Search

Asphaltene as problematic fraction of crude oil is known that is separated from crude oil because of variations in temperature, pressure, and compositions. The deposition of asphaltene causes many problems including tubing blockage and rock wettability alteration, therefore, the study of asphaltene deposition has been highlighted. In the present study, the impacts of various effective parameters and inhibitors on asphaltene deposition rate have been studied. The effect of flow rate and ratio of precipitant to crude oil have been investigated. The SDS, triton x-100, and salicylic acid abilities in reduction of asphaltene deposition have been evaluated by using capillary setup. The experiments show that SDS has the better performance than salicylic acid and triton x-100. Next, the impact of concentration of SDS on rate of deposition has been studied. The obtained results show that increment in concentration of SDS decreases the rate of asphaltene deposition. The current study can be used as a helpful tool for petroleum engineers dealing with asphaltene deposition problems. [ABSTRACT FROM AUTHOR]

Marine fuel oil stability has always been an issue for bunkering companies and ship owners all around the world and the problem has become even more apparent with the introduction of the Global Sulphur Gap by the International Maritime Organization (IMO) in 2020. In this article, the historical background and the technical reasons why marine fuel oils lose their stability, as well as methods for preventing such instability from occurring, are presented. While it is possible to make fuel compositions stable by adjusting their composition in such a way that the components of the fuel are compatible, considering that marine fuel oils are often comprised of the least value-added products, the method of adding special fuel oil stabilizers (also known as "asphaltene dispersants") is usually preferred. An overview of such stabilizers is presented; their chemical composition, based on the information provided by the manufacturers and/or inventors is studied. In addition, the experimental research of the produced marine fuel oil and its components is carried out. The results of the model composition studies show that adding even as little as 10% of residual asphaltene-rich components can make a composition with a high stability reserve unstable. It was also shown that the content of the asphaltene-rich component in a stable fuel can be increased from 3% to 10% by introducing stabilizers in low amounts (up to 2000 ppm), thus lowering the amount of higher value-added, mostly naphthene-paraffinic-based components. Different methods of fuel stability evaluation were studied and tested, most of them being in correlation with one another. Several types of stability enhancers were tried out on unstable fuel, with stabilizers based on alkylphenol formaldehyde resin showing the best results. [ABSTRACT FROM AUTHOR]

Abstract The precipitation of wax crystals will lead to the formation of gelation structures in waxy crude oils, and the presence of asphaltenes will affect the gelation and flow process of waxy crude oils. In this work, five waxy oils with different asphaltene contents were formulated, and the effect of asphaltene on the gelation and flow behavior of wax-containing simulated oils was investigated. The results show that asphaltenes can improve the low-temperature rheology of wax-containing simulated oils to a certain extent. When the asphaltene contents in wax-containing simulated oils increased from 0 wt% to 0.5 wt%, the pour points decreased from 25 °C to below 0 °C, while the gelation temperatures and storage modulus were also decreased from the initial 29.01 °C to 25.64 °C and 33262 Pa to 5.9 Pa, respectively. The results were due to the fact that the increase of asphaltene contents weakened the gelation network structure strength of wax-containing simulated oils and inhibited gelation process. Meanwhile, in the range of low asphaltene contents, the apparent viscosity of wax-containing simulated oils at 10 °C decreased from 531.5 mPa·s to 7.6 mPa·s with the increase of asphaltene contents. [ABSTRACT FROM AUTHOR]

The article delves into the intricate phenomenon of deposition in heat exchangers and how a piece of equipment known as the benchtop heat exchanger test instrument (BHETI) has been developed to expedite the examination of this phenomenon. The BHETI subjects samples to substantial stress, facilitating the assessment of an oil's tendency to generate deposits. Tests were conducted on two crude oil blends referred to as blend A and blend B using a BHETI unit. This equipment permits testing under various controlled conditions, including temperature, pressure, and volumetric flow rate. The results indicated that blend A exhibited a higher susceptibility to deposition compared to blend B due to its elevated concentration of light hydrocarbons. The wall temperature exerted a significant influence on the deposition rate, with higher temperatures leading to elevated deposition rates. Conversely, lower oil flow rates resulted in increased deposition rates. Furthermore, extended-term tests unveiled fluctuations in deposition rates over time when blending the two oil samples, suggesting intermittent fouling processes, possibly attributable to thermodynamic imbalances induced by mixing, rendering the oil's asphaltenes less stable. The outcomes were subjected to analysis employing the Colloidal Instability Index (CII), which indicated that the majority of samples exhibited values exceeding 0.9, signifying asphaltene instability. Additionally, the examination of saturated, aromatic, and NSO (nitrogen, sulfur, oxygen) fractions revealed decreased saturation and increased aromatics after the deposition tests. [ABSTRACT FROM AUTHOR]

Ethylene tar is the main byproduct of ethylene synthesis obtained via pyrolysis of hydrocarbon feedstock. With the growing demand for ethylene, the efficient use of ethylene tar is of great importance from both an economic and an ecological point of view. It contains significant amounts of polycyclic aromatic hydrocarbons, which can be designated as technogenic asphaltenes. Such polyaromatic structures can be isolated and used as a synthetic platform for modification and molecular engineering, similar to petroleum asphaltenes. In this study, the possibility of modifying technogenic asphaltenes by oxidizing reagents used previously for petroleum asphaltenes was shown for the first time. Technogenic asphaltenes contain significantly fewer heteroatomic structures and have a lower molecular weight compared to petroleum asphaltenes. The compositional features of technogenic asphaltenes ensure deeper oxidation with the formation of various O-containing products, whose properties can vary significantly depending on the reaction conditions. At the same time, the general patterns of oxidative modification of technogenic asphaltenes correspond to the oxidation processes of petroleum asphaltenes. The modification products obtained in this way can be used as sorbents, catalysts, fillers for polymers, adhesive additives for road bitumens, etc. [ABSTRACT FROM AUTHOR]

