Seismic wave propagation in multi-scale fractured media

Offer Description

Tectonic processes and the industrial exploitation of the subsurface induce brittle deformations in the earth crust, leading to fractures at all scales. These fractures are organized in networks which are basically characterized by their density, connectivity, and distribution of aperture, length and orientation. Determining these parameters are essential for predicting the hydrogeological behavior of reservoirs or understanding the fatigue of soils and engineering structures. However, direct measurements of fracture parameters are rarely available. Apart from outcrops, cores and borehole images, fractured rocks are seen in an effective way through mechanical properties derived from mechanical tests or seismic wave data. The aim of the PhD project is to improve our understanding of the interaction between seismic waves and fractures.

Geological observations have evidenced that a power law is appropriate to describe the density of a fracture set as a function of fracture size (e.g., Bonnet et al., 2001). Nevertheless, for either theoretical or computational reasons, studies on seismic wave propagation in fractured media have been restricted to a short range of sizes so far. To overcome this limitation, the present project will build on recent progresses in non-periodic homogenization (e.g., Capdeville et al, 2010; Guillot et al, 2010; Cupillard & Capdeville, 2018; Capdeville et al, 2020) to compute effective properties of fractures following realistic power law distributions. The numerical methodology will be tested and validated against laboratory experiments on core samples.

References:

Bonnet, E., O. Bour, N. E. Odling, P. Davy, I. Main, P. Cowie, and B. Berkowitz (2001). Scaling of fracture systems in geologic media, Rev. Geophys. 39, 347–383.

Capdeville, Y., L. Guillot, and J. Marigo (2010). 2-D non-periodic homogenization to upscale elastic media for P-SV waves. Geophys. J. Int. 182, 903–922.

Capdeville, Y., P. Cupillard, and S. Singh (2020). An introduction to the two-scale homogenization method for seismology, Adv. Geophys. 61, 217–306.

Cupillard, P. and Y. Capdeville (2018). Non-periodic homogenization of 3-D elastic media for the seismic wave equation. Geophys. J. Int. 213(2), 983–1001.

Guillot, L., Y. Capdeville, and J. Marigo (2010). 2-D non-periodic homogenization of the elastic wave equation: SH case. Geophys. J. Int. 182, 1438–1454.

Funding category: Autre financement public

PHD Country: France

Requirements

Specific Requirements

Le candidat doit être titulaire d'une maîtrise en sciences quantitatives de la Terre, géophysique, physique, géomécanique, mathématiques appliquées ou informatique. Il/elle est passionné par les sciences et possède de solides compétences en rédaction scientifique. Une expérience en programmation informatique et une solide maîtrise de la langue anglaise sont requises. La langue française est préférable, mais pas nécessaire.

The candidate should hold a MSc in quantitative Earth Sciences, Geophysics, Physics, Geomechanics, Applied Mathematics or Computer Science. He/she is passionate about science and has solid scientific writing skills. An experience in computer programming and a strong command of English language are required. French language is preferable, but not necessary.

Additional Information

Work Location(s)

Number of offers available 1

Company/Institute Université de Lorraine, GeoRessources, RING

Country France

City VANDOEUVRE LES NANCY

Where to apply

Website https://www.abg.asso.fr/fr/candidatOffres/show/id_offre/121362

Contact

Website https://www.ring-team.org/