During the 70's, the oil industry suffered two separate oil shocks. S-OIL was founded in 1976 to ensure stable import of crude oil and the steady supply of petroleum products to the markets.

The construction of an oil refinery began on a 400,000 pyong plot of land inside an industrial complex located in Ulsan City. In May 1980, 4 years after the construction started, commercial operation of the oil refinery began. As the Company began commercial operation of the lube base oil production plant in January 1981, the Company came to commence full-scale operation of the ‘oil refining and lubricant production’ system.

Remarkable growth continued thereafter to become a fully-functional oil refining company, and today, S-OIL runs a crude oil refinery with a capacity of 580,000 barrels/day, a B-C cracking center with a capacity of 292,000 barrels/day, BTX production plant with an annual capacity of 900,000 ton, a para-xylene production plant with an annual capacity of 650,000 ton, a lube base oil plant with a capacity of 24,000 barrels/day

S-OIL is able to import a stable volume of crude oil from an oil-producing country at favorable conditions by maintaining close and friendly relations with the oil-producing country. The Company made special efforts to promote profitability and improve operating rate by pushing full-fledged crude oil processing projects by actively utilizing the prevailing overseas market situation.

S-OIL also is continuously expanding the sales foundation in the domestic market. As a result, the Company was able to realize the trade surplus starting in 1982 and lay a foundation for stable growth. In May 1987, 7 years after the Company began commercial operation, the Company had its initial public offering as an enterprise that grows together with its shareholders, employees and customers.