Casing running tools (CRT) connect to the top drive main shaft and hoist, lower, spin, and make-up casing connections. They automate pipe handling operations, thereby increasing safety and efficiency. 

CRTs also reciprocate and rotate the casing string, as well as circulate 5,000 psi. Operators use the CRT to navigate through difficult well bore sections. The automated process increases productivity and ensures correct placement of the casing string prior to cementing operations.

Gripping

A CRT uses either an external or internal gripping mechanism. Internal CRTs use a set of pads or rollers that distribute and equalize a force perpendicular to the internal bore of the casing string. This decreases any wear associated with handling the pipe. 

External CRTs handle larger hoisting loads and exhibit a greater torsional capacity. They also are able to handle smaller diameter pipes, as internal CRTs are unable to fit inside. The external CRT functions by gripping the external diameter of the casing string with either rollers or pads.

Video credit: Odfjell Well Services