Properties Of Heavy Crude Oil Research Articles

Effect of hydrotreatment process on the physicochemical properties of a Colombian heavy crude oil post-catalytic aquathermolysis

Steam injection with catalysts is a method with high potential for heavy crude oil recovery and the fulfillment of fuel demand. This investigation aims to evaluate dispersed catalysts, produced in catalytic aquathermolysis, under hydrotreating conditions to improve the properties of heavy crude oils. The hydrotreating process of the improved crudes obtained in the catalytic aquathermolysis on a Colombian heavy crude of 12.8°API was analyzed. The aquathermolysis tests were conducted under conditions typical of steam injection, a widely used technology for enhanced oil recovery. Iron and molybdenum naphthenates were used as precursors. The upgraded crude oils showed a decrease in viscosity up to 90 % in comparison to non-catalytic aquathermolysis crude oil, and the conversion of 540 °C+ fractions with simulated distillation analysis was in the range of 10–20 % at 410 °C. The hydrotreating results showed that the activation of iron and molybdenum catalysts reduced the viscosity and increased the conversion of the 540 °C+ fraction by about 80 % and 30 %. Simulated distillation findings indicate that the conversion of heavy fractions contributes to the formation of lighter fractions such as naphtha, distillates, and VGO. As a result, the generation of these lighter fractions leads to viscosity reduction.

Modeling the Kinetics of Heavy Crude Oil Cu-Oleate Aquathermolysis

During steam injection processes, oil-soluble catalysts have demonstrated high efficiency by improving the flow properties of heavy crude oil into the reservoir. In order to gain a deeper understanding of the effect of this catalyst type and its reaction mechanism, further studies based on complex kinetic models are required. The catalytic effect of copper oleate on aquathermolysis of heavy crude oil was studied using experimental data obtained with a water/oil ratio of 3:7, a temperature range of 250 to 300 °C, and up to 72 h of reaction time. A kinetic model was developed to predict the yield of the SARA fractions and gases. The calculated kinetic parameters presented a proper fit concerning experimental data with average absolute error values lower than 4%. Results showed that copper oleate reduces the polyaddition reactions of heavy fractions, favoring the production of lighter compounds. A set of in-series and parallel reactions indicate that the reaction gas and aromatic compounds are mainly produced from the asphaltene fraction, where aromatic fractions subsequently generate saturates hydrocarbons.

Emulsifying stability and viscosity reduction for heavy crude oil in surfactant-polymer composite system

Heavy crude oil is one of the most precious and complex molecular mixtures available, with considerable economic relevance. Nevertheless, its high viscosity and complicated chemical compositions pose an exceptional challenge for viscosity reduction with a compound emulsification system in heavy oil exploitation. Here, two types of polymers were synthesized and compounded with surfactant SDS to reduce the heavy crude oil viscosity. Their emulsifying properties in demineralized water and mineralized water were measured to evaluate their differences from macroscopic views. Furthermore, the corresponding emulsion system (involving resins, asphaltenes, surfactants, polymers, etc.) was also simulated and computed using molecular dynamics simulation to investigate the relationships of various compositions on emulsifying properties at the molecular scale. The results showed that the surfactant-polymer composite system formed by the amphiphilic polymer had an obvious advantage in emulsifying stability with the water segregation rate of 60.6% after 48 h in the simulated salinity and the viscosity reduction rate reached more than 92.1% after optimization. Besides, the electrostatic interaction is the major part of the potential energy in emulsion systems at a ratio of 87.8%. The divalent cations (Ca2+ and Mg2+) resulted in the shrinkage or collapse of molecular conformation of the water-soluble polymer by 19%. The variation of interaction energy in salt solutions for different emulsifying systems caused a series of experimental and simulated distinctions, such as solution viscosity, interface behaviors, the number of hydrogen bonds, and the spatial distribution function, which ultimately determined the emulsifying properties of heavy crude oil. Notably, this work offers insight into the interactions and influences of complex mixtures in oil–water systems. It also facilitates to design and apply the innovative functional chemical additives in heavy crude oil extraction and transportation.