The destruction of polymers under the influence of ultraviolet (UV) radiation is the cause of their aging and deterioration of strength properties. Asphaltenes are low-value waste products after the refining and deasphalting of heavy crude oil, which absorb UV radiation well. Asphaltenes require rational utilization, which suggests their use as UV stabilizing agents for polymers. In this work, asphaltenes were used to prevent UV aging of polypropylene (PP) by adding them in a mass fraction from 5% to 30% within an asphaltene/PP composite material. Rheometry, calorimetry, X-ray diffraction analysis, and tensile strength of PP films containing asphaltenes were performed before and after their intense UV irradiation for accelerated aging. Asphaltenes slightly reduce the viscosity, crystallinity, and mechanical strength of the initial PP due to their plasticizing effect. However, this deterioration in properties is more than compensated when studying UV-aged samples. Intense UV aging causes multiple catastrophic drops in the viscosity and strength of pure PP with the preservation of crystallinity due to the break of polymer chains and a decrease in molecular weight by approximately eight times. Asphaltenes suppress the destruction of PP, which is expressed in a significantly smaller decline in its viscosity and strength due to UV aging. The most optimal content of asphaltenes is 20%, which suppresses UV destruction by six times and best preserves the strength properties of PP. [ABSTRACT FROM AUTHOR]

The products from the reaction of petroleum asphaltenes with sulfuric acid under various conditions, accompanied by oxidation, sulfonation, and decomposition reactions, were studied. The change in the content of stable free radicals and vanadyl complexes in the products from the reaction of asphaltenes with sulfuric acid in relation to the time and temperature was determined by EPR spectroscopy. The chemical processes in the reaction of asphaltenes with sulfuric acid take place most strongly in the first hour, being accompanied by peak growth of the concentration of stable free radicals. With increase in the length of treatment of the asphaltenes with sulfuric acid there is a decrease in the concentration of stable free radicals accompanied by a decrease in the content of sulfo groups in the products. After only 30 min of the process there was a marked decrease in the content of vanadyl complexes in the reaction products. [ABSTRACT FROM AUTHOR]

Acidic and basic ion‑exchange resins were prepared by chemical modification of petroleum asphaltenes. The resulting products were characterized by IR spectroscopy and MALDI mass spectrometry. Feasibility was demonstrated for carrying out catalytic acylation of salicylic acid in the presence of acidic and basic catalysts derived from petroleum asphaltenes to give acetylsalicylic acid. Asphaltene‑derived ion‑exchange resins containing either sulfonic acid (SA) or amino groups (AA) were used as catalysts. These catalyzed reactions gave acetylsalicylic acid in 78% and 73% yield, respectively. [ABSTRACT FROM AUTHOR]

The methodologies of asphaltenes‐containing petroleum materials: saturated, aromatics, resins, asphaltenes group‐type composition analysis are performed with the use of column adsorption‐desorption or thin layer chromatography (TLC)‐flame ionization detection under normal phase conditions with silica gel as the adsorbent. In a three‐step procedure, the TLC chromatogram is developed within a decreasing distance by the mobile phase with increasing elution strength (polarity). The n‐alkane used in the first step does not dissolve asphaltenes, which leads to the occlusion effect and an underestimation of the percentage of saturated hydrocarbons. In this article, the reverse order of the subsequent elution steps was proposed: the solvent polarity is simultaneously reduced and the chromatogram development distance is increased in the order dichloromethane:methanol 95:5 v/v, 3 cm; toluene, 6 cm; and n‐hexane, 10 cm. It was also intentional to reduce the weight of the applied sample to 5 μg for bitumen and 2 μg for asphaltene purity testing. It should be the rule that in stepwise TLC chromatogram development, the first mobile phase is a good solvent for all testing components. The IP 469 procedure should be corrected. [ABSTRACT FROM AUTHOR]

Although the quality of coal tar does not meet the demands for blended marine fuel, the properties of its components after processing are improved, and they can be considered as inexpensive blending components. Three types of coal tar products including light coal tar I, light coal tar II, and hydrogenated coal tar have been obtained and used in production of residual marine fuels. To minimize costs, a linear optimization method has been used, and all properties of the resulting products have met the required criteria. In addition, a novel analytical method was used to characterize the fuel stability. The analysis of a hydrocarbon composition and a mechanism of interaction between the resin and asphaltene have shown the main coal tar components affecting fuel oil stability are polycyclic aromatic hydrocarbons (PAHs) and resin. A condensation of PAHs and resin into asphaltene and an increasing complexity of asphaltene structure causes deposition of oil products under heating. Hydrogenation is able to effectively reduce the PAH content and the volume of formation of massive asphaltenes thus preventing fuel flocculation and deposition during aging in fuel tanks. [ABSTRACT FROM AUTHOR]

