Our riser engineering capability is based on 27 years experience working with riser design in the industry. Our directors and senior engineers have been with the company since its foundation, while we continue to employ and train new engineers in the art of riser system design. We play an active industry participation role in writing and updating industry codes of practice and guidelines for riser design, and we continue to improve our own engineering design methodology to enable safe design in ever challenging locations around the world.

Our early design experience was gained in the relatively shallow yet harsh environmental conditions of the North Sea, and our company grew in tandem with the ever increasing importance of riser design for floating production developments in deepwater locations around the world such as Offshore Brazil, Offshore West Africa and in the Gulf of Mexico. From time-to-time we have set records for designing new riser configurations and in the deepest water. We have been involved in riser design to water depths over 2,500 metres.

Riser Configuration Design

Our key capability is Riser Configuration Design. This involves determining the riser configuration parameters that enable the riser to safely operate in extreme seastate environments and to be able to safely withstand the fatigue damage applied to the riser during its life in operation.  Our ability to be able to achieve this is based on experience of delivering riser solutions to our clients for over twenty years in many locations around the world and across the full range of riser types.

This experience is supported by and built on an advanced analysis capability that enables us to accurately compute the inherently nonlinear dynamic response of these riser systems to attached vessel motions, wave and current loading. Our in-house developed riser engineering analysis tools are world leading and have been consistently validated through independent model testing and results monitored from actual risers in operation.

Life-cycle Development

We apply our riser analysis and design capability across the life-cycle of the development. This includes early feasibility studies and riser concept selection work. We perform riser FEED work, and we have worked with project teams to deliver the detailed engineering design of the riser. As part of our Riser Delivery Management Service, we provide project management functions that support the execution phase of the projects for the risers. As part of this work, we can analyse and develop safe installation procedures for the risers. We apply our riser engineering capability into operations, where we can reassess ongoing fatigue life and resolve problems with risers in operation.

Finally, we can offer an independent design verification service to meet with relevant legislation requirements and to provide operators with technical assurance on the design. For example, we are registered as a Certified Verification Agent (CVA) for risers in the Gulf of Mexico, and we perform riser verification activities to meet UK legislation requirements for safety critical risers in a floating production facility.

Our clients include oil companies, riser suppliers, subsea contractors and regulatory authorities.

Our Capabilities

Specific capabilities in relation to the various riser configuration types are listed as follows:

Flexible Riser Design

• We are a world leading authority on flexible pipe technology, and we provide advice to our clients that is independent of manufacturers
• We have developed methods for analysing flexible pipe cross-section response including armour wire stress and flexible pipe fatigue.
• We perform structural design of flexible riser accessories such as riser bases, bend stiffeners, subsea arches, clamps etc.
• Location, size, spacing of distributed buoyancy sections
• Riser interference design for crowded turrets
• Riser installation procedure development

Steel Catenary Riser Design

• Riser configuration design to API R2D and other relevant industry codes
• Riser touchdown response analysis including riser-soil interaction modelling and fatigue response calculation
• Vortex Induced Vibration (VIV) response analysis and strake design
• Flex-joint specification and stress joint design
• Hull-riser interface design including impact of vessel motion responses
• CP and corrosion design
• Influence of insulation of riser hydrodynamic characteristics
• Fracture mechanics assessment and welding considerations

Hybrid Riser Design

• Optimal flexible jumper, steel riser length, buoyancy can size configuration design
• Jumper configuration design at riser base on seabed
• Bundled riser design capability as well as single hybrid riser concepts
• VIV response and strake design for vertical steel riser section
• Tow-out and installation analyses and installation procedure development

Top Tension Riser (TTR) Design

• Single and dual casing riser design for top tensioned dry tree risers
• Riser configuration design including buoyancy size and location, and top tension specification
• Riser dynamic analysis using time and frequency domain methods using in-house developed software Flexcom and DeepRiser
• Detailed analysis of Air Can and Lateral Hull Guide gaps for SPAR risers
• Evaluation of riser stroke and dry tree access platform requirements
• Keel joint, wellhead stress joint, and upper and lower transition joint structural design including material and weld requirements
• VIV response analysis including strake and fairing design
• Interference assessment of riser array pairs, considering both riser VIV drag enhancement on the upstream riser and wake induced drag reduction on the downstream riser.
• Tensioner and buoyancy can design
• Hull-riser design considerations for SPARs, TLP’s and Semisubmersibles

Umbilical Riser Design

• We perform umbilical riser configuration design as an integral part of the overall riser system design
• Our capability includes both thermoplastic and steel tube umbilical riser design

Integrated Riser-Mooring-Vessel Design Capability

• We have developed an integrated riser-mooring-vessel design capability that:
• Accounts for the riser forces in the mooring design
• Enables vessel modified motions (from attached risers and moorings) to be input to riser response calculations
• Our design capability is supported by coupled riser-vessel-mooring numerical models