Interactions between fine particles and heavy crude oil: an experimental study using thermo-gravimetric and rheological analyses

The dissolution of fine particles into flowing and stranded fluids is not only one of the most prominent formation damage problems but also, is prejudicial to economic viability of oil-bearing matrices. To this end, the present paper investigates the effect of fine particles dissolution on rheological properties of heavy crude oil (API 16.6°). Because of the siliceous nature of the candidate formation, fine particles were modeled by nanoparticles. Considerations were given to silica oxide (Si-NP), alumina oxide (Al-NP) and iron oxide (Fe- NP). NPs were mixed into the dead heavy oil. Both thermogravimetric and rheological studies were used to evaluate the effect of fine migration on crude oil properties. The former revealed that the dissolution of Si-NP has the most prominent effect on physical properties compared to Al-NP and Fe-NP. The dissolution of Si-NP increased the oil viscosity up to 26 cP which was 22% larger than the oil without Si-NP. Increasing the load in Si-NP enhanced the stripping of the heaviest fractions of the crude oil (asphaltenes) from the bulk. The study attributed these results to the decrease in activation energy. The findings of this study can help for better understanding of crude oil upgrading using NP dissolution.

Effect of asphaltene adsorption on the magnetic and magnetorheological properties of heavy crude oils and Fe3O4 nanoparticles systems

An essential understanding of the adsorptive phenomena involving nanomaterials and asphaltenes has received considerable attention in oil recovery and production applications. Particularly, iron oxide-based nanoparticles have emerged as advanced materials due to their unique physicochemical properties, including thermal conductivity and superparamagnetism. On this basis, the kinetics and adsorption isotherms of magnetite (Fe3O4) nanoparticles/asphaltene systems were investigated, as well as the synergistic effect of resins acting as stabilizing colloidal agents. The results indicated rapid asphaltene adsorption that, essentially, follows the phenomenological external mass transfer (EMT) model. At the equilibrium, the asphaltene adsorption was adequately described by the monolayer Langmuir model. By these findings, it was studied for the first time the effect of the adsorbed asphaltenes on the magnetic dipolar interactions in nanoparticles/asphaltene powder state configurations, by applying a simple analytical model based on magnetic susceptibility and demagnetizing field concepts. It was proven accurately that asphaltenes coated the surfaces of the nanoparticles forming layers that stimulate a steric repulsive barrier between particles and, thus, reducing the intensity of interactions. Accordingly, a theoretical method was validated to estimate the magnetic-size distribution parameters by comparison with the physical distribution data obtained by Transmission Electron Microscopy (TEM). Finally, from the magnetically modified dynamic rheological properties, it was inferred that isotropic aggregates are naturally formed in the absence of the magnetic field, and these morphological features were not dramatically changed after the imposition of the field, leading to direct extrapolation of the modeling-based procedure for powders to real colloidal configurations applied in oil field operations.

Effect of enhanced oil recovery on the composition and rheological properties of heavy crude oil

The composition and rheological properties of ten samples of heavy crude oil from five different wells were investigated before and after integrated oilfield treatment with gel-forming and oil-displacing systems for increasing oil recovery. The study of the viscosity and viscoelastic properties of oil samples in a wide temperature range (from −30 to 70 °C) made it possible to determine their gelation and glass transition temperatures and also to establish the effect of enhanced oil recovery treatment on these characteristics. It was found that the treatment can either increase or decrease the viscosity of oil, and the same applies to the gelation and glass transition temperatures as well as to the contents of saturates, resins, and asphaltenes. The rheological properties of oil samples were closely related to their group composition, while the changes in the latter as a result of oilfield treatment were dependent on the relative position of the injection and production wells. The work allowed finding universal correlations between the group composition of heavy oil, its viscosity, and test temperature.

Computational study on effect of Mahua natural surfactant on the flow properties of heavy crude oil in a 90° bend

In this paper, A computational study is performed in this paper to investigate the influence of natural surfactant in a 90° bend on the flow properties of heavy Crude Oil. In ANSYS Fluent, computational fluid dynamics (CFD) code is used to investigate the flow phenomena in horizontal pipe bends. A suitable approach for transporting heavy oil through pipes is blending of surfactant with heavy crude oil for 'core annular flow' (CAF). This analysis analyzes the core annular flow numerically using the Large Eddy Simulation (LES). The prime objective of present work is to achieve understanding of the actions of high-sulphur crude oil flow across turbulent core annular flow in transporting pipes line. High-sulphur crude oil blended and additives are the two-phases in horizontal pipe.