The appearance of terminal blend rubberized bitumen (TB) has improved a series of defects of traditional rubber bitumen, such as high viscosity, poor storage stability. Therefore, its wide application prospect is self-evident. However, different degrees of thermal-oxidative aging problem still exist in the process from production to use of TB, which seriously affects the service life of pavement. To improve the anti-aging performance of TB, grafting activated crumb rubber (GACR) was obtained by using acrylamide, and then compounded with TB. Firstly, TB was prepared in the self-developed nitrogen protection device. Secondly, GACR modified bitumen (GACR-MB), TB/CR composite modified bitumen (TB/CR) and TB/GACR composite modified bitumen (TB/GACR) were developed in the atmospheric environment. Finally, the performance of four kinds of crumb rubber modified bitumens before and after aging was compared and analyzed by testing high and low temperature rheological properties. The results show that GACR slowed down the formation rate and aggregation degree of asphaltenes and other macromolecular substances, and TB/GACR showed excellent aging resistance. [ABSTRACT FROM AUTHOR]

Cardanol is a natural material that acts to stabilize asphaltenes in crude oil. However, its derivative, polycardanol, obtained via cationic polymerization, has divergent behaviour, with reports of its acting both as asphaltenes stabilizer and flocculant. Recently, it was demonstrated that the reaction conditions influence the conversion rates, structures, and molar masses of the products from synthesizing polycardanol initiated with BF3 · O(C2H5)2. Seeking to elucidate the influence of these variables on the phase behaviour of asphaltenes, in this work six products, previously synthesized and characterized, had their performance evaluated by asphaltenes precipitation onset, using n‐heptane titration and monitoring by near‐infrared spectroscopy, using asphaltenes model systems (C5I and C7I) at 1.00 wt./vol.% in toluene. All the products had the ability to flocculate asphaltenes and have potential for deasphalting process. Flocculation efficiency increased with rising molar mass, higher reaction conversion degree, and presence of lateral hydrocarbon chains. The most efficient structures were not affected by the presence of unreacted cardanol. This indicated that the reaction does not require a purification step. Aged cardanol was also able to produce flocculant polymer, indicating that the distillation of cardanol is not required. The cost to obtain a product without needing reagent distillation becomes lower. [ABSTRACT FROM AUTHOR]

The precipitation and deposition of asphaltene on solid surfaces present a significant challenge throughout all stages of petroleum recovery, from hydrocarbon reservoirs in porous media to wellbore and transfer pipelines. A comprehensive understanding of asphaltene aggregation phenomena is crucial for controlling deposition issues. In addition to experimental studies, accurate prediction of asphaltene aggregation kinetics, which has received less attention in previous research, is essential. This study proposes an artificial intelligence-based framework for precisely predicting asphaltene particle aggregation kinetics. Different techniques were utilized to predict the asphaltene aggregate diameter as a function of pressure, temperature, oil specific gravity, and oil asphaltene content. These methods included the adaptive neuro-fuzzy interference system (ANFIS), radial basis function (RBF) neural network optimized with the Grey Wolf Optimizer (GWO) algorithm, extreme learning machine (ELM), and multi-layer perceptron (MLP) coupled with Bayesian Regularization (BR), Levenberg–Marquardt (LM), and Scaled Conjugate Gradient (SCG) algorithms. The models were constructed using a series of published data. The results indicate the excellent correlation between predicted and experimental values using various models. However, the GWO-RBF modeling strategy demonstrated the highest accuracy among the developed models, with a determination coefficient, average absolute relative deviation percent, and root mean square error (RMSE) of 0.9993, 1.1326%, and 0.0537, respectively, for the total data. [ABSTRACT FROM AUTHOR]

Oil-based foam stabilized by dispersed asphaltene is potential in the oil recovery process of water-sensitive formations. But asphaltenes are prone to aggregate, which jeopardizes the stability of the foam. This paper investigated the effect of different VO79 (model asphaltene compound violanthrone-79) systems on the performance of oil-based foams through surface tension and foaming tests. And simulations were performed to investigate the microscopic mechanism of ODA (octadecyl amine) and Span20 (sorbitan monolaurate) on the dispersion effect of VO79 and the effect of their mixtures on the interfacial film formation. The experimental results showed that the mixed system of ODA, Span20, and VO79 significantly enhances the performance of the oil-based foam. According to simulative results, ODA and Span20 blending are able to form ODA: Span20 molecular pairs, inhibiting the aggregation of model asphaltenes. The blend of ODA, Span20, and VO79 tends to form a ternary supramolecular complex, assembling into a dense and stretchable interfacial film. The synergistic effect generated by the ternary blends is capable of optimizing the performance of oil-based foams. [ABSTRACT FROM AUTHOR]

