Structural Assessment
In-place, removal-condition and damaged-condition analysis of jackets, topsides, modules and subsea structures, including reassessment of ageing assets to current code.
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Technical Studies & Assessments
Structural, marine and constructability assessments that answer the question actually being asked — can this be lifted, moved, installed, removed or dismantled safely, and what governs?
Overview
Most offshore problems are not analysis problems — they are definition problems. The wrong load case, an unverified weight report or an unstated assumption about crane availability will invalidate a technically perfect calculation.
VORYX technical studies start by pinning down what governs, then analyse it properly. Our team has supervised the fabrication, load-out and installation of the structures being assessed, which changes both what gets checked and what gets flagged.
Studies are sized to the decision they support: a two-week feasibility check to unlock a tender, or a full structural assessment package for marine warranty approval.
Scope of Work
Heavy Lift & Load-Out
Lift point and padeye design, sling and spreader arrangements, dynamic amplification and skew load factors, load-out by skidding, SPMT or lift, and grillage and sea-fastening design.
Transportation & Installation
Motion response and barge stability, tie-down design, upending and launch analysis, on-bottom stability during installation, and weather-window and operability criteria.
Onshore Dismantling & Yard
Yard capability and quay assessment, reception and cutting sequence, temporary support and stability during dismantling, and material segregation and recycling routes.
Risk Workshops
HAZID, HAZOP, ENVID, dropped object and SIMOPS studies — chaired, documented and closed out with owners and dates against every action.
Constructability & Operability
Design reviews from the perspective of the yard, the vessel and the offshore crew — access, tolerances, installation aids, hook-up and future intervention.
Methodology
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1
Fix the governing case
Identify the condition that actually controls before building any model — often a transient case such as load-out, upending or a partially severed structure rather than the operational case.
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2
Verify the inputs
Weight and CoG reports are challenged against as-built information and, where possible, weighing records. A lift study built on an unverified weight report is a schedule risk, not an engineering deliverable.
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3
Analyse to the applicable code
ISO 19902 / API RP 2A for structures, DNV-ST-N001 for the marine operation, with load and consequence factors set to the correct operational reference period and alpha factors.
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4
Test the sensitivities
Sling length tolerance, CoG shift, marine growth, corrosion allowance, soil variation and weather exceedance — reported as utilisation trends, not a single pass/fail.
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5
Work the risk workshop
Bring the analysis into HAZID and constructability review so mitigations are engineered, not just recorded as actions.
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6
Close out with the warranty surveyor
Package the analysis for MWS review and carry it through comment and approval to certificate of approval.
Deliverables
- Structural analysis and code-check reports
- Lift, padeye and rigging design with utilisation summary
- Load-out and grillage / sea-fastening design package
- Transportation motion and stability analysis
- Installation and removal method statements
- Yard capability and dismantling sequence assessment
- HAZID / HAZOP / dropped object study reports and action registers
- Constructability and operability review findings
- Marine warranty survey documentation package
- Weight control report and data verification register
Standards & Codes
Work is delivered against the applicable international and regional framework. The codes below are those most commonly governing this scope — the controlling set is confirmed per project and jurisdiction.
- ISO 19902 Fixed steel offshore structures
- ISO 19901-6 Marine operations
- API RP 2A-WSD Planning, designing and constructing fixed platforms
- DNV-ST-N001 Marine operations and marine warranty
- DNV-ST-C502 / DNV-RP-C205 Environmental conditions and loads
- ASME VIII Div 2 Design by analysis
- PD 5500 / BS EN 13445 Pressure vessel assessment
- IMCA guidance Lifting, marine and diving operations
Frequently Asked
Can you assess a structure with incomplete as-built records?
Yes — and this is common on ageing assets. We define the minimum survey and inspection scope needed to close the critical gaps, then run the assessment with explicit sensitivity on the remaining unknowns rather than burying them in a conservative blanket assumption.
Do you support marine warranty survey approval?
Yes. We prepare the analysis package to MWS expectations, respond to comments and support the approval process through to certificate issue.
How quickly can a feasibility study be turned around?
A focused feasibility check — can this be lifted with this vessel, is this cut achievable, will this load-out work — is typically one to three weeks. Full analysis packages for warranty approval run longer and are scoped case by case.
Do you chair risk workshops?
Yes — HAZID, HAZOP, ENVID, SIMOPS and dropped object studies, chaired independently with full documentation and action close-out tracking.
Need a technical assessment before you commit?
Talk to an engineer who has delivered this scope offshore.
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