Dispersed Nickel-Based Catalyst for Enhanced Oil Recovery (EOR) Under Limited Hydrogen Conditions

Heavy crude oil enhanced into a lighter oil by hydrocracking process with nickel nanoparticles (Ni NPs) as catalysts. Ni NPs were synthesized by colloidal method (chemical reduction of metal salts). The reduction of nickel nitrate hexahydrate ((Ni(NO3)2·6H2O) was done using sodium borohydride (NaBH4) as a reducing agent in presence of polyvinylpyrrolidone which worked as a protective and stabilizing agent; ethanol was used as a solvent. The properties of the nanoparticles were investigated by FT-IR, TEM, XRD, and HRTEM. These techniques confirmed the formation of Ni NPs with an average size of 10 nm and a tetragonal structure. The experiments were carried out in a batch reactor at 45 Kgf cm−2 (initial H2 pressure), 380 °C, stirring speed of 500 rpm and reaction time of 1 h. In all cases, the increase in the concentration of Ni nanoparticles improved the physical and chemical properties of heavy crude oil, even in limited hydrogen conditions; these properties were measured in terms of viscosity, SARA analysis, sulfur and nitrogen removal, and chromatographic analysis of gaseous products. The asphaltenes conversion was of 26.31% and moderate sulfur removal was achieved, these results are promising for EOR application.

Effect of the NiO/SiO2 Nanoparticles-Assisted Ultrasound Cavitation Process on the Rheological Properties of Heavy Crude Oil: Steady State Rheometry and Oscillatory Tests

This manuscript has the primary objective of demonstrating the changes in the rheological behavior of heavy crude oils (HO) in response to the application of ultrasound cavitation assisted with NiO...

Effect of pressure, temperature and gas phase composition on the rheological properties of heavy crude oil

Influence of pressure, temperature and the nature of gas on the viscosity of heavy crude oil from the Tatarstan field was studied using rheology method (rheometer MCR 302). The effect of temperature from 25 to 125 °C and pressure from 0.1 to 12.5 MPa on crude oil viscosity was investigated. It was found that an increase in temperature of 125 °C leads to a decrease of viscosity by 8 times. At the same time, an increase of pressure up to 10 MPa leads to an increase in viscosity by 38% at low temperatures. Also the influence of the nature of gas (nitrogen, argon and air) on the viscosity of crude oil at different temperatures and pressures was analyzed. It is shown that crude oil viscosities depend on gas composition. On the other hand, the influence of the composition of binary gas mixtures in a wide range of temperatures and pressures on the viscosity of heavy oil has been studied. The activation energies of flow are calculated for two types of gas mixture. It is shown that the gas phase at different ratios of the components does not significantly affect the rheological parameters of crude oil.

Experimental and Theoretical Study on Supramolecular Ionic Liquid (IL)-Asphaltene Complex Interactions and Their Effects on the Flow Properties of Heavy Crude Oils.

A combined study for understanding the molecular interactions of asphaltenes with molecular species such as ionic liquids (ILs) comprised experimental measurements and computational numerical simulation calculations, using density-functional theory (DFT) with dispersion corrections, molecular dynamics (MD) calculations, and experimental rheological characterization of the heavy crude oils (HCOs), before and after doping with ILs, respectively. The main results show that ILs influence the asphaltenic dimer association by forming supramolecular complexes that modify the properties of crude oils such as viscosity and interfacial tension. The IL-cation and asphaltene-π ligand molecular interactions seem to dominate the interactions between ionic liquids and asphaltenes, where ILs' high aromaticity index induces a strong interaction with the aromatic hard core of asphaltenes.

Enhancing the production of light olefins from heavy crude oils: Turning challenges into opportunities

The large reserves of heavy crude oils and the significant demand of light olefins, particularly propylene, have created new opportunities for developing advanced catalyst and process technologies that efficiently upgrade asphaltenes-enriched crudes to high values chemicals. Indeed, many petrochemicals are produced during crude oil refining as side streams, because the primary goal of the crude oil refinery is the production of transportation fuel. This paper attempts to briefly review the properties of heavy crude oils, the major process technologies for the production of light olefins such as steam cracking and fluid catalytic cracking and finally the catalyst technology mainly focused on ZSM-5 and HY zeolites. We include not only the current understanding of the olefin production technologies, but also the challenges involved in the upgrading of unconventional crudes and residue with high content of heteroatoms and unsaturated poly-aggregate asphaltenes. A strategy for processing unconventional oil that involves the utilization of steam (catalytic) cracking process, in a FCC-type configuration, and enhanced cracking catalyst with high hydrothermal stability is also analyzed.

