Rheological Properties Of Crude Oil Research Articles

Insights into the effect of water content on asphaltene aggregation behavior and crude oil rheology: A molecular dynamics simulation study

In the production and transportation of crude oils, the interaction between asphaltene components and water is inevitable, significantly impacting asphaltene aggregation, deposition behaviors, emulsion stability, and rheological properties of crude oils. However, the comprehension of the oil-water interaction mechanisms and corresponding viscosity responses remains unclear. Hence, we performed molecular dynamics (MD) simulations to investigate the effect of varying water content on distinct asphaltene aggregation states and the rheological behavior of crude oils. The microscopic mechanisms underlying the aggregation and rheological properties were elucidated. Our MD results show that with the continuous introduction of water, the original bulk phase aggregation of asphaltenes undergoes a transition towards interfacial adsorption behavior, culminating in the formation of water-in-crude oil emulsions. The strength and driving forces of this interfacial adsorption are influenced by different polar functional groups of asphaltene. Besides, by elucidating the contributions of external molecular friction and internal structural deformation to the viscosity, two viscosity-influencing mechanisms are revealed. Furthermore, we delineate a physical viscosity scheme. These intriguing discoveries hold promise for advancing the comprehension of rheological behavior in crude oils with distinct aggregation states, providing theoretical guidance for efficient development of crude oils.

Effect of a novel type of water-in-oil nanocomposite viscosity improver on rheological properties of crude oil

The waxy crude oil was routinely transported by means of adding pour point depressants (PPD), which can significantly improve the flow behavior of waxy crude oil. In this study, the physical properties of crude oil were first characterized. Subsequently, a novel variety of W/O nanoemulsion was prepared based on water in an EVA/toluene solution at a 3:1 proportion, and evaluated as a viscosity improver. It was found by virtue of the laser particle size analyzer that the EVA emulsion reaches the nano-scale. EVA nanoemulsion can present a behavior similar to nanocomposite PPD, and form a denser and regular structure with wax crystals via heterogeneous nucleation. Compared with conventional EVA, EVA nanoemulsion further reduces the oil viscosity, gel point and yield value by 52.8%, 0.05 °C and 29.6%. In addition, the impact of particle size of EVA nanoemulsion on the rheology of crude oil was discussed. In combination with DSC curve and POM, the action mechanism of EVA nanoemulsion on crude oil was analyzed.

The Chemical Performance Evaluation for Pour Point Depressant (PPD) Testing, X Oil Field, Vietnam

Pour Point Depressant (PPD) Testing are used extensively to modify the crystallinity of hard waxes and to reduce the natural pour point of crude. The best PPD chemical and best dosage for crude oil treatment will be chosen based on the laboratory test results to: Reduce pour point of crude oil; Reduce viscosity of crude oil; Improve rheological properties of crude oil; Reduce wax deposition rate and pipeline restart pressure. The chemical performance evaluation for PPD, proposed to use at X Oil Field has been conducted in Crude oil and Petroleum products Lab. The following properties have been determined in laboratory for blank sample (which is a mixture of H1, H4 and H5 crude oil samples with ratio of 2.1:1.4:1.0) and sample treated by PPD (rundown crude oil sample): Pour Point (for blank sample and treated sample); Wax Appearance Temperature (WAT) and Wax Disappearance Temperature (WDT) (for blank sample); Dynamic Viscosity (for blank and treated samples); Yield Stress by Rheometer (for blank and treated samples) for 100 mins, 1000 mins and 02 days shut-in times; Wax Deposition Rate by Cold Finger for blank and treated samples; Restart Pressure by Restart Loop (for blank and treated samples) for 100 mins, 1000 mins and 02 days shut-in times.

Flow Measurement and Instrumentation

Crude oil flow in the pipelines is a source of major problems with heavy substance deposits on the wall surfaces. This situation can lead to lines blocking. Therefore, it is mandatory to have information concerning the flow. For this purpose the rheological properties of the crude oil are needed in order to propose adapted solutions. This paper deals with the study of the rheological properties of Algerian crude oil at different temperatures as well as its flow in pipe. The experimental results obtained with a modern rheometer can be used to predict the crude oil transport characteristics. The crude oil rheogram shows a non-Newtonian behavior which can be described by the Ostwald law. The shear stresses computations obtained from an analytical model and the MPTT model are compared and give the friction factor distribution across the pipe section. The obtained results are presented and discussed.

