2026 Volume 68 Issue 2 Pages 167-172
Since the late 1940s, the development of natural gas dissolved in water for mining purposes in the Niigata region has been active. In 1958–1959, production of natural gas dissolved in water and the drainage amount of associated groundwater peaked. Land subsidence became evident during this period. The drainage of natural gas dissolved in water into a river for mining purposes and new mining was completely prohibited in 1973, and operations have since shifted to full groundwater return. This full-return method has been in operation for over 50 years, and its effectiveness in controlling geological strata compaction at depths related to operation has been verified through various monitoring methods. Based on the evidence, production of natural gas dissolved in water began in stages in the newly developed area in 2021. It will be required to continuously aim for the safe, secure, and sustainable development of natural gas dissolved in water in Niigata.
