Casing Running Tool (CRT) is rigged to the bottom of the top drive.  A CRT can latch on casing internally or externally. CRTs are used to fill, circulate, reciprocate, rotate, make and brake connections. CRTs are a safer, more efficient way to circulate casing.

As the Oilfield Industry has improved their safety requirements, so has Pathmaker. We have introduced two different brands of CRTs into our company. Volant and Draw Works CRTs can both bit casing internally and externally. They also both have their positives for different types of jobs. CRTs will save time in the operation for circulating. When having problem with a well or just like to circulate casing down, there is no need to send a person up the derrick to make up a drive head. Just sting in the CRT, latch tool using top drive and start pumping. CRTs can also save money on tread repair. Making up top drive heads, you always have the possibility to damage threads in casing. CRTs in combination with screw in stump drastically drops the percentage of thread damage during circulating operations.  This is a big thing with premium pipe as well as all pipe. "Why would you want to make up a connection that could possibly damage, when breaking back out?"
One Way is Always the Best Way

Draw Works Tool -  Information sheet

Volant - Information sheet