DeepOcean Deploys Dual-Scope Subsea Inspection Method

Subsea inspection and maintenance campaigns are typically constrained by vessel time and operational complexity, particularly in offshore oil and gas fields. In this context, DeepOcean has implemented a dual-scope subsea inspection and 3D scanning methodology at the Sangomar field, working with Woodside Energy (Senegal) B.V.

Combining inspection and 3D capture in one campaign
At the Sangomar Phase 1 Development offshore Senegal, the operation covered 69 subsea structures, including 17 subsea trees. The campaign combined routine inspection with full-field 3D scanning in a single remotely operated vehicle (ROV) deployment, eliminating the need for separate inspection runs.

This approach differs from conventional subsea inspection, where visual inspection and 3D data acquisition are conducted in separate campaigns. By integrating both scopes, DeepOcean reduced vessel time while increasing the total volume of collected data, improving efficiency in subsea inspection workflows.

Photogrammetry and multi-source data integration
The methodology is based on photogrammetry, which converts 2D imagery into spatially accurate 3D representations. The system integrates multiple data inputs, including ROV video, sonar, and computer-aided design (CAD) references, to generate detailed digital models of subsea infrastructure.

The operational setup includes ROVs equipped with specialized scanning sensors, inspection engineers, and data processing systems. Proprietary subsea 3D imaging software converts collected data into digital twin models, enabling detailed visualization and measurement of subsea assets.

These models support inspection, maintenance, and repair (IMR) planning by providing spatial context and enabling identification of structural anomalies such as cracks or deformation relative to critical components.

Reduced vessel time and expanded data output
The combined operation was completed in slightly more than half the time typically required for two separate inspection and scanning campaigns. At the same time, the dataset generated from the operation was effectively doubled, as both inspection and 3D reconstruction outputs were captured simultaneously.

The campaign was executed without deploying additional offshore personnel, relying instead on a remotely supported system architecture. This has implications for offshore logistics, where personnel transfer and accommodation contribute significantly to operational cost and risk.

Supporting subsea IMR strategies
The Sangomar field, located approximately 100 kilometers south of Dakar, began production in June 2024. DeepOcean’s scope includes subsea inspection, maintenance, and repair services, covering engineering, survey, intervention, and underwater inspection of floating production storage and offloading (FPSO) units.

The dual-scope methodology contributes to IMR strategies by enabling higher-resolution data capture during baseline surveys, supporting more accurate planning and execution of future maintenance activities. Within a digital supply chain context, the integration of digital twin models enhances asset visibility and lifecycle management.

By combining inspection and 3D modeling into a single operation, the approach demonstrates a shift toward more data-intensive and time-efficient subsea survey methodologies, particularly in deepwater developments.

Edited by Aishwarya Mambet, Induportals Editor, with AI assistance.

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