Simulation of fluid flow in the pore space of the core obtained by x-ray microtomography

2019 ◽  
Author(s):  
Evgeny Marfin ◽  
Denis Chachkov ◽  
Alexey Abdrashitov ◽  
Aidar Kadyirov
Keyword(s):  
X Ray ◽  
Author(s):  
Elena P. Osipova ◽  
◽  
Angela G. Astarkina ◽  
Sergey V. Astarkin ◽  
Daniil A. Strelnikov ◽  
...  

To assess the influence of zeolite group minerals on the migration of reservoir fluids in terrigenous deposits, complex (X-ray and gas-geochemical) studies of core material in the Yamal oil and gas region field were conducted. 54 core samples from the Pyakyakhinsky and Yuzhno-Messoyakhsky deposits were studied including 43 zeolitized and 11 non-zeolitized samples. The core samples were studied by gas chromatography to determine the content of hydrocarbons adsorbed in the pore space of the core, as well as by X-ray diffractometry to determine the mineral composition of the samples under study. The regularities of hydrocarbons distribution in the studied samples depending on the degree of their zeolization are established. The differences in the distribution of hydrocarbons in zeolitized and non-zeolitized siltstones have their own explanation. Having an ordered crystal structure and a certain size of the entrance windows zeolites are able to sorb.


2015 ◽  
Vol 55 (2) ◽  
pp. 468
Author(s):  
Hamed Lamei Ramandi ◽  
Peyman Mostaghimi ◽  
Ryan T. Armstrong ◽  
Christoph H. Arns ◽  
Mohammad Saadatfar ◽  
...  

A key parameter in determining the productivity and commercial success of coal seam gas wells is the permeability of individual seams. Laboratory testing of core plugs is commonly used as an indicator of potential seam permeability. The highly heterogeneous and stress-dependent nature of coal makes laboratory measurements difficult to perform and the results difficult to interpret. Consequently, permeability in coal is poorly understood. The permeability of coal at the core scale depends on the geometry, topology, connectivity, mineralisation and spatial distribution of the cleat system, and a better understanding of coal permeability, that and the factors that control this depends on having a better understanding and detailed characterisation of the system. The authors used high resolution micro-focus X-ray computed tomography and 2D-3D image registration techniques to overlay tomograms of the same core plug, with and without X-ray attenuating fluids present in the pore space, with 2D scanning electron microscope images to produce detailed 3D visualisations of the geometry and topology of the cleat systems in the coal plugs. Novel filtering algorithms were used to produce segmentations that preserve cleat aperture dimensions and together with large-scale fluid flow simulations, they performed directly on the images and were used to compute porosities and permeabilities. Image resolution and segmentation sensitivity studies are also described, which show that the core scale permeability is controlled by a small number of well-connected percolating cleats. The results of this study demonstrate the potential of simple image-based analysis techniques to provide rapid estimates of core plug permeabilities.


Author(s):  
Mohamed R. Khodja ◽  
Jun Li ◽  
Syed Rizwanullah Hussaini ◽  
Abdelwahab Z. Ali ◽  
Hani S. Al-Mukainah ◽  
...  

We describe a study focused on the absolute permeability of reservoir carbonate rocks from the Middle East and involving comparison of experimental data and numerical estimates obtained by combining digital-rock and Lattice-Boltzmann Methods (LBM). The question of the “representativeness” of the site at which the simulation is performed is addressed as follows. First, a low-resolution, CT X-ray scan of the core plug is performed to identify regions of large porosity (millimeter-sized vugs, etc.). These regions are then avoided to postselect smaller sites (site volume ~ 1 mm3) which are to be scanned at higher resolutions (voxel size < dominant pore-throat size of the core plug). A “representativeness” criterion based on an empirically-inspired “representativeness” measure (R-measure) is used to eliminate those sites for which R > b, where b is an upper bound (typically, b = 1). Essentially, the measure estimates how well the postselected sites capture the experimental porosity and the dominant pore-throat size of the core plug. This leads to a small set of sites for which the simulations are both computationally manageable and yield a reasonable estimate of the permeability: the experimental and predicted values differ by a factor of about 3 on average, which is a particularly significant result given the challenging heterogeneous pore space of carbonate samples. We believe the suggested methodology to be an adequate and practical way to circumvent upscaling.


Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3774 ◽  
Author(s):  
Linxian Gong ◽  
Lei Nie ◽  
Yan Xu

The pore geometry and topology properties of pore space in rocks are significant for a better understanding of the complex hydrologic and elastic properties. However, geometry and topology information about the sandstone pore structures is not fully available. In this study, we obtained the topological and geometrical pore parameters from a representative elementary volume (REV) for fluid flow in sandstone samples. For comparison, eight types of sandstones with various porosities were studied based on the X-ray micro-computed tomography technique. In this study, the REV size was selected based on the parameters from the respective pore network models (PNM), not just the porosity. Our analysis indicates that despite different porosity, all the sandstone samples have highly triangular-shaped pores and a high degree of pore structural isotropy. The high porosity group sandstones exhibit wider ranges of pore sizes than the low porosity group sandstones. Compared to the high porosity group sandstones, the low porosity group sandstones samples showing a higher global aspect ratio, indicating some pores exist in the form of bottlenecks. The pore topological properties of different sandstones show a high dependence of the porosity. The high porosity group sandstones obtain large coordination numbers, large connectivity densities and low tortuosities. The results from this study will help better understand the complex pore structure and the fluid flow in sandstone.


