Quantitative Risk Assessment for a Floating Production Storage and Offloading in Brazil

Geosyntec undertook a quantitative risk assessment (QRA) for the Cidade de Paraty Floating Production Storage and Offloading (FPSO) vessel, which will operate in the Lula oil field. The Lula oil field, which is the largest hydrocarbon find in the world since the Kazakh Kashagan discovery in 2000, is located in the Santos Basin, 250km south of Rio de Janeiro. It is estimated to hold five to eight billion barrels of oil equivalent. Due to the size of the field and the water depth, which in areas is in excess of 2000m, it will be developed using a number of FPSOs.

Geosyntec Scope of Services

The QRA, which was undertaken during the detailed design of the spread-moored FPSO, was one of a range of safety studies culminating in the preparation of a Design Safety Case. The safety studies were undertaken to comply with the requirements of Single Buoy Moorings Inc. (SBM) Offshore, the operator, Petrobras, and regulations in Brazil. In order to determine the robustness of the design, SBM Offshore required the preparation of a predictive hazard analysis. This analysis was carried out as a QRA, which used a standard approach applied in the offshore oil and gas industry. The assessment included a parts count, frequency assessment, consequence assessment, and risk determination. The aim of the study was to perform a quantitative review of all the identified hydrocarbon and non-hydrocarbon hazards on the FPSO to demonstrate the technical integrity and robustness of the design. The hazards assessed were taken from the Project Hazard Identification Study (HAZID) and reviewed against hazards identified in other QRAs undertaken by Geosyntec to ensure completeness. The QRA was undertaken using an Excel-based spreadsheet approach supported by Visual Basic for Applications (VBA) coding. This approach provided a significant level of transparency to the study, which facilitated the ready interrogation of inputs and results. The QRA calculated: The Individual Risk Per Annum (IRPA), The Potential Loss of Life (PLL), and The Temporary Refuge Impairment Frequency (TRIF), where applicable, for topsides releases (gas, two phase and liquid), riser releases (gas and two-phase), CO2 dispersion (asphyxiation), ship collision, helicopter transport, other fires (non-process), loss of mooring, structural failure, engine room flooding, and dropped objects.

Notable Accomplishments

The results of the assessment were mapped to SBM Offshore’s risk matrix for personnel and asset risk. Sensitivity analyses were carried out to assess the impact of varying the key input data and assumptions, and a risk control measures review meeting and assessment were undertaken to identify potential risk control measures. These measures could be implemented to reduce the calculated risks on the FPSO as part of the process of ensuring an “as low as reasonably practicable” (ALARP) design.

Project Overview

  • Location: Brazil
  • Client: Confidential
  • Project Practice Areas: Civil Site Engineering and Design, Facility Hazard Definition and Risk Management
  • Type of Facility: Floating Production Storage and Offloading (FPSO) vessel
  • Type of Work: Quantitative Risk Assessment
  • Company: MMI Engineering

Our Consultants

  • Chris Robinson, Ph.D., CEng, MIMechE

    Chris Robinson is a Principal Engineer based in England, with more than 23 years of professional experience focused on fluids systems engineering, computational fluid dynamics (CFD), gas dispersion, and aerodynamics. This experience has been developed through work in Government, academia, and 15 years of consultancy experience across a wide range of industries. Chris' practice uses CFD to optimize waste water and drinking water processes. He has performed design and design assurance ...
  • David Sanderson, CEng

    David Sanderson is a Senior Principal Engineer based in England with more than 20 years of experience focused on process safety, structural integrity and reliability, complex finite element analysis, structural mechanics (dynamics and non-linear), and multimedia communication of complex technical issues. Key projects and client services undertaken by David include: development of integrity assurance schemes for two BP North Sea platforms; development of monitoring schemes for offshor ...
  • Andrew Nelson, CEng

    Andrew Nelson is a Senior Principal Engineer based in Australia with more than 20 years of experience in technical safety engineering and risk management. His practice is focused on hazardous industries including upstream and downstream oil and gas. He co-developed Geosyntec's major hazards assessment capability and supported the development of Geosyntec's major hazards engineering team. Andy's primary areas of interest are quantifying the effects of fires and explosions and developin ...
  • Simon Thurlbeck, Ph.D., CEng

    Simon Thurlbeck is a Senior Principal Engineer based in England with more than 30 years of structural engineering and research experience focused on fire and explosion risk management for high-hazard industries including upstream oil and gas. Simon's practice includes risk identification, hazard modelling, and the assessment, design, and specification of systems to mitigate the effects of major hazard events. Simon also conducts and manages beyond-design studies such as ship impacts, ...
  • Alastair Painter

    Alastair Painter is a Senior Principal Engineer based in Texas with more than 30 years of experience in the areas of technical safety, reliability and performance assessment applied to facilities utilized in the upstream, midstream and downstream segments of the energy sector. He has applied his expertise to a diverse range of facilities, including drilling rigs, subsea oil and gas production, offshore process facilities, liquefied natural gas (LNG), refineries and petrochemical ...
Geosyntec Consultants
Geosyntec is a specialized consulting and engineering firm that works with private and public sector clients to address new ventures and complex problems involving our environment, natural resources, and civil infrastructure.

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