Correlation of Surface and Interfacial Tension of Light Hydrocarbons in the Critical Region

1961 ◽  
Vol 1 (04) ◽  
pp. 259-263 ◽  
Author(s):  
E.W. Hough ◽  
G.L. Stegemeier
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Interfacial Tension ◽  
Critical Pressure ◽  
Binary Systems ◽  
Gas Oil ◽  
Light Hydrocarbons ◽  
Two Phase ◽  
Component Systems ◽  
Two Phases

Abstract Empirical equations for surface tension of propane and normal butane as functions of reduced temperature are obtained from experimental data. Another correlation relating surface tension to enthalpy of vaporization is given for these two compounds. In addition, new parachor numbers are calculated for the normal paraffin hydrocarbons. These numbers are utilized for the calculation of interfacial tension of two-component systems as functions of pressure and temperature, using a modified form of Weinaug-Katz equation. The experimental data for two binary systems are approximated by the correlation. From these results it is found that the inter facial tension in the high-pressure region remains extremely low at large pressure decrements below the critical pressure. Thus, it appears that condensate systems may have flow characteristics almost like single-phase conditions even though the pressure is within the two-phase region. Experimental data have shown that interfacial tension divided by density difference approaches zero as the critical pressure is approached. A calculation of wetting-phase saturations indicates that the saturation gradient at the two-phase contact becomes increasingly abrupt as the critical pressure is approached. Discussion Prediction of the surface and interfacial tension of the light hydrocarbons and of two-component hydrocarbon mixtures at various temperatures and pressures may be made if other physical properties are known. Extensive experimental work on single-component and binary systems is the basis for the correlations outlined in this paper. Interfacial tension is defined as the specific surface-free energy between two phases of unlike fractional composition, while surface tension is defined as the specific surface-free energy between two phases of the same fractional composition. The usual definitions relating interfacial tension to a liquid-liquid interface and surface tension to a gas-liquid interface are not clearly defined when the critical region is included, and there is no sharp distinction between a gas and a liquid phase. Interfacial tension is probably the most important single force that makes one-half to one-third of the total oil actually in place in a reservoir rock unrecoverable by conventional gas-drive or waterflood methods. A rough estimate of this figure for the United States is 100 billion bbl. Interfacial tension presently is used by petroleum engineers in the estimation of saturation gradients at the gas-oil contact and at the oil-water contact. The data in this paper should prove useful for estimates of reserves involving gas-oil contacts. Relative permeability undoubtedly is influenced by interfacial tension, for sufficiently small values. These data should be useful in determining how small the values are. In addition, these data should eventually add to our fundamental knowledge of surfaces. At the critical point, all surface excesses approach zero and the thickness becomes very large. SINGLE-COMPONENT SYSTEMS It has been observed that the following relationships are good approximations to the physical properties of propane and n-butane. For propane, For n-butane, Guggenheim's values for these constants, not specifically for hydrocarbons, are SPEJ P. 259^

Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

2021 ◽  
Vol 1022 ◽  
pp. 194-202
Author(s):  
R.Kh. Dadashev ◽  
R.A. Kutuev
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Concentration Dependence ◽  
Experimental Error ◽  
Binary Systems ◽  
Experimental Studies ◽  
Study Results ◽  
Component Systems ◽  
Minimum Depth ◽  
Surface Tension Isotherms

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

A model describing the variation in free energy in compound and single phase regions in binary systems containing miscibility gaps

1965 ◽  
Vol 18 (12) ◽  
pp. 1897
Author(s):  
JD Esdaile
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Binary Systems ◽  
Atomic Fraction ◽  
Two Phase ◽  
Phase Fields ◽  
Isothermal Diagram ◽  
Integral Free Energy ◽  
Miscibility Gaps ◽  
Straight Lines

A model is derived to represent the variation of free energy of combination of one gram-atom of two components, represented by A and B, in intermediate single, or compound, phases in a binary system as a function of composition at constant temperature, and with a minimum of experimental data. The derivation of the model involves the, assumption that the straight lines representing the free energy of the two phase fields adjacent to a compound phase, on an isothermal integral free energy against atomic fraction diagram, intersect at the mid-point of the compound phase. A relation between logaA, logaB, and the atomic fraction NB is developed so as to conform with the preceding requirement and yield an almost horizontal tangent to the curve representing the compound phase at NB = � for a hypothetical symmetrical isothermal diagram. The equations developed on these bases are extended to non-symmetrical systems. These are shown to be successful in predicting the variation in free energy of compound phases, as a function of composition, in binary systems for which experimental data are available.

