System Of Immiscible Fluids Research Articles

Analysis of Linear Encroachment in Two-Immiscible Fluid Systems in a Porous Medium

The flow of two immiscible fluids in a porous medium was analyzed accounting for boundary and inertia effects. This problem was first solved by Muskat using Darcy’s equation for fluid flow in a saturated porous medium. In the present analysis the boundary and inertia effects have been included to predict the movement of the interfacial front that is formed as one fluid displaces the other. In the present work a theoretical study that accounts for the boundary and inertia effects in predicting the movement of the interface for linear encroachment in two immiscible fluid system in a porous material is presented for the first time. The results of the present study when compared with the Muskat’s model show that consideration of the boundary and inertia effects becomes important for low values of mobility ratio (ε<1.0) and higher values of permeability (K>1.0 × 1.0−10 m2).

Imbibition of Surfactant Solutions

ABSTRACT The goal of dilute surfactant flooding is to reduce the interfacial tension of the oil/water system to very low values in order to release the residual oil. The question then arises whether oil that would normally be produced by imbibition is lost as a result of such flooding; since the surfactant decreases or eliminates the capillary forces that underlie imbibition. To study the imbibition behaviour of surfactant solutions, we first focussed on miscible-fluid systems. Both theoretically and experimentally we have shown that miscible fluids can indeed be imbibed, depending on the affinity of the different fluids for the solid. These effects persist as long as equilibrium (complete mixing) has not been attained. A similar behaviour is expected for low-tension immiscible fluid systems. We present experimental results showing that indeed the (equilibrium) interfacial tension between model oils and surfactant solutions is not the driving force behind imbibition. For the surfactant systems studied, the conclusion is that lowering the interfacial tension has some effect on the imbibition rate but no effect on ultimate recovery.

Simulation of thermocapillary convection in a two-layer immiscible fluid system using a boundary element method

A boundary element method for simulating thermocapillary convection in a two-layer immiscible fluid system with flat and free interface has been developed. The divergence theorem is applied to the non-linear convective volume integral of the boundary element formulation with the pressure penalty function. Consequently, velocity gradients are eliminated and the complete formulation is written in terms of velocity. This avoids the difficulty of convective discretizations and provides considerable reductions in storage and computational requirements while improving accuracy. In this paper, we give the influence of different parameters (Marangoni number, Reynolds number) on thermocapillary convection in cavity with two-layer immiscible fluids. As shown by the numerical results, when the physical parameters between liquid encapsulant and melt are chosen appropriately, the detrimental flow in the bottom melt layer can be greatly suppressed. The influence of the free interface on thermocapillary convection is also shown.

Effect of the wettability of the reservoir rock on the flow into a well

The effect of the wettability of the reservoir rock on the productivity of a well in a flooded reservoir is analyzed for immiscible fluid systems of the oil-water type by means of a computational experiment. The calculations take into account the presence of a drilling mud filtrate penetration zone in the neighborhood of the well.

Development of a steady relief at the interface of fluids in a vibrational field

The vibrations of a vessel strongly influence the behavior of the interface of the fluids in it. Thus, vertical vibrations can lead both to the parametric excitation of waves (Faraday ripples) and to the suppression of the Rayleigh-Taylor instability [1–2]. At the present time, the influence of vertical vibrations on the behavior of a fluid surface have been studied in sufficient detail (see, for example, review [3]). The behavior of an interface of fluids in the case of horizontal vibrations has been studied less. An interesting phenomenon has been revealed in the experimental papers [4, 5]: in the case of fairly strong horizontal vibrations of a vessel containing a fluid with a free surface, the fluid collects near one of the vertical vessel walls, the free surface being practically plane and stationary with respect to the vessel, while its angle of inclination to the horizon depends on the vibration rate. But if there is a system of immiscible fluids with comparable but different densities in the vessel, horizontal vibrations lead to the formation of a steady wave relief at the interface. An explanation of the behavior of a fluid with a free boundary was given in [6] on the basis of averaged equations of fluid motion in a vibrational field. The present paper is devoted to an analysis of the behavior of the interface of fluids with comparable densities in a high-frequency vibrational field.

