Ultrasonic impact treatment for useful life improvement of downhole tools

Abstract

The useful life of a downhole tool is improved through application of an ultrasonic impact treatment. In an example method, operational parameters of an ultrasonic impact treatment device are selected based upon the one or more physical characteristics of the downhole tool. The ultrasonic impact treatment device is configured to correspond to the selected operational parameters. A residual compressive stress layer is then induced along a surface of the downhole tool using the configured ultrasonic impact treatment device, thereby improving the useful life of the downhole tool.

What is claimed is: 
     
         1 . A method to improve useful life of a downhole tool, the method comprising:
 providing a downhole tool having one or more physical characteristics;   selecting operational parameters of an ultrasonic impact treatment device based upon the one or more physical characteristics of the downhole tool;   configuring the ultrasonic impact treatment device to correspond to the selected operational parameters; and   to inducing a residual compressive stress layer along a surface of the downhole tool using the configured ultrasonic impact treatment device, thereby improving the useful life of the downhole tool.   
     
     
         2 . A method as defined in  claim 1 , wherein the surface of the downhole tool comprises threads of the downhole tool. 
     
     
         3 . A method as defined in  claim 1 , wherein the surface of the downhole tool comprises welded portions of the downhole tool. 
     
     
         4 . A method as defined in  claim 1 , wherein the surface of the downhole tool comprises external pockets along the downhole tool. 
     
     
         5 . A method as defined in  claim 1 , wherein the one or more physical characteristics of the downhole tool comprise at least one of a thread root radii, corner radii, downhole tool material, or the material hardness of the downhole tool. 
     
     
         6 . A method as defined in  claim 1 , wherein configuring the ultrasonic impact treatment device further comprises determining at least one of a geometry or material used for a contact probe of the ultrasonic impact treatment device based upon the one or more physical characteristics of the downhole tool. 
     
     
         7 . A method as defined in  claim 6 , wherein the geometry or material used for the contact probe comprises at least one of a contact probe diameter, treatment angle or contact probe material hardness. 
     
     
         8 . A method as defined in  claim 1 , wherein the operational parameters of the ultrasonic impact treatment device comprise at least one of an operating frequency, oscillating amplitude, treatment travel speed, output power range or excitation voltage. 
     
     
         9 . A method as defined in  claim 1 , wherein the method is used to repair a downhole tool whose protective coating has been eroded, the method further comprising re-applying the protective coating atop the residual compressive stress layer. 
     
     
         10 . A method as defined in  claim 1 , wherein the residual compressive stress layer is induced along an internal diameter of the downhole tool. 
     
     
         11 . A method as defined in  claim 1 , wherein the downhole tool is used in a downhole operation. 
     
     
         12 . A method to improve useful life of a downhole tool, the method comprising inducing a residual compressive stress layer along a surface of the downhole tool using an ultrasonic impact treatment device, thereby improving the useful life of the downhole tool. 
     
     
         13 . A method as defined in  claim 12 , wherein the method is used to repair a downhole tool whose protective coating has been eroded, the method further comprising re-applying the protective coating atop the residual compressive stress layer. 
     
     
         14 . A method as defined in  claim 12 , wherein the residual compressive stress layer is induced along an internal diameter of the downhole tool. 
     
     
         15 . A method as defined in  claim 12 , further comprising configuring operational parameters of the ultrasonic impact treatment device based upon one or more physical characteristics of the downhole tool. 
     
     
         16 . A method as defined in  claim 15 , wherein configuring the operational parameters further comprises determining at least one of a geometry or material used for a contact probe of the ultrasonic impact treatment device. 
     
     
         17 . A method as defined in  claim 16 , wherein the geometry or material used for the contact probe comprises at least one of a contact probe diameter, treatment angle or contact probe material hardness. 
     
     
         18 . A method as defined in  claim 15 , wherein the operational parameters of the ultrasonic impact treatment device comprise at least one of an operating frequency, oscillating amplitude, treatment travel speed, output power range or excitation voltage. 
     
     
         19 . A downhole tool produced using either of the methods of  claim 1  or  12 .