It is very important to evaluate how coal tar asphaltenes (CTA) and corn cob (CB) could be used comprehensively in order to achieve zero waste. Catalytic co-pyrolysis is a feasible method to reduce CO 2 emissions, realizing the development and utilization of biomass energy, and the recycling of asphaltenes. In this study, the catalytic effect of K on co-pyrolysis was more obvious than that of Ca, Co, Ni, Cu and Zn based on the analysis of TG/DTG, FTIR and Py-GC/MS. The response surface design method and artificial neural network were introduced to comprehensively investigate the effects of mixing ratios, metal loads and heating rates on the catalytic co-pyrolysis. The results showed that K-catalysis co-pyrolysis effectively improved the yield of gas and char, and increased the content of phenolics. In particular, when the load of K was 5.3 wt%, the heating rate was 476 °C/min, and the proportion of CB was 38 wt%, the maximum solid yield was 35.16 wt%, and the solid product had good catalytic ability. Based on the above analysis, the mechanism of K-catalysis co-pyrolysis was proposed. Catalytic co-pyrolysis is a feasible method to reduce CO 2 emissions, realizing the development, utilization of biomass energy and the recycling of asphaltenes. In this study, the effects of K had more obvious catalytic effect than Ca, Co, Ni, Cu and Zn on the co-pyrolysis compared by TG/DTG, FTIR and Py-GC/MS. The response surface design method and artificial neural network were introduced to comprehensively investigate the effects of mixing ratios, metal loadings and heating rates on the catalytic co-pyrolysis. The results showed K-catalysis co-pyrolysis effectively improved the yield of gas and char, increased phenolic content, and the solid product had good catalytic ability. Based on the above analysis, the mechanism of K-catalyzed co-pyrolysis was proposed. [Display omitted] • Catalytic fast co-pyrolysis of corn cob and coal tar asphaltenes are investigated. • Metals, gas-liquid-solid products and influencing factors are analyzed. • K-catalysis increases phenols' content, and co-pyrolysis coke has catalytic ability. • Oxygenated compounds crack into small molecules such as ketones and aliphatics. • ANN model predicts product distribution by mixing ratio, heating rate and metal load. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The most used oil deasphalting processes are Residuum Oil Supercritical Extraction Kerr-McGee (ROSE), thermal hydrocracking, and liquid-liquid extraction at lower temperatures from 100° to 150°C. All these processes require a large amount of thermal energy, in which the growing global demand for energy emerges the need to improve more efficient, economical, and environmentally friendly techniques. This work proposes a cold extraction asphaltenes process from oil. In addition to removing asphaltenes, the solubilization of asphaltenes in two Deep Eutectic Solvents (DES) (Thymol:C 8 Ac. and Menthol:Thymol) is proposed. These solvents have the advantage of lower toxicity, recyclability, and chemical and thermal stability. The study of the use of these solvents in the oil industry is recent and has shown great potential for its application on a large scale. These asphaltenes were solubilized without saturation up to an initial concentration of 7 g/L, maintaining solubilization for 48 h. These results are a basis for future studies on a pilot scale for industrial application and bioconversion of asphaltenes into value-added products. [Display omitted] • High-efficiency post-salt oil cold clearance process was carried out. • Deep eutectic solvents Thymol:Octanoic Acid (C 8 Ac.) and Menthol:Thymol exhibit high stability in asphaltenes solubilization. • A sustainable approach for solubilizing asphaltenes was proposed. [ABSTRACT FROM AUTHOR]

Some oil wells in the Tahe oilfield have been reported to produce extremely heavy oil due to asphaltene deposition. To enhance the flow of crude oil through the wellbore, engineers adopted the use of light oil from nearby wells to dissolve the heavy crude in the wells' sections to maximize recovery from the Tahe oilfield. However, this mixing has led to the problem of accelerated asphaltene deposition, which often blocks the wellbore in the process. In this research, the factors that influence the stability of diluted heavy oil, temperature, and mixing ratio on asphaltene deposition characteristics under high pressure are studied using a high-temperature and high-pressure crude oil flow property experimental device based on the differential pressure method. The results under high pressure show that the initial deposition pressure of asphaltene decreases as the experimental temperature increases. With an increase in the mixing light oil ratio, the initial deposition pressure of diluted heavy oil increases, and the deposition trend of asphaltene strengthens. The asphaltene accumulation and deposition will be aggravated by filling quartz sand and pipe diameter changes. The research here is helpful to understand the deposition characteristics of asphaltene during the production of diluted heavy oil. It offers significant guidance in the prevention and control of asphaltene precipitation in heavy oil wells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Interactions forces of bubbles and asphaltenes in aqueous solutions were quantified. • Surface forces of bubbles and oil droplets with asphaltenes were measured. • Hydrophobic interactions drive attachment of bubbles and oil droplets with asphaltenes. • High salinity condition facilitates attachment of bubbles and oil droplets with asphaltenes. • The presence of surfactants hinders attachment of bubbles and oil droplets with asphaltenes. Surface interactions of bubbles and oil with interface-active species like asphaltenes influence many interfacial phenomena in various engineering processes. It holds both fundamental and practical significance to quantitatively characterize these interactions. The surface forces of air bubbles, asphaltenes and asphaltenes-toluene droplets in various aqueous solutions have been quantified using an integrated thin film drainage apparatus and an atomic force microscope coupled with bubble probe. The effects of asphaltenes concentration, pH, salinity, Ca2+ ions and surfactants have been examined. Hydrophobic interaction drives attachment of bubbles and asphaltenes surfaces or oil droplets under high salinity condition. Increasing asphaltenes concentration in oil droplets enhances their hydrophobic attraction with bubbles due to strengthened asphaltenes adsorption and aggregation at oil–water interface. Increasing pH weakens the hydrophobic interaction as oil surfaces become more negatively charged and less hydrophobic. Under low salinity condition, strong electrical double layer and van der Waals repulsion inhibits the bubble-oil droplet contact. Introducing Ca2+ ions and surfactants leads to strong steric repulsion, preventing bubble-oil contact. This research has advanced our mechanistic understanding of how bubbles and oil droplets interact in aqueous systems and offers useful insights to modulate such interactions in oil production, water treatment and other interfacial processes. [ABSTRACT FROM AUTHOR]

