Home
Services
Engineering for Projects
Concept Development
Concept Development
The concept development phase of an engineering project offers the opportunity to maximise value using limited funds. Our expertise includes small, medium size and large developments.
Concept Select
Concept Select
Leveraging our expertise and understanding of the full project lifecycle allows you to obtain a thorough and critical assessment of the available concept select options.
FEED
FEED
Providing High-value, Independent Front End Engineering Solutions
Detailed Design
Detailed Design
Atteris is accustomed to the Detailed Design phase requirements for complex projects.
Safety and Risk Engineering
Safety and Risk Engineering
Efficient and effective workshops, practical risk registers and action plans to minimise project risks to as low as reasonably practicable.
Construction Support
Construction Support
Atteris has engineering professionals with significant expertise in project management and construction support.
Engineering Capabilities
Flow Assurance
Flow Assurance
Flow assurance is one of the earliest and most crucial activities to be undertaken in any subsea project.
Subsea Equipment
Subsea Equipment
Subsea structures and package-engineering services for procurement of vendor-supplied equipment.
Dynamic Systems
Dynamic Systems
From FE dynamic analysis to flexible pipe SME support, Atteris provides their expertise to assist Client Projects and Operation.
Subsea Pipelines
Subsea Pipelines
Practical subsea pipeline design, engineering, installation and operational knowledge required to deliver successful and cost-effective projects, in the most challenging subsea environments.
Pipeline Shore Crossings
Pipeline Shore Crossings
Shore crossings often represent challenging sections in pipeline, umbilical and cable routes.
Onshore Pipelines
Onshore Pipelines
Atteris combines practical expertise with sound engineering process to identify and mitigate risks associated with pipeline problem areas.
Life Of Field
Operations Support
Operations Support
Since 2015 Atteris has been supporting production engineers monitor and maintain the integrity, availability and reliability of producing subsea and pipeline assets.
Integrity Management
Integrity Management
Atteris delivers clear, accurate and concise integrity management strategy and performance standard documents to our clients.
Life Extension
Life Extension
Reduce total cost of ownership by enabling assets to continue operating beyond its original design life.
Decommissioning
Decommissioning
Decommissioning is the final stage in the asset lifecycle.
Technology
AIMS Software
AIMS Software
A broad set of tools for Asset Integrity Management.
CONNECT
CONNECT
Atteris’ in-house software CONNECT has been designed to save you time and money.
CORUS 3D
CORUS 3D
Atteris’ extensive project expertise has provided unique opportunities to develop advanced engineering models for the assessment of flowline, umbilical and cable on-bottom stability.
Data Visualisation
Data Visualisation
Through automation of analysis tools it is now common to have large quantities of data to be reviewed and assessed.
HDD Automation
HDD Automation
Through many years of experience in HDD Atteris has developed several in-house tools to allow for rapid evaluation of design concepts.
Resources
About Us
- Industry Sectors
- Our Leadership Team
Careers
Contact

Scroll down scroll down button

Decommissioning of FPSO Turret Mooring Buoy

Home
|resources
|case studies
|decommissioning of fpso turret mooring buoy

TBA

Decommissioning of FPSO Turret Mooring Buoy

Benefits

Atteris’ dynamic analysis demonstrated that the turret mooring buoy of a client’s FPSO mooring system could be brought to the surface safely via the sequential release of the supported risers and mooring lines. This operation was proven to be achieved without the need for any corrective ballasting, simplifying the operation to minimise risk and expense.

The analysis also showed that 3 mooring lines should remain as these were critical to the stability of the buoy. This conclusion resulted in the amendment of the decommissioning strategy and improved safety of the operation.

Background

OrcaFlex analysis was performed to simulate the proposed decommissioning method for the FPSO turret mooring buoy which consisted of a 9-point mooring system and was located in 826 m water depth. The purpose of the analysis was to determine the response of the buoy as the supported risers and mooring lines are released in a predetermined sequence.

Work Performed by Atteris

The submerged depth of the disconnected FPSO turret mooring buoy and the configurations of the attached lazy wave risers and 9-point mooring lines were modelled in OrcaFlex to replicate the as-surveyed conditions. Based on the model, the following were determined:

The change in depth and stability of the spider buoy as the risers and mooring legs are released to complete the re-float for recovery procedure
The number of risers and / or mooring lines that require to be released to allow the buoy to float to the surface.

Download PDF

Related Posts

Seawater Intake and Outfall

Seawater Intake and Outfall

CASE STUDIES

Seawater Intake and Outfall

Tags:
Energy Transition
HDD
Shore Crossing
Tunnelling

Maitland to Burrup Subsea Corridor Assessment

Maitland to Burrup Subsea Corridor Assessment

CASE STUDIES

Maitland to Burrup Subsea Corridor Assessment

Tags:
Shore Approach
Shore Crossing
Subsea Pipeline

Simpson Pipeline – Decommissioning Stability Study

Simpson Pipeline – Decommissioning Stability Study

CASE STUDIES

Simpson Pipeline – Decommissioning Stability Study

Tags:
Decommissioning
On-bottom Stability
Subsea Pipeline