Vibration-damping sub including a plurality of angled shaped holes

Abstract

Provided is a vibration-damping sub, a tool string, and a method. The vibration-damping sub, in one aspect, includes a tubular damping body having a tubing wall defining a longitudinal axis and opposing ends for connecting the tubular damping body within a tool string between a vibration source and a vibration-sensitive tool. The vibration-damping sub, according to this aspect, may further include a plurality of shaped holes extending through the tubing wall and configured to impede propagation of mechanical waves along the tubular damping body, wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 5 degrees relative to perpendicular to the longitudinal axis of the tubular damping body for redirecting the mechanical waves.

What is claimed is: 
     
         1 . A vibration-damping sub, comprising:
 a tubular damping body having a tubing wall defining a longitudinal axis and opposing ends for connecting the tubular damping body within a tool string between a vibration source and a vibration-sensitive tool; and   a plurality of shaped holes extending through the tubing wall and configured to impede propagation of mechanical waves along the tubular damping body, wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 5 degrees relative to perpendicular to the longitudinal axis of the tubular damping body for redirecting the mechanical waves.   
     
     
         2 . The vibration-damping sub as recited in  claim 1 , wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 30 degrees relative to perpendicular to the longitudinal axis of the tubular damping body. 
     
     
         3 . The vibration-damping sub as recited in  claim 1 , wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 40 degrees relative to perpendicular to the longitudinal axis of the tubular damping body. 
     
     
         4 . The vibration-damping sub as recited in  claim 1 , wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of 45 degrees±2 degrees relative to perpendicular to the longitudinal axis of the tubular damping body. 
     
     
         5 . The vibration-damping sub as recited in  claim 1 , wherein the opposing ends are a vibration source end and a vibration-sensitive tool end, and further wherein the angle (θ) of each of the plurality of shaped holes points toward the vibration source end. 
     
     
         6 . The vibration-damping sub as recited in  claim 1 , wherein the plurality of shaped holes comprise a first grouping of shaped holes each having a first shape and a first size and a second grouping of shaped holes axially spaced from the first grouping of shaped holes and having one or both of a second shape different than the first shape and a second size different than the first size. 
     
     
         7 . The vibration-damping sub as recited in  claim 1 , wherein the plurality of shaped holes comprise axially spaced rows of circumferentially shaped holes, wherein the circumferentially shaped holes in each row are misaligned with, or at a different spacing than, the circumferentially shaped holes of an adjacent row. 
     
     
         8 . The vibration-damping sub as recited in  claim 1 , wherein the tubular damping body further comprises a plurality of contiguous tubular portions formed of different materials having different mechanical impedances. 
     
     
         9 . The vibration-damping sub as recited in  claim 8 , wherein the plurality of contiguous tubular portions comprise two or more tubular portions axially arranged with respect to one another or two or more tubular portions circumferentially arranged with respect to one another. 
     
     
         10 . The vibration-damping sub as recited in  claim 1 , wherein the plurality of shaped holes comprise smooth inner surfaces. 
     
     
         11 . A tool string, comprising:
 a vibration-sensitive tool;   a vibration source coupled to vibration-sensitive tool, the vibration source capable of generating a mechanical vibration in excess of a design threshold for the vibration-sensitive tool; and   a vibration-damping sub rigidly coupled between the vibration-sensitive tool and the vibration source, the vibration-damping sub including:
 a tubular damping body having a tubing wall defining a longitudinal axis and opposing ends for connecting the tubular damping body within a tool string between a vibration source and a vibration-sensitive tool; and 
 a plurality of shaped holes extending through the tubing wall and configured to impede propagation of mechanical waves along the tubular damping body, wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 5 degrees relative to perpendicular to the longitudinal axis of the tubular damping body for redirecting the mechanical waves. 
   
     
     
         12 . The tool string as recited in  claim 11 , wherein the vibration source comprises a perforating gun supporting one or more shaped charges for perforating a wall of a wellbore, wherein a detonation of the shaped charges generates the mechanical vibration. 
     
     
         13 . The tool string as recited in  claim 11 , wherein the tubular damping body has no damping components that are directly moveably coupled to the tubular damping body. 
     
     
         14 . The tool string as recited in  claim 11 , wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 30 degrees relative to perpendicular to the longitudinal axis of the tubular damping body. 
     
     
         15 . The tool string as recited in  claim 11 , wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of 45 degrees±2 degrees relative to perpendicular to the longitudinal axis of the tubular damping body. 
     
     
         16 . The tool string as recited in  claim 11 , wherein the opposing ends are a vibration source end and a vibration-sensitive tool end, and further wherein the angle (θ) of each of the plurality of shaped holes points toward the vibration source end. 
     
     
         17 . The tool string as recited in  claim 11 , wherein the plurality of shaped holes comprise a first grouping of shaped holes each having a first shape and a first size and a second grouping of shaped holes axially spaced from the first grouping of shaped holes and having one or both of a second shape different than the first shape and a second size different than the first size. 
     
     
         18 . The tool string as recited in  claim 11 , wherein the plurality of shaped holes comprise axially spaced rows of circumferentially shaped holes, wherein the circumferentially shaped holes in each row are misaligned with, or at a different spacing than, the circumferentially shaped holes of an adjacent row. 
     
     
         19 . The tool string as recited in  claim 11 , wherein the tubular damping body further comprises a plurality of contiguous tubular portions formed of different materials having different mechanical impedances. 
     
     
         20 . The tool string as recited in  claim 19 , wherein the plurality of contiguous tubular portions comprise two or more tubular portions axially arranged with respect to one another or two or more tubular portions circumferentially arranged with respect to one another. 
     
     
         21 . A method, comprising:
 lowering a tool string via a conveyance into a wellbore, the tool string including:
 a vibration-sensitive tool supported on the conveyance; 
 a vibration source coupled to the conveyance and capable of generating a mechanical vibration in excess of a design threshold for the vibration-sensitive tool; and 
 a vibration-damping sub rigidly coupled between the vibration-sensitive tool and the vibration source, the vibration-damping sub including:
 a tubular damping body having a tubing wall defining a longitudinal axis and opposing ends for connecting the tubular damping body within a tool string between a vibration source and a vibration-sensitive tool; and 
 a plurality of shaped holes extending through the tubing wall and configured to impede propagation of mechanical waves along the tubular damping body, wherein each of the plurality of shaped holes extends through the tubing wall at an angle (θ) of at least 5 degrees relative to perpendicular to the longitudinal axis of the tubular damping body for redirecting the mechanical waves; and 
 
   operating the vibration source to generate a mechanical wave in excess of a design threshold for the vibration-sensitive tool, the plurality of shaped holes dampening the mechanical wave to below the design threshold for the vibration-sensitive tool.