Experimental Investigation of Polymer-Coated Silica Nanoparticles for EOR under Harsh Reservoir Conditions of High Temperature and Salinity

Abstract

Laboratory experiments have shown higher oil recovery with nanoparticle (NPs) flooding. Accordingly, many studies have investigated the nanoparticle-aided sweep efficiency of the injection fluid. The change in wettability and the reduction of the interfacial tension (IFT) are the two most proposed enhanced oil recovery (EOR) mechanisms of nanoparticles. Nevertheless, gaps still exist in terms of understanding the interactions induced by NPs that pave way for the mobilization of oil. This work investigated four types of polymer-coated silica NPs for oil recovery under harsh reservoir conditions of high temperature (60 ∘C) and salinity (38,380 ppm). Flooding experiments were conducted on neutral-wet core plugs in tertiary recovery mode. Nanoparticles were diluted to 0.1 wt.% concentration with seawater. The nano-aided sweep efficiency was studied via IFT and imbibition tests, and by examining the displacement pressure behavior. Flooding tests indicated incremental oil recovery between 1.51 and 6.13% of the original oil in place (OOIP). The oil sweep efficiency was affected by the reduction in core’s permeability induced by the aggregation/agglomeration of NPs in the pores. Different types of mechanisms, such as reduction in IFT, generation of in-situ emulsion, microscopic flow diversion and alteration of wettability, together, can explain the nano-EOR effect. However, it was found that the change in the rock wettability to more water-wet condition seemed to govern the sweeping efficiency. These experimental results are valuable addition to the data bank on the application of novel NPs injection in porous media and aid to understand the EOR mechanisms associated with the application of polymer-coated silica nanoparticles.

Sorption of Nanomaterials to Sandstone Rock

“…Additionally, nanomaterials could be in competition with weakly associated alkali cations, as described by Qiu et al [35]. According to Van den pol et al [36], alkali consumption is increasing with cation exchange capacity (CEC).…”

Lignin Nanoparticles as Highly Efficient, Recyclable Emulsifiers for Enhanced Oil Recovery

“…However, it is mainly utilized as sacrificial agent, in combination with more expensive petroleum sulfonate surfactants. , Currently, there are also a number of inorganic nanoparticles employed as emulsifiers in EOR applications, such as SiO 2 nanoparticles. These, however, often require more complex grafting modifications to make them amphiphilic, or should be used in combination with surfactants giving a higher total concentration. − Lignin nanoparticles (LNPs) are excellent emulsifiers, as well as Pickering emulsion stabilizers, which have been proved by previous research. − If successful, preparation of LNPs as bio-emulsifiers for EOR would provide a new platform for high value-added applications of lignin. More importantly, due to the alkali solubility properties of lignin, , it is expected that the stable emulsion produced from LNPs can be demulsified to facilitate the separation of oil and water and recover the emulsifier.…”

Thermophysical Properties of Nanofluid in Two-Phase Fluid Flow through a Porous Rectangular Medium for Enhanced Oil Recovery

“…Despite several experimental and modeling investigations, there is currently no exact explanation for the impacts of nanoparticles on the rise in oil recovery during nanofluid flooding, which limits the adoption of the method in the industry. Some suggested theories for understanding the influence of nanofluids on oil extraction include surface tension-lowering techniques [ 32 , 33 , 34 , 35 ], the alteration of the porous medium’s wettability [ 36 , 37 , 38 ], and the change in viscosity [ 39 , 40 , 41 , 42 , 43 , 44 ].…”