Sound propagation in capillary‐tube‐type porous media with small pores in the capillary walls

1991 ◽  
Vol 90 (6) ◽  
pp. 3299-3306 ◽  
Author(s):  
W. Patrick Arnott ◽  
James M. Sabatier ◽  
Richard Raspet
Keyword(s):  
Porous Media ◽  
Sound Propagation ◽  
Capillary Tube ◽  
Tube Type ◽  
Capillary Walls

Experimental Study of Wettability Alteration to Preferential Gas-Wetting in Porous Media and Its Effects

2000 ◽  
Vol 3 (02) ◽  
pp. 139-149 ◽  
Author(s):  
Li Kewen ◽  
Firoozabadi Abbas
Keyword(s):  
Porous Media ◽  
Oil Recovery ◽  
Capillary Tube ◽  
Gas Condensate ◽  
Water Flooding ◽  
Wettability Alteration ◽  
Glass Capillary ◽  
Gas Reservoirs ◽  
Gas Well ◽  
Gas Condensate Reservoirs

Summary In a recent theoretical study, Li and Firoozabadi [Li, K. and Firoozabadi, A.: "Phenomenological Modeling of Critical-Condensate Saturation and Relative Permeabilities in Gas-Condensate Systems," paper SPE 56014 available from SPE, Richardson, Texas (2000)] showed that if the wettability of porous media can be altered from preferential liquid-wetting to preferential gas-wetting, then gas-well deliverability in gas-condensate reservoirs can be increased. In this article, we present the results that the wettability of porous media may indeed be altered from preferential liquid-wetting to preferential gas-wetting. In the petroleum literature, it is often assumed that the contact angle through liquid-phase ? is equal to 0° for gas-liquid systems in rocks. As this work will show, while ? is always small, it may not always be zero. In laboratory experiments, we altered the wettability of porous media to preferential gas-wetting by using two chemicals, FC754 and FC722. Results show that in the glass capillary tube ? can be altered from about 50 to 90° and from 0 to 60° by FC754 for water-air and normal decane-air systems, respectively. While untreated Berea saturated with air has a 60% imbibition of water, its imbibition of water after chemical treatment is almost zero and its imbibition of normal decane is substantially reduced. FC722 has a more pronounced effect on the wettability alteration to preferential gas-wetting. In a glass capillary tube ? is altered from 50 to 120° and from 0 to 60° for water-air and normal decane-air systems, respectively. Similarly, because of wettability alteration with FC722, there is no imbibition of either oil or water in both Berea and chalk samples with or without initial brine saturation. Entry capillary pressure measurements in Berea and chalk give a clear demonstration that the wettability of porous media can be permanently altered to preferential gas-wetting. Introduction In a theoretical work,1 we have modeled gas and liquid relative permeabilities for gas-condensate systems in a simple network. The results imply that when one alters the wettability of porous media from strongly non-gas-wetting to preferential gas-wetting or intermediate gas-wetting, there may be a substantial increase in gas-well deliverability. The increase in gas-well deliverability of gas-condensate reservoirs is our main motivation for altering the wettability of porous media to preferential gas-wetting. Certain gas-condensate reservoirs experience a sharp drop in gas-well deliverability when the reservoir pressure drops below the dewpoint.2–4 Examples include many rich gas-condensate reservoirs that have a permeability of less than 100 md. In these reservoirs, it seems that the viscous forces alone cannot enhance gas-well deliverability. One may suggest removing liquid around the wellbore via phase-behavior effects through CO2 and propane injection. Both have been tried in the field with limited success; the effect of fluid injection around the wellbore for the removal of the condensate liquid is temporary. Wettability alteration can be a very important method for the enhancement of gas-well deliverability. If one can alter the wettability of the wellbore region to intermediate gas-wetting, gas may flow efficiently in porous media. As early as 1941, Buckley and Leverett5 recognized the importance of wettability on water flooding performance. Later, many authors studied the effect of wettability on capillary pressure, relative permeability, initial water saturation, residual oil saturation, oil recovery, electrical properties of reservoir rocks, reserves, and well stimulation.6–16 reported that it might be possible to improve oil displacement efficiency by wettability adjustment during water flooding. In 1967, Froning and Leach8 reported a field test in Clearfork and Gallup reservoirs for improving oil recovery by wettability alteration. Kamath9 then reviewed wettability detergent flooding. He noted that it was difficult to draw a definite conclusion regarding the success of detergent floods from the data available in the literature. Penny et al.12 presented a technique to improve well stimulation by changing the wettability for gas-water-rock systems. They added a surfactant in the fracturing fluid. This yielded impressive results; the production following cleanup after fracturing in gas wells generally was 2 to 3 times greater than field averages or offset wells treated with conventional techniques. Penny et al.12 believed that increased production was due to wettability alteration. However, they did not demonstrate that wettability had been altered. Recently, Wardlaw and McKellar17 reported that only 11% pore volume (PV) water imbibed into the Devonian dolomite samples with bitumen. The water imbibition test was conducted vertically in a dry core (saturated with air). Based on the imbibition experiments, they pointed out that many gas reservoirs in the western Alberta foothills of the Rocky Mountains were partially dehydrated and their wettability altered to a weakly water-wet or strongly oil-wet condition due to bitumen deposits on the pores. The water imbibition results of Wardlaw and McKellar17 demonstrated that the inappropriate hypothesis for wetting properties of gas reservoirs might lead to underestimation of hydrocarbon reserves.

