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Improved tools are needed to manage major accident hazard of progressively more complex offshore oil&gas systems in environmentally sensitive areas. Inherent safety principles provide a strategic opportunity to reduce major accident hazards since the early design phase, but a suitable metric to orient safer design choices is needed to apply such principles intro practice. This study aims at providing a systematic approach to the assessment of the hazard profile of alternative process designs in offshore oil & gas production facilities. A novel methodology providing a ranking of inherently safer solutions in conceptual design is described. The methodology is able to highlight the different contributors to the safety profile of the offshore oil & gas production system, linking them to the specific features of the design. The proposed approach, based on multi-criteria Key Performance Indicators (KPIs), addresses different targets (people, assets, environment) and provides a quantitative assessment of the safety score, accounting for both the possible accident consequences and their credibility. An application to a case study concerning an offshore facility for gas production is discussed to demonstrate the potential of the methodology.

Chemical storage of electric energy is recognised as a potential solution to improve the penetration of renewable energy. The coupling of renewable power production with offshore oil & gas exploitation by converting electricity into synthetic fuels represents an opportunity to valorize renewables in remote areas in an energy transition panorama. The present study aims at a comparison of alternative power-to-gas and power-to-liquid strategies for the conversion of offshore wind power into different chemical energy vectors (hydrogen, synthetic natural gas and methanol), taking advantage of conventional offshore oil & gas infrastructures for energy conversion and synthetic fuel transportation. A set of technical, economic, environmental and profitability performance indicators was defined to allow the comparison. A case study in the North Sea was analysed. The results showed that electrolyzers capacity and offshore-onshore distance play an important role on economic indicators. Sensitivity analysis was carried out to test the robustness of the results.

For the design and operation of Oil and Gas (O&G) facilities, a Quantitative Risk Assessment (QRA) should be performed to quantify the risk of major accidents due to multiple hazards and sources at the plant level, thus allowing the effective identification and allocation of safety barriers. In this work, a novel approach for the multi-hazard and multi-source aggregation of risks is proposed, accounting for the uncertainties typically unexpressed in a conventional QRA (both on the frequency and severity of the accidental scenarios). The multi-hazard risk assessment framework proposed is applied to assess the Location-Specific Individual Risk (LSIR) for a representative Upstream O&G plant (case study), using a model based on multistate Bayesian Networks (BNs) for different functional units, each one undergoing an initiating event of Loss Of Primary Containment (LOPC). Estimates of frequency and severity for each possible accident scenario are aggregated to eventually calculate the overall LSIR. Moreover, LSIR's confidence intervals are provided to describe the uncertainty associated to the estimates, and the frequency and severity contributions to risk are derived for targeted prioritization of the safety barriers in view of the risk reduction.

Oil spills during offshore operations are likely to cause severe contamination of the sea. The identification of the environmental effects of accidental releases from offshore oil and gas facilities plays a crucial role in the prevention and mitigation of marine pollution. Key Performance Indicators (KPIs) are largely recognized as an effective tool to address and communicate multifaceted issues related to accidental events in the framework of risk management. In the context of Oil Spill Risk Assessment (OSRA) studies, this study proposes a set of KPIs addressing the potential environmental contamination caused by on-surface oil spills from offshore oil and gas installations. A layered approach was defined, based on three different levels of KPIs having an increasing complexity and providing an increasing amount of information. The environmental KPIs defined allow a preliminary quantitative assessment of the environmental contamination due to the oil spill scenarios defined in the ENVironmental hazards IDentification (ENVID) studies carried out for oil and gas installations, providing a preliminary ranking of the expected environmental effects of the spills and supporting their prioritization in order to select those which should undergo a more accurate Environmental Risk Assessment study (ERA).

Due to rapidly increasing world population and growing energy demands, the development of cleaner technologies to exploit renewable energy systems has become of primary importance in the collective efforts to reduce greenhouse gases emissions. The chemical conversion of renewable power into synthetic liquid fuels, such as methanol, allows an easier storage and transportation and avoids any fluctuating issues. Alternative process routes for methanol production other than from raw materials derived from fossil fuels have, during the past decade, grown in interest, where valorising the carbon capture and utilization concept and promoting synergies with the oil & gas industry are potentially achieved. The aim of this study is, in this regard, to investigate the sustainability aspects of alternative processes for synthetic methanol synthesis by applying a systematic methodology based on multi-criteria performance indicators (such as technological, economic, environmental and inherent safety). A total of eleven alternative methanol production schemes, based on synthetic methane or carbon dioxide transformation, are considered, analyzed and comparatively evaluated. The present results demonstrate that the process schemes using catalytic hydrogenation of carbon dioxide offers the best performance when considering a methanol capacity of 500 kg/h. A sensitivity analysis based on the Monte Carlo approach is also performed to verify the robustness of the results.

