Dispersive Mixing Effects on the Sloss Field Micellar System

1982 ◽  
Vol 22 (04) ◽  
pp. 481-492 ◽  
Author(s):  
Surendra P. Gupta
Keyword(s):  
Fresh Water ◽  
Dispersion Coefficient ◽  
Water Phase ◽  
Simulation Studies ◽  
Middle Phase ◽  
Lower Phase ◽  
Process Mechanism ◽  
Polymer Fluids ◽  
Mixing Effects ◽  
Dispersive Mixing

Gupta, Surendra P., SPE, Amoco Production Co. Abstract This paper presents results of laboratory experiments and computer simulation studies of the micellar/polymer fluids injected in the Sloss field, NE. The paper shows that the dispersion coefficient for the partitioned sulfonate in the oil phase can be an order of magnitude larger than the dispersion coefficient in the water phase. The results show that the two principal components of the micellar fluid (sulfonate and polymer) propagate at different rates because of partitioning and dispersive mixing effects. Sulfonate is produced much earlier than polymer and is concentrated in the produced oil. Sulfonate partitions into the oil phase as a consequence of ion exchange, and the polymer remains in the water phase. The oil phase that contains the partitioned sulfonate i.e., upper-phase microemulsion-has high mobility. The increased dispersion coefficient for a component in the nonwetting phase, in this case the partitioned sulfonate into the oil phase, is supported by an independent study. These mechanisms contribute to early sulfonate breakthrough and a larger sulfonate requirement per barrel of oil displaced than anticipated for a nondispersive displacement. The results of this paper can be beneficial for design of other micellar fluids and performance predictions and interpretation of micellar floods in other fields. Introduction A micellar/polymer pilot was conducted in the Sloss field, Kimball County, NE. Interpretation of the performance of micellar pilots aids in the development of a prediction model. To meet this objective, process variables (e.g., compositional effects) must be separated from field variables (e.g., reservoir description and operating variables), and the process mechanism must be identified. Concurrent with the pilot, research continued on the process mechanism of the micellar/polymer fluids injected in the field test. This paper presents an example of partitioning and dispersive mixing effects in micellar flooding. The paper demonstrates that detailed core effluent analyses in conjunction with numerical simulation studies can reveal displacement mechanisms within the two mixing zones. These zones are between an oil/water bank and a micellar slug and between the micellar slug and a polymer bank. Results of previous studies of the first portion of the mechanism research have been published. Before discussing the results of this paper, the following provides a brief summary of the previous studies. A separate paper discusses results of a Sloss pilot post-test evaluation well. Previous Studies The fluids designed (see Appendix A for details) for the Sloss pilot involved a salinity contrast (or gradient) concept. The salinity of the preconditioning and the makeup brines for the micellar fluid was 12,000 ppm NaCl added to the available Sloss fresh water. The low-salinity fresh water was used for the polymer water. The following summarizes pertinent results of the previous studies. The results showed that the designed micellar fluid forms a middle-phase microemulsion when a volume of the micellar fluid is mixed with an equal volume of crude oil. A middle-phase microemulsion is in equilibrium with excess oil and water phases. A lower-phase microemulsion is generated when the salinity is less than 10,000 ppm NaCl. A lower-phase microemulsion is in equilibrium with an excess oil phase. The final oil saturation after micellar flooding (Sof), in small slug tests, increases as micellar fluid salinity decreases from the designed value. Furthermore, Sof is dependent on the capillary number (viscosity × velocity interfacial tension). SPEJ P. 481^

scholarly journals The Importance of Microemulsion for the Surfactant Injection Process in Enhanced Oil Recovery

2021 ◽  
Author(s):  
Rini Setiati ◽  
Muhammad Taufiq Fathaddin ◽  
Aqlyna Fatahanissa
Keyword(s):  
Interfacial Tension ◽  
Enhanced Oil Recovery ◽  
Oil Recovery ◽  
Recovery Process ◽  
Injection System ◽  
Type I ◽  
Middle Phase ◽  
Interface Tension ◽  
Lower Phase ◽  
Injection Process

Microemulsion is the main parameter that determines the performance of a surfactant injection system. According to Myers, there are four main mechanisms in the enhanced oil recovery (EOR) surfactant injection process, namely interface tension between oil and surfactant, emulsification, decreased interfacial tension and wettability. In the EOR process, the three-phase regions can be classified as type I, upper-phase emulsion, type II, lower-phase emulsion and type III, middle-phase microemulsion. In the middle-phase emulsion, some of the surfactant grains blend with part of the oil phase so that the interfacial tension in the area is reduced. The decrease in interface tension results in the oil being more mobile to produce. Thus, microemulsion is an important parameter in the enhanced oil recovery process.

