Hydraulic fracturing within source rocks for fluids in sedimentary basins

In several systems in the Earths crust, fluids are self-produced inside a rock (dehydration of sediments in the subduction channel, migration of hydrocarbon from a source rock) and escape by creating their own paths. This is a process of reaction-induced fracturing. Primary migration i.e. the transport of hydrocarbon fluids from very low permeability source rocks in which they are generated to more permeable reservoirs or to the surface is an example of both economic and fundamental interest. To evaluate the exploration prospect of partly mature shale plays, an understanding of naturally created fracture networks properties such as crack geometry, fracture density, connectivity between cracks and reservoir permeability is needed. To predict evolution of natural hydraulic fractures generated by a fluid created within a low permeability rock, physical models with analogue materials are used. During their PhD, Dr. Kobchenko and Dr. Zanella developed independently two different experimental approaches to model hydraulic fracturing in analogue media. In this project we use our expertise to develop a new experimental setup, which will better simulate natural hydraulic fracturing. The main objectives are to investigate the geometries of fracturing in anisotropic and low-permeability materials producing an internal fluid (liquid/gas). The set-up will include: homogeneous fluid/gas production, elastic host analogue to simulate fractures, transparency of the setup to follow the process in-situ, using new analogue materials for the host to simulate heterogeneity and anisotropy of the reservoir rock. In this proposed project, the combination of both, physical and geological approaches is essential for the understanding the reaction-induced fracturing within low permeability porous isotropic and anisotropic materials.