The conductor drive chaser, also known as the drive sub, ensures that the tremendous energy imparted by the hydraulic hammer to the conductor does not damage the conductor connection. It is the tool that sits between the hydraulic hammer sleeve and the conductor joint connection thread. CIS designs a wide range of drive chasers and also hold a comprehensive rental fleet of XLC-S connections, because we understand that our customers often require equipment at very short notice.
About the technology
We offer a wide range of drive chasers to suit all applications. These include the standard 3-m drive chaser and the long chaser, which has a 6-m body length. This is used for driving the conductor below the rotary table and enables the drill cuttings to be directed away from the drilling unit’s rig floor. Every CIS drive chaser has a unique profile that matches the corresponding conductor connection thread design. An approved supplier, with many years of experience and offering good reliability, manufactures this equipment. We specify the use of X56–X80 grade carbon steel to ensure that the strength of the chaser at least matches that of the conductor. Operating data are shown overleaf.
Adding value
The drive chaser is fitted to the hammer sleeve with short slings. CIS’s experienced offshore personnel perform this action to ensure that the entire system is safe for the driving project. The CIS design incorporates specific innovations that provide operating advantages. For instance, a special three-piece kit enables the complete guide nose to fl oat and ensures that welded parts cannot become fatigued and drop off during the driving operation.
Project profile
After supplying BP Exploration with a range of conductor drive chasers (XLC-S connection) for a project in Trinidad and Tobago, CIS received a special commendation for its overall conductor driving set-up. BP said this had contributed to the 40–50% reduction in vibration in the rig’s derrick, which had reduced the potential for dropped objects.