Boundary conditions for interfacial fluid systems with spin

Interfacial immiscible fluid systems with hydrodynamic spin are studied within the framework of non-equilibrium thermodynamics. The energy and entropy densities and the momentum, internal angular momentum and heat currents are allowed to be singular at the interface. Balance equations in the bulk and at the surface are derived following the procedure indicated in BAM method. The interfacial entropy production leads, on the one hand, to linear laws at the surface, and on the other hand to boundary conditions for both fluids. Finally, boundary conditions in the de Groot-Mazur approximation are obtained and discussed.

Film Study on Wellbore Placement of Miscible Fluids

Introduction In a previous JPT paper we reported that gravity segregation of different-density fluids in the wellbore strongly affected placement profiles of sequentially injected fluids. That report was based on both experimental and theoretical studies of placement profiles involving immiscible fluids. A significant profiles involving immiscible fluids. A significant finding from the experimental study was that immiscible fluid placement is not affected by tubing tail position nor by injection rate, but by density differences only.In a new study reported here, we observed that miscible and immiscible fluid systems behave differently. Chiefly due to fluid mixing in the wellbore, miscible fluid placement profiles respond to both tubing tail position and injection rate. Hence, injection profiles may be controlled to some extent by proper choices of injection rate and tubing tail proper choices of injection rate and tubing tail position. position. We illustrate the new findings in this paper by applying them to miscible fluid placement problems previously modeled only approximately as equivalent previously modeled only approximately as equivalent immiscible cases. These applications suggest several additional approaches to solving common placement problems. A new 16-mm color film with narration problems. A new 16-mm color film with narration presents results of the current work and those from presents results of the current work and those from prior studies of immiscible fluid placement. prior studies of immiscible fluid placement. Experimental Observations We conducted six miscible fluid placement tests using the apparatus employed in the previous study, with minor modifications. The modifications included placing refractive index detectors to measure mixture placing refractive index detectors to measure mixture concentrations in the exit lines and metering valves to equalize flow through the three exit tubes. Isopropyl alcohol (sp. gr. 0.78 g/cm3) and a mixture (sp. gr. 0.92 g/cm3) of four parts diesel oil per part chlorothane were used as the two miscible fluids.The following observations are based on these and prior flow tests. prior flow tests. 1. Regardless of miscibility, gravity forces cause injected fluid to rise or fall through the in-wellbore fluid, depending on which fluid is heavier. If the two fluids are miscible, a mixing zone occurs at the discharge of the injection tubing. This zone grows as injection continues.2. For miscible systems, the growth and movement of the mixing zone depend on the injection rate, the injected/in-place fluid density ratio, and the tubing tail position relative to the perforations. In contrast, immiscible fluid systems produce a sharp fluid interface that rises or falls solely according to the density ratio and amount of fluid injected; the tubing tail position has no effect for immiscible systems. position has no effect for immiscible systems. 3. In miscible systems the interface between the mixing zone, with its constantly changing composition, and the in-place fluid reaches different perforations at different times; consequently, a perforations at different times; consequently, a different concentration of treatment fluid may be injected through each perforation. With thick intervals and small treatment volumes, some perforations may not receive any treatment fluid. perforations may not receive any treatment fluid. 4. Where a fluid is injected into a well filled with a heavier miscible fluid, injection rate and turbulence can cause the heavier rathole fluid to be displaced from the wellbore. Complete displacement depends on the rate and length of injection, the tubing tail position, and the depth of the rathole. For position, and the depth of the rathole. For immiscible systems, it is not possible to displace a rathole fluid during injection of a lighter fluid.5. Regardless of miscibility, when a heavier fluid is used to displace another fluid and the tubing tail is set at or below the top perforation, the fluid in the dead space above the top perforation cannot be displaced. JPT P. 1451

A Laboratory Model Resembling the “Bishop-Wave” Phenomenon

A description is given of the flow of a three-layer system of immiscible fluids over an obstacle immersed in the lowest liquid. A tentative suggestion is offered that some features of the motion may be similar to the flow of air over the Sierra range near Bishop, California. Some arguments are advanced supporting this suggestion.