| dc.description.abstract | Hot stabs are connectors for subsea fluid transfer between Remote Operated Vehicle (ROV) power sources and subsea equipment. Current hot stab solutions, that are compliant with industry standards, have significant limitations and shortcomings. This thesis aims to develop a new and improved ROV operated fluid connection system to optimize subsea ROV fluid power transfer.
The system needs for the improved fluid stab are specified through a stakeholder needs and requirements mapping, including; the original problem statement and a feasibility study, a mapping of the stakeholders and the life cycle of the improved system, a Concept of Operations mapping stakeholder needs for system characteristics, an extensive mapping of existing hot stab solutions, a needs and requirements study, and finally; a system objectives tree.
Three early concept drafts are developed and evaluated in a trade study together with internal stakeholders. The concept selected in the trade study, namely the Superstab, is taken into detailed concept design, also containing selection of appropriate materials. The detailed concept conforms to stakeholder needs and requirements and show great promise in mitigating the problems and limitations of current hot stab solutions.
The detailed concept is then analysed using the finite element method and the results show that the system can withstand both ROV imposed loads and internal fluid pressure. Computational fluid dynamics simulations are also conducted to study the pressure loss through the system and the results indicate pressure losses slightly higher than the limits set by stakeholders in the needs and requirements study. Further development should therefore focus on optimizing the design with respects to pressure loss.
The Superstab is still at concept level but already provides technical solutions to critical stakeholder needs. If product development is finalized, the Superstab concept provides a generic multipurpose fluid stab fit for different operational scenarios. The concept is ambitious and innovative compared to existing solutions, but the results show great promise in the realization of a new generation of fluid stabs. | |