Core Flooding of Complex Nanoscale Colloidal Dispersions for Enhanced Oil Recovery by in Situ Formation of Stable Oil-in-Water Pickering Emulsions

Abstract

This study reports a Pickering emulsion flooding system, in which the oil–water interface is structurally stabilized by a complex colloidal layer consisting of silica nanoparticles, dodecyltrimethylammonium bromide (DTAB), and poly­(4-styrenesulfonic acid-co-maleic acid) sodium salt (PSS-co-MA). The colloidal layer was generated by adsorption of PSS-co-MA on the silica nanoparticles as a result of the van der Waals attraction and by adsorption of DTAB onto the PSS-co-MA layer as a result of the electrostatic attraction, thus providing the mechanically robust, stable interface. To demonstrate a practical applicability to the enhanced oil recovery, the complex colloidal dispersion fluid was injected into the Berea sandstone for a core flooding experiment. The result revealed that the colloidal dispersion significantly increased the oil recovery by ∼4% compared to the case of flooding water. This means that the emulsion drops in situ produced in the core could readily flow through the rock pores. We attribute this to the fact that the oil–water interface made with the complex colloidal phase not only increased the structural stability of the emulsion drops but also provided them deformability without any drop breakup or coalescence.

Effect of Nanoparticles on Spontaneous Imbibition of Water into Ultraconfined Reservoir Capillary by Molecular Dynamics Simulation

“…Imbibition in porous media is ubiquitous and has numerous applications in many natural and industrial processes, such as groundwater remediation, oil recovery, and nanofluidic devices [1][2][3][4][5][6][7]. For the imbibition phenomena, capillary action is the main transport mechanism for the spontaneous process, which results in the diffusing motion of fluid into porous solids or the capillary [8][9][10][11].…”

Fine-Tuning Nanoparticle Packing at Water–Oil Interfaces Using Ionic Strength

“…Pickering emulsions have found widespread uses, including solid phase extraction, 5,6 drug encapsulation, 7 and enhanced oil recovery. 8,9 Depending on the uniformity of their size, the colloidal particles confined to the interface can densely pack into 2D crystalline arrays as the emulsions coarsen, reducing the interfacial energy. 10 An alternate strategy is to disperse functionalized nanoparticles (NPs) in one fluid and ligands, oligomeric or polymeric, in the second immiscible fluid, that are end-functionalized where the functionalization is complementary to the functionality on the NPs.…”

Mechanical phase inversion of Pickering emulsions via metastable wetting of rough colloids

“…Colloidal particles and liquid interfaces bear significant importance in addressing fundamental scientific questions and present many opportunities in industrial applications, ranging from food 1 to heavy oil processing. 2,3 Since the seminal observations of Ramsden and Pickering, 4,5 partially wetting colloidal particles trapped at liquid interfaces have been proposed as excellent emulsion and foam stabilizers. Depending on their wettability, particles larger than a few nanometers can have energies binding them to a fluid interface that easily exceed thermal energy by several orders of magnitude.…”