The petroleum system concept has been known for a long time, but it has begun to have a serious impact on exploration since an improved definition by Magoon in 1992. Besides the definition of the processes and elements that play a role in the functioning of petroleum systems, its main merit is the introduction of the areal extension of a petroleum system, outside which hydrocarbons generated by the system cannot be found.
The concept is more descriptive than predictive (for this reason its impact on exploration is still limited).
During the last years, efforts have been made to adapt and modify the notion of the areal extension of a petroleum system in such a way that besides for areas of mature exploration, as the Paris basin or the Lower Congo basin, it can also be used for areas of extensive exploration or even for a frontier areas as the Greenland south-western offshore.
We will see when treating the areas mentioned above that for any petroleum system study (be it for proven, hypothetical or speculative systems) it is necessary that at least three different types of documents are prepared beforehand: a timing chart, a cross section illustrating the migration pathways and a map with the geographical extension of each petroleum system. The cross-correlation of the documents belonging to the different petroleum systems may allow the identification, within producing areas where previously no sourcing problems were assumed, of zones where sourcing could be problematic. To the contrary, in basins where sourcing was always considered problematic, some zones might be found to have more potential than presumed.
Only very recently the petroleum system concept has shown its importance for the practice of exploration in general and the acquisition of new acreage in particular. This after a publication by Magoon (1992), in which the notion of the geographical extention of a petroleum system, outside of which no hydrocarbons generated by this system can be found, is defined. This definition (as an area within which a hydrocarbon kitchen and its shows and fields are located) is purely descriptive. In fact the extention of a petroleum system can only be determined after the source rocks have been identified and geochemical correlations have been made between these source rocks, the proven hydrocarbons and the location of the shows and fields. ~ This excludes an easy application in frontier zones. - This means it is not predictable (predictability being the primary quality of any exploration tool) By linking the notion of geographical extention of a petroleum system not only to the location of the proven or potential kitchens, but primarily to the identification and extention of secondary migration pathw