In the midst of political turbulence in Spain, Campsa (Compañía Arrendataria del Monopolio de Petróleos S.A.) was created on October 17th, 1927 in order to manage the state petroleum monopoly. Originally, Campsa was a mixed company, with the State holding only a minority stake, but it was awarded the concession in 1927. The creation of Campsa had a profound effect on Spain’s industrial growth, especially the refining industry.
While Europe was immersed in World War II, on September 30th, 1941, the National Institute of Industry (INI - Instituto Nacional de Industria) was established to promote and finance Spanish industries. During this period, Campsa drilled an appraisal well in Cantabria, an early milestone for exploration in the Iberian Peninsula.
A year later in 1942, control of the monopoly was transferred to the INI, and the state consolidated its stakes in hydrocarbon companies. In November of the same year, the company ENCASO (Empresa Nacional Calvo Sotelo) was established as a stock corporation and began operations in Puertollano and Levante, where it set about constructing the Cartagena refinery.
In 1944, Campsa's first research center was built in Madrid in association with ENCASO, with the aim of keeping Spain from depending on foreign suppliers and technology. During this period, the research center worked on projects related to shale distillation and fertilizer production, advancing towards the optimization of processes based on the shale oils produced in Puertollano. The center underwent significant expansions and acquired a new testing station for lubricants and fuels, as well as an experimental refinery. Over time the company diversified its activities, making particular headway into the field of petrochemicals.
In 1947, a few years after the end of the war in Europe, the Spanish oil industry witnessed some important changes. The 20-year contract between the state and Campsa came to a close, and the petroleum monopoly was reorganized by law on July 17th, 1947. The old leasing contract was terminated and replaced by a program aimed at decentralizing services, which simultaneously reinforced the state's intervention in the petroleum monopoly (CAMPSA). The new law established that the state would recover from the petroleum monopoly the ability to award concessions for nearly all hydrocarbon activities, except those related to distribution and commercialization, which remained under the exclusive control of CAMPSA.
In 1948, the company REPESA (Refinería de Petróleos de Escombreras) was established with the purpose of installing a refinery in the Escombreras Valley in Cartagena. Opened in 1951, REPESA's facilities included a lubricants and asphalts production plant, a cogeneration plant, marine facilities at the Port of Escombreras, and a research center. Repsol was REPESA's star brand.
The company Butano, S.A. was founded on June 11th, 1957, with the aim to provide door-to-door butane gas delivery. The product stood out for its hassle-free installation, safety, and efficient performance as comfort had begun to fill Spain's homes.
In 1961, the Spanish Ministry of Industry authorized the Marathon Oil Company and PETROLIBER (Compañía Ibérica de Petróleos, S.A.) to form a stock corporation that would build and operate an oil refinery with an initial annual capacity of 1.2 million tons. In May 1964, CAMPSA collaborated with Chevron and Texaco to drill an appraisal well in Burgos, which would reach production levels of 85 barrels per day.
Hispanoil (La Sociedad Hispánica de Petróleos S.A.) was founded on May 5th, 1965, with the aim of carrying out exploration and production activities beyond Spain. Its first operation took place one year later in the Sirte basin in the Libyan desert.
In 1966, ENCASO (Empresa Nacional Calvo Sotelo de Combustibles Líquidos y Lubricantes) opened the Puertollano refinery in Ciudad Real, the first in inland Spain. It covered 320 hectares, and it was connected by an oil pipeline to the Malaga marine terminal.
After a public tender in September 1968, Petronor was awarded the installation and operation rights for the refinery in Biscay, which would come into operation two years later. On May 14th, 1971, the National Institute of Industry (INI) was commissioned to set up a crude oil refinery in Tarragona and create a national company, ENTASA (Empresa Nacional Petróleos de Tarragona). The refinery was officially opened by King Juan Carlos on February 19th, 1976 . In August 1975, the existence of the Casablanca oilfield on the Tarragona Coast was confirmed. It is considered the most important oil field to have been found in Spain, producing 13,500 barrels a day.
On July 11th, 1980, the production platform was installed in Casablanca and the Gaviota field was discovered. Two appraisal wells were drilled in the Bay of Biscay: Vizcaya B-1 and C-1 yielding a positive result for natural gas.
Spain’s National Hydrocarbons Institute (INH) was founded in 1981 to ensure the state's energy policy is consistent and effective. It was formed by the shareholders of PETROLIBER, HISPANOIL, CAMPSA, ENPETROL, ENIEPSA, ENAGAS, and Butan,o S.A. This public entity was affiliated with the Spanish Ministry of Industry and Energy. Its main functions were to coordinate, in accordance with Government guidelines, business activities related to hydrocarbons in the public sector, and to strengthen the sector by channeling business initiatives.
On December 17th, 1984, the 45/84 Spanish Law aimed at restructuring the oil industry led to the start of the transition from a controlled industry to one which followed the standards set by the Treaty of Accession to the European Economic Community (EEC), which would be signed by Spain the following year. The Spanish Government pledged to free up all sectors of the economy, including the hydrocarbon industry.