Surfactant-Nanoparticle Formulations at Calcite-Water and Oil-Water Interfaces for Enhanced Oil Recovery

Rezvani, Hosein

Abstract

There is a growing interest in the development of new and innovative enhanced oil recovery (EOR) technologies to reduce the environmental impact of oil production. Surfactant flooding is a well-established EOR method but mainly suffers from high adsorption onto rock or low surface activity resulting in poor EOR. Aqueous surfactant- nanoparticle mixtures have received great attention in different fields like emulsification, foaming, EOR and CO2 sequestration. The use of nanoparticle-surfactant mixtures can promote a more sustainable and efficient EOR process. However, colloidal particle stability under reservoir conditions is considered a great challenge. In addition, the way synergy works in EOR is not clearly understood.
This thesis aims to formulate a particle-surfactant mixture for an efficient EOR in tight calcite-rich reservoirs with a focus on surfactant adsorption behaviour at fluid-fluid and solid-fluid interfaces in the presence of particles and ions. For this, bare silica particles were sterically stabilized using two silanes, namely epoxy silane (ES) and amino silane (AS), and blended with two commercial surfactants, namely alkyl hydroxysultaine (AHS) or binary zwitterionic-nonionic (ZN) surfactant solution (AHS + nonionic C10–12E9), for both additional steric stabilization and EOR. The effects of particle-surfactant mixtures on reservoir properties including rock wettability, static and dynamic surfactant adsorption onto rock, oil-water interfacial tension and emulsification of oil and water were studied to select effective dispersions for spontaneous oil imbibition in a calcite-rich rock. The blend of ES-coated silica particles and surfactants often showed pH-responsive behaviour at rock-water and oil-water interfaces with particles serving as carriers or surface activity improvers for surfactants resulting in different extents of rock wettability alteration and emulsification. Optimum surfactant concentrations determined from static experiments were found to significantly increase crude oil recovery of Permian brine by 36 ± 1% original oil in place (OOIP) in secondary spontaneous imbibition which was further enhanced by 14% OOIP on adding only 0.01 wt.% ES-coated silica. The nanoparticle-surfactant formulation was also efficient in producing residual crude oil in tertiary mode (6% OOIP additional oil recovery). The oil recovery results disclosed a high dependence on the emulsification ability of the blends with particle-AHS dispersion producing more stable emulsions and thus more crude oil compared to that of ZN. These findings contribute to the understanding of EOR mechanisms and provide valuable insights for the development of strategies to maximize oil recovery in tight oil reservoirs.

Citation

Rezvani, H. Surfactant-Nanoparticle Formulations at Calcite-Water and Oil-Water Interfaces for Enhanced Oil Recovery. (Thesis). University of Hull. https://hull-repository.worktribe.com/output/4564632

• Thesis Type: Thesis
• Deposit Date: Feb 27, 2024
• Publicly Available Date: Mar 12, 2024
• Keywords: Chemistry
• Public URL: https://hull-repository.worktribe.com/output/4564632
• Additional Information: Department of Chemistry; University of Hull
• Award Date: Oct 12, 2023