Vibration-damping sub including a plurality of angled shaped holes

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.

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.