Showing papers by "Xiao-Sen Li published in 2020"
TL;DR: In this paper, the X-ray computed tomography (X-ray -CT) has been conducted to detect distribution characteristics of the hydrate-bearing sample during hydrate formation and dissociation.
62Â citations
TL;DR: In this article, the effect of hydrate saturation on the water effective permeability (kw) of the methane hydrate-bearing sediments was systematically investigated in different initial porosities of fine quartz sands, and a new reduction empirical model on the basis of simple cubic model and oblique cubic model was integrated.
42Â citations
TL;DR: In this article, the authors evaluated the kinetics and CO2 recovery of gas (40.0% CO2 + 60% H2) hydrate formation in the presence of cyclopentane (CP) at 276.15 K and 6.0 MPa.
26Â citations
TL;DR: In this paper, a novel experimental apparatus was designed and built to investigate sediment deformation and strain evaluation during methane hydrate dissociation by depressurization, which leads to the decrease of sediment permeability.
26Â citations
TL;DR: In this paper, how to choose a suitable production pressure is a key issue when depressurization is taken as the production way of gas hydrate is considered as a promising energy resource in the future.
Abstract: Natural gas hydrate is considered as a promising energy resource in the future. How to choose a suitable production pressure is a key issue when depressurization is taken as the production way of g...
22Â citations
TL;DR: In this paper, the growth habits of hydrate in porous media and its relative permeability were evaluated by measuring the change of differential pressure with water injection, and it was found that the differential pressure was unstable in the first few minutes and it is not recommended to employ short-term data to evaluate the hydrate sediments.
22Â citations
TL;DR: In this article, the authors analyzed the influence of water saturation on the characteristics of heat transfer and fluid flow in the sediments, thereby affecting the hydrate dissociation behavior, and they showed that the key factor to improve the dissociation rate of hydrates with high water saturation is to increase the diffusion rate of gas.
21Â citations
TL;DR: In this paper, a novel hydrate heat-mass coupling separation (HHMCS) method was studied to reduce the energy consumption of CO2 hydrate separation from Integrated Gasification Combined Cycle (IGCC) syngas.
19Â citations
TL;DR: In this paper, the water effective permeability (kw) of methane hydrates in three fine quartz sands containing various hydrate saturation (SH) were carried out under steady water injection and production.
18Â citations
TL;DR: In this article, the authors studied the influence of cyclopentane (CP) on the formation of CO2 binary hydrate and showed that CP helps to promote the formation and the gas consumption is affected by hydrate formation mode and hydrate density.
17Â citations
TL;DR: In this article, a cylindrical numerical model was established to study the characteristics of drilling fluid invasion into hydrate-bearing sediments and the effects of permeability on this process, and the distributions of temperature, pressure, saturation, and salinity of pore water around wellbore at different time were obtained.
TL;DR: In this article, a novel hydrate drilling experimental apparatus was used to study the drilling process in the hydrate-bearing sediments, and four drilling experiments were carried out in consolidated sediments containing Tetra-n-butyl ammonium bromide (TBAB) hydrate.
TL;DR: In this paper, the authors investigated the influence of CO2 partial pressure on efficiency of CH4-CO2 swap from natural gas hydrates (NGHs), the replacement of CH 4 from NPHs is carried out with simulated Integrated Gasification Combined Cycle (IGCC) syngas under different pressures, and the gas chromatography (GC), in-situ Raman, and powder X-ray diffraction (PXRD) are employed to analyze the hydrate compositions and hydrate structures.
