Flow Properties Of Crude Oil Research Articles

Gamma radiation-induced grafting of poly(butyl acrylate) onto ethylene vinyl acetate copolymer for improved crude oil flowability

Ethylene vinyl acetate (EVA) copolymers are widely employed as pour point depressants to enhance the flow properties of crude oil. However, EVA copolymers have limitations that necessitate their development. This work investigated the modification of EVA via gamma radiation-induced grafting of butyl acrylate (BuA) monomers and the evaluation of grafted EVA as a pour point depressant for crude oil. The successful grafting of poly(butyl acrylate) p(BuA) onto EVA was verified through grafting parameters, FTIR spectroscopy, and 1H NMR spectroscopy. Treating crude oil with 3000 ppm of (EVA)0kGy, (EVA)50kGy, and (1EVA:3BuA)50kGy yielded substantial reductions in pour point of 24, 21, and 21 °C, respectively. Also, rheological characterization demonstrated improving evidenced by a viscosity reduction of 76.20%, 67.70%, and 71.94% at 25 °C, and 83.16%, 74.98%, and 81.53% at 12 °C. At low dosages of 1000 ppm, the EVA-g-p(BuA) exhibited superior pour point reductions compared to unmodified EVA, highlighting the benefit of incorporating p(BuA) side chains. The grafted EVA copolymers with p(BuA) side chains showed excellent potential as crude oil flow improvers by promoting more effective adsorption and co-crystallization with paraffin wax molecules.

Microscopic mechanism of single-walled carbon nanotubes (SWCNTS) as a dispersant for alleviating asphaltene aggregation

The flow properties of crude oil have been seriously affected by the aggregation behavior of asphaltenes. The single-walled carbon nanotubes (SWCNTs) can exhibit positive alleviation effect as a dispersant for asphaltene aggregation, but the influence mechanism at the molecular level is still controversial. With the action of SWCNTs, the rate of asphaltene self-aggregation decreased, and the time to form asphaltene clusters came later. At the same time, the structure of asphaltene clusters became looser. Interestingly, when a small number of asphaltene molecules start to accumulate, the density of asphaltene molecules in the accumulation body is relatively low. In addition, the peak value of RDF between the SWCNTs and asphaltene is much higher than that between asphaltene molecules, which indicates that the interaction between SWCNTs and asphaltene molecules is stronger than that between asphaltene molecules, thus affecting the self-aggregation of asphaltene molecules. In addition to that, it is worth mentioning that in the vmd snapshot, we also observed that the aggregation mode of asphaltene would change to SWCNTs as the core. This work explains the decrease of asphaltene self-aggregation degree and speed with the addition of SWCNTs from the microscopic point of view, which is due to the strong interaction between SWCNTs and asphaltene molecules weakens the interaction between asphaltene molecules.

Performance improvement on the cold flow properties of crude oil with high asphaltene by adjusting the polarity of the third monomer in polymers

AbstractAsphaltenes and waxes are the primary factors affecting the cold flow properties of crude oil. In this paper, based on the binary polymer of acrylate‐maleic anhydride (PM22‐MA), different third polar groups of acrylamide, N‐(hydroxymethyl) acrylamide, N‐phenylacrylamide (NPA), and styrene (SM) were introduced to synthesize a series of ternary pour point depressants (PPDs) to explore the effect of asphaltene on the cold flow properties of Xijiang (XJ) crude oil. Thereinto, PM22‐MA‐NPA containing amide group and benzene ring exhibited the best depressive effect, which decreased pour point by 14°C at 1500 ppm. The mechanism of interaction of the polar groups in PPDs with asphaltene was studied. The polar groups could form stronger hydrogen bonds with asphaltene, delaying the asphaltene macromolecule bonding, allowing the synergistic effect of PPDs and asphaltene to be better utilized to improve the cold flow properties of crude oil. Furthermore, the dipole moment magnitude and electron cloud density were calculated with Gaussian. It was found that the polar group with a dipole moment magnitude of 3.2244 debye and an electron cloud density ranging from −1.6364 to 1.9944 eV was the most suitable third polar monomer for the PPDs of XJ crude oil.

