Video: HORA Hinge-Over Riser Assembly Riser System
- S. B. C. Martins | S. W. Harris (Emas Chiyoda Subsea) | E. Nakajima (Chevron Energy Technology Company)
- Document ID
- Offshore Technology Conference
- Publication Date
- Document Type
- 2017. Copyright is retained by the author. This presentation is distributed with the permission of the author. Contact the author for permission to use material from this video.
- 4.5.5 Installation Equipment and Techniques, 4.2.4 Risers, 4 Facilities Design, Construction and Operation, 7 Management and Information, 4.2 Pipelines, Flowlines and Risers, 4.2 Pipelines, Flowlines and Risers, 4.2 Pipelines, Flowlines and Risers, 7.2 Risk Management and Decision-Making, 7.2.1 Risk, Uncertainty and Risk Assessment, 4.5 Offshore Facilities and Subsea Systems
- HORA, flowline, FSR, riser
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HORA (Hinge-Over Riser Assembly) is a new riser system that improves the traditional Free Standing Riser (FSR). The system includes an articulated horizontal connection located at the base structure, eliminating the requirement for a subsea base jumper between the flowline and riser needed with the conventional FSR. HORA's key advantages compared to the traditional FSR system concept are: (1) shorter installation schedule; (2) increased reliability of the riser system; (3) increased operational flexibility and improved ability to respond to contingencies; (4) lower installation risk; and (5) reduced capital expenditure.
HORA incorporates two novel technologies. The first is a hinge-over system that enables seamless integration of flowline and riser pipelay tasks, also allowing the riser to be laid on the seafloor during installation. The second is a locking mechanism connecting the HORA in-line structure (ILS) with the foundation suction pile, effectively isolating the subsea horizontal connector from any loads that could potentially cause its failure.
This proprietary HORA Technology solution has progressed from the concept to maturity and is a viable option in offshore oil and gas field developments. During the design phase the major focus areas were to effectively isolate the horizontal connection from overstress and fatigue loads due to external loading, as it is the primary flow path component that enables the hinge-over function. In-place and installation analyses were developed to identify these loads and the ILS and locking mechanism were designed using finite-element models (FEM) to address them. FEM was also used to address the in-place riser and installation loads imposed on the hinge-over mechanism. In addition, an offshore installation method has been detailed and a failure modes, effects and critical analysis (FMECA) performed by an independent engineering organization.
HORA is an improvement from the traditional FSR concept and an alternative for offshore field developments and for specific scenarios and applications such as Marine Well Containment Systems (MWCS), Early Production Systems (EPS) or in areas prone to inclement weather, short installation windows or risky environment. This paper presents the engineering solutions to meet the performance targets defined for HORA Technology Development Project.