Hydrodynamic, thermodynamic, and physical properties of released condensate gas in the deep sea

Deep-sea hydrocarbon releases represent a considerable menace to the fragile ecological environment. Nonetheless, most contemporary models have limitations in forecasting the dynamics, physical attributes, and thermodynamic conditions of buoyant bubbles within the water column. This paper introduces a comprehensive bubble transport model that considers various pertinent behaviors of condensate gas bubbles, encompassing hydrodynamics, gas–liquid phase partitioning, and synergistic interactions between mass transfer and hydrate morphology. The model's reliability was substantiated by accurately predicting bubble shrinkage through on-site experiments conducted at various depths within Monterey Bay. The ascent of condensate gas bubbles leaked at 1,400 m in the South China Sea is simulated employing the proposed model. The findings reveal that the presence of a hydrate shell significantly impacts bubble velocity and survival time. The specific hydrate coverage area dictates the transition time for crystallization under identical thermodynamic conditions. The condensate gas bubble ultimately ascends to the sea surface as liquid condensate in which the C6 component emerges as the primary factor. Surface migration capacity and compressibility factors primarily determine the gas bubble evolution of the properties and ascension to the sea surface.