Context
The properties of the rocks found in sedimentary basins which are big depressions filled during the geologic history, impact strongly on their economic potential. Sedimentary basins represent key domains for the human development because they welcome a big part of the population (example of the Paris Basin), correspond to accumulation of resources (hydrocarbons, gases, metals, materials) and constitute successful receptacles for the storage (waste, gaseous reservoir).
The properties of these rocks often arise from the long history of their accumulation but also from the processes which occured during their burial (and often of their return towards the surface). The axis fluid-rock interactions in the sedimentary basins is interested in all the processes, physical - chemical - biological which transformed rocks since their deposition and modified their reservoir properties. The porosity constitutes for example one of these parameters which controls largely the economic potential. The porosity corresponds to all the spaces which exist in a rock, which can be filled by water, gas, hydrocarbons, metals or which can be favorable or not to store gases, materials or waste. Understanding the evolution of the porosity in time represents consequently a major parameter to estimate the potential of a basin. Other parameters are also fundamental and will be studied within the framework of this axis, in particular the temperature evolution, cementation (mineralization) and dissolution episodes, the evolution of the organic matter …
The study of these sedimentary rocks allows to reconstitute the Earth history, including the conditions of deposition (marine, continental, hot, cold environment) and the highlighting of the large processes which affected them (deformation, fluid circulation, erosion)
Stakes
- Identify the rocks where useful substances can be observed
- Estimate the volume of the resources
- Plan the evolution of the long-term sedimentary basins to predict and guarantee a successful storage
- Improve modeling of processes with the acquisition of realistic data and of developing successful applications
Objectives of "Fluid rock interactions in sedimentary basins" thematic axis
The objective of this thematic axis is to structure and to lead a high-level research on the diagenetic evolution of the sediments/sedimentary rocks, and fluid rock interactions in sedimentary basins. The investigated fluids can be fluids located in sedimentary basins but also fluids stemming from deep sources outside the basins.
The purposes of these researches concern the evolution of sedimentary basins, the link between the large-scale geodynamic episodes and the modifications of rocks. Porosity evolution and exchanges between the various reservoirs control closely the resources found in sedimentary basins (metals, hydrocarbons, geothermal science …).
This collaboration aims to
1 Set up a frame of scientific and technical exchanges between the various partners and organize an annual colloquium on the subject,
2 Mutualize equipments and available state-of-the-art digital tools in the laboratories of the partners,
3 Coordinate project proposals on public calls or directly with private companies
4 Obtain financing for developments of analytical and digital tools appropriate to every institute, in a perspective of mutualization through the GIS.
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Scientific and technical questions approached on this axis
- What are the ages, the durations, the spatial extensions and the thermal conditions of the episodes of fluid circulation the sedimentary basins?
- What are the couplings existing between the petrographical, mineralogical, petrophysical, geomechanical and organic evolutions in sedimentary rocks?
- How to feed and to validate databases and simulators of fluid-rock interactions?
- What are the effects of the hydrothermal systems on the mineral and organic diagenesis in the sedimentary basins?
- What are sources and sink of abiotic gas (CO2, N2, H2, H2S, hydrocarbons) in the sedimentary basins?