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In this comprehensive study, we delved into the capabilities of five fungal strains: Aspergillus flavus, Aspergillus niger, Penicillium chrysogenum, Penicillium glabrum, and Penicillium rubens (the latter isolated from heavy crude oil [HCO]) in metabolizing HCO as a carbon source. Employing a meticulously designed experimental approach, conducted at room temperature (25 °C), we systematically explored various culture media and incubation periods. The results unveiled the exceptional resilience of all these fungi to HCO, with A. flavus standing out as the top performer. Notably, A. flavus exhibited robust growth, achieving a remarkable 59.1% expansion across the medium's surface, accompanied by distinctive macroscopic traits, including a cottony appearance and vibrant coloration. In an effort to further scrutinize its biotransformation prowess, we conducted experiments in a liquid medium, quantifying CO2 production through gas chromatography, which reached its zenith at day 30, signifying substantial bioconversion with a 38% increase in CO2 production. Additionally, we monitored changes in surface tension using the Du Noüy ring method, revealing a reduction in aqueous phase tension from 72.3 to 47 mN/m. This compelling evidence confirms that A. flavus adeptly metabolizes HCO to fuel its growth, while concurrently generating valuable biosurfactants. These findings underscore the immense biotechnological potential of A. flavus in addressing challenges related to HCO, thereby offering promising prospects for bioremediation and crude oil bioupgrading endeavors.

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Asphaltenes are the most polar and heavy fraction of petroleum, and their complex structure and toxicity make them resistant to biodegradation. The ability to tolerate high asphaltene concentrations is crucial to reducing the toxicity-related inhibition of microbial growth and improving their capacity for adaptation, survival, and biodegradation in soils highly contaminated with asphaltenes. This study developed a highly tolerant consortium for efficient asphaltene biodegradation in soils from 22 bacterial isolates obtained from heavy-crude oil-contaminated soils. Isolates corresponded to the Rhodococcus, Bacillus, Stutzerimonas, Cellulosimicrobium, Pseudomonas, and Paenibacillus genera, among others, and used pure asphaltenes and heavy crude oil as the only carbon sources. Surface plate assays were used to evaluate the tolerance of individual isolates to asphaltenes, and the results showed variations in the extension and inhibition rates with maximum tolerance levels at 60,000 mg asphaltenes l-1. Inhibition assays were used to select non-antagonistic bacterial isolates among those showing the highest tolerance levels to asphaltenes. A consortium made up of the five most tolerant and non-antagonistic bacterial isolates was able to degrade up to 83 wt.% out of 10,000 mg asphaltenes kg-1 in the soil after 52 days. Due to its biological compatibility, high asphaltene tolerance, and ability to utilise it as a source of energy, the degrading consortium developed in this work has shown a high potential for soil bioremediation and is a promising candidate for the treatment of aged soil areas contaminated with heavy and extra-heavy crude oil. This would be the first research to assess and consider extreme bacterial tolerance and microbial antagonism between individual degrading microbes, leading to the development of an improved consortium capable of efficiently degrading high amounts of asphaltenes in soil.

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Research reports reveal the importance of applying various substances to enhance extra-heavy crude oil pipeline transportation. During the crude oil conduction process, shearing occurs in the equipment and pipe accessories, producing a water-in-crude emulsion associated with forming a rigid film by adsorbing natural surfactant molecules in the droplets water, leading to increased Viscosity. This study presents the effect of a flow enhancer (FE) on the behavior of the Viscosity of an extra heavy crude oil (EHCO) and in emulsions formed with 5% and 10% water (W). The results revealed the effectiveness of the 1%, 3%, and 5% flow enhancer in lowering the Viscosity and presenting a Newtonian flow behavior which will help reduce the cost of heat treatment during the transportation of crude oil through the pipeline.

