Methods to utilize methane gas produced by methane hydrate development as a domestic energy for local consumption

Abstract:

In recent years, methane hydrate has been the focus of attention as a new energy resource. Substantial amount of methane hydrate is known to reside in the surrounding sea areas of Japan.

Methane hydrate is classified into two types depending on its bearing conditions. Research and development of sand-layer type methane hydrate began in 2001. In 2016, second offshore methane hydrate production test was conducted where natural gas was successfully extracted medium term. Currently, the group is working on production engineering development for long term gas production. As for the development of surface layer methane hydrate, gas chimney structures were confirmed at 1,742 points in the Sea of Japan during the investigations from 2013 to 2016. These gas chimney structures are likely to be indicators for surface layer methane hydrate. Particularly in Umitaka Spur, offshore Niigata, large clumps of methane hydrate were discovered with an estimated amount equivalent to approximately 600million m^３ of methane gas. Research study is currently conducted to consider the production technology of surface layer methane hydrate at Umitaka Spur.

As described above, research and development of methane hydrate has been conducted in Japan for commercial purposes. However, production technology is still in the process of being considered and developed. Details of ways to utilize methane gas after gas production are yet to be considered.

In this study, we investigate the methods to utilize surface type methane hydrate upon gas production. The government-led project of methane hydrate development project is targeted to be handed over to private sectors in the future for commercialization project. As the first step for practical application of surface type methane hydrate, we focused on the possibility of consuming methane hydrate originated gas produced at Umitaka Spur, offshore Niigata, as locally produced energy within Niigata prefecture. We will conduct interviews to companies in Niigata such as energy companies related to imported LNG (liquefied natural gas), companies related to utilization of natural gas, and bus companies. It is also necessary to consider the efficiency of the economy, in order to investigate the method and structures to utilize methane hydrate originated methane gas within Niigata.