Reflection seismic is one of the fundamental ways of imaging the subsurface from a geological perspective. 2D and 3D seismic data is a major source of information in the oil industry for both onshore and offshore activities. Knowledge of a sedimentary basin from the perspective of oil systems often begins with the acquisition and analysis of widely spaced 2D seismic data, forming a quadrangular mesh and covering large areas – the regional lines. Based on this analysis, the main petroleum systems or plays (albeit hypothetical) are defined as well as the areas of major interest, where the probability of hydrocarbon accumulations is higher. These areas are then targeted for new, more detailed seismic acquisition campaigns – 2D with a tighter mesh and smaller areas or 3D in very specific areas. These new data are the basis from which potential drilling targets are defined to test for the presence of hydrocarbons and the productivity of the reservoirs containing them. If drilling is successful, seismic data will allow (calibrated with well data) to assess the extent of accumulation and to envision new drilling targets. Even during the production of an oilfield, seismic data remains relevant, for example with the use of 4D seismic – second 3D acquisition with the same parameters in the same area – to assess the amount of hydrocarbons still present.

Recently this type of data has also been used in geothermal energy activities, carbon sequestration in geological reservoirs and wind energy, especially offshore. Other uses include mapping salt structures for use as natural gas reservoirs (gas caverns), and delimiting mineral deposits among other activities involving imaging of the subsurface.

This course will cover the main concepts underlying the interpretation of 2D and 3D seismic data, from its History, the methods of data acquisition, processing, visualization and software. Several mapping exercises will be done using seismic data – faults and horizons – and how they can be used to understand the structure, stratigraphy and geodynamics of a basin. The perspective of hydrocarbon resources will be addressed through reserve and associated risk calculation exercises.