Dynamical mechanism of hydrate formation resulting from free gas migration into seeping seafloor sediments

Abstract

Abstract Generating hydrate-bearing samples of nature-approximation in the lab is critically important for evaluating the integrated physical properties of hydrate-bearing sediments, accurately assessing the potential of marine hydrate resources and establishing a safe and efficient gas production technique; however, current database on generating hydrate-bearing samples of nature-approximation in the lab are still limited due to experimental challenges. Here we report the dynamical formation of gas hydrate resulting from free gas migration into seeping seafloor sediments through visual observation using a magnetic resonance imaging (MRI) device. The effects of core temperature, pore pressure, gas flow rate, and solution salinity are preliminarily explored. The saturations of water, gas, and hydrate are calculated based on the mean intensity (MI) of obtained MRI images. The residual water saturation variation along with gas flow direction during hydrate formation are analyzed. Also, the residual water saturation distribution in the pore space are visually presented.