BROUSSARD, La. — Delmar Systems, Inc. and Shell Deepwater Development, Inc. set another world-record for mooring depth when the two companies partnered to moor the Transocean Marianas in more than 7,500 feet in the Gulf of Mexico. The semi-submersible drilling rig Marianas was moored in 7,569 feet in Mississippi Canyon 657 using a Suction Anchor System and Delmar’s Single Vessel Installation Procedure. The deepest anchor was set at 7,738 feet.
The mooring system consists of eight, 12-foot diameter by 60-foot long suction anchors embedded in the seafloor and attached to 10,000 feet of 3 ¾” wire rope with the specially designed Delmar Sub Sea Connector. The Connector allowed mooring line connection by an ROV provided by Oceaneering International, Inc.
The world-record mooring depth installation was accomplished using only one anchor handling vessel, the Gary Chouest, owned by Edison Chouest Offshore, Inc. Eight mooring systems were pre-installed by the Gary Chouest. Once on location, the rig was connected to all eight mooring legs in a record-breaking 28-hour total time.
“Using this system we have now confirmed that fourth or fifth generation semi submersibles can be moored successfully in more than 7,000 feet,” said Bill Von Eberstein, Shell Deepwater Development, Inc. Drilling Superintendent. “This presents several advantages over dynamically positioned drill ships, the only other alternative to drilling in these ultra deep waters. Reduced day rate / operating costs and superior station keeping ability are the main advantages this system brings to ultra deep water drilling over the drill ship option. We have proven conventional semi’s with the suction anchor system is a cost-effective solution for ultra deep well locations. We look forward to further extending the capabilities of these rigs.”