Natural seeps have been widely used as a proxy in studying oil spills, due to its similar nature to subsea oil spills, i.e., both are hydrocarbon release events in the oceanic environment. However, the physical processes between these two events are not exactly the same, owning to the significant difference of release rate that results in different regimes of characteristic plume scale. As such, understanding the difference and connection between them is critical to appropriately transfer the knowledge of natural seeps to the oil spills. The foremost difference of the fundamental physics between natural seeps and oil spills is the mechanism of ambient water entrainment. The entrainment determines both hydrodynamics and thermodynamics in the plume (for instance, diluting the petroleum fluids; influencing the velocity field; affecting the transport of associated contaminants, etc.).
This proposed work is an integrated effort, synthesizing existing laboratory and field data obtained from the previously funded GISR consortium, with the purpose to understand the physical processes of multiphase plume under a wide range of release conditions. This study’s main objective is to understand and to quantify the difference and connection of the multiphase plumes for small and large release rates, particularly, natural seeps and oil spills. This proposal specifically addresses the GoMRI RFP-VI Theme 1: “Physical distribution, dispersion, and dilution of petroleum (oil and gas), its constituents, and associated contaminants (e.g., dispersants) under the action of physical oceanographic processes, air-sea interactions, and tropical storms.”
This synthesis effort will provide fundamental understanding of bubble plume entrainment and behavior under a variety of flow conditions. The proposed project will fill the knowledge gap in understanding the underline physics of the transition between weak and coherent bubble plumes. This project will also refine an existing integral multiphase flow model that resolve the fate of hydrocarbons and the dynamics of subsea multiphase flows in a wide parameter range of plumes. Together, this two-year synthesis project will add key components that expand the current knowledge of multiphase flow in the full range of characteristic plume scales from individual bubbles to massive blowout.
The proposed project will have a broader societal impact in two major areas: enhancement of scientific infrastructure and education. First, the development of the submersible PIV system will enhance the scientific infrastructure for other relevant studies. Second, the instrumentation developed for the laboratory experiments will create unique resources for interdisciplinary training and education of next generation earth scientists (particularly across the boundary between Engineering and Ocean Sciences through the course development plan and Ph.D. student training).