Pipework Analysis

Point‑Cloud Driven Pipework Replacement

Overview

Subco Engineering was engaged to support a multi‑package scope covering multiple projects, focused on the replacement of corroded FPSO pipework. The work required generating accurate piping isometric drawings and 3D models based on site scan / point‑cloud data, enabling the development of precise replacement spools that integrated seamlessly into the existing topsides layout. The project also incorporated the break‑up of existing spools into smaller, flange‑connected sections, and a comparative structural and pipe stress analysis to validate the modified configuration.

Challenges

1. Complex and Congested FPSO Geometry

The existing pipework sat within a tightly packed process area with limited access. Traditional measurement was not feasible, making reliable 3D scan data essential for design accuracy.

2. Corroded Pipe Sections Requiring Like‑for‑Like Replacement

The degraded spools required replacement while maintaining process alignment, support positions, and compliance with relevant design codes — ensuring no unintended changes to load paths or stress behaviour.

3. Introduction of New Flange Breaks

To improve maintainability, the client requested breaking long spools into multiple sections with bolted flange joints. This required a full assessment of structural and thermal performance impacts.

4. Validation Through Stress Analysis

The introduction of additional weight, flanges, and modified support conditions required a comparative analysis to confirm acceptability of the revised configuration.

Our Approach

1. High‑Fidelity Point‑Cloud Integration

Subco converted point‑cloud scan data into a 3D design environment, allowing engineers to:

• Recreate accurate as‑found pipe geometry
• Identify true support locations
• Determine potential clashes
• Validate all connection points prior to fabrication

This ensured confidence in dimensions and alignment before any cutting or installation work offshore.

2. Generation of Updated Piping Isometrics

Using the scan‑derived model, the team developed:

• Updated isometric drawings for each replacement spool
• Fabrication‑ready deliverables
• All required weld maps, BOMs, and support details

This aligned tightly with the requirements defined across the integrated work packages.

3. Spool Break‑Up Strategy and Flange Placement

In response to the expanded scope, Subco redesigned the pipe spools into shorter, modular sections. This included:

• Introducing new flange joints
• Ensuring bolt access and assembly feasibility
• Maintaining process geometry while improving maintainability

4. Comparative Structural and Stress Analysis

To verify code compliance and safe operation, Subco performed:

• Baseline analysis of the existing pipework (Run 1.0)
• Comparative analysis incorporating new flanges and reconfigured supports (Run 2.0)

This approach quantified any changes in sustained loads, thermal expansion behaviour, and stress hotspots, ensuring the redesigned spools remained within allowable limits.

Outcome

Subco successfully delivered all work packages over 4 project scopes:

• Fully updated CAD models and piping isometric drawings
• A validated spool break‑up design with strategically placed flanges
• Confirmed structural and stress integrity through comparative analysis
• Reduced risk of clash or misalignment during installation thanks to accurate point‑cloud integration

The combined digital engineering workflow resulted in a safe, accurate, and fabrication‑ready solution, eliminating uncertainty and supporting efficient offshore installation.