A New Approach To Improve the Phase Behavior of Supercritical Hydrocarbons Using PR EOS

2008 ◽  
Author(s):  
Moosa Rabiei Faradonbeh ◽  
Alireza Bahramian ◽  
Rahim Masoudi
Keyword(s):  
Phase Behavior ◽  
New Approach

A New Approach to the Phase Behavior of Oppositely Charged Polymers and Surfactants

2002 ◽  
Vol 106 (5) ◽  
pp. 1013-1018 ◽  
Author(s):  
Anna Svensson ◽  
Lennart Piculell ◽  
Bernard Cabane ◽  
Philippe Ilekti
Keyword(s):  
Phase Behavior ◽  
New Approach ◽  
Charged Polymers ◽  
Oppositely Charged

Modelling of the Multiphase Behavior of Methane-Ethane-Nitrogen Mixture at Low Temperatures with an Equation of State

1992 ◽  
Vol 57 (7) ◽  
pp. 1362-1372 ◽  
Author(s):  
Roumiana P. Stateva ◽  
Stefan G. Tsvetkov
Keyword(s):  
Equation Of State ◽  
Natural Gas ◽  
Phase Behavior ◽  
Thermodynamic Model ◽  
Low Temperatures ◽  
Computer Algorithm ◽  
Reasonable Accuracy ◽  
New Approach ◽  
Nitrogen Mixture ◽  
Multiphase Behavior

The paper discusses modelling of the multiphase behavior of the methane-ethane-nitrogen mixture, which is of a considerable interest for the natural gas and oil industries. The thermodynamic model is a modified Redlich-Kwong-Soave equation of state. The computer algorithm is based on a new approach to solving the isothermal multiphase flash problem, when the number and identity of the phases present at equilibrium are unknown in advance. The results demonstrate that Redlich-Kwong-Soave equation of state and the algorithm applied predict with reasonable accuracy the complicated phase behavior and the region of L1L2V equilibrium, observed in the experiment, of the methane-ethane-nitrogen system.

A Rigorous Solution to the Problem of Phase Behavior in Unconventional Formations With High Capillary Pressure

SPE Journal ◽  
2018 ◽  
Vol 23 (04) ◽  
pp. 1438-1451 ◽  
Author(s):  
Sajjad S. Neshat ◽  
Ryosuke Okuno ◽  
Gary A. Pope
Keyword(s):  
Phase Behavior ◽  
Capillary Pressure ◽  
Gas Oil ◽  
Rigorous Solution ◽  
Shale Formations ◽  
New Approach ◽  
Three Phase ◽  
Capillary Equilibrium ◽  
Stability Method ◽  
New Criterion

Summary Phase behavior of hydrocarbon mixtures is affected by the petrophysical properties of the formation. This paper integrates several important thermodynamic and petrophysical aspects of the problem in a rigorous way and introduces a solution that can be applied over the range of pore sizes in tight and shale formations in which hydrocarbons can be practically recovered. A new criterion for phase-stability analysis is introduced that results in discovery of a new range of solutions for the capillary equilibrium problem. A novel three-phase capillary pressure model has been used to estimate the effect of connate water on the gas/oil capillary pressure. The model is then used in conjunction with the new stability method to solve several phase-behavior problems for binary and multicomponent reservoir fluids. We show that the new approach can significantly improve the estimation of phase behavior at high capillary pressure.

A New Approach for Determining Equation-of-State Parameters Using Phase Equilibria Data

1966 ◽  
Vol 6 (04) ◽  
pp. 363-371 ◽  
Author(s):  
K.E. Starling
Keyword(s):  
Equation Of State ◽  
Phase Equilibria ◽  
Phase Behavior ◽  
Equilibrium Phase ◽  
Pure Component ◽  
Hydrocarbon Mixtures ◽  
New Approach ◽  
Pvt Data ◽  
Condensate Reservoir ◽  
Phase Data

