Oil Spill Model Research Articles

Development and testing of a 2D offshore oil spill modeling tool (OSMT) supported by an effective calibration method

An Oil Spill Modeling Tool (OSMT) has been developed in this study to predict the transport and fate of oil spills resulting from surface releases. Particularly, the Kullback-Leibler (KL) divergence method is adopted as a performance metric for the first time to formulate a calibration framework for spill trajectory prediction (STP) from the Lagrangian transport model (LTM). By finding the candidate with minimal KL divergences from modeling scenarios using designed parameter combinations, the prediction discrepancy between simulated trajectories of the LTM and oil slicks detected from satellite images is reduced. The developed approach has been evaluated through a comparison analysis between OSMT and Operational Oil Modeling Environment (GNOME) model. Subsequently, a real case study is conducted to examine the applicability and effectiveness of the OSMT. The study results indicate that OSMT can provide reliable spill trajectory simulations, and the KL divergence-based calibration method is effective in calibrating the oil spill LTM.

Bridging the lab to field divide: Advancing oil spill biological effects models requires revisiting aquatic toxicity testing

Oil fate and exposure modeling addresses the complexities of oil composition, weathering, partitioning in the environment, and the distributions and behaviors of aquatic biota to estimate exposure histories, i.e., oil component concentrations and environmental conditions experienced over time. Several approaches with increasing levels of complexity (i.e., aquatic toxicity model tiers, corresponding to varying purposes and applications) have been and continue to be developed to predict adverse effects resulting from these exposures. At Tiers 1 and 2, toxicity-based screening thresholds for assumed representative oil component compositions are used to inform spill response and risk evaluations, requiring limited toxicity data, analytical oil characterizations, and computer resources. Concentration-response relationships are employed in Tier 3 to quantify effects of assumed oil component mixture compositions. Oil spill modeling capabilities presently allow predictions of spatial and temporal compositional changes during exposure, which support mixture-based modeling frameworks. Such approaches rely on summed effects of components using toxic units to enable more realistic analyses (Tier 4). This review provides guidance for toxicological studies to inform the development of, provide input to, and validate Tier 4 aquatic toxicity models for assessing oil spill effects on aquatic biota.Evaluation of organisms’ exposure histories using a toxic unit model reflects the current state-of the-science and provides an improved approach for quantifying effects of oil constituents on aquatic organisms. Since the mixture compositions in toxicity tests are not representative of field exposures, modelers rely on studies using single compounds to build toxicity models accounting for the additive effects of dynamic mixture exposures that occur after spills. Single compound toxicity data are needed to quantify the influence of exposure duration and modifying environmental factors (e.g., temperature, light) on observed effects for advancing use of this framework. Well-characterized whole oil bioassay data should be used to validate and refine these models.

Computational Multiphase Flow Modelling of Oil Spill Through a Hydrophobic Mesh

The current technologies for handling oil spill clean-up vary in expense and effectiveness and are largely ineffective. Oil spills occur due to accidents from well-heads and damaged facilities in the creeks of the Nigerian Delta and along the coastline of waters where hydrocarbons are prospected all over the world. They are unexpected and known to cause irreparable damage to aquatic environments and marine life. The development of a hydrophobic mesh is proposed to prevent oil from spreading into larger areas and from reaching sensitive coastlines. This will help engineers and clean-up crews in their quest to find an appropriate response to a given oil spill scenario as they race against the clock to prevent further damage and improve the oil recovery process. The overall goal of this project is to create a Numerical Simulation of meshes that repel water and attract oil using ANSYS, a Finite Element Analysis software. The mesh was modelled as a porous medium that acts like a filter that retains water on one side while allowing the passage of oil through it. In the course of this work, appropriate materials selection in fluid flow analysis was carried out. Also, the flow domain geometry was developed in such a way as to simulate a system containing an oil-water interface. Next, domain discretization (meshing) was carried out appropriately. After which appropriate boundary conditions and operating conditions were implanted in the model. Fluent was then set to initialize and run calculations. After calculations were run, results were gotten. These results were then interpreted pictorially. It was seen that the velocity streamlines for the oil phase passed through the hydrophobic mesh, while the velocity streamlines for the water phase were repelled from the hydrophobic mesh wall.

