Wellbore tool with indexing mechanism and method

Abstract

A wellbore tool, a wellbore fluid treatment string and a method with an indexing mechanism. The indexing mechanism can be shifted through one or more inactive positions before finally shifting into an active condition. The indexing mechanism is particularly useful with a plug that lands in a seat to impart an axially directed force on the mechanism before passing through the seat.

1 . A wellbore tool comprising:
 a tubular housing including an upper end, a lower end, and a wall defined between an inner surface and an outer surface;   a tool mechanism capable of being reconfigured from a first inactive position to an active position;   an indexing mechanism for reconfiguring the tool mechanism, the indexing mechanism including an indexing sleeve including an inner bore, the indexing sleeve biased to move axially along the inner surface, and an inner sleeve positioned within the inner bore, the inner sleeve having an axial bore extending therethrough and a wall thickness, and a lever having first and second ends, the lever pivotally connected to the inner sleeve at a fulcrum and being pivotal through a slot in the inner sleeve to protrude at the second end into the axial bore, while the first end engages and stops axial movement of the indexing sleeve; and   an actuator for passing through the axial bore and contacting the second end to drive the first end out of engagement with the indexing sleeve, thereby permitting axial movement of the indexing sleeve to move the tool mechanism from the first inactive position toward the active position.   
     
     
         2 . The wellbore tool of  claim 1  wherein the fulcrum is positioned between the first and second ends. 
     
     
         3 . The wellbore tool of  claim 1  wherein the indexing sleeve includes a plurality of axially spaced apart recesses and the lever engages in the recesses to stop movement of the indexing sleeve. 
     
     
         4 . The wellbore tool of  claim 3  wherein the indexing sleeve includes a support wall axially spaced from the plurality of axially spaced apart recesses, the support wall acting to restrict pivotal movement of the lever when the indexing sleeve is axially moved to position with the support wall behind the lever. 
     
     
         5 . The wellbore tool of  claim 1  wherein the inner sleeve is secured in the tubular housing to remain stationary until the tool mechanism is reconfigured to the active position. 
     
     
         6 . The wellbore tool of  claim 1  wherein the tool mechanism is a ball seat on the inner sleeve and in the active position, the ball seat is non-collapsible. 
     
     
         7 . The wellbore tool of  claim 6  wherein the lever forms the ball seat when the indexing mechanism moves the tool mechanism into the active position. 
     
     
         8 . The wellbore tool of  claim 6  wherein the inner sleeve covers a port through the wall of the tubular housing and in the active position, the ball seat allows the inner sleeve to be moved by a sleeve shifting device to open the port. 
     
     
         9 . The wellbore tool of  claim 6  wherein the ball seat in the inactive position is collapsible. 
     
     
         10 . The wellbore tool of  claim 1  wherein movement of the indexing sleeve drives pivotal movement of the lever to position the first end back into engagement with the indexing sleeve after the actuator passes the lever. 
     
     
         11 . A wellbore sliding sleeve sub comprising: a tubular housing including an upper end, a lower end and a wall defined between an inner surface and an outer surface; a fluid port through the wall of the tubular housing; an inner sleeve having an axial bore and installed substantially concentrically in the tubular housing, the inner sleeve being axially slideable in the tubular housing at least from a first position covering the fluid port to a second position exposing the fluid port to fluid flow therethrough; a ball seat on the inner sleeve including a plurality of levers connected to the inner sleeve about a circumference of the wall, each of the plurality of levers including a first end, a second end and a pivotal connection to the inner sleeve between the first end and the second end, and each lever capable protruding at the second end into the axial bore while the first end extends radially outwardly of the inner sleeve, the ball seat being configurable from (i) an inactive position wherein the plurality of levers is capable of pivoting to collapse and allow passage of an actuator through the axial bore to (ii) an active position, wherein the plurality of levers is fixed against pivotal movement and remains protruding into the axial bore to catch a sleeve shifting device; and an indexing sleeve positioned substantially concentrically between the inner sleeve and the tubular housing, the indexing sleeve controlling the configuration of the ball seat between the active position and the inactive position, wherein the indexing sleeve is biased for axial movement along the tubular housing between a first position allowing collapsing of the plurality of levers and a second position supporting the plurality of levers in the active position. 
     
     
         12 . The wellbore sliding sleeve sub of  claim 11  wherein the plurality of levers controls movement of the indexing sleeve between the first position and the final position. 
     
     
         13 . The wellbore sliding sleeve sub of  claim 11  wherein the first end of each lever is formed to engage the indexing sleeve and movement of the indexing sleeve is permitted when the plurality of levers is driven pivotally to collapse. 
     
     
         14 . The wellbore sliding sleeve sub of  claim 13  wherein the plurality of levers is driven pivotally to collapse by passing an actuator through the axial bore. 
     
     
         15 . A wellbore fluid treatment string comprising a string and a sliding sleeve sub according to  claim 11 , a first annular packer on the string uphole of the sliding sleeve sub and a second annular packer on the string downhole of the sliding sleeve sub, the first annular packer and the second annular packer being expandable to form an isolated wellbore segment therebetween. 
     
     
         16 . A method for actuating a downhole tool to an active position, the method comprising: passing an actuator through a ball seat in the downhole tool to permit incremental movement of an indexing sleeve past the ball seat until the indexing sleeve moves to a final position wherein the ball seat is held by the indexing sleeve against collapsing, thereby configuring the ball seat in an active position to catch a sleeve shifting device conveyed through the string. 
     
     
         17 . The method of  claim 16  wherein during passing the ball seat remains axially stationary in the downhole tool. 
     
     
         18 . The method of  claim 16  wherein passing includes forcing the actuator against levers that form the ball seat and, thereby, driving the levers out of engagement with the indexing sleeve as the actuator passes over the levers; and moving the levers back into engagement with the indexing sleeve when the actuator clears the levers. 
     
     
         19 . The method of  claim 16  wherein during passing, the actuator is shielded from contact with the indexing sleeve. 
     
     
         20 . The method of  claim 16  further comprising launching a sleeve-shifting device to catch in the ball seat and applying fluid pressure to apply a force against the ball seat,