ALGORITHM FOR SOLVING THE PROBLEM OF METHANE HYDRATE DECOMPOSITION IN A CLOSED HYDRATE-CONTAINING REGION OF A POROUS MEDIUM

Abstract

Russia has a law on limiting greenhouse gas emissions, signed by the President of the Russian Federation in July 2021. The list of greenhouse gasses includes methane, and its reserves in the form of gas hydrates largely prevail over the reserves of free methane. The formation of gas hydrates occurs at sufficiently low temperatures and high pressures. A significant part of the “sleeping giants”, as journalists dubbed the methane-containing deposits, are in the Arctic region, and they are very sensitive to warming. The release of this greenhouse potential would have very negative consequences for the Earth’s climate. Thus, it is necessary to study the process of gas hydrate decomposition under thermal impact on a hydrate-containing porous medium. It is worth noting the importance of theoretical research to solve this problem, which includes the construction of a mathematical model of the process under study, algorithmization, software implementation and computational experiments. The paper presents a two-dimensional approximation of the formulated problem of heating at the upper boundary of the porous medium’s closed region containing methane and its hydrate initially. A mathematical model is presented, which is based on the mass conservation equations for methane, water and gas hydrate; Darcy’s law for the motion of the gas and liquid phases; the equation of a real gas state, the energy conservation equation considering thermal conductivity, convection, adiabatic cooling, the Joule-Thomson effect and absorption of latent heat during hydrate formation. An algorithm for the numerical implementation of the mathematical model is constructed and a computer code is developed to calculate main parameters of the process in the work, the computer program is updated to calculate the main parameters of the process researched in the article.