December 2004 Supplement    Rig Floor Equipment

Unconventional casing running system

The Casing Running Tool, hanging below a top drive, eliminates need for specialized casing crews of people working at height on a stabbing board.

Conventional casing operations usually involve specialized crews and equipment brought to a rig site for the sole purpose of installing the casing. Crews rig up and operate the equipment, connect each section of casing, run it in the hole, cement it in place and are demobilized at the end of the job. All the while, the regular drilling crew plays a secondary role and usually just assists in the process. Keep in mind that this same drilling crew just got done drilling the well by connecting sections of drill pipe and running them in the hole. The idea for a better system came about by asking what would it take for the existing rig crew to run the casing, just like they run every other tubular in the hole?

Varco International’s Casing Running Tool, or CRT, is a new product that allows existing rig crews to run casing, and run it faster, better and safer than with conventional casing equipment and crews. The existing driller and rig crew, utilizing a CRT connected to a top drive system, can efficiently and consistently make up and run casing strings, just as strings of drill pipe are run. The top drive provides the torque necessary to connect the casing joints, and all operations can be performed by the existing crews using existing processes. 

Single casing joints can be picked up by the CRT and stabbed into the string. There is no need for a person at the casing stabbing board, thus increasing operation safety and reducing crew requirements. Because the top drive provides the torque to make up the connection, additional casing tongs are not required and fewer personnel are needed on the rig floor during casing operations. In addition, and possibly most importantly, the casing can be rotated into the hole at any time by engaging the top drive. Rotating and circulating the casing in the hole greatly increases the chances of getting the string to bottom. 

The CRT allows existing rig crews to run casing faster and safer. No additional casing crews are required, thus reducing the cost of getting the casing in the hole. The casing string can be rotated and circulated in the hole, the job is safer because fewer people and less equipment are required, and the entire process has been proven to be faster than conventional methods.