The separation of water–oil emulsions differing in the content and ratio of asphalt-resinous substances, as well as dielectric properties when exposed to a high-frequency (HF) electromagnetic field is investigated. The results of experimental studies are presented, showing the correlation between the degree of phase separation from dielectric parameters and the ratio of asphaltenes and resins in oils. It is shown that when water–oil emulsions are exposed to an HF electromagnetic field, the degree of heating and the efficiency of phase separation of the emulsion depend on the total content of asphaltenes and resins, their ratio, and whether the operating frequency of the generator falls within the region of resonant frequencies of the emulsions. [ABSTRACT FROM AUTHOR]

Abstract Asphaltene is often regarded as an undesirable by‐product of petroleum processing, possesses vast reserves with little market value. The typical routes of consuming asphaltene, namely burning and landfilling, pose significant environmental challenges. In this study, low‐value asphaltene is converted into high‐value ethylated carbon clusters (ECC) using a supercritical ethanol technique. The resulting ECC powder demonstrates promising properties for high density polyethylene (HDPE) composite applications. The effects of incorporating ECC on the mechanical, gas barrier, and anti‐aging properties of the composite are investigated. Results show that a 1 wt.% ECC led to a 4.2% and 43.5% increase in tensile strength and elongation at break, a reduction of 45.8% and 30.7% in oxygen and carbon dioxide permeability. Furthermore, ECC exhibits effective UV spectrum absorption and conversion in the wavelength range of 400–600 nm, providing protection against UV spectrum damage to HDPE. The incorporation of ECC not only enhances the properties of polymer composites but also sequesters carbon within the polymer matrix, enabling the valorization of asphaltene while mitigating environmental impact.

Asphalt or oil spills containing asphaltene can contaminate soil, water bodies, and ecosystems. Natural balances are disrupted by this contamination. Asphaltene contaminates water sources such as rivers, lakes, and aquifers, making them unfit for human consumption. Aquatic habitats are damaged, and aquatic organisms cannot reproduce, grow, or maintain health. Air pollutants, including sulfur dioxide, nitrogen oxides, volatile organic compounds, and particulate matter, are released when asphaltene-containing materials are burned. Here, we have developed a new method for the degradation of asphaltene that is fast, clean, and cost-effective. The asphaltene was degraded using NixMnyO piezo catalyst in this study. By using NixMnyO under mechanical force, the result showed that asphaltene was degraded to the extent of 94.7 %. Piezo based on NixMnyO has shown promising reusability when compared to conventional catalysts. Despite being used for 11 runs, it maintained 94% of its activity for 11 consecutive cycles. As well as analyzing the kinetics and thermodynamics of piezo asphaltene degradation, a mechanism pathway was developed for piezo degradation of asphaltene. Radical scavenger experiments showed that superoxide radicals, holes, and hydroxyl radicals are involved in the degradation of asphaltene by NixMnyO piezo catalysts. However, hydroxyl radicals and holes are responsible for the majority of asphaltene degradation.

Asphaltene precipitation and its subsequent deposition always remain a major concern for Oil industry. Formulation of a comprehensive and reliable risk management system for asphaltene prone wells and fields is a challenging task because of the influence of diverse factors. In this study, a decision support system is developed for the asphaltene risk assessment in wells and fields. Since, the data present in the literature is scarce and not consistent, therefore, a hypothetical data of fields and their wells was considered to conduct the study comprehensively. Three hypothetical fields namely; Field A, Field B and Field C were assumed and in each field ten wells were taken into consideration. A decision support system for assessing the risk of asphaltene prone wells was developed using one of the popular and powerful multi-criteria decision making technique i.e. Fuzzy Technique for Order of Preference by Similarity to Ideal Solution (Fuzzy TOPSIS) coupled with Analytic Hierarchy process (AHP). The risk of wells was evaluated using three criteria namely; Detection, Severity and Controls. These criteria were further sub-divided into sub-criteria and their data was assumed. The assumed data was transformed into Triangular fuzzy numbers for calculations. According to the final outcomes, Field A was proved be the most risky field followed by Field B and in the last comes Field C. The outcomes were further validated by other method namely; Fuzzy Complex Proportional Assessment (COPRAS) and all TOPSIS outcomes were found in good relationship with Fuzzy COPRAS. The proposed methodology proposed in this study will be landmark in risk ranking of asphaltene prone wells and fields.

