Resumen de Aportación a la historia de la exploración de hidrocarburos en España durante la primera mitad del siglo XX: el concepto de Sistema Petrolero

J.M. González Muñoz, Pablo Insenser Nieto

• The history of the Petroleum Exploration in Spain during the first half of the 20th century is poorly recorded. During this period several private and public companies licensed some hydrocarbon investigation concessions. Before the first commercial discovery in Castillo gas field (I960), almost 90 wells had been drilled unsuccessfully. The Exploration methodology carried out by the Mining Engineers and Geologists in Spain in the first half of the last century could be divided in two steps:

  i) Prospecting and Mapping: outcrop geological analysis, oil seeps, Reservoir characteristics, presence and quality of seal, and map generation, 2) Selection of a drill hole site. The exploration staff used a simplified and empirical petroleum system related concept. They used several elements which synthesized the know-how of the exploration, using, at the same time, as analogs the oil fields of Romania, Azerbaijan, Iran and the United States. This was the principal terminology: a) Source Rocks or Primary deposits; at this time mainly defined by the oil seeps, b) Receiver Rocks (=Reservoirs); rocks with appropriate Porosity and Permeability (or fracture network), c) Cover Rock (=Seal); characterized by its impermeability, d) Tectonic elements that could facilitate migration or trapping (Trap+Migration).