Rolling-ball Viscometer Research Articles

Development and demonstration of a rolling ball viscometer for molten salts with near-minimum liquidus NaCl–KCl

Development and demonstration of a rolling ball viscometer for molten salts with near-minimum liquidus NaCl–KCl

Evaluating the role of salts on emulsion properties during water-based enhanced oil recovery: Ion type, concentration, and water content

Potential determining ions (SO42−, Mg2+, Na, and Ca2+) positively affect oil recovery. These ions can cause changes in the oil and water system due to their ionic radius and proper charge density. Besides the type of ions, the concentration of these ions is also important. In order to maximize oil recovery, the concentration of these active ions should be at a level that pulls the polar components of the oil towards the oil–water interface and causes the interfacial tension to decrease, resulting in a decrease in capillary force and an increase in oil recovery. In some cases, the presence of various ions in the formation water or injection water provides the conditions for the formation and stability of the emulsion. Emulsion formation sometimes reduces production and sometimes improves production from oil reservoirs. Therefore, it is imperative to study the effects of ions on the formation, stability, and viscosity of emulsions. Regarding the emulsion stability in the presence of different ions, there are high uncertainties, and there is no uniform opinion on this matter. In this study, MgCl2, CaCl2, NaCl, and Na2SO4 were used to investigate emulsion properties. Droplet size and viscosity were measured using an optical microscope and a rolling ball viscometer, respectively, in order to determine emulsion stability. The results have shown that salts with higher positive charge density, such as MgCl2 and CaCl2 can significantly reduce the size of emulsion droplets and increase emulsion stability. Moreover, the presence of divalent anions such as sulfate reduces the amount of asphaltene at the interface between oil and water, thereby reducing the stability of the emulsion. In the order of MgCl2 > CaCl2 > Na2SO4 > NaCl, salts decreased the droplet size and increased the emulsion stability. The viscosity of the emulsion also showed a similar trend, as the average particle size decreases, the viscosity of the emulsion increases. Based on the results, the size of the emulsion droplets decreases up to a certain concentration and then increases. In the case of all salts, this concentration was equal to 10,000 ppm. The viscosity of the emulsion shows an increasing trend up to the concentration of 10,000 ppm, and after this concentration, it shows a decreasing trend. Salt-in and salt-out effects are responsible for the reduction and increase in droplet size. This study can provide insight into the effect of different ions on the stability and viscosity of the emulsion, as well as the design of the injection fluid for the enhanced oil recovery process.

Volumetric, ultrasonic and viscometric behavior of nucleosides (uridine and cytidine) in aqueous L-ascorbic acid solutions at different temperatures

Apparent molar properties (Vϕ, Kϕ,s), limiting apparent molar properties (Vϕo, Kϕ,so), transfer properties (ΔtrVϕo, ΔtrKϕ,so, ΔtrB), hydration number (nH) and relative viscosities (ηr) have been determined from density, speed of sound and viscosity measurements for nucleosides (uridine and cytidine) in water and in aqueous solutions of (0.1043, 0.2104 and 0.3016) mol kg−1 L-ascorbic acid at five different temperatures ranging (293.15–313.15) K by using DSA (density and speed of sound analyzer) connected with rolling ball viscometer. Viscosities of the prepared solutions have been examined to determine the Falkenhagen coefficient A, viscosity B-coefficients and its transfer parameter by using the Jones-Dole equation. The solvation behavior of nucleosides has also been computed. Based on the co-sphere overlap model, variety of intermolecular interactions predominating in the ternary solutions has been explained. By using Hepler's constant and temperature derivative of B-coefficients (dB/dT) the structure making/breaking nature of solute have been examined. Furthermore, the absorption spectra for both the nucleosides (uridine and cytidine) have been recorded in water as well as in L-ascorbic acid with the help of UV–visible spectrophotometer to investigate the interactions prevailing among these systems.

