Development of Monitoring System on Methane Hydrate Production

From 2001, the Japanese government has had a national project, conducted by Research Consortium for Methane Hydrate Resources in Japan, which has been promoting methane hydrate exploitation under the seabed in the deep sea of more than 1000 m depth in Japanese EEZ. This paper briefly describes the development of the monitoring technology, by one of the R&D sub-group of Environmental Impact Assessment Group of the Consortium that is conducted by Engineering Advancement Association of Japan, including both sensor technology and integration technology of the monitoring system in the deep sea on some possible factors which can badly affect to the environment around the methane hydrate production area in the future. Regarding sensor technology, we have had great efforts to develop high-performance sensors for dissolved methane and seafloor displacement, which we thought had not been well developed during our pre-investigation several years ago. As to integration of the total monitoring system, at first, we studied well what items to monitor, how to monitor and how accurate to read. According to the results, we studied the existing related technologies including installation units i.e. mooring type and AUV, electric power supply, data transportation, installation/removal method and so on, so that we could successfully reach some conclusion on total concept of the integrated monitoring system. Based on the concept, we also successfully completed the study on a necessary integrated monitoring system that shall be deployed with the well-developed sensors at the ocean production trial that is planned to carry out in the future.