Basin synthesis 2: subsurface data

The aim of this module is to learn how to organize and integrate a large amount of subsurface data, acquired using a variety of tools, in order to build a geological model of the subsurface. This course is based mainly on the study of the sedimentary series of the Colville Basin (Carboniferous - Upper Cretaceous) in the Alaska Petroleum Reserve (NPRA). The sedimentary systems studied here using subsurface data (seismic and well data) are analogous to the objects analyzed in the field in the "Geology of sedimentary basins" (ENS2) and "Basin synthesis 1: field data" (ENS3) modules. All data are interpreted using Kingdom interpretation software (IHS). Techniques for interpreting 3D seismic data, such as seismic geomorphology, are also presented, with application exercises.

In this module, students will :

• Analyze geological drilling reports (cuttings description);
• Interpreting graphical data;
• Build synthetic seismograms and set seismic lines at wells;
• Correlate several wells with each other using logs;
• Interpret 2D and 3D seismic data (stratigraphy and structure), and use interpretation results to improve correlations;
• Research and use analogous present-day and ancient sedimentary systems to improve interpretations and correlations;
• Create one or more geological model(s) of the area studied, integrating all the results of analysis of the data provided and reflecting on the evolution of the sedimentary system in time and space, as well as on the controlling factors (eustatism vs. tectonics);
• Evaluate the potential of the study area in terms of hydrocarbon reservoirs or aquifers.

Skills to be acquired: be able to work on several types of data at the same time, organize the analysis of these data in a logical order, gather the information provided by each analysis and integrate it, use software to interpret subsurface data, understand the contributions and limitations of each type of data (vertical and lateral resolution problems, etc.), understand the benefits of integrating different types of data to improve the final model, 

Basic geology and sedimentology, notion of sedimentary basin, interpretation of well logs, seismic interpretation, sequence stratigraphy, knowledge of petrophysics.

1. Introduction to the study project2. Analysis of stratigraphic series based on well data (cuttings, core samples, logs, drilling reports)3. Downhole calibration of seismic data4. Interpretation of the major tectono-stratigraphic units on the seismic lines (definition and pointing of the main horizons, production of structural maps and thickness maps)5. Analysis of the tectono-stratigraphic evolution of the Colville Basin (integration of well and seismic data)6. Introduction to seismic geomorphology7. Detailed analysis of units containing potential reservoirs (seismic stratigraphy, petrophysical analysis of logs).