CH4/CO2 replacement is of great significance for the exploitation natural gas hydrate resources and CO2 storage. The feasibility this method relies on our understanding efficiency mechanism. In study, experiments were carried out to study distribution characteristics CH4 in hydrate-bearing sediments during after replacement. Similar previously reported data, also implied that process could be d...

To prevent hydrate plugging conditions in the transportation of oil/gas in multiphase flowlines, one of the key processes to control is the agglomeration/deposition of hydrate particles, which are determined by the cohesive/adhesive forces. Previous studies reporting measurements of the cohesive/adhesive force between hydrate particles used cyclopentane hydrate particles in a low-pressure micro...

During Ocean Drilling Program (ODP) Leg 204, we will drill a transect of sites through the gas hydrate stability zone on the southern part of Hydrate Ridge on the Cascadia accretionary margin offshore Oregon. Massive hydrates are present at the seafloor there, and high-resolution threedimensional seismic data indicate a complicated subsurface plumbing system. The transect will cover two distinc...

The physical samples of natural gas hydrate were obtained first by drilling in permafrost region of Qilian Mountain of China in 2008. Permafrost area in Qilian Mt. is located in lower latitudes at high altitude, and the samples form in the Jurassic stratum under hard rock environment, rather than in unconsolidated soil layer. The environment of the Gas hydrate discovered is different from in th...

Gas hydrate model and free gas model are established, and two-phase theory (TPT) for numerical simulation of elastic wave velocity is adopted to investigate the unconsolidated deep-water sedimentary strata in Shenhu area, South China Sea. The relationships between compression wave (P wave) velocity and gas hydrate saturation, free gas saturation, and sediment porosity at site SH2 are studied, r...

To investigate the effect of particle size porous media on CO2 hydrate formation, formation experiments in with three sizes were performed. Three kinds mean diameters 2.30 μm (clay level), 5.54 (silty sand and 229.90 (fine level) used experiments. In experiments, temperature range was 277.15–281.15 K initial pressure 3.4–4.8 MPa. The final gas consumption increases increase decrease temperature...

abstract: â in this study, the change in the crystalline structure of gas hydrate was predicted for ternary mixture of methane-ethane-water. for this purpose, the tangent plane distance (tpd) minimization method was used. first, the calculations were performed for the binary mixtures of methane-water and ethane-water as the gas and liquid phases. the results show that for a binary mixture of th...

in this work, experimental kinetics data of methane hydrate decomposition at temperatures ranging from 272.15 to 276.15 k and at pressures ranging from 10 to 30 bars were modeled by using chemical affinity. this model proposed a macroscopic model which is independent of any intermediate mechanism like heat or mass transfer. the results show there is good agreement with experimental data. also t...

The amounts of hydrocarbon gases trapped in natural hydrate accumulations are enormous, leading to a recent interest in the evaluation of their potential as an energy source. Earlier studies have demonstrated that large volumes of gas can be readily produced at high rates for long times from gas hydrate accumulations by means of depressurization-induced dissociation, using conventional technolo...

A 403-day in situ field experiment at Ocean Drilling Program Site 892B sought to quantify the flux of methane along a fluid-active fault and to experimentally determine rates of methane hydrate and authigenic carbonate deposition associated with fluid expulsion from the borehole. An instrument package was deployed that osmotically sampled fluid, measured borehole pressure and flow rates, and co...