Novel Homo-and Co-polymers Based on 7-Methacryloyloxy-4-methylcoumarin: Synthesis, Antimicrobial Activity, Pour-Point Depressants and Their Effects on the Rheology of the Waxy Crude Oil

This study aimed to synthesize new polymeric additives including homo- and co-polymers based on 4-methyl-2-oxo-2H-chromen-7-yl methacrylate monomer and evaluating their activity as potential antimicrobials and as pour-point depressants for modification of waxy crude oil rheology. The resultant compounds were characterized by their IR, 1H NMR and 13C NMR spectral data. The formation of the new polymers, namely, poly(7-methacryloyloxy-4-methylcoumarin) [poly(MAOMC)] homo-polymer, poly(7-methacryloyloxy-4-methylcoumarin-co-vinylacetate) [poly(MAOMC)-co-(VA)] and poly(7-methacryloyloxy-4-methylcoumarin-co- octadecyl 4-(methacryloyloxy)benzoate) [poly(MAOMC)-co-(OMAOB)] co-polymers was based on free radical polymerization. The polymerization reaction was carried at 70±2°C using 2,2’-azobisisobutyronitrile (AIBN) as an initiator and dimethylformamide (DMF)/toluene as a solvent in the case of homo-polymer [poly(MAOMC)] and co-polymer [poly(MAOMC)-co-(VA)], while polymerization proceeds at the same temperature by using benzoyl peroxide as an initiator and toluene as a solvent in the case of co-polymer [poly(MAOMC)-co-(OMAOB)] The activities of the resultant compounds as potential antibacterial agents were evaluated against the two Gram-positive (Bacillus cereus and Staphylococcus aureus), the four Gram-negative (Escherichia coli, Neisseria gonorrhoeae, Pseudomonas aeruginosa, and Salmonella typhimrium) bacterial strains, and as antifungal agents against two fungal species (Aspergillus flavus and Candids albicans). The results showed that MAOMC monomer and poly(MAOMC)-co-(OMAOB) copolymer indicated moderate potent activity towards the bacterial and fungal strains used. At the other extreme, the influence of coumarin and octadecyl benzoate based compounds on the pour-point depression and on the rheological properties of crude oil with low asphaltene content was studied. The results indicated that all three polymers exhibited very good efficiency as additives to improve the flow-ability of the tested crude oil. Moreover, the poly(MAOMC)-co-(OMAOB) co-polymer was found to exhibit the highest performance to reduce and depress the pour-point of the tested crude oil and decrease the viscosity to a large extent due to the presence of two aromatic units with the long aliphatic carbon chain in its structure.

Improving the thermo-physical and rheological properties of crude oil (CO) by the synthesized CuO/SiO2/CaP nanocomposite for drag reduction through horizontal pipelines

The thermo-physical properties and rheological behavior of crude oil (CO) have substantial efficacies on transportation, processing, and refinery operation. SiO2 (silica)–CaP (calcium phosphate)–CuO (copper oxide) nanocomposite was synthesized by the sono-co-precipitation technique. In this work, the impact of nanocomposite volume fraction as well as temperature on the thermo-physical and also rheological characteristics of SiO2–CaP–CuO-based CO nanofluid were evaluated. All experimental tests were done in the temperatures and nanocomposite concentrations of 25–55 °C and 0.05–0.75 vol.%, respectively. Also, the drag reduction of the nanofluid in horizontal pipelines was elucidated by the SiO2–CaP–CuO-based CO nanofluid at 25 °C. The highest dynamic viscosity enhancement was found to be about 44.57% for 0.75 vol.% nanocomposite particles. The nanofluids thermal conductivity augmented with nanocomposite volume fraction increment. The greatest increment in nanofluids thermal conductivity was obtained about 17.26% at 0.75 vol.%. Moreover, four correlations were expanded for the dynamic viscosity and thermo-physical characteristics of the nanofluids with relative average deviation (RAD) percentage of less than 1%, which depended on temperature and nanocomposite volume concentration. The empirical relationships indicated a satisfactory compliance with the laboratory data. Additionally, outcomes demonstrated that the drag reduction of hybrid nanofluid in the horizontal pipeline under fully turbulent flow increased with enhancing the nanofluid concentration. Drag reduction of the nanofluids in the rough pipelines was higher than that in the smooth pipeline at the same Reynolds number in the range of 6500–42,000 and different pipe’s diameter (0.5–1 in.). No considerable increase and/or a reduction in hybrid nanofluid thermal conductivity was found for the recovered nanocomposite in various volume concentrations. The highest dynamic viscosity reduction after three times recovery treatment was obtained about 0.7% for 0.5 vol.% nanocomposite particles.