The Growth of Mixing Zone in Heterogeneous Porous Media

2012 ◽  
Author(s):  
M. R. Othman ◽  
R. Badlishah Ahmad ◽  
Z. May
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Short Duration ◽  
Dispersion Coefficient ◽  
Fluid Velocity ◽  
Heterogeneous Porous Media ◽  
Mixing Zone ◽  
Zone Size ◽  
Model Mixing ◽  
Dispersive Mixing

Dengan menggunakan penyelesaian analitikal yang merangkumi fraktal eksponen, pembesaran jarak pencampuran telah dapat ditentukan bagi model satu dimensi. Size zon pencampuran didapati meningkat apabila media berliang menjadi semakin heterogen. Dalam media berliang yang heterogen, saiz zon pencampuran meningkat apabila pemalar penyerakan meningkat terutama sekali pada aliran jangkamasa singkat relatif. Terdapat tiga faktor penting mempengaruhi saiz zon pencampuran penyerakan, ΔxD. Perkara terpenting dalam kajian ini ialah keheterogenan takungan, yang dipersembahkan oleh fraktal eksponen, β. Hasil kajian mendapati bahawa apabila β menjadi kecil (media berliang menjadi semakin heterogen), saiz zon pencampuran meningkat. Satu lagi faktor mempengaruhi ΔxD ialah pemalar penyerakan bersandar masa, Κ(tD). Di dalam takungan heterogen, zon pencampuran meningkat dengan peningkatan nilai pemalar penyerakan pada aliran jangkamasa singkat relatif. Bagi aliran jangkamasa panjang relatif, bagaimanapun, ΔxD terus meningkat walaupun Κ(tD) menjadi tetap. Faktor ketiga ialah purata kelajuan bendalir, ν. Zon pencampuran mempunyai perkaitan songsang dengan kelajuan bendalir dengan cara ΔxD meningkat apabila ν berkurangan. Kata kunci: Kehomogenan; keheterogenan; pekali penyerakan; eksponen fraktal; zon pencampuran; media berliang Utilizing currently available analytical solutions that incorporate fractal exponent, the growth of mixing length of injected solvent was determined for a one-dimensional model. Mixing zone size was found to increase as porous medium becomes increasingly heterogeneous. In a heterogeneous porous media, mixing zone size increases as dispersion coefficient increases particularly at relatively short duration of flow. There are three important factors influencing the size of the dispersive mixing zone, ΔxD. Of particular importance in this study is reservoir heterogeneity, which is represented by a fractal exponent, β. It was discovered that as β becomes smaller (porous medium becomes increasingly heterogeneous), the size of the mixing zone increases. Another factor affecting ΔxD is time dependent dispersion coefficient, Κ(tD). In a heterogeneous reservoir, mixing zone increases with increasing value of dispersion coefficient at relatively short duration of flow. For relatively long period of flow, however? ΔxD continues to increase even though Κ(tD) remains constant. The third factor is average fluid velocity, ν. Mixing zones have inverse relationship with fluid velocity in that ΔxD increases as ν decreases. Key words: Homogeneity; heterogeneity; dispersion coefficient; fractal exponent; mixing zone; dimensionless concentration; porous media

scholarly journals Maximum power of saline and fresh water mixing in estuaries

2019 ◽  
Vol 10 (4) ◽  
pp. 667-684
Author(s):  
Zhilin Zhang ◽  
Hubert Savenije
Keyword(s):  
Fresh Water ◽  
Dispersion Coefficient ◽  
Saline Water ◽  
Maximum Power ◽  
Estuarine System ◽  
Natural Systems ◽  
Gravitational Circulation ◽  
Advection Dispersion ◽  
Physically Based ◽  
Alluvial Estuaries

