , wherein reducing the average length of the extruded rods comprises at least one of milling, cutting, or drying the rods in a manner which results in breakage, thereby reducing the average length. 
     
     
         168 . The method of  claim 155 , further including fractionating the proppant or anti-flowback additive to obtain a subset of rods having a desired length range. 
     
     
         169 . The method of  claim 155 , wherein the proppant or anti-flowback additive has a packed void volume of greater than 40%. 
     
     
         170 . The method of  claim 155 , wherein the proppant or anti-flowback additive has a specific gravity ranging from 3.0 to 3.98 and a conductivity of greater than 3,000 mD-ft at 10,000 psi as measured under API Recommended Practice 61. 
     
     
         171 . The method of  claim 155 , wherein the at least one binding agent is selected from the group consisting of methyl cellulose, polyvinyl butyrals, emulsified acrylates, polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylics, starch, silicon binders, polyacrylates, silicates, polyethylene imine, lignosulfonates, and alginates. 
     
     
         172 . The method of  claim 155 , wherein from about 7 wt % and about 13 wt % of the proppant or anti-flowback additive is crushed at 15,000 psi. 
     
     
         173 . The method of  claim 155 , wherein from about 9 wt % to about 19 wt % of the proppant or anti-flowback additive is crushed at 15,000 psi. 
     
     
         174 . A method for making a proppant or anti-flowback additive, the method comprising:
 mixing an alumina containing material comprising bauxite with at least one binding agent to form an extrudable mixture, wherein the bauxite has an Al 2 O 3  content of greater than about 80 wt %, a TiO 2  content ranging from about 0.15 wt % to 3.5 wt %, and an SiO 2  content of less than about 2 wt %;   extruding the extrudable mixture to form a plurality of extruded rods; and   sintering the extruded rods to obtain the proppant or anti-flowback additive,   wherein the proppant or anti-flowback additive has an average diameter ranging from about 0.5 mm to about 1.5 mm and an average length ranging from about 1 mm to about 5 mm.