Numerical Simulations of Sudden Oil Spills in Typical Cross-Border Rivers in the Yangtze River Delta Region

The Taipu River is an important cross-border river in the Yangtze River Delta region and a direct channel connecting Taihu Lake and Huangpu River. Along the main stream of the Taipu River are many sources of water, such as the Wujiang, Dingzha, and Liantang Rivers. Many boats traverse these rivers transporting a wide variety of goods, including large quantities of oil, chemicals, and other dangerous goods. In the event of accidents on these vessels, spilled cargo will directly threaten the drinking water safety of people in the region. Aiming at simulating and assessing the environmental risks of sudden oil spills in rivers in the Yangtze River Delta region, this paper established a two-dimensional oil spill model of the typical transboundary Taipu River based on the MIKE21 water environment numerical simulation software developed by the Danish Institute of Water Conservancy. The established model will improve emergency response and treatment plans as well as our understanding of river oil spill progressions.

An innovative coupling technique for integrating oil spill prediction model with finite volume method-based ocean model.

Marine oil spill pollution have increased recent years, threatening the safety of the marine environment. This paper proposes a coupling technique: Fast Mapping & Addressing(FMA) that integrates the oil spill model with oceanographic model. The FMA technique is based on hash function and spatial quadtree algorithm to achieve efficient addressing from an unstructured to a structured grid. The oil spill model simulates the oil spill process, while the ocean model simulates the ocean currents. The efficiency is improved about ten times compared to the interpolation algorithm. Results reveal the difference between the simulation results of the ocean model and the measured data is minimal, with an MAE(Mean Absolute Error) and RMSE(Root Mean Square Error) of about 0.06m. Moreover, two oil spill events in China's nearshore were selected to simulate and verify the results. Indeed, our model's results agree with the observed data, demonstrating that our model can achieve a satisfied simulation of oil spill.

Modelling of marine debris pathways into UK waters: Example of non-native crustaceans transported across the Atlantic Ocean on floating marine debris

The long-distance transfer of non-native, potentially invasive species via floating marine debris is an increasing threat to biodiversity and conservation efforts. To address the lack of understanding around mechanisms and pathways of species transfer via marine debris, a novel modelling approach was applied to recreate the likely trajectory and source of a large piece of debris fouled by non-native species collected from UK marine waters. This approach applied the Oil Spill Contingency and Response (OSCAR) simulation tool, an adapted oil spill modelling programme, which was informed by a combination of biological trait information for the foulant species, marine debris characteristics and hydrodynamic data. The modelling output suggested an origin in the Western Atlantic, a scenario concurrent with the known distribution of the foulant species. This modelling approach represents a valuable tool with which to determine the origin and trajectory of invasive species transferred via marine debris.

Modeling Time-Dependent Aquatic Toxicity of Hydrocarbons: Role of Organism Weight, Temperature, and Substance Hydrophobicity.

Oil spill exposures are highly dynamic and are not comparable to laboratory exposures used in standard toxicity tests. Toxicokinetic-toxicodynamic (TKTD) models allow translation of effects observed in the laboratory to the field. To improve TKTD model calibration, new and previously published data from 148 tests were analyzed to estimate rates characterizing the time course of toxicity for 10 fish and 42 invertebrate species across 37 hydrocarbons. A key parameter in the TKTD model is the first-order rate that incorporates passive elimination, biotransformation, and damage repair processes. The results indicated that temperature (4-26 °C), organism size (0.0001-10 g), and substance log octanol-water partition coefficient (2-6) had limited influence on this parameter, which exhibited a 5th to 95th percentile range of 0.2-2.5 day-1 (median 0.7 day-1 ). A species sensitivity distribution approach is proposed to quantify the variability of this parameter across taxa, with further studies needed for aliphatic hydrocarbons and plant species. Study findings allow existing oil spill models to be refined to improve effect predictions. Environ Toxicol Chem 2022;41:3070-3083. © 2022 ExxonMobil Biomedical Science Inc. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