Laboratory evaluation of a novel multifunctional chemical solution for asphaltene precipitation and aggregation problem: Comparison with an industrial chemical solution

Asphaltene deposition in the near-wellbore area and within the pipelines reduces productivity and is costly. There are usually 2 methods to remedy this hardship that are using dispersants or inhibitors to preventing asphaltene deposition or using solvents when asphaltene deposits on inner surface of pipes or in the porous media. In this study, additive called AUT Force 110 has been developed and its properties have been inspected. This solvent has multifunctional efficiencies (MS) such that can be used as asphaltene inhibition and dispersion and dissolve asphaltene deposits. Furthermore, its performance is compared to an industrial solvent called PL5001 (CS). Analyzing the fourier-transform infrared spectroscopy (FTIR) of the two additives were found to have polar functional groups of hydroxyl, thiol, carbonyl and carboxylic acid in their molecule. The existence of various functional groups gives the MS molecule the ability to interact with adjacent molecules through hydrogen bonding. In addition, aliphatic compounds were observed in the MS molecule with a low carbon number, which leads to its compatibility with crude oil. In contrast, the CS consists mainly of aromatic rings. Two carbonyl and ether functional groups were also observed in its molecular structure, which are very low in concentration compared to polar compounds of MS. Then, the confocal microscopy imaging was used to observe asphaltene aggregates with precipitant. The crude oil and n-heptane were combined in a ratio of 1–30 volumes. The addition of 100 ppm MS reduced about 87% of the mean diameter of asphaltene aggregates; while this reduction was less than 70% by adding CS. Also, adding MS narrowed the dispersion range of the asphaltene particles diameter to 2–16 μm. The carboxylic acid and thiol functional groups play important roles in asphaltene dispersion in MS system. Both MS and CS delayed the onset of asphaltene precipitation, however MS has greater asphaltene inhibition power as well as improving the rheological properties of crude oil and n-heptane solution due to the reduction in the size of asphaltene aggregates, the interaction of MS with asphaltene, and the reduction of the interaction between the asphaltene-asphaltene molecule besides the polar nature of MS. Turbiscan test was also used to measure the solvation power of two additives. The solubility number of MS was lower than that of CS and was reported to be a good solvent, indicating that it has better solvation power than CS. Because MS has the ability to hydrogen bond with asphaltene molecules as both donor and acceptor. Secondly, its aliphatic chains cause steric hindrance, which contributes to the stability of asphaltenes within MS.

Impact of the Composition and Content of Dissolved-State Paraffins in Model Oil on the Aggregation State of Asphaltenes and the Stability of Water-in-Model Oil Emulsion

Paraffins cause many issues during the production and transportation of crude oils. To date, there is abundant research on the rheological properties of crude oils after paraffin crystallization an...

Experimental investigation of the rheological behavior of algerian crude oils from the quagmires

In this work, the rheological behavior for three types of crude oil coming from different quagmires namely Amassak, Tamendjelt and Tin Fouye of the TFT sector (Tin Fouye Tabankort/South Algeria) has been experimentally investigated. A controlled stress rheometer (AR 2000, TA Instrument) was used throughout this investigation. The experimental measurements in terms of flow and dynamic tests were carried out at different temperatures during the shear rate over the range of 0–700 s−1 and frequency range of 0.1–10 rad/s. The obtained results show that the viscosity and shear stress of the crude oils decreases about 53.30%, 58.80%, and 59% respectively, when the temperature increased from 10 to 20 °C. The yield stress required to flow of crude oils also decreased to 37.06%, 89.78%, and 77.53% respectively. The dynamic analysis of the crude oils by identifying of the storage modulus (G′) and the loss modulus (G″) has indicated that the rheological properties of crude oils were significantly temperature-dependent.

