Development and Evaluation of Surfactant Nanocapsules for Chemical Enhanced Oil Recovery (EOR) Applications

Abstract

The primary objective of this study is the synthesis of nanocapsules (NC) that allow the reduction of the adsorption process of surfactant over the porous media in enhanced oil recovery processes. Nanocapsules were synthesized through the nanoprecipitation method by encapsulating commercial surfactants Span 20 and Petro 50, and using type II resins isolated from vacuum residue as a shell. The NC were characterized using dynamic light scattering, transmission electron microscopy, Fourier transform infrared, solvency tests, softening point measurements and entrapment efficiency. The obtained NC showed spherical geometry with sizes of 71 and 120 nm for encapsulated Span 20 (NCS20), and Petro 50 surfactant (NCP50), respectively. Also, the NCS20 is composed of 90% of surfactant and 10% of type II resins, while the NCP50 material is 94% of surfactant and 6% of the shell. Nanofluids of nanocapsules dispersed in deionized water were prepared for evaluating the nanofluid—sandstone interaction from adsorption phenomena using a batch-mode method, contact angle measurements, and FTIR analysis. The results showed that NC adsorption was null at the different conditions of temperatures evaluated of 25, 50, and 70 °C, and stirring velocities up to 10,000 rpm. IFT measurements showed a reduction from 18 to 1.62 and 0.15 mN/m for the nanofluids with 10 mg/L of NCS20, and NCP50 materials, respectively. Displacements tests were conducted using a 20 °API crude oil in a quarter five-spot pattern micromodel and showed an additional oil recovery of 23% in comparison with that of waterflooding, with fewer pore volumes injected than when using a dissolved surfactant.

Effect of the nanoparticles in the stability of hydrolyzed polyacrylamide/resorcinol/formaldehyde gel systems for water shut‐off/conformance control applications

“…Displacement tests were carried out to evaluate sweep efficiency and oil recovery through waterflooding after gel placement in the presence and absence of nanoparticles. To evaluate gel strength and resistance in the absence and presence of nanoparticles as a function of pore volumes injected (PVI), a quarter five‐spot pattern micromodel that allows visualizing fluids displacement was used (Figure ) . The cell consists of three acrylic plates that assembled in parallel simulates a heterogeneous porous media with an injector and a producer well in each corner.…”

“…The dimensions of the cell are 25 cm × 12 cm × 2 cm. Reproduced from Cortés et al . [Color figure can be viewed at wileyonlinelibrary.com]…”

Design and Tuning of Nanofluids Applied to Chemical Enhanced Oil Recovery Based on the Surfactant–Nanoparticle–Brine Interaction: From Laboratory Experiments to Oil Field Application

“…This enhanced performance for the displacement fluid in the presence of nanoparticles was also narrowly related to the superior performance obtained by the nanofluid regarding the capillary number, which involved a greater wettability alteration of the porous media, and a higher displacement fluid viscosity. surfactant to the oil-water interphase [12,44]. In this way, the fluid injection, including nanoparticles and surfactants, would increase the sweep efficiency by decreasing the fingering of the displacement front, as demonstrated in other studies [96].…”

“…However, the nanoparticle-surfactant assembly also can interact with the brine/oil interphase, and in this way, the adsorbed surfactant on the nanoparticle surfaces would still have a major role in the displacement performance [45,47]. The main mechanism consists of the targeted deliverability of the surfactant due to the ability of the nanoparticles to transport the surfactant to the oil-water interphase [12,44]. In this way, the fluid injection, including nanoparticles and surfactants, would increase the sweep efficiency by decreasing the fingering of the displacement front, as demonstrated in other studies [96].…”

“…The authors determined that recovery enhancement was related to the improvement of the capillary forces of the displacement fluid, such as the IFT, which they reduced from 21 mN•m −1 to 1.2 mN•m −1 . Cortés et al [44] synthesized nanocapsules for controlled delivery of encapsulated surfactants with two different types of these tensoactive agents, namely Span 20 and Petro 50. The authors concluded that the surfactant adsorption on the rock was negligible, while the IFT was reduced up to 0.15 mN•m −1 with just 10 mg•L −1 of the material.…”