Investigation on the effect of CuO nanoparticles on the IFT and wettability alteration at the presence of [C12mim][Cl] during enhanced oil recovery processes

In the current study, the effect of CuO nanoparticles (CuO-NPs) at the presence of dodecyl-3-methylimidazolium chloride ([C12mim][Cl]) is investigated on the interfacial tension (IFT) reduction, wettability alteration, and even tertiary oil recovery. Since the prepared solutions with CuO-NPs are completely dark and it is impossible to measure the IFT of these solutions in the presence of crude oil using the pendant drop method (since one of the phases must be transparent for IFT measurement using the pendant drop method), n-heptane (representative of saturates) and toluene (representative of aromatics) are used only for IFT measurement of solutions prepared by CuO-NPs, while rest of the experiments are performed using crude oil. The obtained results reveal that CuO-NPs are not stable in the aqueous solution in the absence of surfactant which means fast precipitation of CuO-NPs and a high risk of pore plugging. In this way, the stability of CuO-NPs is investigated at the presence of dodecyl-3-methyl imidazolium chloride ([C12mim][Cl]) as an effective surfactant for stabilizing the CuO-NPs in the aqueous solution (more than 1 month without precipitation using 1000 ppm of IL). Further measurements reveal that although the presence of IL in the aqueous solution can reduce the IFT of oil/aqueous solution system, especially for the aqueous solutions prepared by formation brine (0.65 mN.m−1), the presence of CuO-NPs has no considerable effect on the IFT. On the other hand, not only the contact angle (CA) measurements reveal the considerable effect of IL on the wettability alteration toward water-wet condition (68.3° for IL concentration of 1000 ppm) but also the addition of CuO-NPs can significantly boost the wettability alteration toward strongly water-wet condition (23.4° for the concentration of 1000 ppm of CuO-NPs). Finally, several core flooding experiments are performed using different combinations of chemicals to find the effect of these chemicals on the tertiary oil recovery factor. The results reveal that the presence of CuO-NPs can enhance the oil recovery of injected chemical slug (aqueous solution prepared by dissolution of IL with an oil recovery factor of 10.1% based on Original oil in place (OOIP)) to 13.8, %, 16.9%, and 21.2% based on OOIP if 500, 1000, 2000 ppm of CuO-NPs existed in the solution concomitant with 1000 ppm of [C12mim][Cl].

Modification of Xanthan Gum for a High-Temperature and High-Salinity Reservoir

Tertiary oil recovery, commonly known as enhanced oil recovery (EOR), is performed when secondary recovery is no longer economically viable. Polymer flooding is one of the EOR methods that improves the viscosity of injected water and boosts oil recovery. Xanthan gum is a relatively cheap biopolymer and is suitable for oil recovery at limited temperatures and salinities. This work aims to modify xanthan gum to improve its viscosity for high-temperature and high-salinity reservoirs. The xanthan gum was reacted with acrylic acid in the presence of a catalyst in order to form xanthan acrylate. The chemical structure of the xanthan acrylate was verified by FT-IR and NMR analysis. The discovery hybrid rheometer (DHR) confirmed that the viscosity of the modified xanthan gum was improved at elevated temperatures, which was reflected in the core flood experiment. Two core flooding experiments were conducted using six-inch sandstone core plugs and Arabian light crude oil. The first formulation—the xanthan gum with 3% NaCl solution—recovered 14% of the residual oil from the core. In contrast, the modified xanthan gum with 3% NaCl solution recovered about 19% of the residual oil, which was 5% higher than the original xanthan gum. The xanthan gum acrylate is therefore more effective at boosting tertiary oil recovery in the sandstone core.

Green Enhanced Oil Recovery for Carbonate Reservoirs

Green enhanced oil recovery (GEOR) is an eco-friendly EOR technique involving the injection of specific green fluids to improve macroscopic and microscopic sweep efficiencies, boosting residual oil production. The environmentally friendly surfactant-polymer (SP) flood is successfully tested in a sandstone reservoir. However, the applicability of the SP method does not extend to carbonate reservoirs yet and requires comprehensive investigation. This work aims to explore the oil recovery competency of a green SP formulation in carbonate through experimental and modelling studies. Numerous formulations of SP with ketone, alcohol, and organic acid are selected based on phase behavior and interfacial tension (IFT) reduction capabilities to examine their potential for enhancing residual oil production from carbonate cores. A blending of nonionic green surfactant alkyl polyglucoside (APG), xanthan gum (XG) biopolymer, and butanone recovered 22% tertiary oil from the carbonate core. This formulation recovered more than double residual crude than that of the APG, XG, and acetone. Similarly, a combination of APG, XG, acrylic acid, and butanol increased significantly more oil than the APG, XG, and acrylic acid formulation. The APG, XG, and butanone mixture is efficient with regards to boosting tertiary oil recovery from the carbonate core.

