The is a

gas field A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presenc ...

located in the southwest of Nagaoka,

Niigata Prefecture is a Prefectures of Japan, prefecture in the Chūbu region of Honshu of Japan. Niigata Prefecture has a population of 2,131,009 (1 July 2023) and is the List of Japanese prefectures by area, fifth-largest prefecture of Japan by geographic area ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

. It was discovered in 1979 and is developed by INPEX Corporation. One of the largest in Japan, the field has been in production since 1984, with the completion of the Koshijihara Gas Plant. Even after more than 25 years of continuous output, Minami-Nagaoka still accounts for approximately 40% of Japan's total natural gas production. Inpex websit
Minami-Nagaoka Gas Field and Domestic Natural Gas Business
Retrieved on August 17, 2012

References

Natural gas fields in Japan Geography of Niigata Prefecture Nagaoka, Niigata {{niigata-geo-stub