Abstract Using chemical methods in enhanced oil recovery (EOR) processes is limited since the mechanisms, interactions, and synergisms combined with heterogeneities and network complexities besides the incompatibilities of different chemicals are encountered in the chemical EOR methods with some uncertainties. Also, since using only one chemical, namely surfactant, alkali, and polymer, has a bounded effect on the oil recovery, it is highly required to combine different chemical-based methods to achieve ultimate oil recovery. Unfortunately, since most of the developed surfactants cannot tolerate harsh salinity and temperature conditions, it is highly essential to tailor efficient and stable surfactants for those conditions. Moreover, since crude oil is comprised of thousands of different compounds which are different from one crude oil to the other crude oil, using a specific fraction of oils such as asphaltene and resin has high potential to provide more applicable and generalized results. In the light of this fact, the current investigation is designed and performed for the first time to combine different methods for better synergies for higher oil production using a new class of surfactant (1-tetradecyl-3-methylimidazolium chloride ([C14mim][Cl])), titanium oxide nanoparticles (TiO2–NPs), and alkali (Ca(OH)2) concomitant with NaCl and KCl with concentrations of 50,000–200,000 ppm. The point is that, instead of using crude oil with many compounds, only resin and asphaltene fractions extracted from a heavy acidic crude oil are used as the model oil (8 wt%). The measurements revealed the reducing effect of asphaltene and resin fraction on the interfacial tension (IFT), while the presence of NaCl and KCl makes this trend more complicated. The measurements also revealed an undeniable effect of Ca(OH)2 on the IFT reduction, especially in the presence of NaCl (concentration of 200,000 ppm), no matter using resinous or ASO. Moreover, the IFT measurements revealed the significant effect of used 1-tetradecyl-3-methyl imidazolium chloride ([C14mim][Cl]) on the IFT reduction with minimum values of 0.12 mN/m and 0.32 mN/m for 200,000 ppm of NaCl + Ca(OH)2 of 1500 ppm and 200,000 ppm KCl and Ca(OH)2 of 1000 ppm, respectively. Besides, the measurement revealed that the addition of TiO2 nanoparticles (TiO2–NPs) in the range of 0–100 ppm reduces the IFT to 0.069 mN/m and 0.08 mN/m, respectively. On the other side, the contact angle (CA) measurements and Amott wettability index calculation revealed the better impact of NaCl-based chemical formulation along with the used TiO2–NPs on the wettability alteration toward strongly water-wet conditions than the KCl-based chemical formulations. In the last stage, the performed core flooding experiments using forced imbibition and spontaneous imbibition concepts reveal that the obtained chemical formulations are capable to change the wettability of the rocks toward mixed conditions, while the forced imbibition tests (conventional core flooding experiments) revealed excellent effect of IFT reduction for more oil production with a maximum value of 15.3% based on the original oil in place (OOIP).

As one of the major fractions of petroleum and/or source rock extracts, asphaltene is commonly characte-rized by complicate molecular structures as well as relatively higher molecular weight (MW). The asphaltene occluded biomarkers have been well introduced to be valuable for geochemical research whilst the actual molecular weight and molecular structures of asphaltene macromolecules studies show value in petroleum exploration and production, laboratory treatments as well as petroleum chemical storage and transportation etc. The structure, molecular weight and related experimental measurement methods of asphaltenes reported in this paper are reviewed, in an attempt to provide a more comprehensive understanding on the molecular structure, molecular weight and physicochemical properties of asphaltenes, so as to provide basic data for applying asphaltene geochemical research in the exploration and development study of conventional and unconventional reservoirs. In view of the different views on the structure and molecular weight of asphaltene molecules, the results are reviewed, the main reasons for the controversy are discussed based on the current status of experimental measurement technology, and the future development trend of related researches is pointed out. The current understanding of the structure of asphaltene macromolecules is mainly based on two completely different models, i.e., the island model and archipelago model. The former suggests that asphaltenes have a single aromatic nucleus and the molecular weight characterized is relatively lower. The latter believes that asphaltenes have multiple aromatic nuclei and the molecular weight characterized is relatively higher. The above two models of asphaltene molecular structure are supported by their own experimental measurement results, among which the evidences of the "island" model mainly come from fluorescence spectroscopy, laser vaporization/laser ionization mass spectrometry (L2MS) analysis and stem from various ionization high-resolution (Fourier transform ion cyclotron resonance mass spectrometry, FT-ICR-MS) analysis technologies. The evidences for the archipelago model mainly come from gas phase permeation measurement, size exclusion chromatography and chemical degradation.

The dynamics of the interfacial tension coefficient at the interface between water and model solutions of asphaltenes of different concentrations in toluene has been studied. It has been shown that, over time, the interfacial tension decreases due to the adsorption of asphaltene molecules at the interface. With an increase in the concentration of asphaltenes in the solution, the decrease in interfacial tension occurs more intensively. The results of a study of the elongation of a water drop in a solution under the influence of an electric field are presented. It is shown that after the formation of an adsorption film, a higher electric field must be applied to stretch the droplet, and the relative elongation depends nonlinearly on the applied voltage. [ABSTRACT FROM AUTHOR]

The formation of a durable nanoadsorbent, known as DFCoMn2O4/IL@Ru(II), was achieved by binding a complex of Ru (II) trisbipyridine with ionic liquids (IL) to a dendritic fibrous CoMn2O4 (DFCoMn2O4). The resulting DFCoMn2O4/IL@Ru(II) was characterized using various techniques such as X-ray diffraction analysis (XRD), fourier-transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), and scanning electron microscopy (SEM). DFCoMn2O4/IL@Ru(II) was then employed as an environmentally friendly adsorbent for the removal and adsorption of asphaltene from petroleum. The presence of fibrous CoMn2O4 categories enhanced the adsorption capacity and facilitated the recovery of the adsorbent without significantly reducing the efficiency. The results demonstrated a clear synergistic effect between dendritic fibrous CoMn2O4 and the IL@Ru(II) categories, exhibiting a strong correlation. The utilization of the DFCoMn2O4/IL@Ru(II) system resulted in quasi-second-order adsorption kinetics. The experiment was conducted using the Taguchi method to minimize costs and time. Various amounts of asphaltene, temperatures, and adsorbent quantities were examined. Minitab software was deployed to evaluate the impact of these variables on asphaltene adsorption. The presence of ionic liquid groups enhanced the solubility of the heterogeneous adsorbent in environmentally friendly solvents, thereby enhancing function and reducing the time.

