Mathematical Modelling of Methane Hydrates Dissociation in Porous Medium via Depressurization Technique

The depleting of conventional energy resources and increasing energy demand has led to the development in non-conventional resources. Among the non-conventional resources that is getting more attention is methane hydrates. The current amount of methane hydrates reserves in the world is more than that of the total of oil and natural gas reserves combined. Past research papers introduced different kind of mathematical models to predict the production of methane from its hydrates. Due to the various approach used to construct the model, the effectiveness in using every model may differ one to another depending on the condition or the nature of the methane hydrates reservoir. At the present, there has not been any study in which the efficiency of the mathematical model is tested using data from various research papers that focus on the same area of interest. Thus the objective of this paper is to select various mathematical models that simulate the dissociation of methane hydrates in porous media via depressurization and ultimately, to verify the efficiency of the selected mathematical model by testing it with data from various research paper of the same scope of study. In this paper, the efficiency of a mathematical model by Kim et al. (1987) is investigated by using the available data from other related research papers. The efficiency is determined by comparing the mass generation rate which is calculated based on the data taken from the research paper to the mass generation rate which is determined from the experiment and simulation. Four research papers are used to obtain the required data and the scope of study focuses on depressurization technique only. In the findings, all of the percentage differences are within the range from 20.48% to 2028.05% between the calculated (measured) and predicted data. The large differences are due to the assumptions made in calculations, insufficient data in the research papers, variation in the experiment procedure and settings, and human errors while conducting the experiment. Since the calculated mass generation rate follows the declination trend of the predicted mass generation rate, it is concluded that Kim et al. (1987) mathematical model is the most efficient model to predict the dissociation of methane hydrates in porous media. Thus, the objectives are met. To improve the quality of the project, the mathematical model should be validated with more research papers that provide the necessary information. Apart from that, researchers should consider conducting their own experiments and study other mathematical models.