bp’s Mad Dog Phase 2 project is located in water depths of 4,200 to 7,100 ft [1,280 to 2,164 m] in the Green Canyon area of the Gulf of Mexico. It encompasses 14 oil producers, 7 water injectors, and a new floating production platform with a capacity of up to 140,000 BOE/d. The company wanted to maximize efficiency through an integrated approach to the subsea development and chose Subsea Integration Alliance—which combines the capabilities of OneSubsea and Subsea 7—to engineer, procure, construct, install, and commission capital-efficient, modular subsea solutions with increased delivery and deployment assurance. One element of this challenge was streamlining the connection of various subsea infrastructure components.
The solution proposed was the OCS-V vertical clamp connection system, part of the Schlumberger Transition Technologies portfolio. Smaller and lighter than conventional technologies, the OCS-V system expedites installation and minimizes operational sequences. It replaces conventional connection systems, which have large, complex, and expensive installation or intervention tooling, elastomer secondary seals, and extensive maintenance and storage requirements. Suitable for 4- to 20-in nominal pipe size (NPS), the OCS-V system features
The OCS-V system’s inboard receiver structure is mounted to the subsea host structure, and the outboard receiver connector is mounted to the end termination of a rigid or flexible jumper.
OCS-V systems greatly reduced jumper installation time, decreasing opex and HSE risk. Each jumper was landed and locked with just an ROV fly-to-place Class 7 torque tool. Once the jumper was fully landed, each clamp was torqued and locked within 30 min, 50% faster than with a conventional system.
Because a surface vessel was not required onsite to deploy and retrieve the running tools, greenhouse gas emissions were reduced by 13.5 metric tons of CO2e per jumper—a 40% reduction compared with legacy systems. For the 14 jumpers installed, this amounts to eliminating 189 metric tons of CO2e. Seven additional jumpers with OCS-V systems are planned for installation.
Early technical engagement with bp on the Mad Dog Phase 2 project resulted in viable project economics and expedited installation of subsea clamp connection systems, simultaneously reducing greenhouse gas emissions.