SPILLMOD – МОДЕЛЬ ГИДРОДИНАМИЧЕСКОГО ТИПА ДЛЯ ИНФОРМАЦИОННОЙ ПОДДЕРЖКИ РЕАГИРОВАНИЯ НА РАЗЛИВЫ НЕФТИ В МОРЕ

A mathematical model of the evolution of marine oil spills with taking into account the processes of spreading and weathering, has been implemented as a software package called SPILLMOD. In doing so, a new Eulerian-Lagrangian method for Computational Fluid Dynamics (CFD) has been developed in the context of solving shallow-water-type equations with the capability to handle the situation where advancing/vanishing layer of the light fluid (oil) only partially covers the heavy (water) in a domain with an arbitrary configuration of the coastline shape. When calculating the evaporation of high-viscosity oil types, the effect of reduction the evaporation rate due to molecular diffusion of lighter oil fractions within the oil layer is taken into account. Simulation of the natural dispersion of oil layer is carried out considering multiple factors, such as: sea surface conditions, experimental data on oil film crushing in the wave mixing layer, turbulent diffusion in the upper layer, as well as changes of physical and chemical properties of oil over time. An additional module in the model is designed to estimate domain boundaries of possible spill detection for different sources of uncertainties during oil spill modeling. Modeling examples of application in realistic configuration of port-water areas for an actually occurred emergency situation of oil spill demonstrate the declared qualities of the model as a tool for supporting emergency response operations.

Simulating and Predicting Offshore Oil Spills by Using Cellular Automata

In recent years, offshore oil spill accidents have caused substantial damage to both marine organisms and marine ecology. Accurate simulation and prediction of oil spills could provide a scientific basis for assessing losses due to oil spills and provide support for emergency decisions regarding oil spills. We analyzed the advantages and disadvantages of existing oil spill models and constructed an offshore oil spill model based on cellular automata (CA). By considering both the flow field and wind field, we formulated new CA rules for the diffusion and drift of a pollution zone, and in our model, the cellular state in eight-neighborhood mode is updated in accordance with these rules, which makes the model suitable for dynamic simulation of offshore oil spills. We also constructed a model on the basis of fuzzy comprehensive evaluation for evaluating the oil spill grade. Finally, we developed a software system, the Ocean Oil Spill Information System (OOSIS), which includes all necessary functions such as basic operations, data management, information query, oil spill analysis, and oil spill assessment. OOSIS is used to verify the constructed oil spill model, and the sea breeze and current data from the National Oceanic and Atmospheric Administration were used to realize the dynamic simulation and prediction, grade evaluation, and cleanup plan generation for offshore oil spill.

Oil Spill Modeling for the Mariner Oil Field, East of Shetland, United Kingdom, North Sea

Oil Spill Modeling for the Mariner Oil Field, East of Shetland, United Kingdom, North Sea

Numerical Study on the Influence of Model Uncertainties on the Transport of Underwater Spilled Oil.

Oil pollution influences marine biology, ecology, and regional sustainable development capacity, but model uncertainties limit the ability of the numerical model to accurately predict the transport and fate of the underwater oil spill. Based on a three-dimensional underwater oil spill model validated by satellite images of the oil slick at the sea surface, the Penglai 19-3 oil spill accident in the Bohai Sea was simulated; in addition, several sensitivity experiments were set up to investigate the influence of model uncertainties in the background wind, current, start time of the oil spill, and spill site on the transport of underwater spilled oil in the Penglai 19-3 oil spill accident. The experimental results indicate that the uncertainty in the background wind has a certain impact on the simulated centroid position at the sea surface, and little effect on the simulated underwater results, while the uncertainty in the background current has a significant influence on the transport of the underwater spilled oil both at the sea surface and underwater. An uncertainty of 24 h in the start time of the oil spill can cause more than 1 time larger than the benchmark case displacement of the oil spill centroid point and sweeping area at the sea surface, as the periodic tidal current is the main constituent of the ocean current in the Bohai Sea. The uncertainty in the spill site has a large influence on the final position of the oil spill centroid point, but the oil spill trajectories do not intersect with each other within 48 h, which makes it possible to identify the oil spill platform from the actual observations. The influence of uncertainties in the important model inputs and key model parameters on the transport of underwater spilled oil in the Penglai 19-3 oil spill accident is evaluated for the first time, which is of substantial significance for improving the prediction accuracy of the transport and fate of underwater oil spills.