Some oil fields produce from different reservoirs, which may be incompatible generating precipitates. These precipitates are often asphaltenes, which can be an emulsion stabilizing agent negatively affecting the oil treatment processes. In this work, the influence of oil incompatibility on the stabilization of water-in-oil emulsions was studied. Emulsions were evaluated from three different oils (A, B and C) and their mixtures (AB, AC, BC and ABC). The results showed that there is a relationship between separation kinetics of emulsions and asphaltene precipitation. The separation kinetics of the emulsions was faster for more compatible oils. We observed that oil A, which was the less stable regarding asphaltenes, and the ABC mixture, which was the most incompatible mixture, both presented the slowest kinetics of emulsion separation. On the other hand, mixture BC which had the highest compatibility among the other mixtures presented a faster kinetic of emulsion separation. [ABSTRACT FROM AUTHOR]

A modfied polyisobutylene succinimide T154) asphaltene dispersant was prepared by modifying PIBSA with hexyl hexanol, and was applied to the preparation of FCC slurry scale inhibitor. The effects of modification temperature, modification time and material mass ratio on asphaltene dispersion and scale inhibitor on FCC slurry were investigated. The results showed that when the modification temperature was 240 °C, the modification time was 4 h,and the mass ratio of polyisobutylene succinimide m) to hexyl hexanol m) was 1u 1,the dispersion performance was better than polyisobutylene succinimide. The product had exceHent thermal stability; when the dosage of scale inhibitor was 150 g/g, the scale inhibition rate was 91.3. [ABSTRACT FROM AUTHOR]

Copyright of Scientific Bulletin of National Mining University is the property of National Mining University, State Higher Educational Institution and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The usual problem of meltable phase-change agents is the instability in their form upon heating, which can be solved by placing them into a continuous polymer matrix. Epoxy resin is a suitable medium for dispersing molten agents, but it is necessary to make the obtained droplets stable during the curing of the formed phase-change material. This work shows that molten paraffin wax forms a Pickering emulsion in an epoxy medium and in the presence of asphaltenes extracted from heavy crude oil. Theoretical calculations revealed the complex equilibrium in the epoxy/wax/asphaltene triple system due to their low mutual solubility. Rheological studies showed the viscoplastic behavior of the obtained dispersions at 25 °C, which disappears upon the heating and melting of the paraffin phase. Wax and asphaltenes increased the viscosity of the epoxy medium during its curing but did not inhibit cross-linking or reduce the glass transition temperature of the cured polymer. As a result of curing, it is possible to obtain phase-change materials containing up to 45% paraffin wax that forms a dispersed phase with a size of 0.2–6.5 μm. The small size of dispersed wax can decrease its degree of crystallinity to 13–29% of its original value, reducing the efficiency of the phase-change material. [ABSTRACT FROM AUTHOR]

Asphaltenes interaction produces problems in oil transport and recovery, and understanding the association process is vital to improving economic and industrial production. Here, we propose the COSMO model in combination with molecular dynamics (MD) simulations to complement the results obtained by Newtonian mechanics with quantum results to get reliable association data. Four asphaltene molecules were studied with toluene and heptane solvents. COSMO showed molecular interaction tendencies, which were later verified with MD. The average aggregation number was calculated through MD and turned out to be entirely dependent on the aromaticity due to π-π stacking. The aromatic rings are responsible for aggregation, while the sulfur heteroatom plays a less fundamental role. Viscosity is also related to the aggregation process; a higher tendency in aggregation increases the dynamic viscosity. Diffusion coefficients were correlated with the aromaticity, dipole moment, and molecular weight. Finally, a mathematical comparison between COSMO and MD results is accomplished. [ABSTRACT FROM AUTHOR]

Regular trends in the distribution of hydrocarbon biomarkers (n-alkanes, isoprenanes, steranes, and terpanes) and hydrocarbons of the adamantane series in low-maturity crude oil from the Anastasievsko-Troitskoe oil field (horizon IV) and in products formed by thermolysis of asphaltenes, resins, and acids from this oil were studied by gas chromatography–mass spectrometry. Thermolysis of high-molecular-mass oil precursors yields the same hydrocarbons (HCs) as those present in the initial oil, and also protoadamantanes (precursors of adamantanes). HCs of the adamantane series are not formed, and their presence in this crude oil is due to their supply from other oil source strata. The experiments show that the n-alkanes present in the initial oil in small amounts are released under more severe conditions. [ABSTRACT FROM AUTHOR]

The Hildebrand solubility parameter has been applied in several areas of science and engineering, assuming a relevant role in new scientific developments and practical applications in industry. This review shows its importance and relationship with development of research in flow assurance activities, especially involving heavy fractions of oils such as asphaltenes, resins and wax. The examples described illustrate its relevance and scope in the approaches of interest of flow assurance. They also show that it is a versatile property for many new applications, including the development of methodologies to obtain more reliable values for the various petroleum fluids and theoretical developments for its estimation in a wide range of temperature and pressure. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The catalytic activity of metal oxides in the processes of low- and high-temperature oxidation (LTO and HTO, respectively) of oil was studied on model systems consisting of oil-saturated quartz sand with additives of Al2O3, Cr2O3 and MgO using thermal analysis methods. The used additives were shown to shift the LTO and HTO processes to the low-temperature region. The catalytic activity of a natural reservoir carbonate rock without and with water was studied. This study established that at room temperature in dry carbonate rock, the oil components undergo dealkylation and polycondensation of aromatic fragments for a week. In the presence of water, the polycondensation processes are suppressed, and the cracking of resin and asphaltene occurs. The cracking reactions lead to a decrease in the content of heteroatoms in resins and asphaltenes. [ABSTRACT FROM AUTHOR]