Study on the influence of polar groups in pour point depressant on flow properties of Karamay crude oil

Pour point depressant (PPD) is a crucial addition in the petroleum industry which can significantly enhance the flow properties of crude oil by preventing wax from precipitating out of it. The flow assurance effect of PPD on crude oil is impacted by its molecular structure. As a result, we concentrate on the PPD with various molecular structures, such as carboxyl and benzene rings, to investigate its impact on the flow behavior of crude oil. Then, FTIR and contact angle test were used to describe the characteristics of PPD (SAF-n and SAFS-m). The Karamay crude oil was tested using the following items: pour point, rheology, viscosity, viscoelasticity, and POM. When the crude oil was treated with 1000 ppm SAFS-1, the pour point decreased from 12 to −14 °C and the viscosity decreased from 40.1 to 6.3 pa·s at 0 °C. Meanwhile, the results show that the more variety polar groups PPD has, the more its dispersion increases and the stronger its interactions with crude oil are when its molar ratio of non-polar groups are suitable. These effects may be caused by the PPD changing the crystallization characteristics of wax and the aggregate state of resin and asphalt.

Effect of modified ethylene vinyl acetate copolymers pour point depressants on flow properties of crude oil and corresponding mechanism analysis

In order to explore the influences of the alkyl chain length and type of polar groups of the PPDs (pour point depressants) on the crystallization characteristics and flow ability of crude oil, a series of new maleic anhydride derivative graft modified EVA (ethylene vinyl acetate) copolymers PPDs were synthesized. All the new copolymers were characterized by fourier transforms infrared (FT-IR) spectrum analysis, proton nuclear magnetic resonance ( 1 H NMR) and gel permeation chromatography (GPC). The results showed that all the new PPDs exhibited better performance in improving the fluidity and delaying the gelling of crude oil than EVA PPD. Moreover, copolymer containing alkyl chain with 18 carbon atoms exhibited better performance than those bearing alkyl chains of other carbon number in depressing the pour point, a pour point drop up to 19 ℃ was obtained by using 0.1 wt% of that PPD, which was conductive to co-crystallization of PPD molecules and wax molecules. However, copolymer containing benzene ring exhibited the best performance in depressing the pour point by 22 ℃ at the concentration of 0.1 wt%, which can change the growth characteristics of wax crystals and delay the aggregation of asphaltene and resin, thus effectively improve the flow ability of crude oil. • A series of new graft modified ethylene vinyl acetate (EVA) copolymers PPDs were synthesized. • The effects of graft modified EVA copolymers PPDs were obviously superior to that of EVA PPD. • 0.1wt% EM-B PPD exhibited best depression effect on the crude oil with 25wt% wax content. • The mechanisms of the interaction between crude oil and PPD were analyzed and described in detail.

Studies on Naturally Extracted Surfactant to Enhance Flow Properties of Crude Oil

Indian heavy crude oil sample from Gujarat was studied for improvement of properties such as pour point, wax crystal structure, particle size analysis and viscosity by addition of a novel surfactant extracted from a tropical Indian plant Sapindus mukorossi. Characterization was done to find the effect of surfactant addition on individual components of the crude oil such as saturates, asphaltenes, resins and aromatics. The objective was to increase the flowability of the oil and determine which components of the surfactant interact with the crude oil to improve its flow behavior. Heavy crude oil sample was mixed with 4% w/w of Sapindus followed by stirring the samples for one hour and proceeding for tests. The results showed that pour point decreased by a significant amount after adding Sapindus to it and that decrease in pour point was due to reduction in the amount of saturates, aromatics, resins and asphaltenes present in the crude oil. There was a profound reduction in size of wax crystals when investigated under microscopic and particle size analysis. Surfactant addition had a tremendous effect on viscosity. The viscosity of crude oil at 30°C after addition of surfactant, was even less than that of heavy crude without surfactant at 50°C.