Application of naturally extracted surfactant from Madhuca longifolia to improve the flow properties of heavy crude oil through horizontal pipeline

Madhuca longifolia or Mahua is a natural alternative of surfactants and cleaners. Having enormous applications in cleaning industries and its potential biodegradability, the surfactant extracted from Mahua was used as flow improver for transportation of heavy crude oil through pipeline. The beneficial effects of the surfactant on improvement of pressure drop, drag reduction and head loss for flow of crude oil has been investigated at different operating conditions through a horizontal pipeline of diameter 1.5 inch. The results showed significant influence of surfactant on the pressure drop and percentage of drag reduction. Heating of crude from 25 °C to 40 °C reduced pressure drop from 10.6 psi to 4.3 psi at a flow rate of 60 L/min whereas addition of 2000 ppm surfactant at 25 °C reduced the pressure drop to 2.6 psi at same flow rate. At same temperature, the head loss decreased from 6.77 L/min to 4.88 L/min when 2000 ppm surfactant was added to the crude oil. It was also noticed that viscosity reduction at 25 °C after addition of 2000 ppm surfactant was even greater than heating the crude to 40 °C. This can immensely serve the purpose of pipeline transportation of heavy crude oil where viscosity is a major issue. The experimental results were compared with existing models like Cross, Carreau and Krieger & Dougherty model and the crude oil was found to follow Krieger-Dougherty model. Considering the effectiveness of the surfactant, biodegradability and cost effectiveness, this novel surfactant can be used as a flow improver for crude oil during transportation through pipelines even at low temperatures.

Effect of Natural Surfactant on the Rheological Characteristics of Heavy Crude Oil

In present work, an attempt has been made to investigate the possibility of transporting heavy crude oil with and without addition of natural additive. The physical, chemical and rheological properties of heavy crude oil have been determined at different temperature condition. The rheological characteristics include steady and unsteady flow, viscoelastic and thixotropic characteristics etc. Madhuca longfolio was used as an additive with the heavy crude oil. The surfactant was mixed in heavy crude oil of 1000 and 2000 ppm. The heavy crude oil shows the non-Newtonian flow characteristics at low temperature and decreases with increase in temperature. Fourier transform infrared spectroscopy (FTIR) results reveals that a significant decrease in concentration was found in alcoholic, ketones and alkanes group which increases the viscosity of crude oil. The rheological results show that there is a reduction in viscosity with addition of Madhuca longfolio as additive in heavy crude oil suspension which is useful for design of pipeline of oil transportation system.

Analysis of the asphaltene properties of heavy crude oil under ultrasonic and microwave irradiation

Using new technologies are quite significant in the production and development of heavy oil reservoirs. In this study, the effects of microwave (MW) and ultrasonic (US) waves on the properties of Ellam heavy crude oil of the southwest oil reservoirs of Iran have been investigated. Experimental results show that different processes occur in samples under MW radiation for 5, 10, 15 and 20min. Under MW for 5 and 10min we have viscosity reductions from 15.836 mPa.s to 12.234 mPa.s and 11.122 mPa.s, respectively. This is due to volume expansion with decreasing viscosifying component and high absorption capacity of heavy molecules of oil toward MW that charges the cracking process. US waves increase the viscosity of oil for all time durations because the power from US waves causes the evaporation of light compounds. Next, the effect of MW and US radiation on the asphaltene clusters using microscopic images was investigated. Results of asphaltene particle size distribution show that increasing duration of wave radiation makes the particles smaller, and the size range of asphaltene particles in the samples under MW radiation is much smaller than for the samples under US wave radiation. Moreover, in samples under MW radiation, the large particles cannot be seen. Consequently, the average particle size of asphaltene is smaller in samples under US wave radiation. But the particle size range is high, and large-sized particles in different time intervals of US radiation are observed. The results of scanning electron microscopy show that microwaves make the asphaltene conglomerate forming particles smaller and more regular in shape than the primary state, whereas ultrasonic waves completely alter the structure of the asphaltene particles, creating asphaltene clusters with a different structure. Based on the Fourier transform infrared spectra, ultrasonic exposure increases the cracking rate of the weaker bands and the condensation of aliphatic bands more than does exposure to microwaves, due to an increase in the intensity of the spectra.

