Surfactant screening for foam EOR: Correlation between bulk and core-flood experiments

Abstract

Aqueous foams play an important role in many industrial processes, from ore separation by froth flotation to enhanced oil recovery (EOR). In the latter case, the foam is used as a means of increasing the sweep efficiency through the oil bearing rock -the complex, structure dependent, flow behaviour of the foam [Jones et al., 2013] means that it has improved penetration of lower permeability regions than would be obtained with a Newtonian fluid. An understanding of how foam behaves when flowing through a rock is therefore of great importance when selecting suitable surfactants for EOR processes.Previous tests have suggested that there is no reliable correlation between bulk foam behavior and foam behavior in a rock core, especially in the presence of oil [Dalland et al., 1994;Mannhardt et al., 2000]. We present a comparative study of bulk stability tests and core floods with foam, both with and without oil. Core-flood tests were conducted in rock cores with a diameter of 1 cm and length of 17cm, significantly smaller than typical cores [Jones et al, 2015]. Apparent viscosity / injected gas fraction response curves were obtained, both with and without oil in the system. This current work found that there is a positive correlation between bulk foam stability and core flood performance in the absence of oil. Bulk foam experiments can therefore be a useful screening tool to get a good indication of the surfactant performance in the core flood. However, there was no correlation found between bulk foam stability and the performance in the core for the experiments performed in the presence of oil.It is crucial to select the right surfactant, as it stabilizes the foam. The surfactant selection is specific to the application; it depends of the rock chemistry, water salinity, reservoir temperature and the oil type. The general consensus is that the most representative test of the foam behavior, especially in presence of oil, is the coreflood experiment at the reservoir conditions. However coreflood tests are timedemanding and expensive so that only a limited number of surfactants can be tested. Bulk foam tests

An Overview of the Present Stability and Performance of EOR-Foam

“…In their result (Figure 6), it can be observed that as the concentration of foaming agent increases, the foam height and foam half-life increased considerably, while the surface tension lowered. From the figure, it can also be observed that the IFT values are in direct relationship with the half-life value, hence this clearly supports the findings of Jones et al (2016) above with respect to foam stability. Therefore, the plot of IFT and foam half-life could serve as a method to describe the foam quality and the stability.…”

“…The work of Jones et al (2016) described the relationship between the foam half-life and IFT to measure the foam stability. They found that, foam stability assessment could not be established from the plot of foam half-life against the IFT in the absence of oil.…”

“…Jones et al (2016) studied the µ app of six different foaming solutions (solution 1-6) to describe the foam quality as the parameter index for stability in the absence and presence of oil. The results are presented in Figure 4, which is a plot of µ app as a function of the foam quality.…”

Simultaneous feasible injectivity of foam and hydrolyzed polyacrylamide to optimize the oil recovery enhancement

“…Although both mechanisms are within the mechanism of capillary pressure, capillary adsorption utterly depends on the surfactant formulation in comparison to the capillary snap-off. Two-dimensional presentation of foam system are being graphically depicted in Figure 1 (Jones et al, 2016a(Jones et al, , 2016bKapetas et al, 2016Kapetas et al, , 2017Khoshnevis et al, 2017;Li et al, 2006;Razmjoo et al, 2017).…”

A rigorous approach to analyze bulk and coreflood foam screening tests

“…This diffusion causes the coarsening of bubble sizes with time as the smaller bubbles gradually coalesce into larger bubbles. Finally, the foam becomes dry and takes polyhedral structure (Jones et al 2016). Recently, the coarsening behavior has been investigated in porous media by Jones (2018) at both pores and core scales using micromodel and sandstone core.…”