Experimental study on adsorption and wettability alteration aspects of a new chemical using for enhanced oil recovery in carbonate oil reservoirs

Unveiling the revolutionary role of nanoparticles in the oil and gas field: Unleashing new avenues for enhanced efficiency and productivity

Prominent oil corporations are currently engaged in a thorough examination of the potential implementation of nanoparticles within the oil and gas sector. This is evidenced by the substantial financial investments made towards research and development, which serves as a testament to the significant consideration given to nanoparticles. Indeed, nanoparticles has garnered increasing attention and innovative applications across various industries, including but not limited to food, biomedicine, electronics, and materials. In recent years, the oil and gas industry has conducted extensive research on the utilization of nanoparticles for diverse purposes, such as well stimulation, cementing, wettability, drilling fluids, and enhanced oil recovery. To explore the manifold uses of nanoparticles in the oil and gas sector, a comprehensive literature review was conducted. Reviewing several published study data leads to the conclusion that nanoparticles can effectively increase oil recovery by 10 %-15 % of the initial oil in place while tertiary oil recovery gives 20-30 % extra initial oil in place. Besides, it has been noted that the properties of the reservoir rock influence the choice of the right nanoparticle for oil recovery. The present work examines the utilization of nanoparticles in the oil and gas sector, providing a comprehensive analysis of their applications, advantages, and challenges. The article explores various applications of nanoparticles in the industry, including enhanced oil recovery, drilling fluids, wellbore strengthening, and reservoir characterization. By delving into these applications, the article offers a thorough understanding of how nanoparticles are employed in different processes within the sector. This analysis may prove highly advantageous for future studies and applications in the oil and gas sector.

A comparative study on the design and application of new nano benzimidazolium gemini ionic liquids for curing interfacial properties of the crude oil-water system

Gemini surface active ionic liquids (GSAILs) are considered a new prosperous class of ionic liquids and recognized as high performance materials. The present study explores the capabilities of the newly synthesized GSAILs, constructed from two benzimidazole rings attached via a four or a six carbon spacer, namely [C₄benzim-C_n-benzimC₄][Br₂], n = 4 and 6. The products were characterized with FT-IR, NMR, XRD, TGA, DTG and SEM methods and were used in curing interfacial properties of the crude oil-water system. The interfacial tension (IFT) was reduced to about 64 and 71% under critical micelle concentrations (CMCs) of 0.028 and 0.025 mol dm^-3 at 298.2 K for n = 4 and 6 GSAILs, respectively. Temperature significantly assisted this effect. Both the GSAILs could transfer the wettability of the solid surface from oil-wet to water-wet. Further, stable oil/water emulsions were produced, having emulsion indices of 74.2 and 77.3% for n = 4 and 6 GSAILs, respectively. Compared to homologous imidazolium GSAILs, the benzimidazolium products revealed better performance in the sense of exhibiting desired effects on the investigated interfacial properties. These can be attributed to the stronger hydrophobicity of the benzimidazolium rings as well as better spreading of the molecular charges. The Frumkin isotherm could exactly reproduce the IFT data, leading to precise determination of the important adsorption and thermodynamic parameters.

Achieving the Super Gas-Wetting Alteration by Functionalized Nano-Silica for Improving Fluid Flowing Capacity in Gas Condensate Reservoirs

It is well-known that the production of gas-condensate reservoirs is significantly affected by the liquid condensation near the wellbore region. Gas-wetting alteration can be one of the most effective approaches to alleviate condensate accumulation and improve liquid distribution. However, gas well deliverability is still limited because the wettability of cores is altered only from liquid-wetting to intermediate gas-wetting by using traditional chemical stimulation. To solve this bottleneck problem, herein, we developed a fluorine-functionalized nanosilica to achieve super gas-wetting alteration, increasing the contact angles of water and n-hexadecane on the treated core surface from 23 and 0° to 157 and 145°, respectively. The surface free energy reduces rapidly from 67.97 to 0.23 mN/m. The super gas-wetting adsorption layer on the core surface formed by functionalized nanosilica not only increases the surface roughness but also reduces the surface free energy. The core flooding confirms that the required pressure for displacement is apparently reduced. Meanwhile, the core permeability can be dramatically restored after the super gas-wetting alteration. The microscopic visualization is employed to further understand the impact of fluorine-functionalized nanosilica on the fluid flow behavior and mechanism in porous media. The oil saturation in the micromodel decreases sharply from 48.75 to 7.84%, eliminating the "water locking effect" and "Jiamin effect", which indicates that the added functional nanosilica effectively improves fluid flow capacity and may contribute to production in the gas condensate reservoirs. In addition, this work reveals the fluid flow behavior and mechanism in the reservoir in detail, which will expand the better application of this material to many oilfields and other mining engineering systems.

