The former Nansei Sekiyu K.K. joined the Taiyo Oil Group in December 2016 and was absorbed and merged with Taiyo Oil on December 1, 2024 to become Okinawa Operations. Going forward, Okinawa Operations will continue to fulfill its mission of providing a stable supply of petroleum products to Okinawa Prefecture. At the same time, Okinawa Operations will study issues, such as the commercialization of sustainable aviation fuel (SAF) and renewable diesel manufacturing toward achieving carbon neutrality.
Obtained license for the reclamation of a public water body (total area of 660,000 ㎡) to construct a refinery that produces 80,000 barrels (approximately 13,000 kiloliters) per day.
January 1972
Commenced operation of Nishihara Refinery.
April 1972
In line with the return of Okinawa to Japan, changed company name to Nansei Sekiyu K.K. as a Japanese company.
1986
Commenced construction for modernization of land shipping terminal (increased shipping points from 7 to 14, and introduced computer management).
October 1986
Received a commendation from the Minister of Labour— a first within Okinawa Prefecture—during the National Industrial Hygiene Week.
1995
Augmented capacity of crude oil distillation unit to 100,000 barrels per day.
2002
Augmented capacity of catalytic reforming unit to 13,500 barrels per day.
April 2008
Transferred all 87.5% of shares owned by parent company TonenGeneral to Petrobras ; composition of shareholders became Petrobras (87.5%) and Sumitomo Corporation (12.5%).
2008
Installed 2 bioethanol storage tanks.
2010
Commenced supply of E3 gasoline (gasoline mixed with 3% bioethanol) on the main island of Okinawa.
October 2010
Petrobras acquired all 12.5% of shares owned by Sumitomo Corporation, making Nansei Sekiyu into a fully owned subsidiary.
April 2015
Stopped petroleum refining unit.
May 2015
Continued petroleum sales by selling petroleum products procured from external parties.
March 2016
Discontinuation of petroleum refining processed by the Ministry of Economy, Trade and Industry.
April 2016
Started operating as an oil storage facility (warehouse operations) that accepts, stores, and ships petroleum products.
Taiyo Oil Co., Ltd.
December 2016
Taiyo Oil acquired all shares owned by Petrobras, making Nansei Sekiyu a fully owned subsidiary under the umbrella of the Taiyo Oil Group.
December 2024
Taiyo Oil absorbed and merged with Nansei Sekiyu and established Okinawa Operations.