Abstract. According to Kleidon (2016), natural systems evolve towards a state of maximum power, leading to higher levels of entropy production by different mechanisms, including gravitational circulation in alluvial estuaries. Gravitational circulation is driven by the potential energy of fresh water. Due to the density difference between seawater and river water, the water level on the riverside is higher. The hydrostatic forces on both sides are equal but have different lines of action. This triggers an angular moment, providing rotational kinetic energy to the system, part of which drives mixing by gravitational circulation, lifting up heavier saline water from the bottom and pushing down relatively fresh water from the surface against gravity; the remainder is dissipated by friction while mixing. With a constant freshwater discharge over a tidal cycle, it is assumed that the gravitational circulation in the estuarine system performs work at maximum power. This rotational flow causes the spread of salinity inland, which is mathematically represented by the dispersion coefficient. In this paper, a new equation is derived for the dispersion coefficient related to density-driven mixing, also called gravitational circulation. Together with the steady-state advection–dispersion equation, this results in a new analytical model for density-driven salinity intrusion. The simulated longitudinal salinity profiles have been confronted with observations in a myriad of estuaries worldwide. It shows that the performance is promising in 18 out of 23 estuaries that have relatively large convergence length. Finally, a predictive equation is presented to estimate the dispersion coefficient at the downstream boundary. Overall, the maximum power concept has provided a new physically based alternative for existing empirical descriptions of the dispersion coefficient for gravitational circulation in alluvial estuaries.

scholarly journals Holocene development of the Arresø area, north-east Sjælland, Denmark.

2017 ◽  
Vol 65 ◽  
pp. 25-35
Author(s):  
Ole Bennike ◽  
Pernille Pantmann ◽  
Esben Aarsleff
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Water Phase ◽  
Ostrea Edulis ◽  
Land Area ◽  
Marine Fauna ◽  
North East ◽  
Acidic Waters ◽  
Area North ◽  
Alkaline Waters

The Arresø area in north-east Sjælland, Denmark, was deglaciated about 18,000 to 16,000 years ago. In the Holocene it was probably a land area until it was transgressed by the sea c. 8500 years BP. During a first marine phase the area housed a species-rich marine fauna that included the oyster Ostrea edulis, the salinity and water temperatures were higher than at present, and there was a wide connection to the Kattegat sea. At about 6500 years BP there was a short-lived lake or brackish-water phase, but marine conditions were soon re-established with a fauna less diverse than before, and both salinity and water temperatures decreased. The present lake Arresø became isolated from the sea about 2500 years BP. The transition from brackish water to fresh water was rapid; the lake developed from shallow alkaline waters to deeper more acidic waters and finally to eutrophic waters.

scholarly journals Efficient Preparation of Bafilomycin A1 from Marine Streptomyces lohii Fermentation Using Three-Phase Extraction and High-Speed Counter-Current Chromatography

Marine Drugs ◽  
2020 ◽  
Vol 18 (6) ◽  
pp. 332
Author(s):  
Ye Yuan ◽  
Xiaoping He ◽  
Tingting Wang ◽  
Xingwang Zhang ◽  
Zhong Li ◽  
...  
Keyword(s):  
Crude Extract ◽  
High Speed ◽  
Solvent System ◽  
Bafilomycin A1 ◽  
Middle Phase ◽  
Two Phase ◽  
Rapid Separation ◽  
Lower Phase ◽  
Three Phase ◽  
Counter Current

An efficient strategy was developed for the rapid separation and enrichment of bafilomycin A1 (baf A1) from a crude extract of the marine microorganism Streptomyces lohii fermentation. This strategy comprises liquid−liquid extraction (LLE) with a three-phase solvent system (n-hexane–ethyl acetate–acetonitrile–water = 7:3:5:5, v/v/v/v) followed by separation using high-speed counter-current chromatography (HSCCC). The results showed that a 480.2-mg fraction of baf A1-enriched extract in the middle phase of the three-phase solvent system was prepared from 4.9 g of crude extract after two consecutive one-step operations. Over 99% of soybean oil, the main hydrophobic waste in the crude extract, and the majority of hydrophilic impurities were distributed in the upper and lower phase, respectively. HSCCC was used with a two-phase solvent system composed of n-hexane–acetonitrile–water (15:8:12, v/v/v) to isolate and purify baf A1 from the middle phase fraction, which yielded 77.4 mg of baf A1 with > 95% purity within 90 min. The overall recovery of baf A1 in the process was determined to be 95.7%. The use of a three-phase solvent system represents a novel strategy for the simultaneous removal of hydrophobic oil and hydrophilic impurities from a microbial fermentation extract.