Development and testing of a SOSM approach to examine the natural attenuation of oil spillage on shorelines

Understanding the fate and behavior of spilled oil on the shoreline is crucial for helping decision-makers make trade-offs between natural attenuation and shoreline treatments. In this study, primary processes of oil attenuation and translocation on the shoreline, including penetration, washout, and biodegradation, have been considered to develop a numerical model, Shoreline Oil Spill Model (SOSM), for predicting the fate of spilled oil in various shoreline geological compartments. A holistic system design is employed to develop a user-friendly graphical interface system for SOSM. Global and local sensitivity analyses are used to examine the importance of the input factors on different outputs in SOSM. The results of the sensitivity analysis indicate that the input of oil spill mass correlates positively with the oil retention and surface and subsurface oil mass, while the oil concentration and penetration depth are sensitive to the grain size of the beach sediment. Subsequently, the SOSM is tested to hindcast the fate of stranded oil from the Exxon Valdez oil spill. Reasonable validation results have been obtained for the study site. It confirms the utility of the SOSM to examine and predict the level of shoreline oil contamination in the field following accidental spill events.

The bibliometric analysis and visualization mapping of net environmental benefit analysis (NEBA)

This paper aims to determine the worldwide research trends on searching queries of “oil spill* and risk assessment*” and “net environmental benefit analysis” and its most productive authors and journals. A bibliometric approach was performed to analyze publications including highly cited papers and only papers that were published in the Dimensions database from 2000 to 2022, April was selected. The necessary data were extracted from the Dimensions database and processed using visualization and mapping software such as VOSviewer 1.6.17 and Tableau Public 2021.1. The findings identified significant study fields, co-cited authors, country contributions, productive journals, as well as the most cited authors' articles. This study contributes significantly to the relevant studies as one of the few that utilizes bibliometric analysis as a network visualization and mapping technique for the analysis of one of the primary oil spill response decision-making tools and risk assessment sciences. The findings of this study can assist the researcher perform their research more effectively by providing insight into journal selection, contributing authors, research trends, countries, and keywords. Further research is recommended in light of longer period data contained in oil spill response strategies, oil spill modeling, or oil spill risk subjects.

Numerical modeling of oil spills in the Gulf of Morrosquillo, Colombian Caribbean

This study encompasses the analysis of oil spills occurred in the Gulf of Morrosquillo during the loading procedures of oil tankers in the Coveñas maritime Terminal, by means of numerical simulation experiments of the trajectories and weathering processes of oil spilled, which occurred under specific wind, waves, and ocean currents conditions. A three-dimensional (3D) modelling system, OpenOil, which is part of the open-source OpenDrift trajectory framework was used to simulate two contingencies occurred in July and August 2014. During each event, different volumes of Vasconia crude oil spilled on the sea surface were simulated. The resulting slicks were subject to wind drift, Stokes drift from wave forcing, and ocean currents transporting the oil spilled towards the coast. Oil weathering effects (evaporation, emulsification, and biodegradation) are included in the analysis. To calculate weathering of the oil, OpenOil interfaces with the latest version of the open source ADIOS oil library. It should be noted that meteorological and ocean conditions contribute to the oil pathways that in both periods forced the oil slick towards the central coast of the Gulf. The wind speed is an important factor contributing to the rapid evaporation rates of the oil spilled in the warm waters of the Caribbean Sea; hence, allowing a gradual increase of the water fraction, which could lead to the formation of tar balls found in the affected coasts in the areas simulated by the model. The implementation of OpenOil to predict the oil fate and weathering processes in the Colombian basin prove to be a valuable tool that should be used in this maritime terminal to improve planning and preparedness in case of an oil spill. The simulations could be enhanced with higher resolution databases.

