Bibliography - M. Preisig

1. Goumiri, I., Jean Hervé Prévost, and M. Preisig, 2011: The effect of capillary pressure on the saturation equation of two-phase flow in porous media. International Journal for Numerical and Analytical Methods in Geomechanics, John Wiley & Sons, Ltd., doi:10.1002/nag.1022
   [ Abstract ]

   A complete and accurate simulation of two-phase flow in porous media requires knowledge of all the controlling physics (and values of physical parameters) that play a relevant role and an understanding of the effects of each one on the solution. Of particular concern here is the effect of capillary pressure and the length scale over which it is relevant. The goal of this paper is to provide guidance onto when to include the effects of capillary pressure in the model, and onto what are the resulting length scale restrictions if those effects are to be included.

2. Preisig, M., and Jean Hervé Prévost, 2011: Coupled multi-phase thermo-poromechanical effects. Case study: CO₂ injection at In Salah, Algeria. International Journal of Greenhouse Gas Control, doi:10.1016/j.ijggc.2010.12.006
   [ Abstract ]

   Coupled simulations of fluid injection and extraction in porous media are an important tool for assessing feasibility, safety and productivity of such operations. Different methods for coupling the fluid flow with geomechanics are currently used. In this paper we compare one-way and iterative coupling with full coupling. With the fully coupled two-phase thermo-poromechanical model we simulate the CO₂ injection operation, which is ongoing at In Salah, Algeria. The results suggest that pressure increase in the well and ground uplift for a given data set can accurately be modeled using our method. Finally, we illustrate the crucial effect of the temperature difference between injected fluid and reservoir on the possibility of creating and/or re-opening fractures perpendicular to the well in the cap rock that were observed in the field.

3. Preisig, M., and Jean Hervé Prévost, 2011: Fully coupled simulation of fluid injection into geomaterials with focus on nonlinear near-well behavior. International Journal for Numerical and Analytical Methods in Geomechanics, Wiley Online Library, doi:10.1002/nag.1039
   [ Abstract ]

   An important part of our global wealth depends on the extraction of fluids from porous media. More recently, sequestration of carbon dioxide (CO₂) into deep geological layers as a possible measure to mitigate climate change has increased interest in fluid injection into porous media. Sophisticated numerical models play an important role in managing the uncertainties related to the subsurface, and finite element methods are the most versatile tool allowing the coupling of fluid flow, geomechanics and other physical processes. This paper gives insight into two important aspects of fluid injection/extraction in porous media: the correct modeling of the bore hole through specification of initial stresses, which together with a fully coupled strategy allows simulation of nonlinear poromechanics, and the imposition of appropriate boundary conditions that allow the controlled injection/extraction of a total specified amount of fluid in an anisotropic porous medium, without exceeding a safe operating pressure.

4. Prévost, Jean H., and M. Preisig, 2010: Numerical simulation of CO2 injection into an aquifer and the importance of two-way coupling between fluid pressure and geomechanics. Conference of the Engineering Mechanics Institute, 8-11
5. Preisig, M., and Jean Hervé Prévost, 2010: Stabilization procedures in coupled poromechanics problems: A critical assessment. International Journal for Numerical and Analytical Methods in Geomechanics, doi:10.1002/nag.951 1-19
   [ Abstract ]

   Numerical solutions for problems in coupled poromechanics suffer from spurious pressure oscillations when small time increments are used. This has prompted many researchers to develop methods to overcome these oscillations. In this paper, we present an overview of the methods that in our view are most promising. In particular we investigate several stabilized procedures, namely the fluid pressure Laplacian stabilization (FPL), a stabilization that uses bubble functions to resolve the fine-scale solution within elements, and a method derived by using finite increment calculus (FIC). On a simple one-dimensional test problem, we investigate stability of the three methods and show that the approach using bubble functions does not remove oscillations for all time step sizes. On the other hand, the analysis reveals that FIC stabilizes the pressure for all time step sizes, and it leads to a definition of the stabilization parameter in the case of the FPL-stabilization. Numerical tests in one and two dimensions on 4-noded bilinear and linear triangular elements confirm the effectiveness of both the FPL- and the FIC-stabilizations schemes for linear and nonlinear problems.

Direct link to page: http://cmi.princeton.edu/bibliography/results.php?author=4615