On Interfacial-Tension Measurements to Estimate Minimum Miscibility Pressures

2008 ◽  
Vol 11 (05) ◽  
pp. 933-939 ◽  
Author(s):  
Kristian Jessen ◽  
Franklin M. Orr
Keyword(s):  
Phase Equilibrium ◽  
Interfacial Tension ◽  
Crude Oil ◽  
Oil Recovery ◽  
Gas Oil ◽  
Bubble Behavior ◽  
Two Phase ◽  
Rising Bubble ◽  
Water Alternating Gas ◽  
Multicomponent Gas

Summary Measurements of the interfacial tension (IFT) of mixtures of a reservoir fluid and injection gas at various pressures have been proposed as an experimental method for predicting the minimum miscibility pressure (MMP) in an experiment referred to as the vanishing-IFT (VIT) technique. In this paper, we analyze the accuracy and reliability of the VIT approach using phase equilibrium and slimtube experimental observations and equation-of-state (EOS) calculations of the behavior of VIT experiments for the same systems. We consider 13 gas/oil systems for which phase equilibrium and density data and slimtube measurements of the MMP are available. We show that tuned EOS characterizations using 15 components to represent the gas/oil systems yield calculations of phase compositions and densities and calculated MMPs that reproduce the experimental observations accurately. We assume that IFTs can be calculated with a parachor expression, and we simulate the behavior of a series of VIT experiments with different mixture compositions in the VIT cell. We show that compositions of mixtures created in the VIT cell are not, in general, critical mixtures and that calculated estimates of the MMP obtained by the VIT approach depend strongly on the composition of the mixture used in the experiment. We show also that those MMP estimates may or may not differ significantly from values obtained in slimtube displacements. Fortuitously chosen mixture compositions can result in VIT-experiment estimates that agree well with slimtube MMPs, while for other mixtures, the error of the estimates can be quite large. In particular, we show that errors in the VIT-technique estimate of the MMP are often large for gas/oil systems for which the first-contact miscibility pressure (FCMP) is much larger than the slimtube MMP. We conclude, therefore, that the VIT experiment is not a reliable single source of information regarding the development of multicontact miscibility in multicomponent gas/oil displacements. Introduction Many oil fields are now candidates for enhanced-oil-recovery processes such as tertiary gasfloods or miscible water-alternating-gas injection schemes. The MMP is an important parameter in the design and implementation of these displacement processes and, hence, it is equally important that the MMP be determined by a method that is both reliable and accurate. Several methods have been proposed for measurement of the MMP. The slimtube-displacement experiment is the most commonly used approach (Yellig and Metcalfe 1980; Holm and Josendal 1982; Orr et al. 1982). Because of the time-consuming process of performing multiple slimtube-displacement experiments, alternative experimental approaches have been proposed. Some investigators have suggested use of a rising-bubble experiment, in which observations of bubbles of injection gas rising through oil (Christiansen and Haines 1987; Eakin and Mitch 1988; Novosad et al. 1990; Sibbald et al. 1991; Mihcakan and Poettmann 1994), are a basis of a method for determining the MMP. Zhou and Orr (1988) concluded that the changes in bubble behavior observed in the rising-bubble experiment are caused primarily by changes in IFT as components in the bubble dissolve in the oil and components in the oil transfer to the bubble. They showed that rising-bubble experiments could be used to measure the MMP for vaporizing gas drives, but are less accurate for condensing gas drives, while a drop of oil falling through gas could be used to determine the MMP for condensing gas drives. Whether either a falling-drop or a rising-bubble experiment could be used to determine the MMP accurately in condensing/vaporizing gas drives such as those described by Zick (1986), Stalkup (1987), and Johns et al. (1993) has not been determined. Rao and coworkers proposed a different use of IFT observations to determine the MMP (Rao 1997, 1999; Rao and Lee 2002, 2003; Ayirala et al. 2003; Ayirala and Rao 2004, 2006a, 2006b; Sequeira 2006). They measured IFTs for pendant drops of oil suspended in a cell containing a two-phase mixture of the injection gas and the oil. In that approach, known as the VIT experiment, the IFT is measured at a sequence of pressures, and the MMP is taken to be the pressure at which the IFT plotted as a function of pressure extrapolates to zero IFT. Orr and Jessen (2007) presented an analysis of the VIT technique based on EOS calculations for well-characterized ternary and quaternary gas/oil systems and demonstrated that the VIT experiment may give estimates of the MMP that differ significantly from the MMP based on critical tie-lines for condensing, vaporizing, and condensing/vaporizing gas drives. In this paper, we extend the analysis of Orr and Jessen (2007) and calculate the IFT behavior that would be observed in the VIT experiment for gas displacements of multicomponent crude-oil systems. We assess the accuracy of MMP estimated by the VIT approach for 13 multicomponent gas/oil displacements for which experimental phase-equilibrium and slimtube data are available, and we demonstrate that for these multicomponent crude-oil systems, the VIT approach can give estimates of the MMP that are close to the actual MMP or that are significantly in error, depending on the compositions of mixtures created in the equilibrium cell.

