Experiment on the effect of gas-water ratio on methane hydrate formation

It is of great significance for the industrial application of natural gas hydrate to promote the rapid and massive formation of natural gas hydrate. Gas-water ratio is a key factor influencing the formation of hydrate, so it is quite necessary to study the effect of gas-water ratio on the formation of hydrate. In this paper, a new mathematical computation formula for ideal gas-water ratio was proposed. Then, the effect of gas-water ratio on the formation of methane hydrate was investigated under 275.15 K and 6.6 MPa, and the accuracy of the new mathematical computation formula was verified. It is shown that hydrate formation rate increases greatly when gas-water ratio is higher than 1.8. Gas consumption is jointly determined by two factors, i.e., the initial amount of gas and the experimental phase-equilibrium pressure. The actual gas storage capacity of hydrate is more affected by gas-water ratio. Under the condition of ideal gas/water ratio, the formation performance of hydrate with sodium dodecyl sulfate (SDS) solution as the hydrating agent is in accordance with the calculated expectancy. To sum up, appropriate gas-water ratio can not only increase the hydrate formation rate, but also the gas consumption and the actual gas storage capacity of hydrate.