RESUMO

This study aims to develop and evaluate fracturing nanofluids from the laboratory to the field trial with the dual purpose of increasing heavy crude oil mobility and reducing formation damage caused by the remaining fracturing fluid (FF). Two fumed silica nanoparticles of different sizes, and alumina nanoparticles were modified on the surface through basic and acidic treatments. The nanoparticles were characterized by transmission electron microscopy, dynamic light scattering, zeta potential and total acidity. The rheological behavior of the linear gel and the heavy crude oil after adding different chemical nature nanoparticles were measured at two concentrations of 100 and 1000 mg/L. Also, the contact angle assessed the alteration of the rock wettability. The nanoparticle with better performance was the raw fumed silica of 7 nm at 1000 mg/L. These were employed to prepare a fracturing nanofluid from a commercial FF. Both fluids were evaluated through their rheological behavior as a function of time at high pressure following the API RP39 test, and spontaneous imbibition tests were carried out to assess the FF's capacity to modify the wettability of the porous media. It was possible to conclude that the inclusion of 7 nm commercial silica nanoparticles allowed obtaining a reduction of 10 and 20% in the two breakers used in the commercial fracture fluid formulation without altering the rheological properties of the system. Displacement tests were also performed on proppant and rock samples at reservoir conditions of overburden and pore pressures of 3200 and 1200 psi, respectively, while the temperature was set at 77 °C and the flow rate at 0.3 cm3/min. According to the effective oil permeability, a decrease of 31% in the damage was obtained. Based on these results, the fracturing nanofluid was selected and used in the first worldwide field application in a Colombian oil field with a basic sediment and water (BSW%) of 100 and without oil production. After two weeks of the hydraulic fracture operation, crude oil was produced. Finally, one year after this work, crude oil viscosity and BSW% kept showing reductions near 75% and 33%, respectively; and having passed two years, the cumulative incremental oil production is around 120,000 barrels.

RESUMO

Degradation efficiency of a heavy crude oil by a marine microbial consortium was evaluated in this study, with and without the addition of a chemical dispersant (Nokomis 3-F4). 15.50% of total petroleum hydrocarbons (TPH) were removed after 15 days of incubation without dispersant, with a degradation rate of 2.39 ± 0.22 mg L-1 day-1. In contrast, the addition of Nokomis 3-F4 increased TPH degradation up to 30.81% with a degradation rate of 5.07 ± 0.37 mg L-1 day-1. 16S rRNA gene sequencing indicated a dominance of the consortium by Achromobacter and Alcanivorax. Nonetheless, significant increases in the relative abundance of Martelella and Ochrobactrum were observed with the addition of Nokomis 3-F4. These results will contribute to further environmental studies of the Gulf of Mexico, where Nokomis 3-F4 can be used as chemical dispersant.

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The oil and gas industry generates large amounts of oil-derived effluents such as Heavy Crude Oil (HCO) in water (W) emulsions, which pose a significant remediation and recovery challenge due to their high stability and the presence of environmentally concerning compounds. Nanomaterials emerge as a suitable alternative for the recovery of such effluents, as they can separate them under mild conditions. Additionally, different biomolecules with bioremediation and interfacial capabilities have been explored to functionalize such nanomaterials to improve their performance even further. Here, we put forward the notion of combining these technologies for the simultaneous separation and treatment of O/W effluent emulsions by a novel co-immobilization approach where both OmpA (a biosurfactant) and Laccase (a remediation enzyme) were effectively immobilized on polyether amine (PEA)-modified magnetite nanoparticles (MNPs). The obtained bionanocompounds (i.e., MNP-PEA-OmpA, MNP-PEA-Laccase, and MNP-PEA-OmpA-Laccase) were successfully characterized via DLS, XRD, TEM, TGA, and FTIR. The demulsification of O/W emulsions was achieved by MNP-PEA-OmpA and MNP-PEA-OmpA-Laccase at 5000 ppm. This effect was further improved by applying an external magnetic field to approach HCO removal efficiencies of 81% and 88%, respectively. The degradation efficiencies with these two bionanocompounds reached levels of between 5% and 50% for the present compounds. Taken together, our results indicate that the developed nanoplatform holds significant promise for the efficient treatment of emulsified effluents from the oil and gas industry.