The Effect of Wettability and Flow Rate on Oil Displacement Using Polymer-Coated Silica Nanoparticles: A Microfluidic Study

Abstract

Polymer-coated silica nanoparticles (PSiNPs) have been experimentally investigated in core- and micro-scale studies for enhanced oil recovery (EOR). Wettability and flow rate have a considerable effect on oil displacement in porous media. This work investigates the efficiency of PSiNPs for oil recovery on micro-scale at three wettability states (water-wet, intermediate-wet, and oil-wet). In addition, a cluster mobilization regime is considered in all experiments. A microfluidic approach was utilized to perform flooding experiments with constant experimental settings such as flowrate, pore-structure, initial oil topology, porosity, and permeability. In this study, the wettability of the microfluidic chips was altered to have three states of wettability. Firstly, a micro-scale study (brine-oil-glass system) of each wettability condition effect on flow behavior was conducted via monitoring dynamic changes in the oleic phase. Secondly, the obtained results were used as a basis to understand the changes induced by the PSiNPs while flooding at the same conditions. The experimental data were extracted by means of image processing and analysis at a high spatial and temporal resolution. Low injection rate experiments (corresponding to ~1.26 m/day in reservoir) in a brine-oil-glass system showed that the waterflood invaded with a more stable front with a slower displacement velocity in the water-wet state compared to the other states, which had water channeling through the big pores. As a result, a faster stop of the dynamic changes for the intermediate- and oil-wet state was observed, leading to lower oil recoveries compared to the water-wet state. In a cluster mobilization regime, dynamic changes were noticeable only for the oil-wet condition. For the aforementioned different conditions, PSiNPs improved oil displacement efficiency. The usage of PSiNPs showed a better clusterization efficiency, leading to a higher mobilization, smaller remaining oil clusters, and lower connectivity of the residual oil. The knowledge from this experimental work adds to the understanding of the behavior of polymer-coated silica nanoparticles as a recovery agent at different wettability states and a cluster mobilization regime.

Experimental Investigation of the Effect of Silica Nanoparticles on Interfacial Tension and Wettability during Low Salinity Water Flooding: A Micromodel Study

“…Surfasil has a short chain, consisting of dichlorooctamethyltetrasiloxane; when it is applied to a glass surface, the unhydrolyzed chlorines present on the chain react with silanol groups on the glass surface, forming a neutral or hydrophobic surface, depending on the concentration, film over the entire surface [17] . SurfaSil was diluted in heptane at a concentration of 1v/v % and 0.05v/v % to change the wettability towards oil-wet and intermediate-wet states, respectively [15] .…”

Three-Dimensional Numerical Simulations and Antifouling Mechanism of Microorganisms on Microstructured Surfaces

“…In the early 20th century, Wenzel et al [9] and Cassie et al [10] discovered that different surface roughness values would lead to different wettability of materials. Numerous studies have been conducted to explore the influence of wettability on biological attachments [11,12]. Since then, scholars from various countries have begun to design anti-fouling surfaces with different microstructures and have conducted a large number of experimental studies.…”

“…Schumacher et al [13] studied four types of microstructural surfaces with 2-mm spacing and 3-mm height. Patterns designed included geometric features of 2-mm-wide ribs of various lengths (4,8,12, and 16 mm), 2-mm-diameter circular pillars, 2-mm-wide continuous ridges, and 10-mm equilateral triangles. Experimental results showed that these surfaces correspondingly reduced spore settlement by 77%, 58%, 36%, and 31%, respectively.…”

Enhancing Oil Recovery with Hydrophilic Polymer-Coated Silica Nanoparticles

“…The functionalization or coating of the surface layer of the particle with polymer chains or other surface additive materials is a novel active area of scientific research; the technique has been desired for improving dispersion stability, for the stabilization of emulsions, to decrease the trapping or retention of NPs in porous media, and to improve the transport of NPs through reservoir pore channels, fundamental pre-requisites for nanoparticle oil recovery process. Omran et al [12] studied the potential of polymer-coated silica NPs to improve sweep efficiency on a micro-scale. Their study showed that NPs performed more efficiently in water-wet glass micromodels than in intermediate and oil-wet rock models.…”

“…Their study showed that NPs performed more efficiently in water-wet glass micromodels than in intermediate and oil-wet rock models. The displacement efficiency was attributed to the ability of NPs to promote better clusterization of oil, thus leaving small and less connected oil drops trapped in the pores of the micromodel [12]. Saigal et al [13] reported that silica NPs covalently grafted with polymer chains (2-(dimethylamino)ethyl methacrylate) were extremely efficient emulsifier agents at low concentrations.…”