Asphaltene extracted from heavy oil was oxidized by a mixture of propionic anhydride and hydrogen peroxide at a low temperature of 50 °C. Elemental analysis, infrared analysis, proton nuclear magnetic resonance analysis, and gas chromatograph/mass spectrometer analysis results indicated that oxygen addition, side chain cleavage, and condensation reactions mainly occurred in the oxidation process. The oxidation products were divided into 28% methanol solubles and 72% methanol insolubles. There were mainly fatty acids and fatty acid esters in the methanol solubles. There were also small amounts of aromatic compounds with low condensation in the methanol solubles, and the alkyl side chains were mostly short ones. The degree of aromatic ring condensation in the methanol insolubles was slightly higher than that of the pristine asphaltene. There were still some long unbroken chains in the methanol insolubles after the low-temperature reaction. The molecular dynamics simulation results show that the distribution of propionic anhydride around the asphaltene molecules can promote the oxidation of asphaltene. This low-temperature oxidation technology can be used to process asphaltenes to improve the profitability of heavy-oil-processing enterprises. [ABSTRACT FROM AUTHOR]

Asphaltene precipitation/deposition is considered a problem of formation damage, which can reduce the oil recovery factor. In addition, asphaltenes can be deposited in pipelines and surface installations, causing serious complications in guaranteeing runoff, decreasing the production of oil wells. The precipitation of asphaltenes can be minimized by reducing the oil production flowrate or by using chemical inhibitors. Analyzing the stability and precipitation trend of asphaltenes in petroleum is vital for the guarantee of flow. For this purpose, several experimental and numerical methods have been proposed. Once the risk of precipitation is established, strategies can be formulated for the prevention and diagnosis of deposition problems in production or production training. The tests can be performed with dead oil, available in the wellhead, and help in understanding the behavior of the asphaltenes. This review aims to present (i) the problem related to the precipitation of asphaltenes; (ii) thermodynamic models of asphaltene precipitation; and (iii) asphaltene inhibition, control, and removal techniques using nanoparticles. [ABSTRACT FROM AUTHOR]

The present study will evaluate the concentration and stability of the asphaltenes of 5 crudes obtained from the different producing levels of the Pacoa field as well as the mixture of all of them in the central tank at static surface conditions (1 atm) and 60ºF from the methods of "Stability index (IE)", "Colloidal stability index (IEC)", "Stankiewiez stability criterion (CES)", culminated with the "Sepulveda stability criterion (ACC: qualitative and quantitative analysis)" and La Mancha method. [ABSTRACT FROM AUTHOR]

One of the most serious complications in the production, transport and treatment of oil is asphaltene-resin-paraffin deposits. Their formation in underground well equipment, as well as in flow lines, collection system pipelines increase the cost of oil production. There are no sufficiently effective reagents to solve these problems. The results of implementation in many other wells testify to the high efficiency of the new reagent. The effect of reagents on the rheological properties of oil was also studied. Sangachal Deniz oil was used as a crude oil sample. We have developed multicomponent and multifunctional reagents M-R, P-R. In addition, due to paraffin formations in the tubing, they had to change 50-60 pipes for new ones every month. As a result of the introduction of M-R reagents, no paraffin deposits were found in the tubing for almost a year The effect of these reagents on the pour point of oils, dispersion, dissolution, and paraffin deposition has been studied. The use of the new reagent was tested at the mines of the oil and gas production department (OGPD) «28 May». The results of implementation in many other wells testify to the high efficiency of the new reagent. The effect of reagents on the rheological properties of oil was also studied. Sangachal Deniz oil was used as a crude oil sample. The proposed three-parameter Herschel-Bulkley model can be used to assess the rheological parameters of oils during their transportation. This layer, of course, cannot thicken indefinitely. Highly effective multicomponent composite compositions were developed to combat complications in the production of high-asphaltene-resin-paraffin oils. As can be seen from, during the reagent dosing period, there were no particular changes in the well performance. Treatment with hot oil on certain days was, as it were, of a preventive nature, since no changes were observed in the well parameters before and after heat treatment. When a certain layer thickness is formed in the tubing, the linear velocity of oil increases and begins to wash it away. [ABSTRACT FROM AUTHOR]

The flow properties of crude oil often improve by rising the temperatures or diluting the oil with different lower molecular weight hydrocarbons. Nevertheless, operational changes like these often results in the asphaltene deposition problems. Therefore, to address this issue, in this study, two-level full factorial design was applied on two already published experimental dataset of Ashoori et al. and Hu and Guo for studying the effect of three experimental parameters which include the dilution ratio (R), molecular weight of precipitant (M), and temperature (T), on the yield of asphaltene weight percentage. According to the results of Ashoori dataset, all linear and 2-way interactions of input variables were found significant (P value < 0.05) except the interaction between M and T whereas, for Hu and Guo dataset, only linear interaction of variables was found significant (P-value < 0.05). These Pareto, normal, main effects plot and interaction plot charts confirmed that R has the significant positive effects while M and T has a moderate negative effect on response variable for both datasets. The analysis of Variance (ANOVA) technique evaluated the validity of the predictive models and produce satisfactory results (having R2 value approximately 0.99). The results of contour plot and surface plot show that asphaltene precipitation increases at higher values of R and lower values of T and M. Finally, the full factorial technique was also applied on validation experimental dataset and results were found to be similar to Hu and Guo dataset. The study provides an effective methodology for the selection of optimum production parameters. [ABSTRACT FROM AUTHOR]

Copyright of Revista Fuentes, El Reventón Energético is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas & Oil is the property of Editorial Department of Natural Gas & Oil and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)