REPSOL YPF S.A. is a multinational energy company which has its origins in Spain as a result of the early industrial efforts that followed the Spanish Civil War and World War II.
By that time, the Spanish Government - through the National Industry Institute (NII) - decided to foster industry development by creating a number of companies which would be financially supported by the public sector with technological contributions from the national and international private environment.
Thus, REPESA (Escombreras Oil Refinery Corporation) was erected in the late forties-early fifties in southeastern Spain. The corporation was linked to a physical location boasting an excellent port infrastructure. Inland, the formation of ENCASO (Calvo Sotelo National Company) was tied to the occurrence of a shale oil field which provided, for many years, the feedstock for production of fuels and lubes through distillation of the former.
Caltex, the owner of a part of REPESA's shareholding, contributed significantly to the technical development of the Refinery.
From the technological viewpoint, the shale oil Companies in the Puertollano zone (Ciudad Real) were more closely related to the German and Italian industries which were in turn more closely associated with that industrial sector.
In both cases, the international economic and political isolation process the country was undergoing by that time resulted in technological developments and improvements of its own..
With the markets and demand evolution during the 1960's, old slate processing facilities were replaced by a more streamlined "hydroskimming"-type, refining structure using Kellog and Lummus technologies which seemed to better meet demand requirements. A lubes and derivatives production scheme was started up and the country's first petrochemical plant was brought on-stream, where ethylene produced at a plant using Stonne & Webster technology was converted to polymer, i.e. the feedstock for the plastics industry, by companies partly funded by the above-referred National Industry Institute (INI) as well as foreign companies such as Arco, Phillips Petroleum, ICI, Monte Edison, etc. which, acting as partially controlling companies for the former, contributed basically process and technology.
The above plans became more complex as a result of demand and successive energy crises which called for reduced crude oil imports. This led to the construction of conversion units (FCC and coking).
At the same time, other Refining companies tied to economic and/or technological groups were created in different geographical areas of the country. These included ENTASA (Tarragona National Oil Company), located in northeastern Spain, the most important petrochemical area in the country, with technological development based on UOP systems for refining processes and on Linde and others for the petrochemical designs; P