Hydrodynamics and energy analysis of heavy crude oil transportation through horizontal pipelines using novel surfactant

Improvement of flow properties of crude oil through pipelines, the effect of temperature, diameter, water cut, and novel extracted surfactant on pressure drop, shear viscosity was studied along with energy analysis. The impact of diameter, temperature, and the addition of novel surfactant extracted from Madhuca longifolia (Mahua) on pressure drop, shear viscosity, pumping power saving and flow increment were investigated during heavy crude oil flow in horizontal pipelines. Minimum pressure drop was observed in 0.0508 m ID pipeline owing to the collective effect of temperature and 2000 ppm Mahua during the flow of 85% heavy crude oil+15% water. Shear viscosity reduced appreciably in 0.0381 m and 0.0508 m ID pipelines after addition of 2000 ppm Mahua at a temperature of 50 °C. Maximum power saving (130.8%) was achieved and maximum flow increment of 121.8% was accomplished after addition of 2000 ppm Mahua to 85% heavy oil and 15% water mixture during its transportation in 0.0508 m ID pipeline at a 50 °C and at the rate of 7.2 m3/hr. The natural surfactant is substantially efficient to decrease the pumping power consumption for heavy crude oil transportation. It was concluded that the extracted novel natural surfactant is very beneficial for being used as an emulsifier, viscosity reducer, flow improver and also an alternative for the commercial surfactant.

The extraction effect of CO2 injection on the flow properties of crude oil

During CO2 flooding, extraction of lighter hydrocarbons from crude oil makes the remaining oil hard to be recovered. In this work, we design a new experimental method to characterize the effect of CO2 extraction on crude oil. The experimental results show that, the volume of extracted hydrocarbons increases as system pressure increases. The hydrocarbons with wider carbon number can be extracted from crude oil at high pressures. Moreover, the wax precipitation and viscosity of the remaining oil increase with increasing pressure. This study is expected to provide the basic understanding of the mechanisms of CO2 flooding for enhanced oil recovery.

Effect of Inhibitors with Aromatic Solvents towards the Flow Properties of Crude Oil

Effect of Inhibitors with Aromatic Solvents towards the Flow Properties of Crude Oil

Effect of the Evaluation and Mechanism Analysis of a Novel Nanohybrid Pour Point Depressant on Facilitating Flow Properties of Crude Oil

Novel nanohybrid pour point depressants (PPDs) were prepared by combining ethylene–vinyl acetate (EVA) copolymers with nano-SiO2 particles, and a series of experiments were carried out to test the ...

Synthesis of PMMA/modified graphene oxide nanocomposite pour point depressant and its effect on the flow properties of Indian waxy crude oil

Application of Polymeric nanocomposites as pour point depressant (PPD) for crude oil has opened the doors for a new area of research in the petroleum industry. In this research work, a polymer nanocomposite Poly(methyl methacrylate)-Graphene Oxide (PMMA-GO) was synthesized in the laboratory using in-situ free radical polymerization with varying concentrations of Graphene Oxide (0.5%, 1% PMMA), where Graphene Oxide was synthesized using Improved Hummers method and the effect of the nanocomposite on the pour point depression and rheological properties of a Indian waxy crude oil sample is observed. The synthesized nanocomposite is evaluated as pour point depressant considering the improvement in the flow properties of the crude oil. Analysis of the synthesized nanocomposites using techniques such as FTIR, Raman and UV-visible spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Gel Permeation Chromatography (GPC) revealed the formation of PMMA-Graphene Oxide and the intermediate products. Thermogravimetric analysis indicated improved thermal stability of the synthesized nanocomposite than polymer PMMA. XRD analysis confirmed the formation of graphene oxide and the resultant nanocomposite. Efficiency of the synthesized nanocomposite on the flow properties of treated crude oil is compared with the performance of a commercial PPD. Rheological properties of the crude oil treated with synthesized and commercial PPD’s are compared at temperatures 30, 40 and 50 °C and better performance of the synthesized PPD is observed in terms of reduction in apparent viscosity and yield stress. Crude oil treated with PMMA-Graphene Oxide shows up to 23 °C reduction in pour point and 99.8% reduction in apparent viscosity compared with that of virgin crude oil. Reduction of gelation point of nanocomposite treated crude oil by 24 °C from virgin crude oil shows improvement in pipeline restart flow of the studied crude oil. Moreover, yield stress of the crude oil drops from 60 Pa (virgin crude oil) to 0.1 Pa for PMMA-1% Graphene Oxide treated crude oil at 1500 ppm. The reduction in gel strength of crude oil was substantiated by the microscopic analysis of virgin and PPD beneficiated crude oil. The wax crystals take more compact shape and the wax interlocking was reduced significantly in case of PMMA-1% Graphene Oxide treated crude oil. Further, the long term stability of the nanocomposite treated crude oils revealed that its rheological properties undergo lesser degradation with time, as evident by the least increase in apparent viscosity between 16.5% and 32.9% (PMMA-1% Graphene Oxide) and 28%–37.7% (PMMA-0.5% Graphene Oxide) compared to an increase of 40.175%–44.93% observed in case of commercial PPD treated crude oil. These findings show the suitability of nanocomposite PMMA-GO as pour point depressant for Indian waxy crude oil.

