The Evolution of Gas Hydrate Accumulations in Zones of Deep-Sea Mud Volcanoes

Abstract

This paper considers the evolution of gas hydrate accumulation that occurs at deep mud volcanoes. We present a mathematical model and results from numerical simulation of gas hydrate accumulation on the seafloor in deep-seated structures of submarine mud volcanoes. We made a quantitative study of how the depth of a feeding reservoir and the pressure in it can affect the evolution of gas hydrate accumulation at deep mud volcanoes. Numerical simulation showed that the hydrate saturation in zones of submarine mud volcanoes is not constant and its evolution is affected by the geophysical properties of the bottom (temperature gradient, porosity, permeability, and physical properties of the sediment) and by the depth of the feeding reservoir and the pressure in it, with the rate of hydrate accumulation being some tens or hundreds of times greater than that in sedimentary basins at passive continental margins.