Waste bio materials based viscosity reduction and rheological properties of crude oil

The effectiveness of using waste bio materials as viscosity reducing agents was investigated on light and heavy crude oils of Oman. The selected materials are fiber of palm tree, date palm kernel and walnut shell. The utilization of waste bio materials is not only considered as a cost effective, but, environmentally friendly and has less effect on crude oil processing as compared to that of chemical additives. In this study, special piping structure was constructed to measure flowabilty time of crude oil. It was observed that use of bio materials reduced oil flowability time by range of 42–50% using particle size 75 µm and by 66% using particle size 150 µm. Moreover, the effect of different additives and various concentrations of bio materials on oil rheological properties, for instance viscosity and yield stress, were also studied. Results showed that the light crude oil exhibits a non-Newtonian viscoplastic behavior following (Bingham plastic model) whereas the heavy crude oil exhibits a non-Newtonian pseudoplastic behavior (shear thinning model). The use of bio materials reduced the limiting viscosities of the light crude oils by 62% using particle size 75 µm and 75% using particle size 150 µm. However, limiting viscosity of heavy crude oil was reduced by 15%. In addition, it was observed that using bio materials lowered yield shear; light crude reduced by average 32% while heavy crude oil reduced by 10%.

Comparative studies of the rheological behavior and microstructural properties of emulsions (oil/distilled water phase) and (oil/Lias water phase)

The rheological behavior of crude oil and their emulsions were investigated as a function of two water types (distilled water and the LIAS water). The focus of this work is to obtain more knowledge about the effect of LIAS water concentration, which used to maintain pressure and produced from production of crude oil in the oil fields Tin Fouye Tabankort-south Algeria, on the rheological properties of crude oil. The rheological parameters were measured by using AR-2000 rheometer at 15 °C under dynamic and shear testing conditions. The measured data were first classified into two groups for Newtonian and non-Newtonian fluids. Depends on the type and concentration of water, the non-Newtonian behavior was described in better way by the Casson, Power law and the Herschel–Bulkley models. The results indicated that the viscosity, the yield stress, the elastic modulus, (G′), the loss modulus, (G″), and the microstructure of the prepared emulsions not only varied with water concentration but also by water types.

Effect of Average Molecular Parameters of Asphaltenes on the Rheological Properties of Crude Oils from Colorado Oil Field

In our previous articles (Energy & Fuels 2017, 31, 133–139 and Energy & Fuels 2017, 31, 8997–9005), it was presented that the asphaltenes of the Colorado field have different chemical structures, and these change the properties of crystallization of the paraffins. In this paper, we present a new way to understand the effects of the chemical structure of the asphaltenes on crude oil rheology, which includes correlating the average molecular parameters (AMPs) and the concentration of the asphaltenes with rheological properties using chemometric methods such as the partial least squares method. The asphaltenes were separated from six crude oil samples (average °API of 38) and were characterized using nuclear magnetic resonance to determine their main molecular parameters. Rheological properties including viscosity, yield stress, and gel temperature were experimentally determined for each of the crude oil samples and their respective maltenes. The results of a multivariate analysis show that the AMPs of the a...

Viscosity profile prediction of a heavy crude oil during lifting in two deep artesian wells

It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells (> 5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy (Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature (Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.

On the Influence of Micro- and Macro-Cristalline Paraffins on the Physical and Rheological Properties of Crude Oil and Organic Solvents

The influence of micro- and macro-crystalline paraffins on the properties of crude oil and organic solvents was investigated. Micro-cristalline paraffins promote the most pronounced changes in the investigated physical and rheological properties of all tested solutions. The concentration of branched-alkanes in paraffins is the pivotal parameter that promotes these changes.

Rheological properties of crude oils in Yaregskoye and Yaraktinskoye oil fields

Rotary viscometer tests of crude oil with a high content of resins and asphaltenes (Yaregskoye oil field) and crude oil with high paraffin content (Yaraktinskoye oil field) have been conducted. The typical flow curves for these oil types have been plotted. It has been detected that these oils are non-Newtonian fluids, viscosity of which is dependent on shear rate. Based on Arrhenius-Eyring equation, calculations of viscous flow activation energy and complex structural unit (CSU) sizes have been performed. It has been stated that there is a tenfold reduction in CSU size in asphaltic crude oil with the increase in shear rate in a rotary viscometer, while particle size in paraffinic crude oil does not essentially change under the same hydrodynamic conditions.

Effect of ammonium-containing polyalkyl acrylate on the rheological properties of crude oils with different ratio of resins and waxes

A composite additive for oil pipeline pumping has been tested as a viscosity modifier and crystallization modifier (depressant) in two crude oils and gas condensate of West Siberian deposits with the different content of resins and waxes. The additive represents a toluene solution of a cationic surfactant and an amphiphilic copolymer of alkyl acrylate C16-C20 with a salt of acrylic acid and higher amine. Pour points, rheological characteristics, phase transition temperatures, energies of the destruction of supramolecular structures were determined for investigated oils with different concentrations of the additive. The comparison of the efficiency was made for the composite additive, a commercial depressant and surfactant-free additive.