Synthesis and evaluation of oleic acid based polymeric additive as pour point depressant to improve flow properties of Indian waxy crude oil

During production of crude oil, surface temperature is much less than reservoir temperature. As a result hindrance in flow occurs due to wax precipitation in surface flowlines and if the temperature goes below the pour point, crude oil completely stops flowing. This research paper aims at determining the effect of a laboratory synthesized novel Pour Point Depressant (PPD) on the pour point depression and rheological properties of a crude oil sample and comparing its performance with a commercial flow improver. Triethanolamine was polymerized to form its trimer and then esterified with oleic acid to form tri-triethanolamine di oleate. Characterisation of the crude oil sample and the synthesized PPD were performed as per ASTM methods and the effects of the PPD on pour point and rheology of crude oil were thoroughly analysed using pour point apparatus and Physica rheometer respectively. Effect of the synthesized PPD on different components and wax appearance of crude oil is also verified. Experimental investigations furnishes that the synthesized PPD and the commercial flow improver enhanced the flow properties of the crude oil, but the effects of the synthesized PPD are significantly better compared to the commercial one in terms of reduction in pour point, viscosity and yield stress which shows the potential of synthesized PPD to control the flow assurance problem caused by Indian waxy crude oils.

The effect of cationic surfactant additives on flow properties of crude oil

ABSTRACTPretreatment of the crude oil with flow improver or pour point depressants has received the greatest acceptance due to its simplicity and economy. Three cationic surfactants Bola form based on urea were prepared by quaternization reaction with alkyl dihalides of different chain length (hexayl, decyl-, and dodecyl-dibromide). The prepared compounds (U6, U10, and U12) were evaluated as surface active agents as well as pour point depressant for crude oil compared to monosurfactant (U12a) corresponding to (U12). The surface parameters of each synthesized surfactant were calculated from their surface tension profile including the critical micelle concentration, maximum surface excess (Γmax), and the minimum surface area (Amin). The free energies of micellization (ΔG°mic) and adsorption (ΔG°ads) were also calculated. Its pour point and viscosity decreased significantly after adding surfactants. FTIR studies of crude-surfactant mixture showed remarkable decrease in concentration of viscosity enhancing groups such as alkanes, alcoholic, and acidic groups, indicating the effectiveness of both the surfactants.

Simulation of pipelining pours point depressant beneficiated waxy crude oil through China West Crude Oil Pipeline

Flow properties of waxy crude oils, particularly the beneficiated waxy crude oils, are sensitive to shear history that the crude oil experienced, called the shear history effect. To simulate this shear history effect accurately is vital to pipeline design and operation. It has been demonstrated by our previous that the energy dissipation or entropy generation due to viscous flow in the shear process is a suitable parameter for simulating the shear history effect. In order to further verify the reliability of this approach, experimental simulations were conducted for three PPD-beneficiated waxy crude oils transported through the China West Crude Oil Pipeline, a most complicated long-distance- crude-oil-pipeline technically and operationally so far in China. The simulations were made by using a stirred vessel and with the energy dissipation of viscous flow as the shear simulation parameter. Comparison between the flow properties of crude oils obtained from field test and experimental simulations, it is found that the gel points and viscosities from experimental simulations are in good agreement with the field data.

Crystal Structure of n-Paraffin Concentrates of Crude Oils

The n-alkanes are the major constituents of paraffin waxes, which adversely affect the cold flow properties of crude oils and their fractions (gel formation). The n-alkanes crystallize out from the solution as the temperature is lowered. The knowledge of the structure of crystals is essential to understand the gel formation behavior of crude oil. n-Paraffin concentrates were extracted from six Indian crude oils. One particular n-paraffin concentrate was fractionated into smaller fractions by distillation. The crystal structure of these n-paraffin concentrates were determined by X-ray diffraction and correlated with the distribution of the carbon number present in them. It was observed that the crystal structures of these n-paraffin concentrates is greatly influenced by the carbon number distribution and the presence of amorphous content.