INFLUENCE OF THE INLET PRESSURE ON IMPULSE CHARACTERISTICS OF ALUMINUM SAMPLES

In this work, the cavitation water jet technique was used to clean the inner walls of oil pipes after tertiary oil recovery. The surface morphology, depth of impinging pits, and corrosion resistance of aluminum samples after impingement with the cavitation water jet were examined using scanning electron microscopy (SEM), 3D microscopy, and an electrochemical workstation. When the inlet pressure was higher than 3[Formula: see text]MPa, the number of cavitation bubbles generated by the cavitation nozzle increased with an increase in inlet pressure. Moreover, the cleaning effect that the cavitation water jet had on the aluminum samples was higher than that of general water jet technology. There were no obvious changes to the surface of the aluminum samples when the inlet pressure was decreased to 13[Formula: see text]MPa. Meanwhile, the mass loss of aluminum samples also increased. However, the internal corrosion resistance of the pipe wall after impact was relatively low. These results indicate that the impinging efficiency of the cavitation water jet was obviously enhanced and the degree of damage to the oil pipe wall was low at an inlet pressure of 15[Formula: see text]MPa. The best target distance was 8–12[Formula: see text]mm, and at this point, the jet flushing effect was the best. Moreover, the jet velocity at the outlet cavity was 184[Formula: see text]m/s, and the jet strike area was 250[Formula: see text]mm2.

Exploiting Microbes in the Petroleum Field: Analyzing the Credibility of Microbial Enhanced Oil Recovery (MEOR)

Crude oil is a major energy source that is exploited globally to achieve economic growth. To meet the growing demands for oil, in an environment of stringent environmental regulations and economic and technical pressure, industries have been required to develop novel oil salvaging techniques. The remaining ~70% of the world’s conventional oil (one-third of the available total petroleum) is trapped in depleted and marginal reservoirs, and could thus be potentially recovered and used. The only means of extracting this oil is via microbial enhanced oil recovery (MEOR). This tertiary oil recovery method employs indigenous microorganisms and their metabolic products to enhance oil mobilization. Although a significant amount of research has been undertaken on MEOR, the absence of convincing evidence has contributed to the petroleum industry’s low interest, as evidenced by the issuance of 400+ patents on MEOR that have not been accepted by this sector. The majority of the world’s MEOR field trials are briefly described in this review. However, the presented research fails to provide valid verification that the microbial system has the potential to address the identified constraints. Rather than promising certainty, MEOR will persist as an unverified concept unless further research and investigations are carried out.

Statistical Optimization of Temperature, Concentration, RPM and pH for the Surface Tension of Biosurfactant by Achromobacter Xylos GSR21

Achromobacter xylos strain GSR21 plays a crucial role in bioremediation of fossil fuel contamination, biopharmaceutical, cosmetics, chemical, petroleum refining, petrochemical, food industries and tertiary oil recovery (Microbial enhanced oil recovery). Response surface quadratic models (RSQM) was applied to reinforce the censorious operating conditions for the assembly of Achromobacter xylos strain GSR21. The Response surface method (RSM) was application to determine the best degrees of cycle factors (Temperature, Concentration, RPM, pH). Central composite design (CCD) of RSM was used to contemplate the four factors at five levels, and strain GSR21 Achromobacter xylos fixation was approximate as a reaction. Relapse coefficients predicted by examination and therefore the model was settled. R2 value regard for bio-surfactant (mN/m) attempted to be 0.81, showing that the model fitted well with the explorative results. The mathematical model predicted by simulation of the foreseen updated values, and bio-surfactant surface tension was found 50 mN/m. The foreseen model was matched at 98.8% with the test outcomes coordinated under the perfect conditions. Based on the finding research, temperature-40°C, concentration-1.8 g/l, RPM-180 rev/mint and pH-4 was perceived as compelling fragments for Achromobacter xylos GSR21.