Flow Pattern Transition During Gas Liquid Upflow Through Vertical Concentric Annuli—Part II: Mechanistic Models

1999 ◽  
Vol 121 (4) ◽  
pp. 902-907 ◽  
Author(s):  
G. Das ◽  
P. K. Das ◽  
N. K. Purohit ◽  
A. K. Mitra
Keyword(s):  
Experimental Data ◽  
Physical Properties ◽  
Liquid Films ◽  
Mechanistic Models ◽  
Two Phase ◽  
Model Predictions ◽  
Flow Pattern Transition ◽  
Mathematical Equations ◽  
Phase Mixture ◽  
Two Phases

In this paper the transition boundaries between different flow regimes during cocurrent upflow of gas liquid two-phase mixture through concentric annuli has been predicted theoretically. On the basis of the experimental observations (Das et al., 1999), mechanistic models have been proposed to formulate mathematical equations of the regime boundaries as functions of the annulus dimensions, the physical properties, and velocities of the two phases. The analysis has yielded the bubbly-slug transition to occur at a limiting void fraction of 0.2, and the slug-churn transition to occur due to flooding of the liquid films by the Taylor bubbles. A comparison of the model predictions with experimental data corroborate the suitability of the proposed mechanisms.

Correlations of Equilibrium Interfacial Tension Based on Mutual Solubility/Density: Extension to n-Alkane–Water and n-Alkane–CO2 Binary/Ternary Systems and Comparisons With the Parachor Model

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Zehua Chen ◽  
Daoyong Yang
Keyword(s):  
Interfacial Tension ◽  
Binary Systems ◽  
Ternary Systems ◽  
Liquid System ◽  
Mutual Solubility ◽  
Density Difference ◽  
Petroleum Engineering ◽  
Liquid Density ◽  
Relative Deviation ◽  
Two Phases

In this study, new and pragmatic interfacial tension (IFT) correlations for n-alkane–water and n-alkane–CO2 systems are developed based on the mutual solubility of the corresponding binary systems and/or density in a pressure range of 0.1–140.0 MPa and temperature range of 283.2–473.2 K. In addition to being more accurate (i.e., the absolute average relative deviation (AARD) is 1.96% for alkane–water systems, while the AARDs for alkane–CO2 systems are 8.52% and 25.40% in the IFT range of >5.0 mN/m and 0.1–5.0 mN/m, respectively) than either the existing correlations or the parachor model (the AARDs for alkane–CO2 systems are 12.78% and 35.15% in the IFT range of >5.0 mN/m and 0.1–5.0 mN/m, respectively), such correlations can be applied to the corresponding ternary systems for an accurate IFT prediction without any mixing rule. Both a higher mutual solubility and a lower density difference between two phases involved can lead to a lower IFT, while pressure and temperature exert effects on IFT mainly through regulating the mutual solubility/density. Without taking effects of mutual solubility into account, the widely used parachor model in chemical and petroleum engineering fails to predict the IFT for CO2/methane–water pair and n-alkane–water pairs, though it yields a rough estimate for the CO2–water and methane–water pair below the CO2 and methane critical pressures of 7.38 and 4.59 MPa, respectively. However, the parachor model at least considers the effects of solubility in the alkane-rich phase to make it much accurate for n-alkane–CO2 systems. For n-alkane–CO2 pairs, the correlations developed in this work are found to be much less sensitive to the liquid density than the parachor model, being more convenient for practical use. In addition, all the IFTs for the CO2–water pair, methane–water pair, and alkane–CO2 pair can be regressed as a function of density difference of a gas–liquid system with a high accuracy at pressures lower than the critical pressures of either CO2 or methane.

Correlation of Interfacial Tension of Two-Phase Three-Component Systems

1957 ◽  
Vol 49 (6) ◽  
pp. 1035-1042 ◽  
Author(s):  
Nelson F. Murphy ◽  
John E. Lastovica ◽  
James G. Fallis
Keyword(s):  
Interfacial Tension ◽  
Two Phase ◽  
Component Systems

Dependence of the Equation of State in Surface Tension Prediction by the Theory of Capillarity

2009 ◽  
Author(s):  
Aaron P. Wemhoff
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Vapor Pressure ◽  
Interfacial Tension ◽  
Saturated Vapor ◽  
Saturation Pressure ◽  
Liquid Density ◽  
Fluid Models ◽  
Vapor Density ◽  
Surface Tension Data