Laboratory measurement of oil viscosity reduction due to CO<SUB align="right">2 injection at high-pressure, high-temperature conditions

This work presents the use of rolling-ball viscometer to measure viscosity reduction of two dead oil samples injected with CO2 at a temperature of 168°F and a pressure range of 1,114.7 psi-3,514.7 psi. First, a new digital control unit was designed to replace the analogue unit. Afterwards, viscometer was calibrated with Cannon S-6 and S-60 viscosity standards. Next, validation was conducted by measuring the viscosity of n-decane at a temperature range of 77°F-266°F and a pressure range of 514.7 psi-2,014.7 psi. Next step was the investigation of CO2 effect in reducing n-decane viscosity at 130°F-266°F temperature range and 1,014.7 psi-2,014.7 psi pressure range. Results showed significantly reduced viscosities of the CO2 mixture compared to n-decane viscosities, especially at lower temperatures. Afterwards, viscosity of two distinct crude samples was measured at 168°F and 14.7 psi-3,514.7 psi pressure interval. Next, CO2 was injected to respective oil samples and system viscosity was measured at the same temperature and at pressures between 1,114.7 psi and 3,514.7 psi. [Received: September 20, 2021; Accepted: January 30, 2022]

Physical properties and reaction kinetics of CO2 absorption into unloaded and CO2 loaded viscous monoethanolamine (MEA) solution

In order to comprehensively understand how solvent free concentration and high viscosity affect mass transfer and consequently absorption flux, CO2 absorption kinetics into unloaded and CO2 loaded viscous monoethanolamine (MEA) solution were studied in this work using the string of discs contactor. Moreover, density and viscosity of unloaded and loaded viscous MEA solutions were measured using an Anton Paar DMA 4500 density meter and an Anton Paar Lovis 2000 ME rolling-ball viscometer, respectively, and the results were correlated using Redlich-Kister and modified Vogel-Tamman-Fulcher equations as a function of temperature, concentration and CO2 loading. Overall mass transfer coefficients of CO2 absorption in viscous MEA solution were measured over a wide temperature range of 298.15 to 343.15 K and CO2 loading in the range of 0 to 0.4 (mol CO2/mol MEA). A simplified kinetic model was applied to interpret the mass transfer data and explain reaction kinetics between CO2 and unloaded and loaded viscous MEA solution. The effect of temperature, CO2 loading and viscosity on second order reaction rate constant and overall mass transfer coefficients was also discussed.

Experimental measurement and compositional modeling of crude oil viscosity at reservoir conditions

In the present study, experimental and modeling investigations were performed and combined to implement trustworthy paradigms to predict the viscosity value under different circumstances and a wide variety of conditions. The experimental approach was conducted on a considerable number of Iranian crude samples using a Rolling Ball viscometer. Accordingly, more than 1000 experimental points were gained. These latter were utilized as a databank in the modeling approach which included many advanced soft computing techniques, namely radial basis function (RBF) neural network, multilayer perceptron (MLP), support vector regression (SVR), adaptive neuro-fuzzy inference system (ANFIS), decision trees (DTs) and random forest (RF). When performing the modeling tasks using these techniques, two distinct cases were considered: the first includes all available parameters as inputs such as pressure, temperature, API°, Mw of C12+ and the mole fractions till C11; whereas in the second case, a grouping scheme was considered to reduce the number of fractions. The obtained results revealed that DTs for the first case is the best implemented model with an overall average absolute relative deviation (AARD) of 3.379%. In addition, the comparison results with the preexisting approaches showed the superiority of the newly proposed model.

High-Temperature, High-Pressure Viscosities and Densities of n-Hexadecane, 2,2,4,4,6,8,8-Heptamethylnonane, and Squalane Measured Using a Universal Calibration for a Rolling-Ball Viscometer/Densimeter

The development of reference correlations for viscous fluids is predicated on the availability of accurate viscosity data, especially at high pressure, high temperature (HPHT) conditions. The rolling ball viscometer (RBV) is a facile technique for obtaining such HPHT viscosity data. A new, universal RBV calibration methodology is described and applied over a broad T-p region and for a wide range of viscosities. The new calibration equation is used to obtain viscosities for n-hexadecane (HXD), 2,2,4,4,6,8,8-heptamethylnonane (HMN), and 2,6,10,15,19,23-hexamethyltetracosane (squalane) from 298 – 530 K and pressures to 250 MPa. The available literature data base for HMN is expanded to 520 K and 175 MPa and for squalane to 525 K and 250 MPa. The combined expanded uncertainties are 0.6% and 2.5% for the densities and viscosities, respectively, each with a coverage factor, k = 2. The reliability of the viscosity data is validated by comparison of HXD and squalane viscosities to accepted reference correlations and HMN viscosities to available literature data. The necessity of this new calibration approach is confirmed by the large deviations observed between HXD, HMN, and squalane viscosities determined using the new, universal RBV calibration equation and viscosities determined using a quadratic polynomial calibration equation. HXD, HMN, and squalane densities are predicted with the Perturbed Chain Statistical Associating Fluid Theory using pure component parameters calculated with a previously reported group contribution (GC) method. HXD, HMN, and squalane viscosities are compared to Free Volume Theory (FVT) predictions using FVT parameters calculated from a literature correlation for nalkanes. Although the FVT predictions for HXD, a normal alkane, result in an average absolute percent deviation (∆AAD) of 3.8%, predictions for HMN and squalane, two branched alkanes, are four to 13 times larger. The fit of the FVT model for the branched alkanes is dramatically improved if the FVT parameters are allowed to vary with temperature.