Climate Change Impacts on Coastal and Offshore Petroleum Infrastructure and the Associated Oil Spill Risk: A Review

Climate change has been observed worldwide in recent decades, posing challenges to the coastal and offshore oil and gas infrastructure. It is crucial to identify how climate change affects these infrastructures and the associated oil spill risk. This paper provides an analysis of the vulnerability of coastal and offshore oil and gas infrastructure in response to climate change. The paper examines oil spill incidents worldwide and addresses climate change’s possible influences on oil spill risk. Moreover, available oil spill modeling and decision support tools for oil spill response are reviewed considering climate change. The paper signals the need for emerging decision and modeling tools considering climate change effects, which can help decision-makers to evaluate the risk on time and provide early warnings to adapt or prevent the unforeseen impacts on the oil industry partially resulting from global warming, including oil spill accidents.

Applying finite-time lyapunov exponent to study the tidal dispersion on oil spill trajectory in Burrard Inlet

This study used a combination of Finite-Time Lyapunov Exponent (FTLE) values, residual currents, and tidal excursion lengths to systematically investigate the effects of tidal dispersion on oil spill trajectories in Burrard Inlet, BC, Canada, which is a tidally dominated estuary. The FTLE analysis results showed that tidal type and tidal phase significantly influenced the FTLE fields because the flow structure and the location of saddle points varied as a function of the tidal type and tidal phase. Some transport barriers formed in the Inner Harbour, which blocked the water exchange between the western and eastern parts of the inlet. Moreover, tidal mixing in the wider regions of Burrard Inlet (i.e., the western Outer Harbour) was relatively weak than in the narrower areas (i.e., First Narrows and Second Narrows). The observations from the FTLE analysis agreed well with the residual currents and tidal excursion results. The drifter trajectories were consistent with the Lagrangian coherent structure lines extracted from the FTLE analysis. To verify the tidal dispersion impact on an oil spill trajectory in the inlet, the FTLE fields were compared with a real oil spill that occurred in Burrard Inlet in 2015 (the M/V Marathassa oil spill). The FTLE fields reasonably explained the spilled oil’s trajectories from the real event. In addition, a set of stochastic oil spill models were run in this study and found that the FTLE analysis was a reliable tool for oil spill tracking. Overall, the FTLE method would be a valuable addition to practical oil spill response planning.

MODELLING THE IMPACT OF THE OIL SPILL POLLUTION IN ILDIR BAY, TURKEY

On the 18 of December 2016 a Panama-flagged ship, M/V Lady Tuna, was stranded off the coast of Ildır Bay, Turkey. According to the authorities 75.38 m3 (approximately 73 tons) heavy fuel-oil was released to the sea. It is the worst environmental disaster in the region mainly affecting the coastal areas of the Ildır Bay. To better understand the effects of the oil spill, a series of models were set-up in the region. The fate of the oil spill was predicted by MEDSLIK-II oil spill model forced by currents and temperature from an Aegean Sea circulation model based on NEMO (Nucleus for European Models of the Ocean) and winds from an atmospheric Re-Analysis model (ECMWF, ERA-INT). A couple of sensitivity experiments were conducted by changing the discharge duration and amount, the sensitivity results were compared with observations. The model results are in good agreement with the available observations. The model successfully predicts the path of the oil spill in the sea surface and its final destinations along the coast. The oil makes first land contact after 36 hours of accident. Due to the dominated and consisted southward currents and weak wind speed at the time of the accident, the effects of the oil were luckily limited without any high dispersion at the coast.

