Mathematical Model of Decomposition of Methane Hydrate during the Injection of Liquid Carbon Dioxide into a Reservoir Saturated with Methane and Its Hydrate

Abstract

The article describes a mathematical model of pumping of heated liquid carbon dioxide into a reservoir of finite extent, the pores of which in the initial state contain methane and methane gas hydrate. This model takes into account the existence in the reservoir of three characteristic regions. We call the first region “near”, the second “intermediate”, and the third “far”. According to the problem statement, the first region contains liquid CO2 and hydrate, the second region is saturated with methane and water, the third contains methane and hydrate. The main features of mathematical models that provide a consistent description of the considered processes are investigated. It was found that at sufficiently high injection pressures and low pressures at the right reservoir boundary, the boundary of carbon dioxide hydrate formation can come up with the boundary of methane gas hydrate decomposition. It is also shown that at sufficiently low values of pressure of injection of carbon dioxide and pressure at the right boundary of the reservoir, the pressure at the boundary of hydrate formation of carbon dioxide drops below the boiling pressure of carbon dioxide. In this case, for a consistent description of the considered processes, it is necessary to correct the mathematical model in order to take into account the boiling of carbon dioxide. Maps of possible solutions have been built, which show in what ranges of parameters one or another mathematical model is consistent.

Numerical Simulation of Natural Gas Hydrate Exploitation in Complex Structure Wells: Productivity Improvement Analysis

“…For the numerical analysis of NGH production capacity prediction, a series of mature hydrate exploitation simulators were developed internationally, such as TOUGH + HY-DRATE, MH-21HYDRES and CMG-STARS [12][13][14]. In this work, the CMG-STARS code was used to simulate the exploitation of NGH reservoirs by adding hydrate formation and decomposition reaction kinetic equations [15,16].…”

Dissociation and Combustion of a Layer of Methane Hydrate Powder: Ways to Increase the Efficiency of Combustion and Degassing

“…This simulation should deal not only with the kinetics of dissociation of natural gas hydrate, but also the mechanisms of transfer in a porous space. The account of heat and mass transfer in modeling of the injection of carbon dioxide in the gas hydrate deposits is given in [27,28]. The effect of heat transfer on the gas hydrate dissociation in porous media is given in [29].…”