this paper proposes an extension of markov chain model to characterize of geological formations and to make conditioning on any number of well data possible. in this study, lithofacies cycles of the amiran formation at type and pirshamsedin sections are examined by markov method and entropy analysis as well as field observations, and depositional environment has interpreted by proposed ideal se...

A general analysis of poroelasticity for vertical transverse isotropy (VTI) shows that four eigenvectors are pure shear modes with no coupling to the pore-fluid mechanics. The remaining two eigenvectors are linear combinations of pure compression and uniaxial shear, both of which are coupled to the fluid mechanics. After reducing the problem to a 2 × 2 system, the analysis shows in a relatively...

In order to study the impact of on sandstone, dynamic is conducted sandstone through drop hammer test, wave velocity test impacted specimen by using instrument, and damage effect analyzed calculation formula. The results show that greater velocity, smaller measured sandstone.

A simulated annealing algorithm is employed to generate a stochastic model for a Berea sandstone and a Fontainebleau sandstone, with each a prescribed two-point probability function, lineal-path function, and "pore size" distribution function, respectively. We find that the temperature decrease of the annealing has to be rather quick to yield isotropic and percolating configurations. A comparis...

The present study investigated the distribution and abundance of epibenthic molluscs and their feeding habits associated to substrate features (coverage and rugosity) in a sandstone reef system in the Northeast of Brazil. Rugosity, low coral cover and high coverage of zoanthids and fleshy alga were the variables that influenced a low richness and high abundance of a few molluscan species in the...

We simulate transport of a solute through three-dimensional images of different rock samples, with resolutions of a few microns, representing geological media of increasing pore-scale complexity: a sandpack, a Berea sandstone, and a Portland limestone. We predict the propagators (concentration as a function of distance) measured on similar cores in nuclear magnetic resonance experiments and the...

Compaction bands are localized, planar zones of compressed material that form perpendicular to the maximum compressive stress. Compaction bands have been observed in porous sandstone formations in the field and in laboratory compression tests on porous sandstone, plaster, glass beads, polycarbonate honeycombs and metal foams. Because the permeability of the compacted material is much reduced, c...

A study was undertaken to determine why bacteria could penetrate lengths of consolidated sandstone (Berea) faster when the sandstone was sterilized by autoclaving than when dry heat (150 degrees C, 3 h) was used. Changes in permeability, porosity, and pore entrance size of the rock as a result of autoclaving were not sufficient to explain the differences in penetration times observed, but elect...