[Study of Effective Screening of FPSO (Fire and Explosion Assessment) On Oil and Gas Using Comparison Tool]

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Study of Effective Screening of FPSO (Fire and Explosion Assessment) On Oil and Gas Using Comparison Tool

Introduction

Fires and explosions have been identified as major potential hazards for Oil and Gas Floating Production Storage Offloading (FPSO) installations and pose risk to personnel, assets, and the environment. Current fire and explosion assessment (FEA) tools require physical effect modeling software and follows standards from API, ISO, and engineering practices. However, the tools are not specific to any particular system such as an FPSO, and do not provide comprehensive guidance for safety engineers to perform FEA.

This paper discusses the development of a screening and comparison tool for FEA on FPSOs and the incorporation of an expert system into the tool. The results are computerized using MS Excel/VBA to provide a structured and comprehensive assessment on each equipment and module handling natural gas, crude oil, methanol and diesel on FPSO topsides.

This tool features built-in calculations for jet and pool fire size estimation for gas/liquid releases, and the ability to perform Quantitative Risk Analysis (QRA) to specify the personnel and equipment risk for varying leak sizes and process conditions. Control and recovery measures are incorporated as an expert system based on report findings, engineering practices, and relevant standards. Bowtie analysis is applied in the tool to define detailed control and recovery measures for the FPSO based on the incident scenarios. An explosion assessment is performed by incorporating physical effect modeling software results.

Unique features provided in the tool include fire and radiation contour mapping on an FPSO layout to help determine personnel and equipment risk more accurately and fire pump sizing that can be used to verify the amount of water deluge system required to mitigate fires and explosions. In addition, flexibility of data input (process data, failure rate data, etc.) and user interfaces assist safety engineers to screen and compare process alternatives, check design quality, and evaluate design options at any design stage.

Literature Review

Oil and gas floating production storage and offloading (FPSO)

An FPSO is floating production storage and offloading, which is a concept that can make the development of the small and/or remote fields in deeper water possible, as the oil and gas industry goes towards deeper water (Shimamura, 2002). The FPSO is typically based on a ship vessel with equipment built in modules which is then positioned in vessel deck, as shown in Fig. 1. The FPSO receives production fluids from one or a number of undersea oil reservoirs via risers. The fluid is then separated at the topside (vessel deck) into oil, gas, and water; then contaminants are reduced by a separation system. Oil is stored in the vessel hull and then offloaded to an oil tanker periodically. Depending on the amount of gas produced, gas is either exported, reinjected, used as fuel, or a combination of the above. Since it is based on a ship, the FPSO features several advantages (Shimamura, 2002). An FPSO is faster to build ...