Journal of Petroleum Science and Technology
Volume:13 Issue: 3, Summer 2023

Chemical - Thermal Technology is used to upgrade the quality and to decrease the viscosity of Iranian extra-heavy crude oil in atmospheric pressure. In this present study, quality preparation of [OMIM][NTf2]-ZIF-8 (IL@ZIF-8) nanostructures were performed solvothermal by using an oil-soluble long chain Ionic Liquids, [OMIM][NTf2] and a zeolitic imidazolate framework, ZIF-8. This complex was used in the thermal cracking of heavy oil as a chemical additive. The injection of a small amount of the IL@ZIF-8 into extra-heavy oil caused the production of gaseous compounds, naphtha, middle distillates, lubricating oil,  and tar. The viscosity measurement results show an evident viscosity reduction of 91% for extra-heavy oil after chemical-thermal cracking at 370 °C for a maximum of 120 min. The technique is ideally suited for cracking extra-heavy Iranian Crude oils, such as in the Nowrooz-Soroosh oilfields. To our knowledge, no report has been found about the chemothermal cracking of heavy crude oils, especially by using IL@ZIF-8 metal-organic frameworks.

An oligomer produced from unsaturated and reactive components (green oil) is formed when hydrogen sulfide (H2S) is removed from the exhaust stream of the methyl tert-butyl ether (MTBE) plant. A remedy to minimize this contaminant formation is using adsorbents with low reactivity toward the olefinic precursors. Here, the green oil formation on the surface of different types of commercial alumina is studied. Results confirm that the regular commercially activated alumina has low H2S adsorption capacity. Still, the alumina alkalized with 3.98 wt.% of Na2O has a breakthrough time of more than 29 h and stable performance in a cyclic operation. Moreover, the promoted alumina with a wide pore diameter (about 9 nm) and low surface area (about 215 m2/g) is less susceptible to deactivation by forming green oil. It is supposed that the capillary condensation of C3/C4 unsaturated compounds and acidic sites of the alumina intensify the oligomerization inside the pores of an adsorbent.

In recent years, nanoparticles have attracted great attention in the oil and gas industry, while one of the most applicable nanoparticles is nanoclay, especially in drilling, which enhances the rheology of the drilling fluids. However, the experimental analysis of nanoclay in EOR processes was rarely investigated. One of the main parameters that play an important role in the success of the EOR process is nanoclay stability. This research focuses on the comprehensive stabilization analysis of montmorillonite nanoclay in the presence of surfactants (SDS, CTAB) and KCl. Sets of experiments such as nanofluid preparation, nanofluid stability via imaging analysis, DLS and Zeta potential, XRD and SEM analysis, and clay swelling tests were performed in this research. All of the experiments were done at ambient pressure and temperature. Four different nanoclay concentrations (0.1, 0.25, 0.5, and 1 weight percentages) and surfactant concentrations of 0.5 are applied. Ultimately, the experiments’ results confirm the nanoclay’s stability in the presence of the surfactant employed in the study that lasted 24 hours. It is found that the optimum nanoclay concentration during the stability experiments is 0.1.

1-Dodecyl-3-methylimidazolium chloride (DDMIC) and 1-(Naphtymethyl)-3-methylimidazolium chloride (NMIC) were synthesized, and their adsorption effects on A516-Gr70 steel were investigated as a green corrosion inhibitor in 3.5 wt.% NaCl solution saturated with CO2 at 25 °C. Potentiodynamic polarization (PDP), Scanning Kelvin probe (SKP), and electrochemical impedance spectroscopy (EIS) techniques were used to study the inhibition properties of these compounds in different concentrations. The main advantages of the two studied inhibitors, i.e., DDMIC and NMIC, are environment friendly; moreover, the inhibition performance of DDMIC is excellent, and it can reach 97% protection performance in a sweet corrosion environment. SKP studied the effects of these inhibitors on the Volta potential of the carbon steel surface. SKP analysis revealed that the trend of metal surface coverage by DDMIC can be traced via Volta’s potential results. Based on SKP results, the real work function of metal surface atoms was calculated. Quantum chemical parameters of inhibitor molecules were studied by integrating density functional theory (DFT) and SKP methods. The integration results described the electron transfer mechanism during the adsorption process. Ultimately, SKP and DFT results revealed that the aromatic ring of NMIC affected its adsorption on the metal surface.

This study investigates, the performance of ZSM-5 zeolite catalysts with different Si/Al ratios equal to 40, 120, and 200 in the n-hexane catalytic cracking process in a fixed bed microreactor at 550°C under atmospheric pressure with a WHSV = 4 h-1. To improve the acidity of the catalysts and increase the yield of light olefins, the best catalyst among the three synthesized catalysts was modified by lanthanum and cerium metals. These two rare earth metals were chosen as modifiers since they were expected to improve the acidic properties of the parent catalyst. Furthermore, XRD, FT-IR, FESEM, EDX Dot-Mapping, BET, and NH3-TPD analyses were used to evaluate and characterize the synthesized catalysts. According to the results, the Z-La catalyst has significantly improved catalytic performance, such as the yield of light olefins, P/E ratio, and a decrease in the production of light alkanes and aromatic compounds compared to other catalysts. The yield of light olefins obtained from it was equal to 62.91%, and the P/E ratio was equal to 3.25. This significant progress in this catalyst compared to other catalysts in this research is due to adding La to H–ZSM-5 zeolite, which causes changes and modifies the acidity properties of this catalyst (S/W ratio of acidity = 0.54).

The ion-specificity of minerals’ wettability is an active research area of particular importance in ion-engineered waterflooding as a promising enhanced oil recovery method. In this process, the wettability of the oil-brine-rock (OBR) system is changed by designing the ions of injected water. Though the contribution of ions to the wetting character of carbonates, particularly dolomite (CaMg(CO3)2), has been investigated by various studies, the contribution of ions still needs to be resolved. Through a systematic experimental investigation, the present paper sheds light on the contribution of the main constituent ions of natural brines to retrieving the water-favoring virtue of oil-bearing rocks majorly composed of dolomite. The static wettability measurements showed distinct affinity of individual surface-active ions to the dolomite/water interface, following the order SO42- > NO3- > Ca2+ > Mg2+. To clarify the effect of mixed electrolytes, results of experimental scenarios showed the assisting role of sulfate and, to a lesser extent, nitrate to restore the hydrophilic virtue of oil-aged dolomite samples, irrespective of the divalent cations, which was also mirrored to incremental oil displacement upon enriching those anions in dynamic core flooding tests. The cooperation of SO42- and NO3- anions yielded optimal wettability alteration in static experiments and maximum oil mobilization in core flooding tests. Insights provided here improve our knowledge of the ion-dependent wettability response of dolomite with implications to diverse fields of surface science, particularly for the rational design of brine composition to acquire optimal performance of water-based EOR operations.