Risk Assessment of a Tanker Based Floating Production Storage and Offloading (FPSO) System in Deepwater Gulf of Mexico

Abstract

Floating Production, Storage and Offloading (FPSO) systems are gaining significant consideration for deepwater oilfield development in the Gulf of Mexico (GOM). The risks associated with a FPSO system differ from those for the existing systems such as the conventional steel jacket, compliant tower, TLP, and SPAR. The first phase of a Joint Industry Project (JIP) focused on the evaluation of risks associated with the production operations from a GOM FPSO. The JIP objectives included demonstration of the acceptability of a FPSO in the GOM; identification of accidental events and FPSO components with high environmental pollution, loss of life, and financial risks; and recommendation of reasonably practicable risk reducing measures. The JIP was sponsored by 10 oil companies, 3 FPSO contractors, 4 certification agencies, and MMS. The risk assessment work was done on a converted tanker FPSO concept developed for the GOM by a major oil company. This paper focuses on the key safety issues that are important for the development of FPSOs in the GOM. The hazards evaluated and various risk assessment tasks undertaken in the JIP are briefly discussed and important issues are highlighted. Additionally, the potential differences in risks from a system using a new-built vessel are identified. The JIP has helped to better understand the safety of FPSOs in the GOM by determining the potential improvements to layout, design, operational, and mitigation measures. Introduction Currently, there are at least 45 FPSOs installed worldwide but none in the US GOM. These are operating in both benign and extreme environments, and have different configurations and designs. Most are conversions from single hull tankers. Majority in the North Sea is new-built with double hulls [1]. The recent installations indicate that the industry confidence in producing from FPSOs is on the rise, and they are now being installed in harsher environments and deeper waters, as permanent and larger production units. Figure 1 identifies the areal extent of existing platforms and the pipeline infrastructure in the US GOM and the current deepwater offshore leases. There are over 4,000 offshore platforms and about 20,000 miles of pipelines of various sizes installed in the US GOM. The majority of the GOM production facilities are supported by steel jacket platforms, tripods, or caissons in water depths up to 1,000 ft. There are a few steel jacket platforms in water depths exceeding 1,000ft. MMS defines the deepwater zone as tracts with water depths exceeding 1,000 ft. Approximately 10 production facilities using novel technology systems such as the guyed/compliant tower, tension leg platform, and SPAR have been installed in water depths up to 4,000 ft. All of the existing platforms utilize pipelines, which transport the produced oil and gas to an existing pipeline network or directly to shore facilities. Existing GOM pipeline and platform infrastructure covers up to a 130-mile wide strip reaching to the 650-ft. water depth contour from North Padre Island to Viosca Knoll. In some areas, this network extends to nearby installations in water depths deeper than 1,000 ft. All current deep water platforms are located reasonably close to an existing pipeline network and do not require offshore storage and/or shuttle tanker transportation of produced oil. MMS have recently awarded a significant number of deep and ultra-deepwater leases that extend to 10,000-ft water depths [Figure 1]. Existing pipeline network is generally far away from most of these recent leases. Seabed topography is also more complex than what is encountered in the currently developed areas. In some western regions of the GOM, the fields in 4,000 ft to 10,00

Compliance for FPSO-Gulf of Mexico and Speculative Builds

“…Many of the previously cited risk assessments 6,9 were efforts by industry to demonstrate this in a general basis for FPSOs on the GOM. The US has been normally prescriptive in nature towards compliance with CFR specified requirements.…”

Collision Risks Associated with FPSOs in Deep Water Gulf of Mexico

“…As part of the FPSO JIP [1], a shipping traffic database for the Gulf of Mexico was developed based on the number of vessel movements to and from the ports throughout the area as well as based on local knowledge of the shipping activity (i.e. no traffic surveys were carried out).…”

“…In line with the general methodological approach, the consequences are evaluated in terms of risk to persons, impairment of safety functions, pollution and production delay or loss [1,2]. According to the scope of the Base Case study work, the consequences are evaluated only for the FPSO system and the surrounding environment.…”

“…A companion paper, OTC 11000 [1] provides details of the JIP work scope and identifies the hazards that were evaluated, and OTC 10998 [2] provides details of the overall risk assessment methodology and OTC 10999 A companion paper, OTC 11000 [1] provides details of the JIP work scope and identifies the hazards that were evaluated, and OTC 10998 [2] provides details of the overall risk assessment methodology and OTC 10999…”

Applying a Decision-Analysis-Based Method to the Evaluation of Potential Risk-Reducing Measures: The Case of a Floating Production Storage and Offloading Unit in the Gulf of Mexico

“…In particular, the Joint Industry Project "Risk Assessment of a FPSO System in the Gulf of Mexico", completed in 1999, has striven to demonstrate the acceptability of such a solution to regulatory authorities 1,2,3 . During the course of the JIP, several quantitative risk analyses have been performed regarding various aspects of the design and operation of the FPSO, which has lead to the identification of risk-reducing measures.…”