VISION & MISSION

The unprecedented scale of the Deepwater Horizon oil spill highlighted a critical need to understand the important processes affecting fate and transport of petroleum fluids over the wide range of scales, from the wellhead to the beach, in the Gulf of Mexico and to assess the benefits of potential spill response activities. This consortium proposal focuses on evaluating the mechanisms controlling fate and transport of oil in the Gulf of Mexico through laboratory, field, and numerical experiments.

The vision of the Gulf Integrated Spill Research Consortium (GISR; pronounced Geyser) is to understand and predict the fundamental behavior of petroleum fluids in the ocean environment. This capability is critical to inform decisions during response to oil spills and for development of mitigation plans, ultimately yielding significant environmental and financial savings. The Mission of this proposal is to develop a multi-scale modeling system validated by field and laboratory experiments to track the pathways of transforming hydrocarbons released from deep oil spills in the Gulf of Mexico. Our approach will be to conduct a multi-scale suite of field and laboratory experiments that target critical deficiencies in our understanding of the physical, chemical, and biological behavior of petroleum fluids as they transit the Gulf from a deep oil spill to the beach, m  arsh, estuary, or atmosphere, and to synthesize this understanding through the application of a validated, multi-scale numerical model of petroleum fate and transport in the Gulf.

RESEARCH THEMES

The overarching outcome of GISR will be the validated set of numerical models. This output corresponds jointly to GRI Theme 1 (Oil and gas transport) and Theme 2 (Transformation) since these models must accurately account for the behavior of petroleum fluids from the wellhead to the beach. Because the current state of knowledge of the fate and transport of oil and gas in the ocean environment is incomplete, GISR will also conduct a multi-scale suite of field and laboratory experiments to elucidate the fundamental behavior of petroleum hydrocarbons in the oceans.

Objectives. This project will achieve the primary mission of GISR by pursuing the following specific objectives:

Build a multi-scale modeling system for fate and transport of oil in the Gulf of Mexico. Understanding the behavior of spilled petroleum in the deep and coastal Gulf of Mexico requires simulation of a wide range of scales from dissolution and weathering of individual bubbles or droplets (10 µm to 1 cm) to plume generation in the near field of the release (10 cm to 1000 m), including the subsurface intrusion of dissolved and dispersed hydrocarbons and far-field transport in the basin-scale circulation of the Gulf (100 m to 1000 km). To span this range of scales and processes, we will deploy a multi-scale suite of models for evaluation of ocean circulation and petroleum fate and transport from deepwater spills to coastal bays. This will be accomplished using existing hydrodynamic and transport models that will be applied to study baseline and synthetic weather conditions, including tropical storms, using a coupled atmosphere-ocean model.

Validate and improve models using data from the Deepwater Horizon accident and new experiments. Model validation will quantify model skill and illuminate gaps in our theoretical understanding of petroleum fate and transport in the ocean. Thus, the specific aims of this section are first to test the model suite through hindcasting of the Deepwater Horizon accident and second to perform targeted laboratory and field tests to elucidate mechanisms of oil and gas fate and transport from accidental releases. The experiments will pursue a similar multi-scale approach to the models. Field experiments include a simulated deepwater blowout of oil and gas (using petroleum or surrogate fluids) to study the near-field plume dynamics largely not quantified during the Macondo spill (Deep-Plume) augmented by a separate tracer experiment using a sulfur-fluoride tracer (CF3SF5) to quantify the basin circulation and chemical/biological behavior of the deep carbon system (Deep-SF). Laboratory experiments target several droplet-scale processes, including droplet-turbulence interaction, dissolution, evaporation and effect of dispersants on the initial droplet size. All of these field and laboratory observations will be used to validate the multi-scale modeling system.

Integration of Consortium Activities. All of the proposed consortium activities are tightly integrated. Each of the numerical models employed will be nested together to simultaneously cover the wide range of necessary scales at adequate resolution. The laboratory experiments will improve modeling of droplet and bubble scale processes, focusing on areas of uncertainty in the models. The models and field experiments are linked through validation of the model processes using data from the field observations. Ultimately, these activities serve to close the gaps necessary to model the fundamental behavior of petroleum fluids in the ocean environment.

Scientific and Societal Impact. Spill management options must balance methods that reduce shoreline impact with the tradeoff of possible generation of hypoxic regions in deep waters. This balance requires the ability to predict shoreward transport and subsurface fractionation and biodegradation of spilled oil and gas. The activities proposed by GISR will yield considerable insight on these processes with the goal of validating a multi-scale suite of numerical tools for oil spill modeling. The work will also benefit the physical, chemical and biological oceanography of the Gulf of Mexico through the collection of new field data on large-scale circulation in the Gulf. In addition to these science outcomes, the tools developed here will benefit society by greatly improving our ability to anticipate and mitigate the impacts of future spills. Moreover, the system will quantify human health risk to oil spills and test the efficacy of mitigation strategies by accurately predicting the fractionation of oil and gas among surface, subsurface and atmospheric exposure pathways. Ultimately, these activities serve to close the gaps necessary to improve the response to future oil spills and to responsibly continue deepwater oil development and exploration.