Modeling Emulsification Influence on Oil Properties and Fate to Inform Effective Spill Response

Water-in-oil emulsification affects spilled oil fate and exposure, as well as the effectiveness of oil spill response options,viachanges in oil viscosity. While oil weathering processes such as evaporation, dissolution, photo-oxidation, and biodegradation increase oil viscosity about 10-fold, incorporation of water droplets into floating oil can increase viscosity by another order of magnitude. The objective of this study was to evaluate how changes in viscosity by oil type, with weathering, and with emulsification affect oil fate. Oil spill modeling analyses demonstrated that the increase in viscosity from emulsification prolonged floating oil exposure by preventing the oil from dispersing into the water column. Persistent emulsified oils are more likely to come ashore than low viscosity oils that readily disperse. Through a rapid increase in viscosity, emulsification restricted entrainment and slowed evaporation. Water column exposure to dissolved concentrations increased with lower viscosity oils. Thus, the ability to emulsify, and at what weathered state, are important predictors of oil fate. Oil viscosity is an important consideration for choosing response alternatives as it controls effectiveness of mechanical removal,in-situ-burning and surface-active chemicals. Therefore, understanding and quantification of oil emulsification are research priorities. The most influential model input determining emulsification and the emulsion’s viscosity is its maximum water content, as it controls the ultimate viscosity of the emulsion. Viscosities were also influenced by the volatile content and initial viscosity of the oil. Algorithms quantifying emulsion stability under field conditions have not been developed, so emulsions were assumed stable over the 30-day simulations. Changes in emulsion stability over time would affect oil properties and so floating oil and shoreline exposures, as well as response effectiveness. However, water column exposures to dissolved concentrations are determined within a few days of oil release, and as such would not be affected by differences in long-term stabilities of the emulsions.

Oil spill modeling of Chengdao oilfield in the Chinese Bohai Sea

Offshore oil exploration and development is faced with complex operational conditions and harsh environments. Once an oil spill occurs, it will cause serious damage to the marine ecological environment. The Chengdao oilfield is located in the south of the Chinese Bohai Sea, which is an important oil production area of the Shengli oilfield. At present, the trajectories and fate of spilled oil under complex marine conditions are still unclear and the potential impacts in different areas of the Chengdao oilfield are unknown. Aiming to solve the above problems, this paper carries out numerical simulations of oil spills in the Chengdao oilfield. The hydraulic model of the Chengdao oilfield is constructed and its accuracy is evaluated against tide level and tidal current data from different ports along the coast. By coupling the hydrodynamic field and wind field, an oil spill model of the Chengdao oilfield considering weathering effects could be constructed. The effects of hydrodynamic factors and environmental factors on an oil spill in the Chengdao oilfield are studied. Weathering processes such as evaporation and emulsification are considered in the simulations. The research results can provide theoretical and technical support for the emergency responses to the oil spills in the Chengdao oilfield.

Assessing the environmental risk posed by a legacy tanker wreck: a case study of the RFA War Mehtar

The ocean floor is littered with thousands of wrecks containing hazardous fuels, lubes, armaments and cargoes that have polluted, are polluting, or will pollute the marine environment. The UK Ministry of Defence manages the environmental risk associated with its ∼5,700 military wrecks through the Wreck Management Programme. This paper explores the methods used to assess the environmental risk associated with the wreck of the Royal Fleet Auxiliary (RFA) tanker RFA War Mehtar, which lies at approximately 39 m depth, 15 nm east of Great Yarmouth, United Kingdom. The methods employed include archival research, computational oil spill modelling combined with sensitivity mapping, environmental sampling and hydrocarbon concentration analysis, multibeam echosounder sonar surveys and neutron backscatter probe measurements. Each method is described, and its efficacy discussed. The archival research was essential to determine what fuel and cargo the RFA War Mehtar sank with; but only when high-resolution multibeam sonar images were combined with the ship’s plans and neutron backscatter measurements from individual tanks could one confidently conclude that the wreck does not pose a significant pollution risk.