Development of a rolling ball viscometer for simultaneous measurement of viscosity, density, bubble-point pressure of CO2-expanded liquids

In this work, a rolling ball viscometer was developed that makes it possible to measure viscosity, density, and phase equilibria simultaneously. The cell is mounted inside a high-pressure vessel and can be used at pressures up to 30 MPa and temperatures up to 200 °C. Calibration of the viscometer was carried out by using water at inclined angles from 10° to 30° at temperatures of 40 °C and 80 °C and at pressures up to 20 MPa with toluene viscosity being used for confirmation; viscosity measurements of toluene were found to agree with literature data to within 0.66% in average relative deviation. Viscosity, density, and bubble-point pressure of ethanol + CO2 systems were measured at 40 °C; bubble-point pressures for the ethanol + CO2 system agreed to within 2.2% of the literature. Viscosity of the ethanol + CO2 system were measured at saturated and pressurized liquid states and viscosity values decreased with increasing CO2 composition, and decreased to about half the value of pure ethanol for 0.32 mol fraction of CO2.

Viscosity Measurements of Two Potential Deepwater Viscosity Standard Reference Fluids at High Temperature and High Pressure

This paper reports high-pressure viscosity measurements for Krytox GPL 102 lot K2391 and tris(2-ethylhexyl) trimellitate (TOTM). These two viscous liquids have recently been suggested as potential deepwater viscosity standard (DVS) reference fluids for high temperature, high pressure viscosity studies associated with oil production from ultradeep formations beneath the deepwaters of the Gulf of Mexico. The measurements are performed using a windowed, variable-volume, rolling-ball viscometer at pressures between 7 and 242 MPa and temperatures between 314 and 527 K with an expanded uncertainty of 3% at a 95% confidence level. The viscosity results are correlated using an empirical temperature/pressure-dependent function and a modified Vogel–Fulcher–Tammann (VFT) Equation. The present viscosity data for TOTM and Krytox GPL 102 lot K2391 are in good agreement with the available reported data in the literature at lower temperatures and pressures. The viscosity values of TOTM and Krytox GPL 102 lot K2391 are 9....

High-temperature, high-pressure viscosity of n-octane and isooctane

Experimental viscosity data are reported for n-octane and isooctane (2,2,4-trimethylpentane) at pressures between 4 and 242MPa and temperatures between 303 and 523K. These extreme conditions are representative of those encountered in ultra-deep petroleum formations beneath the deepwaters of the Gulf of Mexico. The measurements are performed using a windowed, variable-volume, rolling-ball viscometer. A comparison of reported viscosity values with available literature data for n-octane and isooctane covering limited pressure and temperature ranges shows that the average absolute percent deviation (AAPD) varies between 1.0% and 2.5%. The data are correlated by a non-linear surface fit as a simultaneous function of temperature and pressure that yields AAPD values of 0.6% and 0.8% for n-octane and isooctane, respectively. The viscosity data are also correlated with a model suitable for use in reservoir simulators; the free volume theory model with density values obtained from the Peng–Robinson equation of state (PR EoS), the volume-translated PR EoS (VT-PR EoS), the perturbed chain statistical associating fluid theory (PC-SAFT EoS), and the PC-SAFT EoS in which the parameters are fit to high temperature, high pressure density data (HTHP PC-SAFT EoS). If the parameters of the free volume theory model are fit with the EoS incorporated into the model, comparable results are obtained with each of the density models. However, if the parameters of the free volume theory model are first fit using experimental density data and then an EoS is incorporated into the free volume theory model, the best viscosity results are obtained with the most accurate density models, which are the HTHP PC-SAFT and VT-PR EoS.

