ExxonMobil Drilling Campaign in Equatorial Guinea
Location: Zafiro & Zafiro South Field, Equatorial Guinea
Objective: Safely moor the Development Driller III on numerous well centers throughout the Zafiro and Zafiro South fields. Many of the locations are in shallow water with vast amounts of subsea infrastructure.
Solution: Delmar mobilized a strategic array of mooring equipment to moor the DDIII in some of the most heavily congested shallow water fields in existence. Delmar provided the engineering and offshore personnel to support eight rig moves over the course of 10 months.
Summary: Delmar Systems, Inc. was contracted by Transocean to provide engineering, operational procedures, mooring equipment, and offshore personnel to support numerous rig moves for the Development Driller III in the heavily congested fields near the Zafiro Producer and Serpentina FPSOs. Two preset mooring systems were deployed to the field allowing the rig to leapfrog from one mooring system to the next. Submersible buoys were strategically deployed to ensure that the mooring systems remained suspended above the surrounding infrastructure. Anchors were preset to eliminate the risk of handling the heavy components above the subsea assets.
More Detailed Scope of Work:
Delmar Systems, Inc. was contracted by Transocean to provide engineering, operational procedures, mooring equipment, and offshore personnel to support numerous rig moves for the Development Driller III in the heavily congested fields near the Zafiro Producer and Serpentina FPSOs. Delmar conducted a FEED study to assess the required supplemental mooring equipment required for the campaign. Strategic allocation of Delmar rental equipment consisting of wires, chains, buoys, and anchors was mobilized to Equatorial Guinea to compliment the rig’s self-contained system.
Once locations were confirmed by the client, detailed engineering plans were drafted, and a dynamic motion mooring analysis completed for each of the locations. Detailed mooring patterns and line configuration drawings, identifying each component in the mooring system were created. Delmar engineering and operations worked together to develop the site and vessel specific preset installation and rig connection procedures for each of the locations.
Delmar mobilized a crew of offshore personnel to preset the mooring equipment and coordinate the rig move activities for the duration of the campaign. Delmar installed a combination of OMNI-Max and conventional drag anchors at eight well locations. Some proved rather challenging due to the complex soil conditions encountered upon arrival.
Delmar safely and successfully moved the DDIII to each of the proposed well locations. In between rig moves, the Delmar crews leapfrogged the mooring equipment to the next location, minimizing the rig critical path time required to moor at each location.
Using Del-3DM, Delmar engineers flanged up with the Oceaneering provided survey equipment and provided real-time 3D monitoring of the hook-up and catenary profiles relative to the abundant subsea infrastructure. This proved invaluable in mitigating risks associated with hooking up preset mooring lines draped above the abundance of subsea infrastructure.