It is an introductory course actually dealing with Petroleum Geology, whichcomprises all these geological disciplines that are of greatest significance for the finding and recovery of oil and gas. Since most of the obvious and “easy to find” petroleum already has been discovered, it is necessary to use sophisticated methods in the exploration of sedimentary basins.
These include advanced geophysical techniques and basin modelling. There is also much more emphasis now on enhanced recovery from the producing fields. Petroleum technology has made great progress and many new tools and modelling programs have been developed, both in exploration and production. It is, however, important to understand the geological processes, which determine the distribution of the different sedimentary rocks and their physical properties. This knowledge is fundamental to being able to successfully apply the methods currently available. Therefore, in the context of the course the following topics are discussed: (i) Analysis of sedimentological models, whichallow for the prediction and location of different facies in the sedimentary basins, and from that, the identification of the likely presence of the parent/source rocks (with a high content of mature organic matter), reservoir rocks and caprocks. The distribution and geometry of potential sandstones or carbonate reservoirs requires detailed sedimentological models, thus, the fundamental concepts of sequence stratigraphic analysis have been a useful tool in such reconstructions; (ii) Description of the major sedimentary environments (sedimentary facies) that determine the distribution of reservoir rocks and their primary composition, as well as analysis of the diagenetic processes, whichgreatlyaffect the porosity, permeability and other physical properties (such as acoustic impedance) in both sandstone and limestone reservoirs and, finally, description of the chemical processes controlling crucial mineral reactions; (iii)Fundamentals oftectonics and structural geology, whichprovide an understanding of the subsidence, folding and uplift responsible for the creation and dynamic history of a basin. The timing of the folding and faulting that forms structural traps is very important in relation to the migration of hydrocarbons; and (iv) Geophysical well-loggingmethods, which have developed from simple electric and radioactive logs to highly-advanced logging tools, providing detailed information about the sequence penetrated by the well. Logs provide a continuity of information about the rock properties, which someone can seldom obtain from exposures or core samples. This information makes it possible to interpret not only the lithological composition of the rocks and the variation of porosity and permeability, but also the depositional environment. Also the image logs make possible the detection of bedding and fracturing inside the wells.