Abstract: To investigate the influence of CO2 partial pressure on efficiency of CH4-CO2 swap from natural gas hydrates (NGHs), the replacement of CH4 from natural gas hydrate (NGH) is carried out with simulated Integrated Gasification Combined Cycle (IGCC) syngas under different pressures, and the gas chromatography (GC), in-situ Raman, and powder X-ray diffraction (PXRD) are employed to analyze the hydrate compositions and hydrate structures. The results show that with the P-T (pressure and temperature) condition shifting from that above the hydrate equilibrium curve of IGCC syngas to that below the hydrate equilibrium curve of IGCC syngas, the rate of CH4 recovery drastically rises from 32% to 71%. The presence of water can be clearly observed when P-T condition is above the hydrate equilibrium curve of IGCC syngas; however the presence of water only occurs at the interface between gas phase and hydrate phase. No H2 is found to present in the final hydrate phase at the end of process of CH4-CO2 swap with IGCC syngas.
TL;DR: In this article, the authors investigated the temperature characteristics during hydrate formation in the cyclopentane-methane system using large-scale equipment with bubbling and showed that hydrate-based thermal fluid production can be scaled up by a factor of 80, however, the temperature of the thermal fluid needs to be optimized by adjusting variables accordingly.
TL;DR: In this article, the authors investigated the effective gas permeability of marine natural sediments with different initial porosities during confining pressure loading and unloading, and they found that the permeability was very sensitive to particle size distribution, confined pressure and initial porosity of the sediments.
TL;DR: In this paper, the authors used the Tough+HYDRATE software to stimulate hydrate exploitation in field scale by in situ electrical heating and applied depressurization as a comparison, and found that the most optimal electrical heating power should be 500 W/m with comprehensive consideration of gas production rate, NGH front promoting velocity and energy efficiency.
TL;DR: In this paper, the influence of temperature, water content, gas content, and electrode distance on the changing rules of electrical resistance, as well as measuring electrical resistance in nine samples, were systematically studied.
TL;DR: In this paper, the phase behavior of hydrate in montmorillonite with NaCl solution was investigated using high-pressure micro-differential scanning calorimetry, and the phase equilibrium temperatures and the conversion rate of methane hydrate both decreased with increasing NaCl concentration.
Abstract: In marine sediments, seawater influences the phase behavior of natural gas hydrate. As a porous medium, the water distribution and physical properties of montmorillonite are influenced by the salt ions in seawater. In this work, the bound-water content in, and crystal structure of, montmorillonite is measured to investigate the effect of salt ions on the water distribution in montmorillonite. It can be determined from the results that the bound-water content in montmorillonite decreases as the salt-ion concentration increases. Salt ions affect the intercalation of water molecules in montmorillonite, and they then inhibit the expansion effect of montmorillonite. Next, the phase behaviors of methane hydrate in montmorillonite with NaCl solution are investigated using high-pressure micro-differential scanning calorimetry. The phase behavior of hydrate in montmorillonite with NaCl solution is discussed. In montmorillonite with NaCl solution, the phase equilibrium temperatures and the conversion rate of methane hydrate both decrease with increasing NaCl concentration. The results show that methane hydrate in montmorillonite is influenced not only by the phase-equilibrium effect of salt ions, but also by the formation effect of the salt ions on the bound-water content in montmorillonite.
TL;DR: An experimental drilling apparatus used for evaluating drilling risks related to NGH was developed, which can simulate the comprehensive drilling process, and evaluate the heat and mass transfer process in hydrate-bearing sediments during the drilling process.
Patent•
07 Jul 2020
TL;DR: In this paper, a hydrate generation promoter is proposed for methane storage in the form of a mixed aqueous solution composed of cyclopentane, lauryl sodium sulfate and water.
Abstract: The invention provides a hydrate generation promoter and application thereof in methane storage. The hydrate generation promoter is a mixed aqueous solution composed of cyclopentane, lauryl sodium sulfate and water, and the volume fraction of cyclopentane is 5%-23.4% based on the total volume of the mixed aqueous solution. Based on the total mass of the mixed aqueous solution, the mass fraction oflauryl sodium sulfate is 0.01%-0.08%. The hydrate generation promoter provided by the invention can efficiently and quickly generate methane hydrate at the temperature (25 DEG C) close to the normaltemperature, and can keep stable at a higher temperature.