scholarly journals Maximum power of saline and fresh water mixing in estuaries

2018 ◽  
Author(s):  
Zhilin Zhang ◽  
Hubert Savenije
Keyword(s):  
Fresh Water ◽  
Dispersion Coefficient ◽  
Saline Water ◽  
Maximum Power ◽  
Dissipated Energy ◽  
Estuarine System ◽  
Natural Systems ◽  
Gravitational Circulation ◽  
Advection Dispersion ◽  
Alluvial Estuaries

Abstract. Natural systems evolve towards a state of maximum power (Kleidon, 2016), leading to higher levels of entropy production by different mechanisms, including the gravitational circulation in alluvial estuaries. Gravitational circulation is driven by the potential energy of the fresh water. Due to the density difference between seawater and riverwater, the water level on the river side is higher. The hydrostatic forces on both sides are equal, but have different working lines. This triggers an (accelerating) angular moment, providing rotational kinetic energy into the system, part of which drives mixing by gravitational circulation mixing; the remainder is transferred into dissipated energy by friction while mixing. With a constant discharge over a tidal cycle, the density-driven gravitational circulation in the estuarine system performs work at maximum power, lifting up saline water and bringing down fresh water against gravity. The rotational flow causes the spread of salinity, which is mathematically represented by the dispersion coefficient. Accordingly, a new equation for the dispersion coefficient due to the density-driven mechanism has been derived. Together with the steady state advection-dispersion equation, this resulted in a new analytical model for gravitational salinity intrusion. The simulated longitudinal salinity profiles have been confronted with observations in a myriad of estuaries worldwide. It shows that the performance is promising in eighteen out of twenty-three estuaries, with relatively large convergence length. Finally, a predictive equation is presented for the dispersion coefficient at the boundary. Overall, the maximum power concept has provided an alternative for describing the dispersion coefficient due to gravitational circulation in alluvial estuaries.

The Rules for Achieving High Solubilization of Brine and Oil by Amphiphilic Molecules

1983 ◽  
Vol 23 (02) ◽  
pp. 327-338 ◽  
Author(s):  
M. Bourrel ◽  
C. Chambu
Keyword(s):  
Oil Recovery ◽  
Water Phase ◽  
Phase System ◽  
Middle Phase ◽  
Rich Phase ◽  
Optimal State ◽  
Amphiphilic Molecules ◽  
Three Phase ◽  
Surfactant Systems ◽  
Formulation Variables

Abstract The oil-recovery effectiveness of a chemical flood has been proved related to the phase behavior of the brine/oil/surfactant system. In particular, it is advantageous to formulate the system so that optimal threephase behavior is obtained. However, it also has been demonstrated that all the optimized systems are not equivalent in terms of solubilization. interfacial tensions (IFT's), and oil-recovery efficiency. This paper addresses the conditions that promote high solubilization in microemulsions, a property correlated to the values of the IFT and therefore correlated to the ability of such systems to displace the oil in porous media. When one formulation parameter is changed, another parameter must be varied at the same time for compensation to reoptimize the system. The mechanism of solubilization is investigated experimentally by considering the usual formulation parameters: salinity, oil type, alcohol type and concentration, and surfactant structure and type (anionics and nonionics). The results are interpreted in terms of interaction energies between surfactant, oil, and water. In particular, the role of the alcohol and its impact on the solubilization by amphiphilic systems are discussed in detail and interpreted. Moreover, the concepts developed in this paper explain the effect of the surfactant structure and therefore aid in the design of amphiphilic molecules exhibiting a high solubilizing power for given conditions of brine, temperature, etc. Introduction Mobilization and transport of residual oil by chemical-flooding processes involve various mechanisms that must be considered when formulating a surfactant slug, but, among them, it is well known that IFT's between phases play a major role. Reed and Healy have shown phases play a major role. Reed and Healy have shown that ultralow IFT's can be attained when a microemulsion phase (surfactant-rich phase, the so-called "middle phase (surfactant-rich phase, the so-called "middle phase") is in equilibrium simultaneously with an oil phase") is in equilibrium simultaneously with an oil phase and a water phase. They first have defined the phase and a water phase. They first have defined the concept of optimal salinity as being the point where the IFT's at the oil-middle phase and middle phase/water interfaces are equal. At that point, the volumes of oil and water solubilized in the middle phase generally are identical, although there is no theoretical basis for that. A correlation between the values of the quantities of oil and water solubilized in the middle phase and the values of the IFT's between the phases also has been found: the lower the tension, the higher the solubilization. Therefore, it appears judicious to start the screening procedure of surfactant systems for enhanced oil procedure of surfactant systems for enhanced oil recovery (EOR) by looking for the point where equal volumes of oil and water are solubilized in the surfactant phase of a three-phase system. During recent years, phase of a three-phase system. During recent years, much time has been devoted to discovering that point, and the rules for compensating changes in the formulation variables have been established for anionic and non-ionic surfactants. We must emphasize that, if we start from an optimized system and we change a formulation variable defining the system, the optimal state is lost, and another formulation variable must be changed to reach a new optimal state. All optimized systems are not equivalent, as shown in previous results, and consideration of the amount of previous results, and consideration of the amount of oil and water solubilized in such systems provides a criterion to compare them. In a previous paper, we carried out a systematic study of the effect of the formulation variables on the solubilization at optimum by anionic surfactants. Some results concerning nonionics have been presented recently presented recently. SPEJ p. 327

