Session: 01-01-01 Offshore Platforms - I

Submission Number: 156912

Low-Draft, Low-Motion, and Cost-Effective SCR-Compatible Semi-Submersible Hull for the Central GOM 

A semi-submersible hull with simple geometry, low draft, low motion, and low cost has been developed for use with simple Steel Catenary Risers (SCRs) in the central Gulf of Mexico (GOM). SCRs are well-known for their cost-effectiveness and reliable performance in deepwater, making them a popular choice for offshore operations. However, SCRs require a host platform that can offer low heave motions, especially in the challenging wave conditions encountered in the central GOM environment. To meet this requirement, the hull design ensures that the heave motion RAOs for periods between 10 and 18 seconds remain below 0.33 m/m, effectively minimizing vertical motion during wave action. Additionally, the heave natural period exceeds 22.0 seconds, ensuring stable dynamic responses to varying sea conditions and reducing the risk of excessive motions.

The design features a low draft (less than 30 meters) and simple geometry, which not only reduces hull steel weight but also increases the number of potential competitors for bidding on the project by lowering construction costs. By focusing on SCR compatibility and ease of fabrication, transport, integration, and installation, this design provides a cost-effective and practical solution for deepwater operations. The simplicity of the hull's design streamlines the entire process, from fabrication to deployment, making it a more viable option compared to more complex alternatives.

The hull's applicability has been validated through two case studies. The first case involved supporting a small topsides payload of 11,000 mt at a depth of 1,500 meters, while the second case tested the hull with a medium topsides payload of 25,000 mt at a depth of 2,500 meters. These case studies demonstrate the hull's ability to support a range of payloads at various deepwater depths, highlighting its versatility and reliability in harsh environmental conditions.

Presenting Author: Jun Zou Floating and Green Energy Consulting, LLC

Presenting Author Biography: Dr. Jun Zou obtained his Ph.D. from Texas A&M University in 1997. He is the founder and president of Floating and Green Energy Consulting, a position he has held since September 2023. Prior to this, he was the co-founder of Houston Offshore Engineering (HOE), established in 2005, and served as Director of Naval Architecture for HOE, HOE Atkins, and HOE Kent for over 17 years. Dr. Zou has over three decades of experience in the Oil & Gas industry, along with more than a decade of expertise in the Floating Green Energy sector. He is also a member of the editorial board for an international journal in Ocean System Engineering and has authored or co-authored more than 70 technical papers.