Studies on the influence of long chain acrylic esters polymers with polar monomers as crude oil flow improver additives

This study investigated the efficiency of 22 polymer additives of defined and controlled structural characteristics in improving the flow properties of crude oil. The additives were synthesized by the solution polymerization of alkyl acrylates of various alkyl chain lengths with styrene, acrylic acid and 1-vinyl-2-pyrrolidone as copolymers or terpolymers. Polymerization was performed by tert-butylperoxy-2-ethylhexanoate as initiator in xylene at 92 °C, up to high conversion. The influence of polymerization conditions on additive composition and properties, and their effect on the pour point and rheological properties of crude oil samples from the fields of Števkovica, Obod and Đeletovci located in the northern Croatia were studied. Additive efficiency was dominantly influenced by the alkyl acrylate chain length. The influence of component with carboxyl functional group or heterocyclic-nitrogen compound on additive quality was less obvious. Additive efficiency significantly depended on the properties of crude oil, and n-paraffin content and distribution. The main advantage of the process is that additives can be directly used without purification.

Flow Properties of Difficult-To-Handle Waxy Crude Oils

This paper presents viscosity, gel strength (yield value), and pour-point data for Dickinson (ND), Udang (Indonesia), and Amna (Libya) crude oils, with and without flow improvers (wax crystal modifiers). All three flow properties are necessary to characterize the oil. Low ambient temperatures properties are necessary to characterize the oil. Low ambient temperatures relative to the pour point can cause start-up problems for these crude oils. Introduction The pour point often is used as a total indicator of a crude oil's flow properties. It is not proper to compare only the pour points of crude oils themselves or only pour points relative to ambient conditions in which these pour points relative to ambient conditions in which these oils mill be handled. The Dickinson (ND) crude oil with a pour point of 95 degrees F supposedly would be difficult to work with at temperatures below 95 degrees F; however, this oil actually flows (pours) at room temperature (about 70 degrees F). A 75 degrees F pour point for the Amna crude oil from Libya might not indicate problems. However, this is misleading since a 45 degrees F North Sea temperature could cause unloading problems at the tanker. The Udang (Indonesia) crude oil has a 100 degree F pour point and is actually solid at room temperature. Therefore, although ambient conditions are very important for understanding the flow properties of crude oils, viscosity, gel strength (yield properties of crude oils, viscosity, gel strength (yield value), and pour point are all considered together. Unfortunately, many pipelines still specify pour point as the sole criterion for determining acceptability of a crude oil. This often is an unrealistic and unnecessary constraint because viscosity and gel strength indeed may be more important.This paper combines for the first time data on crude oils treated with flow improvers (wax crystal modifiers) and emulsifiers (surfactants). It also compares various additives, rather than just one type. A variety of crude oils from different parts of the world are considered.Waxy crude oils are becoming more important since they often have low sulfur contents, making them desirable from an environmental viewpoint. Also, waxy crude oils are available, and the need for new supplies has encouraged production of these difficult-to-handle crudes. However, the economic situation now requires better design of new installations because of the high cost involved.Flow improvers (wax crystal modifiers) often decrease the pour point slightly, while both viscosity and gel strength can be reduced appreciably. Previous Investigations Previous Investigations Much of the earlier research was conducted on methods to move the crude oil below its pour point. Above the pour point, the crude oil typically behaves as a pour point, the crude oil typically behaves as a Newtonian fluid. However, as it cools, it becomes non-Newtonian; therefore, its viscosity varies as a function of shear rate (flow rate in a pipe). A crude oil can become time dependent so that there is hysteresis (thixotropic behavior). Much of the waxy crude-oil pipeline problem information was presented in the early pipeline problem information was presented in the early 1970's, particularly by Ford et al. Both a 75 degrees F pour-point crude oil from Libya and a 55 degrees F pour-point pour-point crude oil from Libya and a 55 degrees F pour-point Nigerian crude oil were discussed for pipelining operations. Start-up was the chief concern.Uhde and Kopp discussed various methods of transporting waxy crude oils. JPT P. 1042