Theory of sound propagation in porous media allowing for spatial dispersion

2012 ◽  
Vol 131 (4) ◽  
pp. 3292-3292
Author(s):  
Navid Nemati ◽  
Denis Lafarge ◽  
Aroune Duclos
Keyword(s):  
Porous Media ◽  
Spatial Dispersion ◽  
Sound Propagation

Flow of Oil-in-Water Emulsions Through Tubes and Porous Media

1979 ◽  
Vol 19 (06) ◽  
pp. 369-377 ◽  
Author(s):  
D.A. Alvarado ◽  
S.S. Marsden
Keyword(s):  
Porous Media ◽  
Crude Oil ◽  
Capillary Tube ◽  
Flow Behavior ◽  
Oil Field ◽  
Newtonian Fluids ◽  
Capillary Tubes ◽  
The Past ◽  
Oil In Water ◽  
Physical Laws

Abstract The flow of oil-in-water macroemulsions through both porous media and capillary tubes has been studied experimentally and described mathematically. Macroemulsions are those emulsions with most of their droplet diameters greater than I AM, which is the same order of magnitude as the pore constrictions. The emulsions were pumped with a positive displacement pump through several porous media and capillary tubes connected in series. The rheological behavior of macroemulsions with oil concentrations ranging from 10 to 70 vol% was obtained using capillary tube data. Emulsions with oil concentrations less than 50% behaved like Newtonian fluids, white those with concentrations greater than 50% behaved like pseudoplastic fluids. Viscoelastic effects were not observed for these fluids. A correlation, which uses both capillary and core flow data, was developed for describing the flow of non-Newtonian macroemulsions through porous media. This led to a general equation that reduced to Darcy's law for Newtonian fluids. The average relative error found when applying the method of correlation was +/- 4 %. Introduction The subject of emulsions is a broad field that includes many instances of application in industry. We are interested mainly in one specific area of application here - the oil industry. The study of emulsions has received considerable attention in petroleum research laboratories during the past 15 petroleum research laboratories during the past 15 years. The development of new methods of secondary recovery and the potential application of crude oil transportation through pipelines as stable emulsions have increased the number of research programs dealing with emulsions. programs dealing with emulsions. Macroemulsions, or ordinary emulsions, are dispersions of one liquid within another liquid. third component in an emulsion is the emulsifying agent or emulsifier, which has two principal functions:to decrease the interfacial tension between the liquids, thereby enabling easier formation of the greatly extended interface, andto stabilize the dispersed phase against coalescence once it is formed. With water or brine as one of the liquids, two types of emulsions are possible - oil-in-water (O/W) and water-in-oil (W/O) emulsions. Note that most of worlds's crude oil is produced in emulsion form. These emulsions are generally water-in-crude oil emulsions, which are more viscous than either of their constituents. Since we are interested only in maximum economical oil production, it is a common practice to separate emulsions production, it is a common practice to separate emulsions into their components, thereby obtaining reduced viscosity. This is accomplished in the oil field by using chemical and heat treatments. In contrast to W/O emulsions, O/W emulsions have lower viscosities than their oil constituent. This was considered by some investigators during the development of systems for producing and transporting crude oil as O/W emulsions. During the last decade or so, a number of new secondary oil recovery processes have been developed. These methods include the use of high-viscosity emulsions to displace oil, the use of emulsion slugs between the displacing fluid (water) and the displaced fluid (Oil), and controlled viscosity microemulsions. We see that, for an engineer to describe properly the flow behavior of emulsions in both pipelines and reservoirs, he must know the properties of emulsions and the physical laws properties of emulsions and the physical laws controlling their flow through tubes and porous media. The purpose of this research was to study the flow of O/W macroemulsions through both porous media and capillary tubes. The rheological characteristics of emulsions were analyzed by using capillary viscometers. SPEJ P. 369

scholarly journals Theory of sound propagation in superfluid-filled porous media

2002 ◽  
Vol 300 (6) ◽  
pp. 672-686 ◽  
Author(s):  
T. Buishvili ◽  
Sh. Kekutia ◽  
O. Tkeshelashvili ◽  
L. Tkeshelashvili
Keyword(s):  
Porous Media ◽  
Sound Propagation

Ultrasonic studies of liquid helium in porous media

1987 ◽  
Vol 65 (11) ◽  
pp. 1557-1559 ◽  
Author(s):  
J. R. Beamish ◽  
K. Warner
Keyword(s):  
Porous Media ◽  
Sound Propagation ◽  
Porous Ceramic ◽  
Ultrasonic Waves ◽  
Effective Density ◽  
Biot Theory ◽  
Fluid Density ◽  
Normal Fluid ◽  
Superfluid Fraction ◽  
Viscous Losses

We have studied the propagation of 12 MHz transverse ultrasonic waves in a porous ceramic containing liquid 4He. Both the sound velocity and the attenuation clearly show the superfluid nature of helium. The helium in the pores increases the system's effective density by an amount proportional to the normal-fluid density and so decreases the sound speed. The decoupling of the superfluid fraction below the lambda transition allows us to use the shear wave essentially as a "high-frequency torsional oscillator" to determine the superfluid density and pore tortuosity. The sound attenuation in this system is due to the same mechanism as for fourth sound, namely, viscous losses due to motion of the normal-fluid component. We observed an attenuation proportional to the normal-fluid density and compare this result to predictions of the Biot theory of sound propagation in fluid-filled porous media.

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