Jitendra Sangwai

Production of crude oil from a matured oil reservoir is challenging due to the low recovery factor. Hybrid methods have demonstrated potential in oil recovery from the matured crude oil reservoir. In recent years, the low salinity water with chemicals (viz., surfactant, polymer) and nanoparticles have brought the attention of the researchers due to their ability in altering the interfacial properties of the rock-oil-water systems favorable for crude oil recovery. The current interest by industries in injection fluid (i.e., low salinity water injection) has prompted the invention of a hybrid oil recovery agent for matured crude oil reservoirs. In the current study, a novel silica-based hybrid nanofluids (NFs) of variable silica nanoparticles (NPs) concentration in low salinity seawater with anionic surfactant (AOT: dioctyl sodium sulfosuccinate) and polymer (PVP–K30: polyvinylpyrrolidone) (sometimes referred to as SMART LowSal) are used as an injection fluid in a sand-pack reactor. Oil recovery from oil saturated sand-pack reactor is observed to enhance due to NFs (hybrid) injection after secondary recovery. The characteristic study of relative permeability curves discloses that sand surface was initially water-wet and converted to strongly water-wet in the presence of NFs. A nuclear magnetic resonance (1H NMR) study reveals that adsorption of the chemical appeared on the sand surfaces, which could be the reason for wettability alteration, and thereby enhanced oil recovery. Similarly, the scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDXA) of the sand samples before and after injection disclosed desorption of hydrocarbon from the sand surfaces after NFs injection. An additional 5–10% oil recovery is achieved after chemical flooding due to the injection of NFs. Adsorption isotherm study well agreed with the monolayer adsorption of surfactant on the sand surface.

Nanotechnology is a common word used by academia which is referred to the applied nanoscience conducted at nanoscale (1–100 nm) for variety of industrial applications. Application of nanotechnology in various fields is increasing extensively resulting in an enormous amount of publications in the distinct field. Nanoparticles (NPs) possess unique properties due to their larger surface area which leads to prolong application in multifold. Researchers working in enhanced oil recovery (EOR) areas are trying to get rid of challenges faced by the oil and gas companies for crude oil production. This chapter, therefore, focuses on work carried out by the researchers on chemical and rarely on thermal, gas injection, and biological EOR methods using NPs. Chemical enhanced oil is recovery (CEOR) methods taken into consideration due to their popularity in oilfields than the other existing methods. Viscosity, interfacial tension (IFT), and wettability are the major influencing factors for EOR. The authors intend to make the reader understand the pore-scale mechanism behind the enhanced oil recovery in the presence of NPs. In the early stage of enhanced oil recovery, it is essential to understand the properties of various NPs. Literature review reveals that properties of NPs mostly depend on methods they are prepared. Hence, at the beginning of the chapter, the types of NPs, preparation, and their characterization are explained briefly with the application of various nanoparticles in CEOR. Limitation of NPs application in chemical EOR area is spelled out clearly with the recommendation at the end.