Method for launching replacement balls

Abstract

A method for successively releasing balls into a wellbore during wellbore operations is disclosed. The method includes providing at least a first ball injector for storing at least a primary set of primary balls and at least a second set of redundant balls, releasing a ball from the at least primary set of primary balls and determining if the released ball properly seats and engages its intended corresponding downhole tool. If it is determined that the released ball did not properly engage and actuate its intended corresponding tool, a redundant ball from the second set of redundant balls can be released without interrupting wellbore operations. In an alternate embodiment, the first ball injector can be a primary ball injector for storing and releasing the at least primary set of primary balls, and a second ball injector for storing and releasing the at least second set of redundant balls, the first and second ball injectors arranged in parallel.

We claim: 
     
         1 . A method of successively releasing one or more balls into a fluid wellbore for engaging and actuating an intended downhole tool corresponding thereto comprising:
 storing at least a primary set of primary balls;   storing at least a second set of redundant balls;   releasing a primary ball for actuating a corresponding downhole tool; and   determining if the corresponding downhole tool was actuated by the primary ball, and   if actuated, then releasing a successive primary ball from the at least primary set of primary balls, or   if not actuated, releasing a redundant ball from the second set of redundant balls, the redundant ball corresponding to the primary ball.   
     
     
         2 . The method of  claim 1 , wherein the releasing a primary ball for actuating a corresponding downhole tool further comprises releasing a primary ball from the at least primary set of primary balls stored in at least a first ball injector, and
 storing the at least second set of redundant balls further comprises storing the at least second set of redundant balls in the at least first ball injector.   
     
     
         3 . The method of  claim 2 , wherein the at least first ball injector further comprises a radial ball injector having at least one radial array having an axial bore in fluid communication with the wellbore, and two or more radial bores extending radially away from the axial bore for storing the at least primary set of primary balls and the at least second set of redundant balls. 
     
     
         4 . The method of  claim 3 , wherein at least one primary ball and one redundant ball are stored in the at least one radial array. 
     
     
         5 . The method of  claim 4 , wherein each radial array of a stack of radial arrays contains a primary ball and a corresponding redundant ball. 
     
     
         6 . The method of  claim 1  wherein the at least first ball injector further comprises a first ball injector and at least a second ball injector and the fluid wellbore comprises a multi-injector connector having two or more fluid axial wellbores arranged in parallel and each in fluid communication with the fluid wellbore, each of the two or more axial wellbores supporting the first ball injector and the at least a second ball injector,
 the first ball injector housing the at least primary set of primary balls; and 
 the at least second ball injector housing the at least second set of redundant balls. 
 
     
     
         7 . The method of  claim 6 , further comprising concurrently pumping displacement fluid through each of the first and second ball injectors for positively displacing any balls operably aligned with the axial bore. 
     
     
         8 . The method of  claim 1 , wherein determining the corresponding downhole tool has been actuated by a primary ball further comprises monitoring a pressure in the wellbore wherein an increase in the pressure is indicative of actuation. 
     
     
         9 . A system for successively releasing one or more balls into a fluid wellbore for engaging and actuating an intended downhole corresponding thereto comprising:
 a primary set of primary balls fluidly connected to the fluid wellbore;   at least a second set of redundant balls fluidly connected to the fluid wellbore; and   at least a first ball injector for injecting the primary set of primary balls and the at least second set of redundant balls into the fluid wellbore.   
     
     
         10 . The system of  claim 9 , wherein the at least a first ball injector further comprises a first ball injector having a first axial wellbore and for storing and releasing the at least primary set of primary balls, and at least a second ball injector having a second axial wellbore and for storing and releasing the at least second set of redundant balls. 
     
     
         11 . The system of  claim 10  further comprising a multi-injector connector for fluidly arranging the first and the second axial wellbores in parallel and for fluidly connecting the first and second axial wellbores with the fluid wellbore. 
     
     
         12 . The system of  claim 11  further comprising an isolation gate valve between the multi-injector connector and a wellhead structure. 
     
     
         13 . The system of  claim 12  wherein the wellhead structure further comprises a fracturing head.