Experience with all modern rigs, risers and wellhead types enables us to provide efficient turnaround times of comprehensive, system-focused engineering assessments and well-specific operating guidance for drilling risers.

2H Offshore has extensive experience in the design and analysis of marine drilling risers with over 400 projects conducted worldwide. These include conventional shallow, deep and ultra-deepwater MODU operations, managed pressure drilling, high-pressure SBOP systems and fixed platform drilling.

We have industry-leading experience in harsh environments and new frontiers, which require a total system approach to defining safe operating limits for the drilling riser, wellhead and conductor system. We routinely conduct fitness-for-purpose assessments of low-pressure drilling risers deployed from MODU’s to evaluate stack-up and tensioning requirements and define operating envelopes and drift-off limits. Such studies are essential not only for ultradeep high-pressure/high-temperature wells, but also on workover operations on old wells of limited strength with a heavy BOP stack.

2H pioneered the system approach to drilling riser assessment, where all components of the system including wellhead, conductor, surface casing and riser are considered together. Our strong capability in the design and analysis of these riser systems has developed through a number of international joint industry projects (JIPs) including AMJIG and DeepStar and the preparation of the Deepwater Drilling Riser Integrity Management Guidelines.

In addition to the conventional low-pressure drilling risers used for drilling subsea wells, we have worked on various initiatives to extend vessel depth capability by using high-pressure steel risers and low-pressure aluminium risers and implementation of riser design modifications to accommodate dual gradient drilling.

Key Services

• Tensioner optimisation and recoil analysis
• Strength and operability analysis for drilling risers (API RP 16Q / API RP 2RD)
• Drilling riser operating envelopes and watch circles
• Drilling riser and casing wear assessment
• VIV and wave fatigue assessments of drilling riser, wellhead and conductor
• Rig rotation analysis
• Resonant frequency analysis
• Drift-off / drive-off analysis
• Installation, retrieval and hang-off analysis
• Rig move analysis/riser transit analysis
• Elastoplastic weak point assessment
• Component design and independent analysis of flanges, connectors, cross-over adapters
• Drilling riser monitoring and integrity management
• Managed pressure drilling (MPD) integration engineering and component design and delivery
• Well-specific operating guideline preparation

Project Experience

• Weatherford – feasibility study, design and delivery of MPD riser stack equipment
• Transocean – DDIII drilling riser application assessment
• Total – Donggala HP drilling riser engineering
• Alcoa – Oil and Gas – Mechanically coupled drilling riser design
• BP – Enterprise drilling riser failure assessment
• Chevron/Transocean – Freestanding drilling riser analysis and system engineering
• BP Gulf of Mexico – Deepwater drilling riser monitoring program
• Shell – Ultra-deep water operations Brazil
• Exxon – Ultra-deep water operations Brazil
• Total – Ultra-deep water operations Brazil
• Multiple drilling contractors, Brazil – Drilling riser analysis to Petrobras specifications.