High-strength, low specific gravity, fracturing balls

Abstract

A fracturing ball comprises: a metal or a metal alloy, wherein the fracturing ball is a shell having an outer diameter and an inner diameter, wherein the fracturing ball has a desired specific gravity less than or equal to a necessary specific gravity such that the ball flows to a wellhead of the wellbore after a desired amount of time, and wherein after engagement of the fracturing ball with a baffle, fluid is prevented from flowing across the ball. A method of creating one or more fractures in a zone of a subterranean formation comprises: (A) introducing the fracturing ball into a tubing string of a wellbore; (B) causing or allowing the ball to engage the baffle; (C) creating the one or more fractures in the zone of the subterranean formation; and (D) producing a reservoir fluid from the zone of the subterranean formation.

What is claimed is: 
     
         1 . A method of restricting fluid flow within a tubing string of a wellbore comprising:
 introducing a ball into the tubing string, wherein the ball:
 (A) comprises a metal or a metal alloy; 
 (B) is a shell having an outer diameter and an inner diameter; and 
 (C) has a desired specific gravity that is less than or equal to a necessary specific gravity such that the ball flows toward a wellhead of the wellbore after a desired amount of time; and 
   causing or allowing the ball to engage a baffle, wherein after engagement a fluid is prevented from flowing across the ball.   
     
     
         2 . The method according to  claim 1 , wherein the wellbore penetrates a subterranean formation, and wherein the subterranean formation is a portion of a reservoir or adjacent to a reservoir. 
     
     
         3 . The method according to  claim 1 , wherein the wellbore comprises a first interval. 
     
     
         4 . The method according to  claim 1 , wherein the ball comprises steel or aluminum. 
     
     
         5 . The method according to  claim 1 , wherein the ball has an outer diameter in the range of about 1 inch to about 4.5 inches. 
     
     
         6 . The method according to  claim 1 , wherein the desired amount of time is the time necessary to complete a hydraulic fracturing operation. 
     
     
         7 . The method according to  claim 1 , wherein the ball has a specific gravity in the range of about 0.5 to about 2. 
     
     
         8 . The method according to  claim 1 , wherein the ball has a shell thickness, and wherein the shell thickness of the ball is the difference between the outer diameter and inner diameter of the ball. 
     
     
         9 . The method according to  claim 8 , wherein the metal or metal alloy, the shell thickness, and the outer diameter of the ball are selected such that the ball has the desired specific gravity. 
     
     
         10 . The method according to  claim 8 , wherein the ball is capable of withstanding a desired pressure differential and/or hydrostatic pressure after engagement with the baffle. 
     
     
         11 . The method according to  claim 10 , wherein the metal or metal alloy, the shell thickness, and the outer diameter of the ball are all selected such that the ball has the desired specific gravity and is capable of withstanding the desired pressure differential. 
     
     
         12 . The method according to  claim 1 , wherein the methods further comprise introducing more than one ball into the tubing string. 
     
     
         13 . A method of creating one or more fractures in a zone of a subterranean formation comprising:
 (A) introducing a ball into a tubing string of a wellbore, wherein the wellbore penetrates the subterranean formation, and wherein the ball:
 (i) comprises a metal or a metal alloy; 
 (ii) is a shell having an outer diameter and an inner diameter; and 
 (iii) has a specific gravity less than or equal to 1.5; 
   (B) causing or allowing the ball to engage a baffle, wherein after engagement a fluid is prevented from flowing across the ball;   (C) creating the one or more fractures in the zone of the subterranean formation, wherein the fluid is prevented from flowing across the ball prior to and during the creation of the one or more fractures; and   (D) producing a reservoir fluid from the zone of the subterranean formation,    wherein the production of the reservoir fluid occurs after the creation of the one or more fractures, and wherein the ball flows towards a wellhead of the wellbore prior to or during the production of the reservoir fluid.   
     
     
         14 . The method according to  claim 13 , wherein the wellbore comprises a casing, and wherein the tubing string and/or the casing comprise one or more ports. 
     
     
         15 . The method according to  claim 14 , wherein the wellbore further comprises a sliding sleeve, wherein the sliding sleeve is located adjacent to the port, and wherein the ball engages the sliding sleeve during introduction. 
     
     
         16 . The method according to  claim 15 , wherein when the ball engages the baffle, the baffle and sleeve moves, and wherein the movement causes the sleeve to be in an open position. 
     
     
         17 . The method according to  claim 16 , wherein the sleeve is opened prior to the creation of the one or more fractures. 
     
     
         18 . The method according to  claim 13 , further comprising creating one or more fractures in more than one or multiple zones of the subterranean formation. 
     
     
         19 . The method according to  claim 13 , wherein the specific gravity of the ball is selected based on the density of the produced reservoir fluid. 
     
     
         20 . A fracturing ball comprising:
 a metal or a metal alloy,
 wherein the fracturing ball is a shell having an outer diameter and an inner diameter, 
 wherein the fracturing ball has a specific gravity less than or equal to a necessary specific gravity such that the ball flows to a wellhead of the wellbore after a desired amount of time, and 
 wherein after engagement of the fracturing ball with a baffle, fluid is prevented from flowing across the ball.