Downhole Tool Actuation Methods

Abstract

Methods for actuating tools within a wellbore include disposing the tool and an associated tool actuator within the wellbore. The tool actuator includes an amount of flammable, non-explosive material and a heating igniter. The tool actuator actuates the tool by generating gases which create a pressure differential.

What is claimed is: 
     
         1 . A method of actuating a downhole tool within a wellbore, the method comprising:
 disposing the downhole tool and an associated tool actuator into the wellbore, the tool actuator including a power charge with a non-explosive heating igniter; and   initializing a burn of the power charge by energizing the heating igniter with electric power to create a pressure differential adapted to allow for actuation of the downhole tool.   
     
     
         2 . The method of  claim 1  wherein the burn of the power charge generates a pressure differential adapted to actuate the downhole tool. 
     
     
         3 . The method of  claim 1  wherein the actuator comprises:
 an outer casing; 
 an amount of flammable material within the casing; and 
 the non-explosive heating igniter is retained within the casing and in contact with the flammable material, the heating igniter being energizable by electric power to reach a temperature sufficient to ignite the flammable material. 
 
     
     
         4 . The method of  claim 2  wherein the pressure differential generates a compressive axial force which moves a piston to cause the tool to be actuated. 
     
     
         5 . The method of  claim 1  wherein the tool is a mechanical packer, bridge plug, lock, composite frac plug which is set within the wellbore by application of compressive force. 
     
     
         6 . The method of  claim 1  wherein the tool is a valve which is actuated between open and closed positions by application of compressive force. 
     
     
         7 . The method of  claim 3  wherein the heating igniter comprises a metallic resistive heating element, a coil of wire or a cartridge heater. 
     
     
         8 . The method of  claim 3  wherein the heating igniter is formed of stainless steel. 
     
     
         9 . The method of  claim 1  wherein the flammable material comprises one or more of perchlorates, nitrates, oxamides, sulfur and carbon compounds. 
     
     
         10 . A method of actuating a tool within a wellbore, the method comprising:
 disposing the tool and an associated tool actuator into the wellbore, the tool actuator including a power charge having a non-explosive heating igniter and an amount of non-explosive, flammable material contained within a casing;   initiating the power charge by energizing the heating igniter with electric power to ignite the flammable material; and   ignition of the flammable material generating gas to form a pressure differential which is effective to actuate the tool.   
     
     
         11 . The method of  claim 10  wherein the heating igniter is energized by a power source which is located at a surface location with respect to the wellbore. 
     
     
         12 . The method of  claim 10  wherein the tool is a mechanical packer, bridge plug, lock, composite frac plug which is set within the wellbore by application of compressive force. 
     
     
         13 . The method of  claim 10  wherein the tool is a valve which is actuated between open and closed positions by application of compressive force. 
     
     
         14 . The method of  claim 10  wherein the heating igniter comprises a metallic resistive heating element, a coil of wire or a cartridge heater. 
     
     
         15 . The method of  claim 10  wherein the heating igniter is formed of stainless steel.