Pore-scale investigation on compaction-dependent characteristics of granular packs and their impact on multiphase fluid distribution
Open Access
- Author:
- Torrealba, Victor Antonio
- Area of Honors:
- Petroleum and Natural Gas Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Zuleima T. Karpyn, Thesis Supervisor
Turgay Ertekin, Thesis Honors Advisor - Keywords:
- Petroleum engineering; porous media; fluid flow; compaction; mul
- Abstract:
- Understanding the coupled effect of rock deformation and changing stress conditions on multiphase flow in porous media is of fundamental importance for the study of depleting oil and gas reservoirs, active aquifers, and nuclear waste disposal sites. These geomechanical properties are not well understood for complex porous systems, and their impact on fluid flow behavior is often misconceived. The purpose of this investigation is to contribute in filling this gap in understanding by conducting experiments involving single- and multi-phase flow through bead packs at different confining pressure conditions. Cycles of drainage and imbibition were conducted on a water-wet soda-lime glass bead pack with varying confining stress conditions. The power of X-ray microtomography was harnessed to quantify and visualize the degree of compaction the system underwent, and the residual saturation of the water and oil phases for each stress condition after a given injection process. Gradient-based segmentation methods were found to be a suitable tool to differentiate between the two fluids phases, and the moving solid phase. The degree of compaction was the main variable controlling the fluid displacement mechanism and phase trapping. It was found that an increase in confining pressure has a stabilizing effect on the displacing front under both drainage and imbibition. Additionally, it was found that the compaction process after imbibition promotes the disconnection of blobs, which in turn decreases the mobility of the oil phase, and hence, translates into poor oil recovery by water flooding. Finally, it was observed that for the confining pressure range under consideration, porosity and tortuosity operate under two distinct rates of change, each corresponding to a given confining pressure interval. Finally, the specific surface area was found to be a more sensitive pore-scale property than porosity, and in turn, caution must be taken when considering the scaling-up of this property for modeling purposes at the pore- or field-scale. These results will improve the current understanding of coupled geomechanics and fluid flow in porous media, and increase the predictive capabilities of pore-scale modeling tools.