Pressure balanced ultra-short disposable setting tool

Abstract

A setting tool for setting an auxiliary tool in a well, the setting tool including an inner mandrel having an upper section and a lower section, the upper section having an internal chamber suitable for housing a power charge; an outer cylindrical piston enclosing the upper section of the inner mandrel; a slidable ring formed concentrically, and between the inner mandrel and the outer cylindrical piston; and an actuation chamber located between the outer cylindrical piston, the ring, and the inner mandrel. The slidable ring is fixedly attached with a breaking pin to the upper section of the inner mandrel.

What is claimed is: 
     
         1 . A setting tool for setting an auxiliary tool in a well, the setting tool comprising:
 an adaptor sub for affixing an ignitor;   an inner mandrel having an upper section and a lower section, the upper section having an internal chamber configured to house a power charge, and the lower section configured to connect to an adjusted sub for affixing the auxiliary tool;   an outer cylindrical piston slidably located over the inner mandrel;   a slidable ring slidably located around the upper section of the inner mandrel and fixedly attached to the outer cylindrical piston;   an actuation chamber located between the inner mandrel and the outer cylindrical piston; and   a passage through a wall of the upper section of the inner mandrel, wherein the passage fluidly communicates the internal chamber and the actuation chamber,   wherein activation of the power charge by the ignitor causes gas to pressurize the actuation chamber and the outer cylindrical piston to stroke downward to set the auxiliary tool in the well, after breaking a breaking pin that holds the slidable ring fixedly attached to the inner mandrel.   
     
     
         2 . The setting tool of  claim 1 , wherein the inner mandrel, the slidable ring, and the outer cylindrical piston are concentrically positioned, in this order, prior to activation. 
     
     
         3 . The setting tool of  claim 1 , wherein the setting tool contains no hydraulic fluid. 
     
     
         4 . The setting tool of  claim 1 , wherein the adaptor sub further comprises a manual back-off for gas bleeding. 
     
     
         5 . The setting tool of  claim 1 , wherein the setting tool is self-venting through a venting mechanism. 
     
     
         6 . The setting tool of  claim 1 , wherein the lower section of the inner mandrel has a first region having a first thickness T 1  and a second region having a smaller second thickness T 2 , the first region being separated by a shoulder from the second region. 
     
     
         7 . The setting tool of  claim 6 , wherein the outer cylindrical piston ( 250 ) has a shoulder that extends radially toward the inner mandrel. 
     
     
         8 . The setting tool of  claim 7 , wherein the shoulder of the outer cylindrical piston is configured to contact the first region of the lower section when the outer cylindrical piston is sliding along the first region, and to not contact the second region of the lower section when the outer cylindrical piston is sliding along the second region. 
     
     
         9 . The setting tool of  claim 8 , wherein the pressured gas from the actuation chamber is (1) prevented to escape when the shoulder of the outer cylindrical piston is in contact with the first region of the lower section of the inner mandrel, and (2) allowed to escape from the actuation chamber, through a passage, when the shoulder of the outer cylindrical piston is not in contact with the second region of the lower section of the inner mandrel. 
     
     
         10 . The setting tool of  claim 1 , further comprising a first venting mechanism located at an interface between the outer cylindrical piston and an adjuster sub, which is attached at the lower section of the inner mandrel,
 wherein the first venting mechanism is closed when the outer cylindrical piston is not actuated, and the first venting mechanism is open when the outer cylindrical piston is fully stroked.   
     
     
         11 . The setting tool of  claim 10 , further comprising a second venting mechanism located at an interface between the outer cylindrical piston, the slidable ring, and the upper section of the inner mandrel,
 wherein the second venting mechanism is closed when the outer cylindrical piston is not actuated, and the second venting mechanism is open when the outer cylindrical piston is fully stroked.   
     
     
         12 . The setting tool of  claim 1 , further comprising:
 a dampening element located between the slidable ring and the inner mandrel so that when the outer cylindrical piston is fully stroked, the slidable ring squeezes the dampening element against a shoulder of the inner mandrel.   
     
