Kaombo Ultra-Deepwater Hybrid Risers

2H worked as part of an integrated engineering team with HMC on the fast-track detailed design and analysis of 18 free-standing hybrid risers in ultra-deepwater, offshore Angola.


Offshore Angola

Hybrid Risers

Offshore Angola


Offshore Angola

Project Background 

With an approximate value of USD $3.5 billion, Block 32 is the largest SURF EPCI contract to date. The Total development offshore Angola was planned with 18 free-standing hybrid risers (FSHRs) for production and gas lift, water injection, service and gas export functions, to be installed in water depths ranging from 1,600m to 1,700m. 

Project Scope 

2H worked in an integrated engineering organisation with HMC as part of the SURF EPCI consortium with Technip. Our scope varied per engineering package and our responsibilities included: 

  • Full global riser configuration and analysis, including interface engineering to the different HMC packages, as well as interfaces with Technip and the FPSO Contractor. 

  • Buoyancy tank detailed design, including all drawings and specifications. 

  • Shared responsibility for the detailed design of the upper and lower riser assemblies with HMC, which included structural design and also extended to system sizing and weight management, cathodic protection, preparation of detailed fabrication drawings, material take-offs and specifications for varied items. 

  • Continuous specialist support to HMC during procurement and fabrication activities. 


Ultra-deepwater developments pose significant challenges and when combined with novel hybrid riser designs, a fast-track schedule and the need to rapidly mobilise an experienced integrated team, the Block 32 project was a formidable prospect. 2H’s past experience with industry-leading FSHR designs, fabrication, installation, as well as flexible riser engineering and procurement meant we could offer a versatile and experienced team. We supported the integrated organisation’s activities in various design aspects and provided continuous support through fabrication and installation; from design of the upper and lower assemblies, considering varied fabrication requirements and tolerance constraints, through to installation of the flexible jumper and assurance of the design to interface with a subsea flexible riser base spool and the FPSO turret. 

Offshore installation started in Q4 2016 and after which they tied the six fields back to the two internal turret-moored FPSOs. 2H provided ad-hoc project support throughout the installation. 

First oil took place in July 2018.