Viscosity Modification of Heavy Crude Oil by Using a Chitosan-Based Cationic Surfactant

Abstract

Recently, global attraction has shifted toward heavy unconventional crude oil due to the depletion of light oil resources. Generally, heavy crude oils are highly viscous in nature; due to this, their production and transportation are challenging. Asphaltenes and resins content directly affects the viscosity of crude oil. Many viscosity reducing agents affecting asphaltenes dispersion have been developed in the recent past. The current work proposes a novel environmentally friendly chitosan-based cationic surfactant (CBCS), which can interact with polar and nonpolar constituents of crude oil matrix, thereby reducing its viscosity. The CBCS was synthesized by a two-step process. First, chitosan was modified to ortho-carboxymethyl chitosan (O-CMC). In the second step, CBCS was prepared by the reaction between O-CMC and an intermediate, which was obtained by the reaction between 4-(dimethylamino) benzaldehyde and bromodecane. The chemical structures of all synthesized compounds were characterized by infrared (IR) spectroscopy, nuclear magnetic resonance ( 1 H NMR and 13 C NMR) spectroscopy, thermo-gravimetry (TG), and X-ray diffraction (XRD). The effect of synthesized surfactant on the viscosity of the sample crude oil was estimated by rheological studies at different temperatures (20, 30, 50, and 70 °C). The results indicated that the viscosity of crude oil had been effectively improved as the concentration of surfactant increased from 0 to 600 ppm. The highest percent degree of viscosity reduction (DVR) was measured at 20 °C in comparison to 70 °C. The main cause of viscosity reduction, asphaltenes dispersion, was investigated by UV−vis spectroscopy analysis and viscosity measurements.

Organic Multiple Redox Semi‐Solid‐Liquid Suspension for Li‐Based Hybrid Flow Battery

“…The reduced viscosity of MRSSL suspension might be related to the function of surfactants in the presence of highly concentrated TEMPO, which can affect the surface tension of the solution [51,52] . This is usually utilized in the viscosity reduction of non‐Newtonian fluid of crude oil [53,54] . Our work provides an effective method to further decrease the viscosity of semi‐solid suspension by adding surfactants [55] …”

Clay-Sand Wettability Evaluation for Heavy Crude Oil Mobility

“…5,6 Thus, the modification of viscosity through surfactants and bioreducers, and the change of fluid-rock interactions, has been a valuable option to improve production. [7][8][9][10] Viscosity bio-reducers are dispersing agents that do not modify the oil fractions at different temperatures but interact with the components at the molecular level, avoiding particle aggregation to reduce the pressure drop. These chemicals can be obtained from vegetal oils [11][12][13] or extracted from plants over fermentation processes.…”

Synthesis and Study of a New Type of Fluorinated Polyether Demulsifier for Heavy Oil Emulsion Demulsification

“…Heavy oil is a kind of unconventional crude oil with large reserves and high exploitation difficulty, which is widely distributed in the United States, Canada, Venezuela, China, and many other countries. − On the one hand, heavy oil has high viscosity, high density, high contents of gum and asphaltene, and rigid thick film with better compactness than conventional crude oil emulsion. − The interpolymerization behavior of water droplets at the oil–water interface is hindered, which makes the emulsion very stable and difficult to demulsify and dehydrate . On the other hand, the developed heavy oil is fully stirred with water through the strong shear action of the pipeline to form a complex and stable emulsion. , At present, the commonly used methods of demulsification and water removal mainly include physical method, chemical method, and biological method. − The chemical demulsification method is widely used in oil field demulsification because of its convenience and efficiency.…”