scholarly journals X-Ray CT analyses, models and numerical simulations – a comparison with common analytical methods of an experimental CO<sub>2</sub> study

2016 ◽  
Author(s):  
Steven Henkel ◽  
Dieter Pudlo ◽  
Frieder Enzmann ◽  
Viktor Reitenbach ◽  
Daniel Albrecht ◽  
...  
Keyword(s):  
High Resolution ◽  
Numerical Simulations ◽  
Analytical Methods ◽  
Rock Properties ◽  
Similar Data ◽  
Sample Material ◽  
Thin Sections ◽  
Deutschland Gmbh ◽  
Before And After ◽  
Reservoir Sandstones

Abstract. An essential part of the collaborative research project H2STORE ("hydrogen to store"), which is founded by the German government, was a comparison of various analytical methods to characterize reservoir sandstones from different stratigraphic units. In this context Permian, Triassic and Tertiary reservoir sandstones were analysed. Rock core materials, provided by RWE Gasspeicher GmbH (Dortmund), GFD Suez E&amp;P Deutschland GmbH (Lingen), E.ON Gas Storage GmbH (Essen) and RAG Rohöl-Aufsuchungs Aktiengesellschaft (Wien), was processed by different laboratory techniques; thin sections were prepared, rock fragments were crushed, cubes of 1 cm edge length and plugs of 5 cm in length were sawn from macroscopic homogenous cores. With this prepared sample material, polarized light microscopy and scanning electron microscopy – coupled with image analyses, specific surface area measurements (BET), He-porosity and N2-permeability measurements and high resolution micro-computer-tomography (µ-CT), which were used for numerical simulations were conducted. All these methods were applied to most of the same sample material, before and after static CO2 experiments under reservoir conditions. A major concern in comparing the results of these methods is an appraisal of the reliability of the given porosity, permeability and mineral specific reactive (inner) surface areas data. The CO2 experiments are modifying the petrophysical as well the mineralogical/geochemical rock properties. These changes are detectable by all applied analytical methods. Nevertheless, a major outcome of the high resolution µ-CT analyses and proceeded numerical data simulations results in quite similar data sets and data interpretations maintained by the different standard methods; even regarding only CT-single scan of the rock samples. Moreover, this technique is not only time saving, but also none destructive. This is an important point, if only minor sample material is available and a detailed comparison before and after the experimental tests on micro meter, pore scale of specific rock features is envisaged.

scholarly journals X-ray CT analyses, models and numerical simulations: a comparison with petrophysical analyses in an experimental CO<sub>2</sub> study

Solid Earth ◽  
2016 ◽  
Vol 7 (3) ◽  
pp. 917-927 ◽  
Author(s):  
Steven Henkel ◽  
Dieter Pudlo ◽  
Frieder Enzmann ◽  
Viktor Reitenbach ◽  
Daniel Albrecht ◽  
...  
Keyword(s):  
High Resolution ◽  
Numerical Simulations ◽  
Surface Area ◽  
Analytical Methods ◽  
Rock Properties ◽  
Similar Data ◽  
Sample Material ◽  
Thin Sections ◽  
Deutschland Gmbh ◽  
Reservoir Sandstones

Abstract. An essential part of the collaborative research project H2STORE (hydrogen to store), which is funded by the German government, was a comparison of various analytical methods for characterizing reservoir sandstones from different stratigraphic units. In this context Permian, Triassic and Tertiary reservoir sandstones were analysed. Rock core materials, provided by RWE Gasspeicher GmbH (Dortmund, Germany), GDF Suez E&amp;P Deutschland GmbH (Lingen, Germany), E.ON Gas Storage GmbH (Essen, Germany) and RAG Rohöl-Aufsuchungs Aktiengesellschaft (Vienna, Austria), were processed by different laboratory techniques; thin sections were prepared, rock fragments were crushed and cubes of 1 cm edge length and plugs 3 to 5 cm in length with a diameter of about 2.5 cm were sawn from macroscopic homogeneous cores. With this prepared sample material, polarized light microscopy and scanning electron microscopy, coupled with image analyses, specific surface area measurements (after Brunauer, Emmet and Teller, 1938; BET), He-porosity and N2-permeability measurements and high-resolution microcomputer tomography (μ-CT), which were used for numerical simulations, were applied. All these methods were practised on most of the same sample material, before and on selected Permian sandstones also after static CO2 experiments under reservoir conditions. A major concern in comparing the results of these methods is an appraisal of the reliability of the given porosity, permeability and mineral-specific reactive (inner) surface area data. The CO2 experiments modified the petrophysical as well as the mineralogical/geochemical rock properties. These changes are detectable by all applied analytical methods. Nevertheless, a major outcome of the high-resolution μ-CT analyses and following numerical data simulations was that quite similar data sets and data interpretations were maintained by the different petrophysical standard methods. Moreover, the μ-CT analyses are not only time saving, but also non-destructive. This is an important point if only minor sample material is available and a detailed comparison before and after the experimental tests on micrometre pore scale of specific rock features is envisaged.