Equilibrium of a Microemulsion That Coexists With Oil or Brine

1983 ◽  
Vol 23 (05) ◽  
pp. 829-847 ◽  
Author(s):  
Chun Huh
Keyword(s):  
Phase Behavior ◽  
Chain Length ◽  
Phase State ◽  
Water Soluble ◽  
The Other ◽  
Ionic Surfactants ◽  
Middle Phase ◽  
Lower Phase ◽  
Optimal Salinity ◽  
Drop Radius

Huh, Chun; SPE; Exxon Production Research Co. Abstract When salinity, or an equivalent variable, is increased, microemulsions generally undergo orderly transitions from a lower-to middle- to upper-phase. Even though the significance of such multiphase behavior has been well recognized in the design of surfactant flood processes, their quantitative nature in terms of the molecular structures of the surfactant lipophile, hydrophile, and the oil and brine salinity has not been fully understood. A theory of lower- and upper-phase microemulsions that gives reasonable predictions of their interfacial tensions (IFT's) and phase behavior is presented. In the theory, the surfactant monomers adsorbed at oil/brine interface cause the interface to bend as a result of an imbalance between the hydrophile/brine interaction on the one hand and lipophile/oil interaction on the other. With sufficient imbalance, high local curvature causes small drops of one phase to disperse into the other. In addition, interactions between these drops are taken into account for the microemulsion equilibrium. The theory also offers a possibility of being able to describe the hydrophile/lipophile-balanced state (optimal salinity state of Healy and Reed) in terms of the tendency of surfactant layer at the oil/brine interface to bend. Introduction Understanding the phase behavior of microemulsions is an important step in designing surfactant flooding processes and interpreting the results when they are applied to recover tertiary oil. It is well established that the phase behavior of many microemulsion systems, even those containing a large phase behavior of many microemulsion systems, even those containing a large number of different components can be represented qualitatively using pseudoternary diagrams similar to those in Fig. 1. Fig. 1a shows the pseudoternary diagrams similar to those in Fig. 1. Fig. 1a shows the lower-phase microemulsion in equilibrium with excess oil, Figs. 1b and 1c the middle-phase microemulsion in equilibrium with both oil and brine, and Fig. 1d the upper-phase microemulsion coexistent with excess water. Even though not all microemulsions conform to this simple picture, it serves as a good approximation frequently enough to use it as a basis for discussing microemulsion phase behavior. Transitions such as those shown by Fig. 1 can be produced by changing any of a large number of variables in a systematic manner. The phase shifts from "a" to "d" generally occur with increases in the salinity of the brine, the alkyl chain length of the surfactant, the aromaticity of the oil, the addition of a highly oil- soluble alcohol and a temperature increase (for non-ionic surfactants). The shifts also occur with decreases in the chain length of oil, the number of hydrophilic groups (e.g., ethylene oxide) of the surfactant, the addition of a highly water-soluble alcohol, and a temperature decrease (for most ionic surfactants). Since microemulsion phase transitions will be determined by the manner in which microemulsion structure depends on changes in the variables described above, many experimental studies have been made to determine microemulsion structure. Ultracentrifuge and light-scattering measurements show that the lower-phase microemulsion consists of spherical oil drops with radius of about 50 to 1,000 k in water. As it moves toward the middle-phase state (see Figs. 1a and 1b), the drop radius grows. On the other hand, the upper-phase microemulsion consists of small water drops in oil, and as it moves toward the middle-phase state (Figs. 1c and 1d), the drop radius again grows. Very little is known about the structure of middle-phase microemulsions. SPEJ p. 829

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