Impact of Rock Heterogeneity on Interactions of Microbial-Enhanced Oil Recovery Processes

Abstract

Residual oil saturation reduction and microbial plugging are two crucial factors in microbial-enhanced oil recovery (MEOR) processes. In our previous study, the residual saturation was defined as a nonlinear function of the trapping number, and an explicit relation between the residual oil saturation and the trapping number was incorporated into a fully coupled biological (B) and hydrological (H) finite element model. In this study, the BH model is extended to consider the impact of rock heterogeneity on microbial-enhanced oil recovery phenomena. Numerical simulations of core flooding experiments are performed to demonstrate the influences of different parameters controlling the onset of oil mobilization. X-ray CT core scans are used to construct numerical porosity-permeability distributions for input to the simulations. Results show clear fine-scale fingering processing, and that trapping phenomena have significant effects on residual oil saturation and oil recovery in heterogeneous porous media. Water contents and bacterial distributions for heterogeneous porous media are compared with those for homogenous porous media. The evolution of the trapping number distribution is directly simulated and visualized. It is shown that the oil recovery efficiency of EOR/MEOR will be lower in heterogeneous media than in homogeneous media, largely 123 374 J. Li et al. due to the difficulty in supplying surfactant to unswept low-permeability zones. However, MEOR also provides efficient plugging along high-permeability zones which acts to increase sweep efficiency in heterogeneous media. Thus, MEOR may potentially be more suited for highly heterogeneous media than conventional EOR.

Microbe-induced fluid viscosity variation: field-scale simulation, sensitivity and geological uncertainty

“…Unable to simulate real field scenarios such as microbe-induced selective plugging and oil viscosity reduction 4. Neglects redox and chemistry of reactions Behesht et al (2008), Bryant and Lockhart (2002), Desouky et al (1996), Gianetto (1999), Islam and Farouq Ali (1990), Li et al (2012), Nielsen (2010), Nielsen et al (2016), Saito et al (2016), Shabani-Afrapoli et al (2011, Sugai et al (2014Sugai et al ( , 2007 Ansah et al (2018b) and Bultemeier et al (2014) production and 36% increase for the Xinjiang field, respectively. Both recovered these oil increments because of reduction in oil viscosity (Segovia et al 2009).…”

Investigation of spore forming bacterial flooding for enhanced oil recovery in a North Sea chalk Reservoir

“…Injection of nutrients/and or bacteria into these preferential pathways and stimulation of the bacterial growth in situ will block the water channels, either with bacterial cells or polymers produced in situ by the growing bacteria. Blocking of these channels will alter the water pathways to the previously unswept pore space (Crescente et al, 2005;Jenneman et al, 1996;Li et al, 2012;Nagase et al, 2002;Yakimov et al, 1997). This concept is known as microbial selective plugging as illustrated in Fig.…”

The Effect of Bacteria Penetration on Chalk Permeability

“…One of them is the changes in flow behavior due to bioclogging or selective plugging (Afrapoli et al, 2011;Armstrong and Wildenschild, 2012). Injection of bacterial populations may serve plugging water-bearing zones and attaining more uniform displacement of oil from heterogeneous rock (Li et al, 2012).…”