2020 ◽  
Author(s):  
Marat Korsik ◽  
Edwin Tse ◽  
David Smith ◽  
William Lewis ◽  
Peter J. Rutledge ◽  
...  

<p></p><p>We have discovered and studied a <i>tele</i>substitution reaction in a biologically important heterocyclic ring system. Conditions that favour the <i>tele</i>-substitution pathway were identified: the use of increased equivalents of the nucleophile or decreased equivalents of base, or the use of softer nucleophiles, less polar solvents and larger halogens on the electrophile. Using results from X-ray crystallography and isotope labelling experiments a mechanism for this unusual transformation is proposed. We focused on this triazolopyrazine as it is the core structure of the <i>in vivo </i>active anti-plasmodium compounds of Series 4 of the Open Source Malaria consortium.</p> <p> </p> <p>Archive of the electronic laboratory notebook with the description of all conducted experiments and raw NMR data could be accessed via following link <a href="https://ses.library.usyd.edu.au/handle/2123/21890">https://ses.library.usyd.edu.au/handle/2123/21890</a> . For navigation between entries of laboratory notebook please use file "Strings for compounds in the article.pdf" that works as a reference between article codes and notebook codes, also this file contain SMILES for these compounds. </p><br><p></p>


2019 ◽  
Vol 11 (1) ◽  
pp. 01025-1-01025-5 ◽  
Author(s):  
N. A. Borodulya ◽  
◽  
R. O. Rezaev ◽  
S. G. Chistyakov ◽  
E. I. Smirnova ◽  
...  

2019 ◽  
Vol 15 (S356) ◽  
pp. 280-284
Author(s):  
Angela Bongiorno ◽  
Andrea Travascio

AbstractXDCPJ0044.0-2033 is one of the most massive galaxy cluster at z ∼1.6, for which a wealth of multi-wavelength photometric and spectroscopic data have been collected during the last years. I have reported on the properties of the galaxy members in the very central region (∼ 70kpc × 70kpc) of the cluster, derived through deep HST photometry, SINFONI and KMOS IFU spectroscopy, together with Chandra X-ray, ALMA and JVLA radio data.In the core of the cluster, we have identified two groups of galaxies (Complex A and Complex B), seven of them confirmed to be cluster members, with signatures of ongoing merging. These galaxies show perturbed morphologies and, three of them show signs of AGN activity. In particular, two of them, located at the center of each complex, have been found to host luminous, obscured and highly accreting AGN (λ = 0.4−0.6) exhibiting broad Hα line. Moreover, a third optically obscured type-2 AGN, has been discovered through BPT diagram in Complex A. The AGN at the center of Complex B is detected in X-ray while the other two, and their companions, are spatially related to radio emission. The three AGN provide one of the closest AGN triple at z > 1 revealed so far with a minimum (maximum) projected distance of 10 kpc (40 kpc). The discovery of multiple AGN activity in a highly star-forming region associated to the crowded core of a galaxy cluster at z ∼ 1.6, suggests that these processes have a key role in shaping the nascent Brightest Cluster Galaxy, observed at the center of local clusters. According to our data, all galaxies in the core of XDCPJ0044.0-2033 could form a BCG of M* ∼ 1012Mȯ hosting a BH of 2 × 108−109Mȯ, in a time scale of the order of 2.5 Gyrs.


Virology ◽  
1995 ◽  
Vol 210 (1) ◽  
pp. 217-220 ◽  
Author(s):  
J.N. Burroughs ◽  
J.M. Grimes ◽  
P.P.C. Mertens ◽  
D.I. Stuart

1988 ◽  
Vol 16 (6) ◽  
pp. 949-953 ◽  
Author(s):  
JOHN P. PRIESTLE ◽  
HANS-PETER SCHÄR ◽  
MARKUS G. GRÜTTER

Summary The three-dimensional structure of human recombinant interleukin-1β has been determined at 0.24 nm resolution by X-ray crystallographic techniques. The partially refined model has a crystallographic R-factor of just under 19%. The structure is composed of 12 β-strands forming a complex network of hydrogen bonds. The core of the structure can best be described as a tetrahedron whose edges are each formed by two antiparallel β-strands. The interior of this structure is filled with hydrophobic side-chains. There is a 3-fold repeat in the folding of the polypeptide chain. Although this folding pattern suggests gene triplication, no significant internal sequence homology between topologically corresponding residues exists. The folding topology of interleukin-1β is very similar to that described by A. D. McLachlan [(1979) J. Mol. Biol. 133, 557–563] for soybean trypsin inhibitor.


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