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

Andrii Dreus,Roman Lysenko,Baochang Liu,Oleksandr Gubin,Volodymyr Bondarenko,V Bondarenko,R Lysenko,F Cawood,M Hardygora,I Kovalevska,K Sai

doi:10.1051/e3sconf/202123001002

Andrii Dreus, Roman Lysenko + Show 9 more

Open Access

https://doi.org/10.1051/e3sconf/202123001002

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Abstract

Development of deep shelf or onshore gas hydrate fields involves drilling wells with subsequent thermal, decompression or chemical action on the bed. In this case, the radius of thermal or decompression action is limited. As the field develops, recovery efficiency decreases, and necessity arises for drilling a new well that influences the cost of the technology. To determine the rational wells location, it is necessary to predict the advance of the phase transformation rate front into the depth of the bed. In this work, to study the movement dynamics of the gas hydrates dissociation front in a porous layer of rock, the Stefan problem solution is used. The method adequacy is substantiated by comparing the calculated results with known experimental data. The temperature fields are modelled in a porous bed during the methane hydrate dissociation. The temperature field dynamics for 200 days in a porous bed during the methane hydrate dissociation caused by thermal action is shown. The influence of porosity and excess temperature on the dissociation front movement rate is revealed.

Highlights

The natural gas hydrate deposits are considered as one of the potential energy reserves of humanity [1,2,3]
A simplified approach is proposed to an assessment of the front movement rate of a gas hydrate phase transition in a porous layer based on the analytical solution of the Stefan problem
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

Summary

Introduction

The natural gas hydrate deposits are considered as one of the potential energy reserves of humanity [1,2,3]. A fairly large number of works are devoted to the study of the gas hydrates dissociation processes in porous media [8]. Basics of mathematical modelling of gas hydrate phase transitions in porous media are studied in the work [13]. Using this approach, a large number of problems have been solved for modelling the heat transfer processes in porous media during the gas hydrates decomposition, as shown in the works [14, 15]. A simplified approach is proposed to an assessment of the front movement rate of a gas hydrate phase transition in a porous layer based on the analytical solution of the Stefan problem

Mathematical model

Results and discussion

Conclusions