Microbial Mineralization of Montmorillonite in Low-Permeability Oil Reservoirs for Microbial Enhanced Oil Recovery

Abstract

Microbial mineralization (corrosion, decomposition, and weathering) has been investigated for its role in the extraction and recovery of metals from ores. Here we report our application of biomineralization for the microbial enhanced oil recovery in low-permeability oil reservoirs. It aimed to reveal the etching mechanism of the four Fe(III)-reducing microbial strains under anaerobic growth conditions on Ca-montmorillonite. The mineralogical characterization of Ca-montmorillonite was performed by Fourier transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscopy, and energy-dispersive spectrometry. Results showed that the microbial strains could efficiently reduce Fe(III) at an optimal rate of 71%, alter the crystal lattice structure of the lamella to promote interlayer cation exchange, and efficiently inhibit Ca-montmorillonite swelling at a rate of 48.9%. Microbial mineralization is ubiquitous in the natural environment. Microbes in low-permeability reservoirs are able to facilitate alteration of the structure and phase of the Fe-poor minerals by reducing Fe(III) and inhibiting clay swelling, which is still poorly studied. This study aimed to reveal the interaction mechanism between Fe(III)-reducing bacterial strains and Ca-montmorillonite under anaerobic conditions and to investigate the extent and rates of Fe(III) reduction and phase changes with their activities. Application of Fe(III)-reducing bacteria will provide a new way to inhibit clay swelling, to elevate reservoir permeability, and to reduce pore throat resistance after water flooding for enhanced oil recovery in low-permeability reservoirs.

Controlling the Hydro-Swelling of Smectite Clay Minerals by Fe(III) Reducing Bacteria for Enhanced Oil Recovery from Low-Permeability Reservoirs

“…Consequently, these bio-mineralization behaviors induced the shrinkage of the swelled smectite clay minerals. The occurrence of the above phenomenon verified our previous research wherein FeRM could weaken the hydro-swelling property of smectite clay minerals by changing the mechanical and mineralogical characteristics of the minerals [20]. Moreover, the size distribution (<60 µm) of the mineral particles decreased before and after the FeRM treatment (Figure S3), indicating that FeRM changed the structure and properties of the smectite clay minerals themselves and their metabolites with the hydro-swelling of clay minerals, and further stabilized or prevented the migration of clay particles to clog the pore-throats.…”

“…On the other hand, the development of pore-throats was controlled by the conversion of smectite to illite under the action of FeRM. The mesopores' volume and surface areas will increase with the smectite layers converting into illite [20,33].…”

“…The physical and chemical properties of clay minerals are largely controlled by the action of bio-mineralization [19]. In response, the changes in these mineral properties also affect the pore structure and permeability of the reservoir, and the formation process, quantity, spatial distribution, and the re-migration and enrichment of the remaining oil [16,20].…”

“…For instance, Kim et al found that the dissimilatory Fe(III) reducing microorganisms (FeRM) could induce the conversion of smectite to a less swellable mineral, smectite [21]. Our group recently reported that FeRM could also facilitate the transformation of smectite to illite, thereby efficiently inhibiting minerals' swelling [20]. With the help of FeRM, the reaction of smectite-illite took place within 14 days at room temperature and pressure.…”

Comparison of Corrosion Rate in the Environment of 10% Acetic Acid solution with different Deflection.

“…The corrosion rate on the 5L-X65 API carbon steel pipe with the three poin loading method on acetic acid solution filled with CO2 gas and H2S in saturated state [13]. Analysis stress Corrosion Cracking on carbon steel pipe API 5L-X65 in Solution 7900 ml of Sea Water and 100 ml of Ammonia filled with CO2 and H2S Gases in Saturated Condition.…”