A Comprehensive Review on Gas Hydrate Reservoirs: Formation and Dissociation Thermodynamics and Rock and Fluid Properties

Abstract

Gas hydrates reservoirs are a type of unconventional reservoir that is an extremely abundant and ubiquitous source of energy. They are also relatively cleaner than most other hydrocarbon sources which makes them an even more attractive source of energy. The potential of this source of energy has, however, not been utilized since very little production has ever taken place from these reservoirs due to their complexity. This research provides an understanding of gas hydrates thermodynamics and reservoir properties in order to assist in properly modelling the hydrate flow in porous media. The research also provides a road map to the current production methods that have been used in pilot tests in order to produce from gas hydrates reservoirs. The production methods explained include depressurization, thermal stimulation, inhibitor injection, combined methods, carbon dioxide injection, and mining. The mechanism of each method is fully explained, and the advantages and disadvantages of each method are also explained. Several case studies worldwide are also discussed to show how each production method has been used to produce from the gas hydrate reservoirs. The results from the case studies are also used to reach conclusions on how each method can be improved upon. To the author's knowledge, no publication has provided a complete overview on gas hydrates and their production mechanism which makes this research a crucial step in providing an overview on many aspects of gas hydrates reservoirs and their production mechanisms and potential. Understanding the mechanisms to produce from gas hydrate reservoirs is a crucial step in the hydrocarbon industry to allow us to tap into this vast source of energy in the near future.

An approximate approach to estimation of dissociation rate of gas hydrate in porous rock bed

“…To assess the efficiency of the considered approach, a comparative analysis of the calculation results has been conducted with the data of the work [27], which presents the results of mathematical processing of experimental data on the methane gas hydrate dissociation in sand. According to the initial data [27] Table 1 presents the results of the parameter K calculation from the equation (10) and that obtained by the authors of the work [27] as a result of the correlation analysis of experimental data. Table 1.…”

“…Value of the parameter K, m/s 1/2 According to the equation (10) According to the data [25] 0.5 4.4410 -4 4.4910 -4 1. 5 5.5810 -4 5.4810 -4 2.…”

“…4, with an increase in porosity, the coefficient K decreases. Based on the equation (10) form, the coefficient K value is influenced by the temperature differences (T w -T f ) and (T f -T r ). It follows from the graph in Fig.…”

“…A fairly large number of works are devoted to the study of the gas hydrates dissociation processes in porous media [8]. The papers [9][10][11] provide an overview of technologies for the gas hydrates recovery from porous media and the modelling specifics of such processes in natural fields. It should be noted that experimental research in real mines and wells is associated with a number of unbiased difficulties [11,12].…”