In the present study, novel processes for the offshore production of methanol via alternative routes than reforming of synthesis gas are investigated. Two process schemes are defined differing in the carbon source in input, i.e. the catalytic hydrogenation of carbon dioxide and the direct oxidation of methane via radical gas reaction. Both the schemes are considered to be installed at the main facility of the Canadian Sable Offshore Project in the Atlantic Ocean, the gas production Thebaud platform. Both offshore wind farm and solar parabolic trough systems are integrated to supply electricity and heat power to each process. The Aspen HYSYS is used to simulate the chemical processes, while Homer Pro and System Advisor Model are adopted for the design of feasible renewable energy plants. A thermodynamic modelling through energy analysis is conducted to evaluate and compare the energy efficiencies of sub-systems and overall schemes. Moreover, a preliminary design analysis is performed to estimate the footprint required for the components of the two schemes located on the offshore facility. The present results reveal that the methane-to-methanol process makes more efficient use of the integrated renewable sources but requires relatively higher space at the installation than the other scheme.

In the current context of global energy transition, the coupling of methanol production with offshore oil & gas operations appears to be a promising option to share infrastructures and convert renewable energy into valuable fuel. However, renewable methanol synthesis has not yet reached the commercial stage. Moreover, there is no evidence on studies integrating offshore multiple resources into methanol process. The novelty of this paper is a performance analysis of emerging routes for methanol production driven by offshore wind-solar energies through exergy and exergoeconomic techniques. Two production schemes (catalytic hydrogenation of carbon dioxide and direct radical oxidation of methane) are properly designed to produce a fixed methanol rate driven by offshore wind farm and solar-thermal plants at a given oil & gas rig. The results demonstrate that carbon dioxide-based route shows the lowest exergy destruction rate (66 MW) and total cost rate (1000 $/h) compared to other option. In conjunction with this, the methane-based route gives a satisfactory exergy efficiency of 87% against a mere 2% of other pathway, as well as higher potential to increase cost savings due to lower exergoeconomic factor. Furthermore, influences of varying some key variables on the proposed parameters of the two options are investigated.

As offshore oil & gas activities are currently evolving towards more productive yet complex situations, the availability of efficient safety metrics has become essential in the early stages of offshore oil & gas projects to underline potential major accidents hazards and clearly communicate safety criticalities. Inherent safety has demonstrated to be a widespread concept in offshore risk management strategies, but there are few preliminary studies in the existing literature about systemic indexing to orient the conceptual and basic design stages of the project lifecycle. In the present work, a methodology for the selection of inherently safer solutions was developed as a support tool for decision-making in early design activities of offshore oil & gas installations. The expected inherent safety performance of alternative design options is assessed by means of a comprehensive set of key performance indicators (KPIs) based on the simulation of consequences of offshore accident scenarios and credit factors of the possible loss of containment events from offshore equipment. The proposed KPIs aim to capture the hazard level of single units and to address selectively multiple targets of the potential threats than personnel and process equipment on the installation, such as marine organisms on the sea environment. Moreover, overall aggregated KPIs were introduced as a sound synthetic measure of the inherent safety performance of the offshore system. The method was applied to the assessment of alternative designs of an offshore production facility, particularly characterized by environmental and safety concerns. The results from the case study evidenced the capability of the proposed method in ranking the potential and credible critical units of each alternative configuration and identifying the relative magnitude of targets contributions to the global safety profile of the installation.

Offshore oil & gas operations are one of the most hazardous upstream activities since limited space and compact geometry contribute to increase the risk of major accidents. Currently many offshore projects are evolving towards the exploitation of more challenging hydrocarbon fields. The use of the inherent safety philosophy in early stages of the offshore installation design can save lifetime costs and pursue high safety standards. Moreover, an index-based design approach is a comprehensive way to communicate the hazard level of a process route. In this study, a method based on Key Performance Indicators (KPIs) was introduced to assess the inherent safety performance of alternative offshore designs through the modelling of credible accidents consequences for different targets. The main goal is to provide an efficient support tool for safety-oriented choices during the preliminary design steps. A case study regarding an offshore platform processing associated gas with hydrogen sulphide was presented.

Accidental oil spills may cause severe marine pollution, with serious impacts to wildlife and their habitats. The fate of oil spilled at sea depends upon multiple factors, such as the released quantity, the oil properties, the meteo-marine conditions. The identification of the hazard associated to offshore oil spills is thus fundamental in order to reduce or mitigate their impact on the different environmental compartments of the sea. The use of indicators represents a widespread approach in offshore risk management to capture and effectively communicate complex issues, as the hazards due to accidental events. This paper presents a methodology based on Key Performance Indicators (KPIs) to assess the environmental hazards caused by oil leakages from offshore oil & gas production facilities. Three different levels of KPIs are defined, based on data and resource availability. The first level of KPIs is associated to the spill features, the second one is based on the inventory of the release and the third type considers the area of the floating oil slick. A case study regarding an offshore oil platform in the Mediterranean Sea is introduced in order to demonstrate the potential of the proposed approach. The results show the potential of KPIs in representing the hazards of different oil spill scenarios, thus offering a tool for hazard screening, as a preliminary step of more detailed oil spill risk assessment studies and contingency planning activities.