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), 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.
The main objective of this course is to prepare geologists, geological engineers and other professionals and students for the use of seismic data in their activity, particularly in the oil industry. Several examples of tools, test data and interpretation techniques will be given that will enable participants to continue their training during and after the course.
During the course and in an organized and systematic manner, we aim to achieve several objectives that are briefly presented:
- General understanding of seismic data acquisition methods
- Understand other data sources used in conjunction with seismic
- Understand seismic data processing
- View seismic data and know how it can be adapted
- Know the various software programs
- Know the various types of data and licenses
- Map geological faults
- Identify structure types and geodynamic environments
- Build simple structural models
- Map 2D and 3D horizons
- Use seismic attributes to identify sedimentary macrostructures
- Identify seismic facies
- Build Wheeler diagrams
- Interpret sequence stratigraphy in a generic way
- Know the elements and processes of the petroleum system
- Map hydrocarbon accumulations
- Quantify a hydrocarbon accumulation
- Determine the risk associated with a hydrocarbon accumulation