Foam flow and its blocking effect in high permeable saturated porous media
Résumé
Liquid foam has been studied as a blocking agent in porous media, especially for Enhanced Oil Recovery applications [1]. The goal of foam injection is to block high-permeability layers in the media in order to reach the oil in low-permeability layers. This technique can also be used for remediation [2]. In fact, reaching pollutants in low-permeability layers can also be difficult during remediation processes. However, contrary to oil industry, soils are non-consolidated porous media with high permeability as well as low pressure and temperature operational conditions. The main goal of this study is to isolate the pollution treatment zone downstream of the groundwater flow by blocking it upstream. That is why, we aim to give a better understanding of foam flow in heterogeneous and high permeability (100-10 000 darcys) porous media, with competition of high velocity groundwater flow (10 m/day). Two different experimental setups were used to obtain the results. The first one is composed of a column of sand or glass beads, instrumented with pressure sensors to monitor the pressure gradient during foam flow. Mass balance was also conducted to measure the water saturation in the column. The second one is composed of a thin 1 m large and 50 cm high tank to model a 2D flow. The tank is instrumented with pressure and water saturation sensors. In addition, an imaging technique is used to measure the evolution of foam volumes, streamlines and water saturations. During the experiments, foam is injected from the bottom of the tank and water is injected from left to right to model a groundwater flow. Finally, the experimental results are compared with numerical models in order to validate them. The validated model can be then used to simulate foam injection for field scale studies.
[1] R. Farajzadeh, A. Andrianov, and P. L. J. Zitha, Investigation of immiscible and miscible foam for enhancing oil recovery, Industrial & Engineering chemistry research, 49.4, 1910-1919 (2009).
[2] G. J. Hirasaki et al., Surfactant/foam process for aquifer remediation, International symposium on oilfield chemistry, Society of Petroleum Engineers (1997).