Simulation of single phase non-Newtonian flow characteristics of heavy crude oil through horizontal pipelines

ABSTRACTThe effect of diameter, velocity, and temperature on flow properties of heavy crude oil in three horizontal pipelines using computational fluid dynamics (CFD) was studied. The flow characteristics were simulated by using CFD software, ANSYS Fluent 6.2. The mesh geometry of the pipelines having inner diameter of 1, 1.5, and 2 inch were created by using Gambit 2.4.6. From grid independent study, 221, 365 mesh sizes were selected for simulation. The CFD ANSYS Fluent 6.2 Solver predicted the flow phenomena, pressure, pressure drop, wall shear stress, shear strain rate, and friction factor. A good agreement between experimental and CFD simulated values was obtained.

Investigation of novel extracted surfactant on rheological properties of heavy crude oil

Naturally extracted surfactant from tropical Indian plant Madhuca longifolia was used to enhance flow properties of heavy crude oil through pipelines. Experimental measurements include viscosity, yield stress, viscoelastic properties, pour point, SARA analysis, microscopic studies and FTIR studies. Experimental verification of Power Law model was justified. Crude oil surfactant mixtures tend to behave like Newtonian fluid as surfactant concentration was increased from 500 to 2,000 ppm. Viscosity of crude with 2,000 ppm surfactant at 30°C was almost same as that of pure crude at 50°C. Presence of surfactant significantly reduced elastic and complex moduli of heavy crude oil at 30°C. Yield stress of crude oil reduced from 0.9 to 0.017 Pa with surfactant addition at 30°C. Microscopic studies showed surfactant addition reduced size of wax crystals appreciably. FTIR studies implied that aldehydic and amine groups are responsible for high viscosity and their concentration reduced after addition of surfactant Madhuca longifolia. [Received: August 4, 2015; Accepted: November 28, 2015]

Investigation of novel extracted surfactant on rheological properties of heavy crude oil

Investigation of novel extracted surfactant on rheological properties of heavy crude oil

Bioremediation of Heavy Crude Oil Contamination

Crude oil contamination is one of the major environmental concerns and it has drawn interest from researchers and industries. Heavy oils contain 24-64% saturates and aromatics, 14-39% resins and 11-45% asphaltene. Resins and asphaltenes mainly consist of naphthenic aromatic hydrocarbons with alicyclic chains which are the hardest to degrade. Crude oil biodegradation process, with its minimal energy need and environmentally friendly approach, presents an opportunity for bioremediation and as well for enhanced oil recovery to utilize heavy oil resources in an efficient manner. Biodegradation entails crude oil utilization as a carbon source for microorganisms that in turn change the physical properties of heavy crude oil by oxidizing aromatic rings, chelating metals and severing internal bonds/chains between molecules. Biodegradation does not necessarily lower quality of crude oil as there are cases where quality was improved. This paper provides information on heavy crude oil chemistry, bioremediation concept, biodegradation enzymes, cases of Microbial Enhanced heavy crude Oil Recovery (MEOR) and screening criteria towards a better understanding of the biodegradation application. Through the utilization of single microorganisms and consortia, researchers were able to biodegrade single pure hydrocarbon components, transform heavy crude oil fractions to lighter fractions, remove heavy metals and reduce viscosity of crude oil.

A Single Pore Model for Displacement of Heavy Crude Oil With Carbon Dioxide

Summary The present problem analyzes displacement of heavy crude oil in a capillary by carbon dioxide (CO2) as seen in enhanced oil recovery (EOR). In immiscible displacement of viscous liquid in a tube by a gas with lower viscosity than the liquid, a gas bubble moves steadily and leaves behind a thin liquid film of thickness h∞ which is known as the Bretherton problem. With the recovery of crude oil in mind, the analysis was confined to cylindrical pores of diameter ≈1 µm, and hence disjoining pressures are included and added to the Laplace pressures. It is observed that, at small capillary numbers, the effect of disjoining pressure dominates, and at large capillary numbers, the Laplace pressure dominates. The key contribution here is the solutions to the mass-transfer problem in the form of CO2 dissolving in oil. We included the changes of the physical properties of heavy crude oil on carbonation on the basis of a real system. The thickness of thin residual oil film decreases in the presence of mass transfer, leading to an increase in oil recovery, but lowers the carbonation because of the convection in the reverse direction. The opposite is true of displacements at low capillary numbers in which the disjoining pressure dominates. The numerical solutions were obtained with ANSYS® FLUENT software for the profile shapes, capillary numbers, the thicknesses of thin oil films left behind, and the net mass-transfer rates. The capillary pressure dominates the net pressure drop that one can lower by lowering the surface tension.