Multiphysics modeling of crack propagation at the cement–steel interface in a CO2 environment

The geological storage of CO2 is a preferred solution to counter greenhouse gas emissions. CO2 is injected into former oil reservoirs or deep aquifers, from which it cannot escape. The storage's leak tightness must be ensured, and IFPEN is a key player in this field. The integrity of the storage wells, made of steel casings cemented to the rock, remains a challenge, especially at the cement-steel interface. This zone, under the effects of geochemical alteration of the cement and steel corrosion by dissolved CO2, represents a potential leakage pathway. Although models exist to separately analyze these phenomena, none of them integrate them in a coupled manner. This thesis aims to develop a multiphysics model to study the fracture of this interface. The model must simultaneously model:
-    The geochemical alteration of the cement by CO2-saturated brine,
-    The corrosion and formation of deposits on the steel casing surfaces,
-    The propagation of a crack at the cement and steel casing interface during reservoir pressurization.
The model will consist of a geochemical module written in Python and a geomechanical model written in Abaqus. Specifically, a dedicated cohesive element will be developed to model the cement-steel interface and its rupture. This model is intended to join the catalog of tools developed by IFPEN for evaluating well integrity. The PhD student will develop skills in geomechanical, geochemical, and corrosion simulations. The topic will suit a student interested in numerical simulation and its challenges (convergence, robustness), geomechanics and geochemistry, with the complexity of couplings, as well as subsurface geoengineering. The thesis will take place at IFPEN Lyon under the supervision of the Navier laboratory (Ecole des Ponts et Chaussées, Université Gustave Eiffel).
 

IFP Energies nouvelles is a French public-sector research, innovation and training center. Its mission is to develop efficient, economical, clean and sustainable technologies in the fields of energy, transport and the environment. For more information, see our WEB site. 
IFPEN offers a stimulating research environment, with access to first in class laboratory infrastructures and computing facilities. IFPEN offers competitive salary and benefits packages. All PhD students have access to dedicated seminars and training sessions. 

Academic requirements    University Master degree in Mechanics of Materials, Material Engineering or Geomechanics
Language requirements    English level B2 (CECR)    
Other requirements    Programing, finite element simulation