Natural gas hydrate(also known as flammable ice)is a common unconventional shallow gas reservoir in seabed reservoirs.It has the characteristics of mud and low permeability.Its safe and efficient development is of great practical significance.During the hydrate exploitation process,both gas seepage and hydrate dissociation behavior change dynamically,and the complex coupling of the two determines the gas production efficiency of hydrate reservoirs,but there is a lack of research on their dynamic coupling prediction models.Therefore,it is necessary to further analyze the gas seepage and hydrate dissociation behaviors during the depressurization production process of gas hydrate reservoirs.The muddy,low-permeability hydrate reservoir using South China Sea soil was remolded within a core holder.The exploitation characteristics during depressurization and the influence of reservoir pressure on gas production were explored.In addition,a prediction model for depressurization extraction that included key indexes of reservoir pressure,hydrate decomposition,and gas production flow rate was innovatively proposed.The spatial and temporal correlation between seepage and dissociation of a muddy,low-permeability hydrate reservoir was predicted with high precision.Correlation coefficients(R2)between measured and predicted values were all distributed above 99%.The results can provide theoretical guidance for the optimization and control of hydrate exploitation in the field.
关键词
天然气/水合物/低渗岩心/相变/模型/多孔介质/降压开采
Key words
natural gas/hydrate/low permeability core/phase transition/model/porous media/depressurization production
维普
万方数据