Some time ago, a series of wells were cut and removed from a platform. One well presented a challenge. The 30’ conductor was found to have a steel cage around it. And this posed problems during decommissioning. As a result, the well could not be removed through the well template.
It was decided not to cut and remove the well to avoid delaying the decommissioning of the platform. The platform was then successfully removed.
A careful ROV survey of the remaining well was recently organised. It was found to be a 30’ conductor and casings. The steel cage surrounding the conductor was imaged and studied. A thick layer of silt had deposited in the well.
A custom-built machine will combine hydrodemolition and 4,000-bar abrasive waterjet cutting to safely remove a 30-foot conductor, overcoming a unique challenge in offshore well decommissioning.
SUBMAR was asked, based on the original drawings and ROV data, to study the dredging, cutting and removal of the well and make proposals. The team set to work enthusiastically and came back with several proposals. The proposal that was retained includes a custom-built machine that both dredges and cuts the well. Several presentations and discussions later, we got the green light to budget the project.
For dredging, we will use our in-house developed hydrodemolition technology and the cutting will be done by using our 4,000bar abrasive waterjet cutting technology. Both techniques are brought together in one and the same machine. That is downright unique. Once the machine is built, it will be extensively tested in a dummy-conductor, both in our test tank and in a dock in the port of Ostend.
We recently received the contract and started preparations. These are going to be exciting times!
Rest assured, we will come back to this soon and will be happy to keep you updated on the evolution of the project. And should you wish to visit us, you are most welcome.
