In Situ Produced Nanoparticles at the Oil–Water Interface for Conformance Control and Enhanced Oil Recovery

Abstract

Nanoparticle-assisted enhanced oil recovery (Nano-EOR) has attracted intensive interest in the laboratory as a promising oil recovery technology. However, the nanoparticles’ stability and long-distance delivery of nanoparticles (NPs) in large-scale reservoirs are two main challenges. In this work, we developed a novel concept of in situ synthesizing NPs at the oil–water interface inside the reservoir for EOR instead of injecting presynthesized NPs from outside. The pore-scale flooding experiments show that EOR efficiencies for tertiary flooding were 6.3% without reaction (Case 3), 14.6% for slow reaction (Case 1), and 25.4% for relatively quick reaction (Case 4). Examination of the EOR mechanism shows that in situ produced SiO2 NPs in microchannels could alter the substrate wettability toward neutral wetting. Moreover, the produced NPs tended to assemble on the immiscible oil–water interface, forming a barrier toward interface deformation. As the reaction continued, excessive surface-modified NPs could also diffuse into aqueous brine and accumulate as a soft gel in the flowing path swept by brine. Collectively, these processes induced a “shut-off” effect and diverted displacing fluids to unswept areas, which consequently increased the sweep efficiency and improved the oil recovery efficiency. Auxiliary bulk-scale experiments also showed that the reaction-induced nanoparticle synthesis and assembly at an immiscible interface reduced the interfacial tension and generated an elastic oil–water interface.

Unveiling the revolutionary role of nanoparticles in the oil and gas field: Unleashing new avenues for enhanced efficiency and productivity

“…Through the application of nanoparticles, information about porosity, permeability, fluid saturation, and geological heterogeneity can be obtained [ 357 , 358 ]. Injecting nanoparticles into the reservoir enables the tracking of fluid flow paths and identification of preferential channels within the rock formation [ [359] , [360] , [361] ]. Also, nanoparticles improve the sweep efficiency and reduce the interfacial tension between oil and water thereby enhancing oil recovery [ 362 , 363 ].…”

Shear-induced structural and viscosity changes of amphiphilic patchy nanocubes in suspension

“…Colloidal self-assembly has attracted much attention in both science and industry owing to their potential applications, e.g., oil recovery, [1][2][3] drug delivery, [4][5][6] catalysis, [7][8][9] and biosensing. [10][11][12] The collective and enhanced dynamics and properties of these materials arise not only from the chemical nature of the nanoparticles, but also from their complex self-assembled structures.…”

Review on Microemulsions for Conformance Improvement Technology: Fundamentals, Design Considerations, and Perspectives

“…Conformance problems are often encountered as a result of the presence of high-permeability streaks between injectors and producers, such as faults, fractures, and thief zones, resulting in significant bypassed oil. Conformance control aims to plug high-permeability regions to divert flow toward unswept low-permeability regions. − This process encompasses the use of a variety of chemical fluids or mechanical means to redistribute the water-drive streamlines. ,− A conforming drive is designed to attain enhanced recoveries for extended periods as well as reduce costs from excessive water recycling. − Chemical conformance treatment may be applied either via injector or producer wells of mature areas with the field. However, it is generally preferred to inject conformance chemicals through a producer well compared to an injector well to attain a faster response to restrict water production. , The injection of conformance control chemicals has been applied with good results, but the application is recognized to be very challenging and dynamic in pilot- and field-scale operations. , …”