Definition - What does Mousehole Connection mean?
Mousehole Connection is a procedure in which a length of tubing or drill pipe is added to a string that is active. The tubing or drill pipe that is required to be added is kept in the Mousehole, an opening in the floor of a rig near the rotary table which is made up to the Kelly. The tubing or drill pipe is then pulled out from the Mousehole and finally trumped up into the string. The complete procedure takes a minute or two to be executed by skilled crew members.
Petropedia explains Mousehole Connection
A Mousehole is used in almost every rig to execute the Mousehole Connection that helps the crew members to add around 30 ft., joints of drill pipe or tubing to the drill string. When a Kelly is near a rotary table and bits drill down, another piece of drill pipe is added so as to continue the process of drilling. The piece of drill pipe stands in the Mousehole located between the vee-door and rotary table. The crew members then swing the Kelly out of the Mousehole and introduce it into the joint. The Kelly is then spinned by the driller using a spinning chain or Kelly spinner. The driller also uses tongs to torque joints. To remove the the pipe from the Mousehole, a new joint or Kelly is raised and screwed into the drill string. A piece of pipe is again placed in the Mousehole for the next connection.