Monitoring wettability alteration by silica nanoparticles during water flooding to heavy oils in five-spot systems: A pore-level investigation (original) (raw)
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Transport in Porous Media, 2011
It is well known that the oil recovery is affected by wettability of porous medium; however, the role of nanoparticles on wettability alteration of medium surfaces has remained a topic of debate in the literature. Furthermore, there is a little information of the way dispersed silica nanoparticles affect the oil recovery efficiency during polymer flooding, especially, when heavy oil is used. In this study, a series of injection experiments were performed in a five-spot glass micromodel after saturation with the heavy oil. Polyacrylamide solution and dispersed silica nanoparticles in polyacrylamide (DSNP) solution were used as injected fluids. The oil recovery as well as fluid distribution in the pores and throats was measured with analysis of continuously provided pictures during the experiments. Sessile drop method was used for measuring the contact angles of the glass surface at different states of wettability after coating by heavy oil, distilled water, dispersed silica nanoparticles in water (DSNW), polyacrylamide solution, and DSNP solution. The results showed that the silica nanoparticles caused enhanced oil recovery during polymer flooding by a factor of 10%. The distribution of DSNP solution during flooding tests in pores and throats showed strong water-wetting of the medium after flooding with this solution. The results of sessile drop experiments showed that coating with heavy oil, could make an oil-wet surface. Coating with distilled water and polymer solution could partially alter the wettability of surface to water-wet and coating with DSNW and DSNP could make a strongly water-wet surface.
Journal of Petroleum & Environmental Biotechnology
The mechanisms involved in nanoparticle application in enhanced oil recovery processes particularly when nanoparticles are used in conjunction with other chemical agents are still controversial. In this study, the main focus is on pore scale investigation of nanoparticle-surfactant mixture flooding as an enhanced oil recovery process. Five spot glass micro model experiments were conducted to study the oil recovery mechanisms in the presence of hydrophilic silica nanoparticles at various concentrations. Macroscopic oil recovery as well as pore fluid distributions were evaluated by the continuous images taken from the micro model during the injection process. The results represent that wettability alteration is the most important factor contributing to additional oil recovery when nanoparticles exist in the injected solution. Nanoparticles could significantly improve the oil recovery obtained during water and surfactant flooding. The oil film on the pore walls were slightly thinned by the sole surfactant solution while with the addition of nanoparticles, it was completely removed and became strongly water wet surface.
Day 1 Tue, May 14, 2019, 2019
Lack of relevant screening methods of oil recovery techniques for water flood with added nanoparticles in a given reservoir are hindering its implementation for enhanced oil recovery (EOR) purposes. Moreover, the understanding of the underlying mechanisms of oil increased by nanoparticles must be improved. In this work, we screened twenty-three different types of silica nanoparticles as additives to injection water for oil recovery applications. The nanoparticles were surface functionalised to remain stable in the injection water and be active at the surface. The hypothesis is that the particles will improve the microscopic oil recovery efficiency of water flood in an oil reservoir. The concentrated solution of nanoparticles were prepared to 0.1 wt % concentration in synthetic North Sea water. Crude oil was obtained from a field in the North Sea. The following investigations were carried out to quickly verify the performance of nanoparticle oil recovery: 1) secondary injection throu...
Processes
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 unders...
Petroleum Science, 2019
The applications of nanotechnology in oilfields have attracted the attention of researchers to nanofluid injection as a novel approach for enhanced oil recovery. To better understand the prevailing mechanisms in such new displacement scenarios, micromodel experiments provide powerful tools to visually observe the way that nanoparticles may mobilize the trapped oil. In this work, the effect of silicon oxide nanoparticles on the alteration of wettability of glass micromodels was investigated in both experimental and numerical simulation approaches. The displacement experiments were performed on the original water-wet and imposed oil-wet (after aging in stearic acid/n-heptane solution) glass micromodels. The results of injection of nanofluids into the oil-saturated micromodels were then compared with those of the water injection scenarios. The flooding scenarios in the micromodels were also simulated numerically with the computational fluid dynamics (CFD) method. A good agreement between the experimental and simulation results was observed. An increase of 9% and 13% in the oil recovery was obtained by nanofluid flooding in experimental tests and CFD calculations, respectively.
Journal of Molecular Liquids, 2019
A large number of core-flooding and micromodel experiments have examined the potential of nanoparticles to increase oil recovery. The mechanism of enhanced oil recovery using nanoparticles (nanoparticles-EOR) is still unclear. Nanoparticles may aid enhanced oil recovery because they may alter rock wettability and possibly reduce oil-water interfacial tension (IFT). The effect of nanoparticles on the oil-water IFT is controversial, as some have found that nanoparticles reduce IFT and others have illustrated that they have no significant effect. Nanoparticles' attachment at the oil-water interface, which causes IFT reduction is complex and bulk fluids properties (water and oil) directly affect their self-assembly. Fully understanding the driving forces causing self-assembly of nanoparticles at the oil-water interface and its controlling parameters are crucial for determining the effect of nanoparticles on IFT. In this research, by investigating the controlling parameters of nanoparticle attachment at the interface (bulk suspension properties including the concentration of nanoparticles, concentration of HCl, salinity, size and charge of nanoparticles, and operating conditions i.e. temperature and pressure), and coupling them with nanoparticles' stability in solution, the conditions under which silica nanoparticles can reduce oil-water interfacial tension are experimentally investigated. The results reveal that by appropriately designing the operating conditions, H +-protected silica nanoparticles can reduce the oil-water IFT. The maximum reduction of the oil-water IFT was obtained for 0.20 wt% silica nanoparticles in a solution containing 0.025 wt% HCl and 0.15 wt% nanoparticles in 0.0076 wt% HCl, where the IFT was reduced from 23.56 ± 0.36 mN/m to 12.81 ± 0.77 mN/m and from 22.61 ± 0.41 mN/m to 14.01 ± 0.87 mN/m, respectively. However, the minimum IFT reduction occurs when the surface energy reduction due to the adsorption of nanoparticles is minimal, i.e. the chance of nanoparticles to desorb from the interface due to thermal fluctuations is high, and nanoparticles' aggregation on the bulk surface is initiating.
