Mule shoe

Axis X lines up with the mule shoe key and the tool face. 

Example 6 Vibration and Shock Analysis—Mule Shoe Engaging Shock... 

A steering tool sensor and electronic package is mounted in a housing in Figure 4-238 with a shock absorber and a spring to decrease the value of deceleration when engaging the mule shoe. 

Retrievable Tools. Retrievable MWD tools similar to the steering tools are available from several service companies. They are generally battery powered and generate coded positive pressure mud pulses or continuous pressure waves. The lower part of the tool has a mule shoe that engages in a sub for orientation. Currently, tools are available for measuring directional parameters and gamma rays. A typical retrievable tool is shown in Figure 4-251. 

Mule shoe A shaped form used on the bottom of orienting tools to position the tool. The shape resembles a mule shoe or the end of a pipe that has been cut both diagonally and concave. The shaped end forms a wedge to rotate the tool when lowered into a mating seat for the mule shoe. 

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