Conductor manufacturers and operators in the southern sector of the North Sea are unlocking significant cost and time savings by deploying CIS’s new large-diameter breakout system. For North Sea operations, conductor landing strings, both full-length and short joint, have historically been sent to Aberdeen to have the short conductor length broken out, as a large enough breakout system has not been available elsewhere.
About the technology
Once a conductor has been driven into place, it is cut to the desired length and prepared for the installation of the wellhead. After the cut is made, a single piece of conductor consisting of one full length and a short joint with a connection in the middle is recovered. The main value in a threaded conductor is the connection, especially when it is a weld-on type. Conductor manufacturers need to recover the short joint and its connector, which must be broken out from the full-length conductor joint. CIS’s breakout machine wraps around a conductor connection and grips both joints of the conductor. The arms are then forced apart by the machine’s heavy-duty hydraulic cylinder. This breaks the connection. The machine then rotates the connection until it becomes free and can be recovered for reuse. The connection can then be dressed, welded onto a conductor with plain ends and then reused as part of another full string of offshore conductors with driveable threaded connections.
CIS’s large-diameter breakout system can be loaded on a truck, transported to a customer’s yard, and then used on-site. Moreover, breakout operations in the UK can usually be completed in less than 24 hours from receipt of initial enquiry. If required, the system can also be shipped to support operations anywhere in the world. This approach offers major cost and time savings because, for example, in the UK, it eliminates round trips to Aberdeen using 40-ft trucks to transport landing strings.
The CIS system can break out connections requiring a force of up to 85,000 ft.lb and for conductors ranging from 185⁄8 to 36 in. This system is portable and self-sufficient, and incorporates all the usual safety measures, including a working cage to shield personnel from equipment failure.
Manufacturer ABB Vetco Gray had accumulated nine conductor landing strings in its yard in Great Yarmouth. Using its large-diameter breakout system, CIS broke out nine 30-in., 1-in. wall thickness RL-4 connections in one day. This was a highly cost-effective solution for the customer.