Abstract Phase equilibria data were used to develop an equation-of-state correlation for complex hydrocarbon mixtures, thereby circumventing difficulties associated with use of pressure-volume-temperature data. Equilibrium phase data for two condensate reservoir fluids were used to determine equation-of-state parameters for hydrocarbons as heavy as C22H46 in a modified form of the Benedict-Webb-Rubin equation of state. Comparative tests of K-values from the resultant correlation were made with data for condensate reservoir, separator and gas plant absorber mixtures. Generally, for temperatures above 0F and computed liquid densities below 0.55 lb-mole/cu ft, the modified BWR equation predicted K-values in close agreement with the experimental data. Introduction Accurate predictions of thermodynamic behavior for complex hydrocarbon mixtures are necessary for many calculations k the petroleum industry. Because of the relatively high cost of extensive experimental data, many correlations for prediction of phase behavior have been developed. Some of these, such as the correlation of K-values presented in the NGAA Equilibrium Ratio Data Book, are totally empirical. Others, such as the Benedict-Webb-Rubin (BWR) equation-of-state method, are semitheoretical. Unfortunately, published correlation methods often do not accurately predict the phase behavior of complex hydrocarbon mixtures, principally because of inadequate representation of the effects of components heavier than decane. This paper presents a new approach to this problem in which basic equation-of-state relations including heavy hydrocarbon effects are applied. Equilibrium phase data for two condensate reservoir fluids containing hydrocarbons as heavy as C22H46 are used to correlate component K-values. The BWR equation was chosen as the prototype equation of state for this study because of its proven capability for accurately predicting phase behavior and thermodynamic properties of light-hydrocarbon mixtures. Research was directed toward development of BWR parameters for the heavy hydrocarbons and modifications of the mathematical form of the BWR equation for application to complex hydrocarbon mixtures. The new equation-of-state approach presented differs considerably from previous methods in that phase equilibria rather than PVT data are used for determination of equation-of-state parameters. It is an explicit approach since the parameters are determined directly from mixture data. As such, it does not encounter problems inherent in the implicit method used by Benedict, Webb and Rubin and numerous other investigators-one in which mixture parameters were postulated to be functions of the pure component parameters. The pure component BWR parameters, in turn, were determined from experimental PVT data. This method has been limited to mixtures containing components lighter than decane because of lack of vapor phase PVT data. Studies have been reported in which BWR parameters have been determined explicitly from PVT data for binary mixtures. However, since small concentrations of heavier components have only a minor effect on PVT behavior, it is doubtful that these explicit methods would yield useful results for condensate systems. Ellington and Eakin have shown that the accuracy of K-values predicted by an equation of state developed from mixture PVT data probably would be more than an order of magnitude lower than the accuracy of the PVT data. On the other hand an equation of state utilizing parameters developed from phase equilibria data should predict K-values with accuracy comparable to be accuracy of the experimental phase compositions. This work applies this explicit approach with the objective of improving hydrocarbon mixture phase behavior predictions. SPEJ P. 363ˆ

The O–C diagrams of minor planets − a new approach to modelling the rotation

1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss
Keyword(s):  
Error Analysis ◽  
Time Dependence ◽  
Theoretical Work ◽  
Minor Planet ◽  
Minor Planets ◽  
New Approach ◽  
Preliminary Results ◽  
Ccd Observations

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.

A New Approach to the Demonstration of Oxidase-Localization Using Tannic Acid Or Catechin

1973 ◽  
Vol 31 ◽  
pp. 698-699
Author(s):  
V. Mizuhira ◽  
Y. Futaesaku
Keyword(s):  
Cross Section ◽  
Tannic Acid ◽  
Elastic Fiber ◽  
The Other ◽  
New Approach ◽  
Tissue Block ◽  
Active Reaction ◽  
The Cross

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.

Processing Immunoperoxidase Labeled Cell Monolayers and Cryostat Sesctions For Electron Microscopy

1985 ◽  
Vol 43 ◽  
pp. 714-715
Author(s):  
K. Chien ◽  
R. Van de Velde ◽  
I.P. Shintaku ◽  
A.F. Sassoon
Keyword(s):  
Cell Monolayer ◽  
Cell Types ◽  
Surface Antigens ◽  
Immunoperoxidase Method ◽  
Reaction Step ◽  
Hot Plate ◽  
Air Drying ◽  
New Approach ◽  
Cell Monolayers ◽  
Glass Slides

Immunoelectron microscopy of neoplastic lymphoma cells is valuable for precise localization of surface antigens and identification of cell types. We have developed a new approach in which the immunohistochemical staining can be evaluated prior to embedding for EM and desired area subsequently selected for ultrathin sectioning.A freshly prepared lymphoma cell suspension is spun onto polylysine hydrobromide- coated glass slides by cytocentrifugation and immediately fixed without air drying in polylysine paraformaldehyde (PLP) fixative. After rinsing in PBS, slides are stained by a 3-step immunoperoxidase method. Cell monolayer is then fixed in buffered 3% glutaraldehyde prior to DAB reaction. After the DAB reaction step, wet monolayers can be examined under LM for presence of brown reaction product and selected monolayers then processed by routine methods for EM and embedded with the Chien Re-embedding Mold. After the polymerization, the epoxy blocks are easily separated from the glass slides by heatingon a 100°C hot plate for 20 seconds.

Phase behavior of cationic and anionic surfactants at low concentrations

1992 ◽  
Vol 50 (1) ◽  
pp. 694-695
Author(s):  
E. Naranjo
Keyword(s):  
Phase Behavior ◽  
Structural Characterization ◽  
Dynamic Systems ◽  
Anionic Surfactants ◽  
Intermolecular Forces ◽  
Stable Form ◽  
Surfactant Mixtures ◽  
Low Concentrations ◽  
Cationic And Anionic Surfactants ◽  
General Method

Equilibrium vesicles, those which are the stable form of aggregation and form spontaneously on mixing surfactant with water, have never been demonstrated in single component bilayers and only rarely in lipid or surfactant mixtures. Designing a simple and general method for producing spontaneous and stable vesicles depends on a better understanding of the thermodynamics of aggregation, the interplay of intermolecular forces in surfactants, and an efficient way of doing structural characterization in dynamic systems.

Sign in / Sign up

Export Citation Format

Share Document