Rheological behavior of an Algerian crude oil containing Sodium Dodecyl Benzene Sulfonate (SDBS) as a surfactant: Flow test and study in dynamic mode

Abstract In order to improve the flow characteristics, this work aims to study the rheological behavior of the oil crude (coming from the oil field of Tin Fouye Tabankort/South Algeria) with and without additive friction reducing. An experimental study was performed by measuring the rheological characteristics by flow tests and dynamic mode (oscillation) at different temperatures (20 °C, 30 °C and 50 °C) using the rheometer AR2000. The temperature of the crude oil varies between these extreme values in the south of Algeria. For this, the effect of the shear rate, the temperature and the additive concentration of Sodium Dodecyl Benzene Sulfonate (SDBS) on the rheological parameters have been studied. The obtained results show that the crude oil exhibits a non-Newtonian behavior at a low shear rate which can be described by the Herschel–Bulkley model. It was also noted that the Newtonian behavior occurs at high values of the gradient of shear rate. The viscoelasticity character of the crude oil by identifying of the elastic modulus (G′) and the viscous modulus (G″), has indicated that the rheological properties of crude oil were significantly influenced by the additive.

Study on the Temperature Distribution of High Pour Point Oil by Integrated Method Based on Well Log, Geological Data and Experiment

High pour point oil reservoir contains various typical properties; such as a kind of high freezing point, high paraffin content and high cloud point temperature reservoir, while the temperature is regarded as high sensitive parameter for oil reservoirs. The current research aim is to develop and assess the effect by cold water flooding, the structure and properties model was built with the combination method of reservoir geological modeling and simulation. Various degrees of cold damage have deep relation with paraffin deposition and reservoir channel plug due to decline of temperature below the cloud point temperature. Precipitated paraffin has changed the rheological properties of crude oil, which can increase filtration resistance and reducing the oil displacement efficiency. Furthermore, model simulation analysis results compared under two different conditions cold and hot water flooding and predicted the inter well temperature field distribution belongs to reservoir through the model numerical simulation. Present study depicts that the integrated method base on log, geological data and experiment can predict and analysis the temperature variation efficiently, while thermal displacement method has efficiently improved the high pour-point oil reservoir development effect, increasing oil mobility and enhancing oil recovery.

Synthesis of phthalimide and succinimide copolymers and their evaluation as flow improvers for an Egyptian waxy crude oil

This paper describes the synthesis, characterization and performance evaluation of three phthalimide and three succinimide copolymers of vinyl acetate, styrene and methyl methacrylate as flow improvers for waxy crude oil. The prepared copolymers were named as; (VA)Ph; (St)Ph; (MMA)Ph; (VA)S; (St)S and (MMA)S. These copolymers were characterized by FTIR and 1H NMR spectroscopy. The molecular weights and nitrogen content of these copolymers were determined by using the GPC technique and the Kjeldhal method, respectively. The rheological properties of crude oil (with and without additives) were studied. From the obtained results, it was remarked that the styrene phthalimide copolymer (St)Ph exhibited the maximum pour point depression (ΔPP500ppm=30). The results of the rheological flow properties showed that the Bingham yield values (τβ) for crude oil without additives at 15, 27 and 39°C were 0.286, 0.131 and 0.075Pa respectively, whereas the τβ for the treated crude oil by the styrene phthalimide (St)Ph copolymer were 0.021, 0.0164 and 0.0081Pa at 500ppm at the same temperatures.

Determination of friction factor of Algerian crude oil during flow in pipe-lines

Crude oil flow in the pipelines is a source of major problems with heavy substance deposits on the wall surfaces. This situation can lead to lines blocking. Therefore, it is mandatory to have information concerning the flow. For this purpose the rheological properties of the crude oil are needed in order to propose adapted solutions. This paper deals with the study of the rheological properties of Algerian crude oil at different temperatures as well as its flow in pipe. The experimental results obtained with a modern rheometer can be used to predict the crude oil transport characteristics. The crude oil rheogram shows a non-Newtonian behavior which can be described by the Ostwald law. The shear stresses computations obtained from an analytical model and the MPTT model are compared and give the friction factor distribution across the pipe section. The obtained results are presented and discussed.