Policy for Environmental Impact Assessment Study in the Phase 2 of the Japan's Methane Hydrate R&D Program

The Research Consortium for Methane Hydrate Resources in Japan (MH21) was established to realize the Japan's Methane Hydrate R&D Program that was released in July 2001. In the Phase 1 of this program (FY2001-2008), Environmental Impact Assessment (EIA) group was established, aiming for the establishment of the environmentally friendly production system considering environmental preservation. This group has conducted fundamental researches such as baseline marine surveys in the eastern Nankai Trough as a model field of this program, and development of numerical models and monitoring sensors concerning the possible environmental risks such as methane leakage and seafloor deformation. By the results of the Phase 1, the MH21 have revealed that thick pore-filling type deposits of MH in sandy layers derived from turbidite (MH concentrated zone) are regarded as the most economically high potential prospect, and the depressurization method would be the most feasible methane gas production techniques to MH concentrated zones. From these results, we could estimate that environmental risks on commercial development of MH concentrated zones are not significant (Yamamoto and Nagakubo, 2009). The main target of the EIA studies in the Phase 2 (FY2009-2015) is to identify the environmental risks and verify its severity through two offshore production tests in Japan. Therefore the MH21 is planning to do the following studies as the EIA through the offshore production tests; (1) conduct detailed marine baseline surveys around production areas before/after tests, (2) develop monitoring system before tests, (3) conduct to monitor expected environmental risks by monitoring system during the tests, (4) improve monitoring system after tests, (5) evaluate the severity of the environmental risks after tests. On the other hand, the MH21 intend to conduct preliminary studies for the EIA to future’s commercial production. The studies should be conducted in consideration of the following principles; (1) compliance of the Japan’s internal law, ‘Mining Act’, (2) economical efficiency, (3) consistency with the EIA procedure and engineering studies of production system. Reference: Yamamoto, K. and Nagakubo, S. (2009): Risk factors of methane hydrate resource development in the concentrated zones distributed in the eastern Nankai Trough, Proceedings of EGU General Assembly 2009.