Predication of stability zones and occurrence zones gas hydrate of multiple-composition natural in seafloor sediments
多组分天然气水合物在海底沉积层中稳定区及存在区的预测

We study feature of stable and existing zones of multiple-composition natural gas hydrate in seafloor sediments. First, the stability surface of hydrate formation with multiple-composition natural gas including methane and propane is set up by regress fitting. The effect of salinity in liquid on stability curved surface is considered by interpolation. Based on the model of hydrate predication, the range of stability zones and occurrence zones are computed for only methane or different fractions of methane and propane with different salinity. Comparing these results, it is shown that the effect of little propane on stability zones and occurrence zones is larger than that with single methane gas. Apparently, it is because propane has a larger effect on the stability temperature and the solubility of natural gas. The effects of other compositions such as CO_2, C_2H_6 and H_2S are briefly discussed in the paper.