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Foam is to be used as a blocking agent for confining a pollutant source zone and avoid spreading in an aquifer. To this end, it is necessary to determine where injected foam flows and stays inside a porous medium. This study examines the use of electrical resistivity tomography for this purpose. Foam is injected in a large-scale 3D heterogeneous porous medium (0.84 × 0.84 × 0.84 m). During the injection, electrical resistivity tomography measurements are performed. We show that combining a large number of measurements with inversion techniques allows for the monitoring of a foam front in 3D during the injection process.

This paper presents a comparison of hydraulic oil conductivity obtained from interpreting bail-down test data to values calculated from theory. The bail-down tests were performed at laboratory scale, on a radial portion of a circular domain filled with calibrated sand allowing hydraulic oil conductivity to be calculated using Parker’s theoretical model (Parker et al. in Water Resour Res 23(4):618–624, 1987). The bail-down tests were interpreted using the modified Bouwer and Rice (Huntley in Ground Water 38(1):46–52, 2000) and the modified Cooper methods (Beckett and Lyverse in API Interact LNAPL Guide 2:1–27, 2002). The results show that (1) both interpretation methods from bail-down test data give similar hydraulic oil conductivities, and (2) the hydraulic oil conductivities estimated from bail-down test data agree well with the hydraulic oil conductivity predicted when using the Parker theoretical model. Overall, this paper confirms that the modified Bouwer and Rice (Huntley 2000) and the modified Cooper methods (Beckett and Lyverse 2002) are valid to estimate hydraulic oil conductivity, giving realistic values despite test conditions not meeting all the assumptions and boundary conditions of each analytical solution.

The injection of steam is a well-established technique for the thermally enhanced remediation of both unsaturated and saturated soils. Under saturated conditions, there is a limitation related to the thermal radius of influence (TRI) which results from the balance between viscous forces due to injection and buoyant forces due to the density difference between steam and water. Targeted preheating of the soil reduces the required time for a gaseous (steam) flow to be established after the beginning of a steam injection into the soil. Compared to non-preheated zones, the region where steam exists reaches a larger lateral extent before buoyancy eventually leads to a vertical breakthrough of the steam. This study investigates the impacts of preheating on the thermal radius of influence by considering different preheating scenarios with a full-complexity, 3D, non-isothermal numerical model including phase change. The achievable benefits of preheating are discussed; the potential costs of preheating are also considered. It is shown that preheating increases the TRI by more than 10 %. This is not much, but it suggests that preheating is an interesting option in cases where the increased TRI leads to a reduced number of injection wells required.

Contamination of soil and groundwater with nonaqueous phase liquid represents a major environmental concern because of the negative effect on human health. Traditional soil flushing techniques have been proved ineffective in heterogeneous aquifers, since liquids for remediation flow preferentially through the most permeable layers and residual oil remains trapped in the low-permeability sediments. To improve the sweep efficiency, fluids with lower mobility than resident liquids can be injected, such as polymers or in situ generated foam. In addition, foam has the potential of selectively reducing mobility in higher-permeability layers compared to lower-permeability layers. The use of foams has not been popular because foam mobility is difficult to predict. In this paper, a series of 1D column experiments were conducted to investigate the variation of the resistance factor RF as a function of the permeability. Five types of sand and calibrated glass beads were used to obtain porous media of permeabilities ranging from 250 millidarcy to 100 Darcy. Two commercial nonionic surfactants, \(\hbox {Triton}^{{\circledR }}\) X-100 (commonly used but toxic) and sucrose laurate (environmentally friendly surfactant, biodegradable), were used at a concentration equal to 10 critical micelle concentration. Columns were first saturated with water and then flushed with 1.5 PV (pore volumes) of surfactant solution in order to achieve the adsorption of molecules into the soil matrix. Then, co-injection of air and surfactant solution was performed at a constant total rate to generate in situ foam. The quality of the foam was varied from 85 to 99 % to investigate the effect of this parameter on the resistance factor. A graphic showing the dependence of RF and the permeability is presented. Results suggest that for the same total flow rate, the RF decreases as permeability increases, but for permeabilities smaller than 1 Darcy, the RF is weak, probably due to the difficulty to generate stable foam under high capillary pressures. Variations in foam quality and surfactant type do not seem to have an important effect on the results regarding RF. The presented results are assistance for predicting foam behavior in porous media of different permeabilities.