     
         13 . A setting tool for setting an auxiliary tool in a well, the setting tool comprising:
 an inner mandrel having an upper section and a lower section, the upper section having an internal chamber suitable for housing a power charge;   an outer cylindrical piston enclosing the upper section of the inner mandrel;   a slidable ring formed concentrically, and between the inner mandrel and the outer cylindrical piston; and   an actuation chamber located between the outer cylindrical piston, the ring, and the inner mandrel,   wherein the setting tool is sized to be pressure balanced when placed in the well.   
     
     
         14 . The setting tool of  claim 13 , wherein the setting tool is pressure balanced when (i) the outer cylindrical piston is sized so that cross-sectional areas of opposite ends are equal, or (ii) an outer diameter of the upper section of the inner mandrel is equal to an outer diameter of the lower section of the inner mandrel, or (iii) the outer cylindrical piston is sized so that cross-sectional areas of opposite ends are equal, and an outer diameter of the upper section of the inner mandrel is equal to an outer diameter of the lower section of the inner mandrel. 
     
     
         15 . The setting tool of  claim 13 , further comprising:
 a passage formed through a wall of the upper section of the inner mandrel, wherein the passage is fluidly connected to the actuation chamber.   
     
     
         16 . The setting tool of  claim 13 , wherein the lower section of the inner mandrel has a first region having a first thickness T 1  and a second region having a smaller second thickness T 2 , the first region being separated by a shoulder from the second region. 
     
     
         17 . The setting tool of  claim 16 , wherein the outer cylindrical piston has a shoulder that extends radially toward the inner mandrel, and the shoulder of the outer cylindrical piston is configured to contact the first region of the lower section when the outer cylindrical piston is sliding along the first region, and to not contact the second region of the lower section when the outer cylindrical piston is sliding along the second region. 
     
     
         18 . The setting tool of  claim 17 , wherein the pressured gas from the actuation chamber is (1) prevented to escape when the shoulder of the outer cylindrical piston is in contact with the first region of the lower section of the inner mandrel, and (2) allowed to escape from the actuation chamber, through a passage, when the shoulder of the outer cylindrical piston is located over the second region of the lower section of the inner mandrel. 
     
     
         19 . The setting tool of  claim 13 , further comprising:
 an adaptor sub attached to the tread of the inner mandrel; and   an adjuster sub attached to a lower end of the inner mandrel.   
     
     
         20 . The setting tool of  claim 19 , further comprising:
 an ignitor located in the adaptor sub; and   the power charge located within the internal chamber,   wherein activation of the power charge by the ignitor causes gas to pressurize the actuation chamber and the outer cylindrical piston to stroke downward to set the auxiliary tool in the well.   
     
     
         21 . The setting tool of  claim 13 , further comprising:
 a dampening element located between the slidable ring and a shoulder of the inner mandrel so that when the outer cylindrical piston is fully stroked, the slidable ring squeezes the dampening element against the shoulder of the inner mandrel.   
     
     
         22 . The setting tool of  claim 13 , further comprising:
 a first venting mechanism located at an interface between the outer cylindrical piston and an adjuster sub attached to the lower section of the inner mandrel, the first venting mechanism being configured to allow the pressured gas from the activation chamber to escape from the setting tool,   wherein the first venting mechanism is closed when the outer cylindrical piston is not actuated, and the first venting mechanism is open when the outer cylindrical piston is fully stroked.   
     
     
         23 . The setting tool of  claim 21 , further comprising:
 a second venting mechanism located at an interface between the outer cylindrical piston, the slidable ring, and the upper section of the inner mandrel,   wherein the second venting mechanism is closed when the outer cylindrical piston is not actuated, and the second venting mechanism is open when the outer cylindrical piston is fully stroked.   
     
     
         24 . A method for using a setting tool in a casing, the method comprising:
 lowering the setting tool into the casing;   igniting a power charge located inside an inner mandrel of the setting tool;   directing a pressured gas, generated by the ignited power charge, through a passage formed through a wall of the inner mandrel, to a shoulder of an outer cylindrical piston;   actuating the outer cylindrical piston with the pressured gas so that the outer cylindrical piston moves along the inner mandrel; and   setting an auxiliary tool attached to the setting tool when the outer cylindrical piston is fully stroked,   wherein the lower section of the inner mandrel has a first region having a first thickness T 1  and a second region having a smaller second thickness T 2 , the first region being separated by a shoulder from the second region.