Organic matter and clays: sedimentary origin, resources and associated reservoirs

Organic matter (OM) is only a small part of the sedimentation. Contrary to the other deposited particles, it can evolve rapidly during burial by interacting with the grains of the host rock and by producing fluids (gases and liquids) which will be very mobile. Because of its degradation by bacteria, its preservation depends on many parameters but especially on the fine granulometry of the grains deposited at the same time. Thus clays represent the most favorable medium for the preservation of OM but their complex mineralogy makes them a particular material which will also be transformed during burial. The products of their interactions were of course of interest to the mining and petroleum industries, since these processes are at the origin of the large series of coal and hydrocarbon production. But recently, studies are increasingly interested in these two elements as tracers of the origin of sediments and as markers of burial, which is of major interest in understanding the filling of basins and their post-depositional evolution.

The sessions are organized through the sequence:
- Introduction
- Organic matter in sediments (origin and nature)
- Coals (formation and classification)
- Clays (origin and evolution with burial)
- Maturation of organic matter (transformations and interactions with clays)
- Non-conventional resources (use of OM-rich clays)

All these notions will then allow the introduction of basin modeling (deposition, geodynamic and post-depositional tectonic history, burial curves and thermal history) which will be addressed in S4 in the Resource Assessment module, "fluids" option.

Students must have a good knowledge of basin geology and sedimentology (S1 and S2 of master).

Knowledge of organic geochemistry may be a plus to acquire the complex concepts of the module.

Graded exercises punctuate the TD/TP sessions and an applied final exam will be conducted on a case study.