Experimental measurement and modeling of saturated reservoir oil viscosity

A novel mathematical-based approach is proposed to develop reliable models for prediction of saturated crude oil viscosity in a wide range of PVT properties. A new soft computing approach, namely least square support vector machine modeling optimized with coupled simulated annealing optimization technique, is proposed. Six models have been developed to predict saturated oil viscosity, which are designed in such a way that could predict saturated oil viscosity with every available PVT parameter. The constructed models are evaluated by carrying out extensive ex- perimental saturated crude oil viscosity data from Iranian oil reservoirs, which were measured using a "Rolling Ball viscometer." To evaluate the performance and accuracy of these models, statistical and graphical error analyses were used simultaneously. The obtained results demonstrated that the proposed models are more robust, reliable and efficient than existing techniques for prediction of saturated crude oil viscosity.

Viscosity of n-hexadecane, n-octadecane and n-eicosane at pressures up to 243 MPa and temperatures up to 534 K

Viscosity data are reported for n-hexadecane (C16), n-octadecane (C18), and n-eicosane (C20) at pressures between (3 and 243)MPa and temperatures between (304 and 534)K. These extreme conditions are representative of those encountered in ultra-deep petroleum formations beneath the deepwaters of the Gulf of Mexico. The measurements are taken with a novel windowed Inconel rolling-ball viscometer designed by our team that is calibrated with n-decane. A comparison of the reported viscosity values with the available literature data that cover limited pressure and temperature ranges, shows that the mean absolute percentage deviation, δ, ranges between 1.1% and 4.8%. The reported data extend the database of viscosity to the high-temperature, high-pressure region where most gaps occur in the literature data for n-hexadecane and n-octadecane. To the best of our knowledge, the results for n-eicosane are the first reported viscosity values at pressures above 2MPa over the entire temperature range. The viscosity results are modeled with the free volume theory model in conjunction with density values obtained using the Peng–Robinson equation of state (EoS) and the PC-SAFT EoS. The δ values obtained with this model range from 2.0% to 3.5%. The data are also correlated by a non-linear surface fit as a simultaneous function of temperature and pressure that yields δ values of 0.40%, 0.43%, and 0.38% for C16, C18, and C20, respectively.

転落球式高圧粘性率計の改良と装置定数の評価

転落球式高圧粘性率計の改良と装置定数の評価

Exploratory Characterization of a Perfluoropolyether Oil as a Possible Viscosity Standard at Deepwater Production Conditions of 533 K and 241 MPa

DuPont’s perfluoropolyether oil Krytox\(^{\textregistered }\) GPL 102 is a promising candidate for the high-temperature, high-pressure Deepwater viscosity standard (DVS). The preferred DVS is a thermally stable liquid that exhibits a viscosity of roughly 20 \(\hbox {mPa} \cdot \hbox {s}\) at 533 K and 241 MPa; a viscosity value representative of light oils found in ultra-deep formations beneath the deep waters of the Gulf of Mexico. A windowed rolling-ball viscometer designed by our team is used to determine the Krytox\(^{\textregistered }\) GPL 102 viscosity at pressures to 245 MPa and temperatures of 311 K, 372 K, and 533 K. At 533 K and 243 MPa, the Krytox\(^{\textregistered }\) GPL 102 viscosity is \((27.2 \pm 1.3)\,\hbox {mPa} \cdot \hbox {s}\). The rolling-ball viscometer viscosity results for Krytox\(^{\textregistered }\) GPL 102 are correlated with an empirical 10-parameter surface fitting function that yields an MAPD of 3.9 %. A Couette rheometer is also used to measure the Krytox\(^{\textregistered }\) GPL 102 viscosity, yielding a value of \((26.2 \pm 1)\,\hbox {mPa} \cdot \hbox {s}\) at 533 K and 241 MPa. The results of this exploratory study suggest that Krytox\(^{\textregistered }\, \hbox {GPL}\) 102 is a promising candidate for the DVS, primarily because this fluoroether oil is thermally stable and exhibits a viscosity closer to the targeted value of 20 mPa \(\cdot \) s at 533 K and 241 MPa than any other fluid reported to date. Nonetheless, further studies must be conducted by other researcher groups using various types of viscometers and rheometers on samples of Krytox GPL\(^{\textregistered }\) 102 from the same lot to further establish the properties of Krytox GPL\(^{\textregistered }\) 102.