Experimental investigation of surface-functionalised silica nanoparticles for enhanced oil recovery
2020
Enhanced oil recovery (EOR) using nanoparticles (NPs) has been proposed as a solution in the petroleum industry to overcome declining production rates. Research has shown that commercially available hydrophilic silica NPs, manufactured by Evonik Industries, as additives to water flood can increase oil production from oil reservoirs. However, recent advances show that surface modification can further improve the microscopic sweep efficiency of NPs due to improved solubility and stability, greater stabilisation of emulsions, and low retention on porous medium compared with bare nanoparticles. The hypothesis above was the initiation of the present project. Evonik Industries developed twenty-three different types of silica nanoparticles with surface functionalities for oil recovery applications. The NPs were supplied to us as special research and development products under the name AERODISP®, or more precisely AEROSIL® particles in liquid solution. Twenty-three unique glass micromodel i...
Enhancing Oil Recovery with Hydrophilic Polymer-Coated Silica Nanoparticles
Energies, 2020
Nanoparticles (NPs) have been proposed for enhanced oil recovery (EOR). The research has demonstrated marvelous effort to realize the mechanisms of nanoparticles EOR. Nevertheless, gaps still exist in terms of understanding the nanoparticles-driven interactions occurring at fluids and fluid-rock interfaces. Surface-active polymers or other surface additive materials (e.g., surfactants) have shown to be effective in aiding the dispersion stability of NPs, stabilizing emulsions, and reducing the trapping or retention of NPs in porous media. These prerequisites , together with the interfacial chemistry between the NPs and the reservoir and its constituents, can result in an improved sweep efficiency. This paper investigates four types of polymer-coated silica NPs for the recovery of oil from water-wet Berea sandstones. A series of flooding experiments was carried out with NPs dispersed at 0.1 wt.% in seawater in secondary and tertiary oil recovery modes at ambient conditions. The dynamic interactions of fluids, fluid-rock, and the transport behavior of injected fluid in the presence of NPs were, respectively, studied by interfacial tension (IFT), spontaneous imbibition tests, and a differential pressure analysis. Core flooding results showed an increase in oil recovery up to 14.8% with secondary nanofluid injection compared to 39.7% of the original oil in place (OOIP) from the conventional waterflood. In tertiary mode, nanofluids increased oil recovery up to 9.2% of the OOIP. It was found that no single mechanism could account for the EOR effect with the application of nanoparticles. Instead, the mobilization of oil seemed to occur through a combination of reduced oil/water IFT, change in the rock surface roughness and wettability, and microscopic flow diversion due to clogging of the pores.
Improving the microscopic sweep efficiency of water flooding using silica nanoparticles
Journal of Petroleum Exploration and Production Technology
Fluid/fluid and fluid/rock interfaces have large influence on the microscopic sweep efficiency of an enhanced oil recovery process. Therefore, modification of these interfaces using nanoparticles to suitable conditions might lead to better recovery factors. Particularly, wettability alteration and interfacial tension reduction are the two key mechanisms which should be considered. This study was designed to address the capability of nanoparticles to be used as a chemical agent for enhanced oil recovery by several core flooding experiments. The injected chemical solution was prepared using synthetic brine containing %3 NaCl, silica nanoparticles, and SDS surfactant. Contact angle in rock/oil/solution system and interfacial tension between oil/solution were measured. In addition, SEM pictures and XRD analysis were taken to conduct a more thorough investigation of effect of nanoparticles on sandstone core plugs. Nanoparticles and surfactant mixture were flooded with various concentrations under different scenarios. The results show the incremental oil recovery of nanoparticles floods in sandstone core samples which ranged from 4.85 to 11.7%. Conversely, the enhanced oil recovery of high concentration of nanoparticle floods in cores was small. It is deduced that the mechanisms responsible for incremental oil recovery are mainly interfacial tension reduction and wettability alteration toward water-wet condition. However, the flooding results as well as experimental study of possible retention revealed that nanoparticles can be considered as an effective chemical agent in enhanced oil recovery.
Petroleum Science, 2021
Enhanced oil recovery (EOR) processes are applied to recover trapped or residual oil in the reservoir rocks after primary and secondary recovery methods. Changing the wettability of the rock from oil-wet to water-wet is named wettability alteration. It is an important factor for EOR. Due to their unique properties, nanoparticles have gained great attention for improving oil recovery. Despite the promising results, the main challenges of applying nanoparticles are related to the colloidal stability of the nanofluids in the harsh conditions of the reservoirs. In recent years, polymer-grafted nanoparticles have been considered as novel promising materials for EOR. The obtained results showed that adding a hydrophobic agent trimethoxy (propyl) silane on the surface of modified silica nanoparticles with polyethylene glycol methyl ether has an effective role in improving retention and wettability alteration, especially in the oil-wet substrate due to hydrophobic interaction. The modified ...