GAS PRODUCTION FROM METHANE HYDRATES IN A DUAL WELLBORE SYSTEM

Abstract

Gas hydrates are ice-like substances that form when methane or some other gases combine with water at high pressure- and low temperature conditions. They can be found in permafrost regions and marine sediments. An enormous potential energy source, it is estimated that the worldwide amount of contained gas in hydrates may surpass the total conventional gas reserve by an order of magnitude.

To extract the gas from hydrates, heating or depressurization can be carried out. A previous study conducted at NUS has demonstrated that a combination of heating and depressurization on a single wellbore production scheme is more efficient than sole depressurization or -heating.

In this study, the feasibility of improving gas production from hydrates using a novel dual wellbore system will be explored. By carrying out depressurization and heating on separate wellbores, the heat transfer between the wellbores can be used more optimally to produce gas from the hydrates. The efficiency of the production schemes at various wellbore pressures and temperatures are compared to that of a single wellbore production scheme.