The theory of capillarity was originally developed by J. D. van der Waals to provide a means of predicting interfacial (surface) tension data using saturation pressure and liquid-vapor density data. This theory was recently extended to the Redlich-Kwong, Soave-Redlich-Kwong, and Peng-Robinson fluid models. The latter two equations of state are more advanced than the Redlich-Kwong model in that they use an acentric factor to predict saturated vapor pressure values more in agreement with experimental data. However, the agreement in the predicted interfacial tension values is worse for the latter two models compared to the Redlich-Kwong model. This study features a sensitivity analysis to show that the predicted interfacial tension values are more sensitive to vapor density than liquid density and vapor pressure, and that increasing the vapor density reduces the corresponding predicted interfacial tension value. Furthermore, all three fluid models tend to overpredict interfacial tension when experimental data are applied in their predictive equations. This study finds that the reason why the simpler Redlich-Kwong model predicts better interfacial tension values than the two advanced models is because the former overpredicts vapor density moreso than the two advanced cubic fluid models, and this in turn reduces the prediction of interfacial tension to make its value more comparable to experimental data.

Velocity Distributions in Two-Phase Vortex Flow

1968 ◽  
Vol 90 (3) ◽  
pp. 368-372
Author(s):  
J. F. Lafferty ◽  
F. G. Hammitt ◽  
R. Cheesewright
Keyword(s):  
Experimental Data ◽  
Analytical Model ◽  
Vortex Flow ◽  
Single Phase ◽  
Gas Jet ◽  
Two Phase ◽  
Two Phases ◽  
Good Agreement

An analytical model is developed to describe gas-jet driven two-phase vortex flow. Utilizing experimental data, the model is used to calculate the velocity distributions of the two phases within an air-water vortex. The computed velocities are in very good agreement with independent measurements and with trends predicted from other investigations of single-phase vortex flow.

Interfacial Tension of the Methane-Normal Decane System

1962 ◽  
Vol 2 (03) ◽  
pp. 257-260 ◽  
Author(s):  
G.L. Stegemeier ◽  
B.F. Pennington ◽  
E.B. Brauer ◽  
E.W. Hough
Keyword(s):  
Interfacial Tension ◽  
Critical Pressure ◽  
High Pressures ◽  
Phase Region ◽  
Density Difference ◽  
Two Phase ◽  
Interfacial Tensions ◽  
Member Aime ◽  
Junior Member

STEGEMEIER, G.L., JUNIOR MEMBER AIME, SHELL DEVELOPMENT CO., HOUSTON, TEX. PENNINGTON, B.F., JUNIOR MEMBER AIME, HUMBLE OIL AND REFINING CO., HOUSTON, TEX., BRAUER, E.B., JUNIOR MEMBER AIME, UNION OIL CO., ABBEVILLE, LA., HOUGH, E.W., U. OF TEXAS, AUSTIN, TEX. Abstract Interfacial tension divided by the difference in density between the liquid and the vapor phases was determined experimentally by the pendant drop method on several isotherms in the two phase region below the critical point for the methane-normal de can e system. The density difference data of Sage and Lacey was used in the calculation of inter facial tension. Both inter facial tension and interfacial tension divided by density difference were found to vanish at the critical point. Interfacial tensions of less than one dyne/centimeter were observed as far as 1,000 pounds per square inch below the critical pressure. EXPERIMENTAL PROCEDURE The interfacial tension divided by the density difference for the methane-normal decane system was determined at the 100 degrees, 130 degrees, 160 degrees and 190 degrees F isotherms, from pressures of about 1,000 psi to the critical pressure, which is more than 5,000 psi for these isotherms. Particular emphasis was placed upon the investigation at pressures slightly below the critical pressure where the interfacial tension is less than 0.5 dyne/cm. Volumetric properties in the two-phase region, including the critical pressures and temperatures, were taken from the work of Sage and Lacey. The experimental pendant-drop technique used for the determination of interfacial tensions at high pressures incorporated the ideas of Michaels and Hauser, Hough, et al, Walker and Heuer. In addition, the technique for determination of extremely small interfacial tension by Jennings was utilized in the region near the critical points. A detailed description of the apparatus is given in a dissertation by one of the authors. Cleaning operations on the stainless-steel sample system included successive washings with chromic acid, tap water and, finally, distilled water. Subsequent cleanings were performed with re-distilled normal pentane, which had an extremely low residue upon evaporation. Specific composition requirements necessitated a fairly precise sample introduction although, for a two-phase, two-component system, the composition of each phase is completely determined if pressure and temperature are controlled. The normal decane was delivered into the evacuated sample system as a liquid from a burette. The methane was then introduced into the system from a calibrated isothermal container, so that pressure differentials could be used to determine the amount introduced. High pressures were obtained by compressing the sample with a mercury injection pump until the critical pressure was reached for the particular isotherm being studied. Experimental data were then obtained for specific pressures by first decreasing the pressure slightly so that two phases would appear, and then photographing a drop at that pressure. Subsequent photographs were made at increments throughout the pressure range. SPEJ P. 257^

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