摘要:

A ternary pore geometry classification scheme for reservoir rocks places intergranular and intercrystalline porosity at a common pole. These porosity types tend to have well interconnected pores and usually are good reservoirs. Intragranular, moldic, and vuggy porosity are grouped at another pole of the classification triangle. Rocks with these porosity types usually have poorly interconnected pores and low permeability. Rocks with microporosity are grouped at the final pole of the triangle. These may be argillaceous sandstones, finely textured carbonates, diatomites,or tripolitic cherts. Water‐wet microporous rocks hold bound water. Rocks with significant amounts of microporosity and/or intragranular, moldic, and vuggy porosity need fractures, either natural or induced, to make an attractive reservoir. Fracture porosity may occur by itself or combined with any other porosity type. Reservoirs typically contain multiple pore types, although one type often predominates. Large scale cavernous features in carbonates occasionally contain oil.

ISSN:0094-243X    

DOI:10.1063/1.34299

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

This paper describes the generation, analysis, and some applications of dense random packings of hard spheres. Particular attention is given to descriptions of the microgeometry of these packings in terms of density, radial distribution functions, and polyhedral analysis.

ISSN:0094-243X    

DOI:10.1063/1.34302

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We consider a porous solid, or a gel, saturated by a two fluid system A+B, in the limit where the thickness &xgr; of the AB interface is smaller than the pore size D. The solid prefers to be in contact with one of the fluids (A). But, if we decrease the chemical potential of B, the B fluid enters the structure. We discuss thereversiblepenetration process.

ISSN:0094-243X    

DOI:10.1063/1.34303

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Measurements of the reflectance of composite materials consisting of random mixtures of Ag and KCl small particles have been made for frequencies from 10–43000 cm−1. The metal volume fraction in these samples was between 5% and 100%. The optical constants of the samples, obtained from Kramers‐Kronig analysis, are shown to agree qualitatively with calculations bsed on Bruggeman’s effective medium approximation.

ISSN:0094-243X    

DOI:10.1063/1.34304

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Relationships between the effective conductivity and bulk and shear moduli of two‐component composites are presented and discussed. Some new identities amongst the geometric parameters which link together these effective properties are given. It turns out the effective medium approximation is consistent with all the new results. This is because the approximation is exact, after certain limits have been taken, for a family of hierarchical models which are described here.

ISSN:0094-243X    

DOI:10.1063/1.34305

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Relationships between the effective conductivity and bulk and shear moduli of two‐component composites are presented and discussed. Some new identities amonst the geometric parameters which link together these effective properties are given. It turns out that the effective medium approximation is consistent with all the new results. This is because the approximation is exact, after certain limits have been taken, for a family of hierarchial models which are described here.

ISSN:0094-243X    

DOI:10.1063/1.34306

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Two distinct theories of the strength of porous solids may be found in the literature, one claiming that the volume of pores dictates strength, the other that the longest pores are crucial because they initiate cracks. Various empirical attempts have previously been made to reconcile these apparently conflicting arguments. This paper shows from first principles, using an energy balance method, that strength must depend on both pore volume and on maximum pore length. The theory was verified by measurements on an ideal porous glass, and was also shown to be useful in describing the behaviour of complex porous materials such as hydraulic cement.

ISSN:0094-243X    

DOI:10.1063/1.34307

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

Various aspects of acoustic propagation in macroscopically disordered, fluid‐saturated porous media are discussed. By treating the oscillatory displacements of the two constituents separately and on an equal footing one is able to describe the attenuation and dispersion of sound due to the relative motion that can occur between the fluid and solid parts. Because there are two degrees of freedom in the formulation, the phenomenological theory predicts two longitudinal modes. The diffusive mode in polymer gels, 4th sound in Heii, the diffusion of a fluid pressure pulse through a porous medium, and the recent observation of a slow compressional propagatory wave in water saturated glass beads, are all shown to be special cases of this additional mode. We show that it is possible to independently measure all the necessary input parameters of the theory, at least in the high frequency limit, and predict all the bulk modes that can propagate in fluid‐saturated porous systems. The predictions are in excellent agreement with our measured values.

ISSN:0094-243X    

DOI:10.1063/1.34308

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

We present a microscopic model for the dynamics of granular systems based on the Hertz‐Mindlin theory of inter‐grain contact forces. We argue that the requirement of rotational invariance implies that both thetranslationalandrotationalmotion of the individual grains must be taken into account. The new rotational degrees of freedom give rise to additional modes whose behavior is studied in ordered and disordered packings. In the limit of long wavelengths our normal mode calculations reproduce the earlier results of Mindlin (ordered packings) and Digby (disordered packings). We discuss experimental results on compressional and shear wave speeds in systems where the contact forces are generated by (hydrostatic and uniaxial) pressure.

ISSN:0094-243X    

DOI:10.1063/1.34292

出版商:AIP    

年代:1984

数据来源: AIP

摘要:

The index of refraction,n, has been measured for the sound mode which propagates in a superleak partially filled with liquid Heiiso that the liquid forms a film on the powder grains. Motivated by a model which treats the scattering from powder grains independently from the scattering from the powder grains independently from the scattering from the vapor spaces, we find that for filling fractionsf≳0.4 the data are well described byn2=P−&bgr;1f−&bgr;2with &bgr;1=0.67 and &bgr;2=1.29 and wherefis the fraction of the pore volume occupied with liquid HeiandPis the fraction of the volume occupied by both liquid and vapor He. Unusual behavior is observed for low filling fractions. Belowf=0.4nrises with decreasingfto a peak value of nearly 10 before dropping precipitously to a constant value of 3.7 in the limit of very thin films.

ISSN:0094-243X    

DOI:10.1063/1.34293

出版商:AIP    

年代:1984

数据来源: AIP