Experimental and Modelling Study of Gravity Drainage in a Three-Block System

Gravity drainage is known as the controlling mechanism of oil recovery in naturally fractured reservoirs. The efficiency of this mechanism is controlled by block-to-block interactions through capillary continuity and/or reinfiltration processes. In this study, at first, several free-fall gravity drainage experiments were conducted on a well-designed three-block apparatus and the role of tilt angle, spacers’ permeability, wettability and effective contact area (representing a different status of the block-to-block interactions between matrix blocks) on the recovery efficiency were investigated. Then, an experimental-based numerical model of free-fall gravity drainage process was developed, validated and used for monitoring the saturation profiles along with the matrix blocks. Results showed that gas wetting condition of horizontal fracture weakens the capillary continuity and in consequence decreases the recovery factor in comparison with the original liquid wetting condition. Moreover, higher spacers’ permeability increases oil recovery at early times, while it decreases the ultimate recovery factor. Tilt angle from the vertical axis decreases recovery factor, due to greater connectivity of matrix blocks to vertical fracture and consequent channelling. Decreasing horizontal fracture aperture decreases recovery at early times but increases the ultimate recovery due to a greater extent of capillary continuity between the adjacent blocks. Well match observed between the numerical model results and the experimental data of oil recovery makes the COMSOL multiphysics model attractive for application in multi-blocks fractured systems considering block-to-block interactions. The findings of this research improve our understanding of the role of different fracture properties on the block-to-block interactions and how they change the ultimate recovery of a multi-block system.

Impact of Spacer and Hydrophobic Tail on Interfacial and Rheological Properties of Cationic Amido-Amine Gemini Surfactants for EOR Application

The impact of spacer length, spacer rigidity, trans and cis conformation of spacer double bond, and hydrophobic tail length of amido-amine cationic gemini surfactants was investigated by means of interfacial and rheological properties. For the study, six cationic amido-amine gemini surfactants were synthesized and used a cationic polyacrylamide. The interfacial tension (IFT) of the surfactants between crude oil and water was measured as a function of the surfactant concentration. It has been observed that the nature of the spacer and hydrophobic moiety have a significant effect on the oil/water interfacial tension. Rheological measurements of the surfactant-polymer hybrid system were performed at various surfactant concentrations, shear rates and temperatures. All synthesized cationic gemini surfactants were compatible with the cationic polyacrylamide since no precipitates were observed. By increasing the surfactant concentration, the storage modulus, as well as viscous properties of the cationic polyacrylamide, decreased at all temperatures because of the effect of charge shielding. On the other hand, the effect of concentration of surfactant was only significant at low shear rates. The storage modulus and viscous properties of the cationic polyacrylamide were also decreased significantly upon increasing surfactant tail length (C12 to C18). However, spacer rigidity, length, and conformation of spacer double bond caused a slight decrease in the storage modulus and viscous properties of cationic polyacrylamide. IFT, rheological properties, and compatibility tests showed huge potential of investigated surfactant-polymer system for enhanced oil production.

Ultrasonic washing for oily sludge treatment in pilot scale

Ultrasonic technology is a promising tool for washing oily sludge to remove oil, however, little information has been provided on the pilot scale application of ultrasonic washing. In this study, the ultrasonic conditions were optimized based on the pilot trial of the effects of ultrasonic properties on oil removal from oily sludge. An ultrasonic power of 0.24 w/cm² was necessary to overcome the energy threshold for oil washing at the frequency of 25 kHz. The removal rate was changed from 46.0% to 60.7% with oily sludge content from 25.0% to 42.0%, respectively. The addition of surfactants could improve oil recovery, and the optimizing content for sodium petroleum sulfonate and Span 80 was 0.3% and 0.03%, respectively. A series of pilot scale test indicated that the oil removal rate could be 82-90% by ultrasound assistant with surfactants (Span 80). Thin-layer chromatographic flame ionization detection showed that the removal rate by ultrasonic wash was dropped with the increase of composition polarity. However, under the assistance of surfactants (Span 80), all compositions could be effectively removed. This pilot study will greatly improve the application of ultrasonic technology in oily sludge treatment.