About the project
Our main question is how hydrocarbons are expelled from source rocks during burial, a process called primary migration that controls how much oil and gas could migrate toward reservoir rocks. More generally, several geological processes involve the expulsion of fluids from low permeability rocks, such as diagenesis of clays in sedimentary basins or dehydration of sediments in subduction zones.
Shales are layered sedimentary rocks, which can be almost impermeable for fluids and act as seals and cap-rock, or, if a shale layer hosts a fracture network, it can act as a fluid reservoir and/or conduit. Organic-rich shales contain organic matter - kerogen, which can transform from solid state to oil and gas during burial and exposure to heat. When the organic matter is decomposing into lighter molecular weight hydrocarbons, the pore-pressure inside the shale rock increases and can drive propagation of hydraulic fractures.
We follow three complementary approaches, including a baseline understanding of the relationship between organic content and maturation as it relates to the geomechanical components of the rock, a thorough analysis of the kerogen lenses to characterize them (size, shape, fabric, anisotropy, volume of total rock, orientation etc.) and how they interact with fractures (size, shape, fabric, anisotropy, volume of total rock, etc.), and analogue modelling of the fracturing process within an anisotropic medium focused on understanding size, shape, density, and orientation of fractures in relationship to the anisotropy.
Financing
The Research Council of Norway (project PROMETHEUS, #267775, 2017-2022)
Cooperation
- The Njord Center, University of Oslo, Norway
- University Grenoble Alpes, France
- British Geological Survey, Nottingham, UK
- Department of Geosciences, University of Oslo, Norway
- University of Nancy, France
