Shihui Ma

TL;DR: In this article, the authors employed a low-field nuclear magnetic resonance to study the gas-water consumption characteristics quantitatively at various formation conditions and determined the hydration number of methane hydrate under different driving forces.

TL;DR: In this paper, confining pressure was applied to simulate a sub-seafloor environment, where methane was repeatedly injected into cores to remold hydrate-bearing marine sediments with different hydrate saturation and water content.

Abstract: The recent increase in atmospheric CO2 concentration makes it necessary to investigate new ways to reduce CO2 emissions. Simultaneously, natural gas hydrate mining technology is developing rapidly. The use of depleted methane hydrate (MH) deposits as potential sites for CO2 storage is relatively safe and economical. This method can alleviate the shortage of hydrate displacement gas with CO2. The purpose of this study was to investigate CO2 hydrate formation characteristics during the seepage process—in reservoirs with excess water—and their effect on CO2 storage. The experimental process can be divided into 5 parts: MH formation, water injection, MH dissociation, CO2 hydrate formation, and CO2 hydrate dissociation. Magnetic resonance imaging was employed to monitor the distribution of liquid water, and the effects of different parameters on the formation and dissociation of CO2 hydrates were analyzed. It was found that a state of initial water saturation can effectively control hydrate saturation in artificial MH reservoirs for hydrate reservoirs with excess gas. In the process of CO2 flow, initial water saturation was not the main controlling factor for CO2 hydrate formation. Increasing the flow pressure and reducing the flow rate were beneficial for CO2 hydrate formation. This study is of great significance for advancing the science of CO2 geological storage in the form of deep‐sea hydrates.

TL;DR: In this paper , a carbonated steel slag (CSS) was creatively adopted as a solid precursor for the synthesis of alkali-activated materials (AAMs), and the physicochemical properties of CSS were fully characterized, influences of mix proportion on strength development of alkaline-activated CSS (AACSS) mortar were investigated.