Toward reservoir oil viscosity correlation

Oil viscosity plays a key role in reservoir simulation and production forecasting, as well as planning thermal enhanced oil recovery methods and these make its accurate determination necessary. In this communication, the most frequently used oil viscosity correlations are evaluated using a large databank of Iranian oil reservoirs which were measured using a Rolling Ball viscometer (Ruska, series 1602). To evaluate the performance and accuracy of these correlations, statistical and graphical error analyses have been used simultaneously. Three of the most accurate correlations for each region, including dead oil viscosity, viscosity below bubble point, viscosity at bubble point and the under-saturated oil viscosity, are recommended for Iranian oil reservoirs. In the last step, four correlations are developed for Iranian oil reservoirs which have simplified functional format. Furthermore, the input data of the latter correlations are those ones that are easily measured in oil fields. The ranges of data used to develop these new correlations cover almost all Iranian oil reservoirs PVT data and consequently they could be reliable for prediction of other Iranian oil reservoirs viscosity. These new correlations are consistent across a wide range of parameters and offer increased accuracy than previously published correlations for viscosity prediction of Iranian oil reservoirs.

Rolling Ball Viscometer Calibration with Gas Over Whole Interest Range of Pressure and Temperature Improves Accuracy of Gas Viscosity Measurement

A practical method for measuring gas viscosity uses gas to calibrate the rolling ball viscometer over the whole interest range of pressure and temperature. It reduces the turbulent effect of gas flow around the ball. The viscometer calibration at only atmospheric pressure yields poor results, because it cannot accommodate the turbulent effect at higher pressures. We used nitrogen to calibrate the viscometer for the pressure up to 8,000 psia and temperature up to 260 °F. Optimal tube inclination angle and also ball/tube diameter ratio ensure the laminar flow around the ball and improve the accuracy of the results. Viscosity measurements of ultrapure CO2 confirmed this technique.

Viscosity of Wort by Rolling Ball Viscometer

Viscosity of Wort by Rolling Ball Viscometer

Viscosity measurements of dilute aqueous suspensions of cellulose nanocrystals using a rolling ball viscometer

Cellulose nanocrystals (NCC) are produced through acidic hydrolysis and mechanical disintegration of cellulose. Plans to produce NCC on an industrial scale point to the need for an efficient method to characterize its suspensions. Viscosity is a bulk property that could be used for this characterization since it accurately describes the suspension and the inherent properties of the nanocrystals. Our objective was to develop a convenient way to characterize diluted aqueous NCC suspensions without the need of complex instrumentation. The viscosity of dilute suspensions was measured with an automated rolling ball viscometer, which requires only a small amount of sample. The feasibility of the proposed procedure was confirmed by using dextran solutions as standards. The NCC suspensions were characterized by their intrinsic viscosity [η], which is directly related to the hydrodynamic dimensions of the nanocrystals. The data obtained were analyzed using the equations established by Huggins and by Fedors. Fedors’ approach gave more accurate results, leading to a value of 213 mL g−1 for the intrinsic viscosity, [η]. The non-Newtonian character of NCC suspensions at increasing concentrations was evaluated.

Viscosity and Thermal Conductivity of 1-Hexyl-3-methylimidazolium Tetrafluoroborate and 1-Octyl-3-methylimidazolium Tetrafluoroborate at Pressures up to 20 MPa

Viscosity and thermal conductivity values are reported for a series of 1-alkyl-3-methylimidazolium tetrafluoroborate compounds with hexyl (1-hexyl-3-methylimidazolium tetrafluoroborate) and octyl (1-octyl-3-methylimidazolium tetrafluoroborate) groups. The viscosity was measured with a rolling-ball viscometer at 293.15 K to 353.15 K and pressures up to 20.0 MPa. The experimental values were correlated with a hybrid VFT–Tait equation. The thermal conductivity was measured using the transient short hot-wire method at 294 K to 335 K and pressures up to 20.0 MPa. The experimental values at 293.15 K and 0.1 MPa agreed with the predicted values proposed by Froba et al.

Thermophysical properties of (diphenyl ether + biphenyl) mixtures for their use as heat transfer fluids

Experimental measurements of density, viscosity and thermal conductivity are reported for pure diphenyl ether and three different binary mixtures of diphenyl ether and biphenyl including the eutectic point. Density has been measured for the liquid phase at temperatures ranging from (298.15 to 363.15)K and for pressures up to 45MPa using a high-pressure vibrating tube densimeter. A Tammann–Tait correlation of the experimental densities has been proposed for each composition. From these correlations, isothermal compressibility, isobaric thermal expansivity and internal pressure have been determined. Moreover, viscosity and thermal conductivity were experimentally determined at atmospheric pressure for several temperatures by using a rolling ball viscometer and a device based in the hot-wire technique, respectively. All the experimental devices used to determine the thermophysical properties were checked finding good agreements with previous literature data. The experimental viscosity values were correlated using the Vogel–Fulcher–Tammann, Avramov–Milchev and MYEGA equation.