Predicting elastic properties and permeability of rocks from 2D thin sections

2018 ◽  
Vol 37 (6) ◽  
pp. 421-427 ◽  
Author(s):  
Nattavadee Srisutthiyakorn ◽  
Sander Hunter ◽  
Rituparna Sarker ◽  
Ronny Hofmann ◽  
Irene Espejo
Keyword(s):  
High Resolution ◽  
Elastic Properties ◽  
Rock Physics ◽  
Depositional Environments ◽  
Rock Properties ◽  
Thin Sections ◽  
2D Simulation ◽  
Computed Tomography Images ◽  
The Difference ◽  
Third Dimension

Predicting rock elastic properties and permeability from high-resolution 2D thin sections has been a challenging problem in rock physics because the 2D thin sections reveal very little about how the microstructure connects in the third dimension. However, 2D thin sections are widely available and inexpensive because they are often produced as a part of the reservoir-quality workflow. Furthermore, they have much higher resolution and greater field of view than micro X-ray computed tomography images, which are commonly used for rock properties estimation. The 2D thin sections we studied are from various hydrocarbon-bearing clastic formations with a variety of provenances, depositional environments, and burial histories. The high-resolution 2D images were scanned from these physical 2D thin sections. K-means segmentation was then employed to identify different minerals and pores for creating 2D binary images. The focus of this study is to simulate 2D elastic properties and permeability from 2D thin sections and then to employ various empirical relations to transform these 2D simulation results to 3D intrinsic rock properties. We compared the rock properties from this process to those from core measurements and measured wireline logs and found that these 2D to 3D rock property transformations yield promising results, especially for elastic properties. The results show that 2D thin section images have high enough resolution to resolve grain contacts very well. Predicting the permeability from 2D thin sections is still challenging since the process requires fitting the physical equation in order to retrieve the fitting coefficient for prediction due to our lack of understanding of the difference between 2D and 3D pore size distribution.

Digital reconstruction of reservoir sandstones to predict hydraulic and mechanical rock properties

2021 ◽  
Author(s):  
Maria Wetzel ◽  
Thomas Kempka ◽  
Michael Kühn
Keyword(s):  
Numerical Simulations ◽  
Mineral Content ◽  
Practical Importance ◽  
Rock Physics ◽  
Mineral Dissolution ◽  
Rock Properties ◽  
Digital Rock Physics ◽  
Digital Rock ◽  
Reservoir Sandstones ◽  
The Impact

&lt;p&gt;Quantifying trends in hydraulic and mechanical properties of reservoir sandstones has a wide practical importance for many applications related to geological subsurface utilization. In that regard, predicting macroscopic rock properties requires detailed information on their microstructure [1]. In order to fundamentally understand the pore-scale processes governing the rock behaviour, digital rock physics represents a powerful and flexible approach to investigate essential rock property relations [2]. This was shown, e.g., for hydraulic effects of anhydrite cement in the Bentheim sandstone in relation to an unsuccessful drilling campaign at the geothermal well Allerm&amp;#246;he, Germany [3]. Rock weakening due to decreasing calcite mineral content was also demonstrated by application of numerical simulations [4].&amp;#160;&lt;/p&gt;&lt;p&gt;In the present study, a process-based method is used for reconstructing the full 3D microstructure of three typical reservoir reference rocks: the Fontainebleau, Berea and Bentheim sandstones. For that purpose, grains are initially deposited under the influence of gravity and afterwards diagenetically consolidated. The resulting evolution in porosity, permeability and rock stiffness is examined and compared to the respective micro-CT scans of the sandstones. The presented approach enables to efficiently generate synthetic sandstone samples over a broad range of porosities, comprising the microstructural complexity of natural rocks and considering any desired size, sorting and shape of grains. In view of a virtual laboratory, these synthetic samples can be further altered to examine the impact of mineral dissolution and/or precipitation as well as fracturing on various petrophysical correlations, what is of particular relevance for a sustainable exploration and utilisation of the geological subsurface.&lt;/p&gt;&lt;p&gt;[1] Wetzel M., Kempka T., K&amp;#252;hn M. (2017): Predicting macroscopic elastic rock properties requires detailed information on microstructure. Energy Procedia, 125, 561-570. DOI: 10.1016/j.egypro.2017.08.195&amp;#160;&lt;br&gt;[2] Wetzel M., Kempka T., K&amp;#252;hn M. (2020): Hydraulic and mechanical impacts of pore space alterations within a sandstone quantified by a flow velocity-dependent precipitation approach. Materials, 13, 4, 3100. DOI: 10.3390/ma13143100&lt;br&gt;[3] Wetzel M., Kempka T., K&amp;#252;hn M. (2020): Digital rock physics approach to simulate hydraulic effects of anhydrite cement in Bentheim sandstone. Advances in Geosciences, 54, 33-39. DOI: 10.5194/adgeo-54-33-2020&amp;#160;&lt;br&gt;[4] Wetzel M., Kempka T., K&amp;#252;hn M. (2018): Quantifying rock weakening due to decreasing calcite mineral content by numerical simulations. Materials, 11, 542. DOI: 10.3390/ma11040542&amp;#160;&lt;/p&gt;

The High Resolution Appearance of Biological Substrates

1969 ◽  
Vol 27 ◽  
pp. 416-417
Author(s):  
Glen B. Haydon
Keyword(s):  
High Resolution ◽  
Phase Image ◽  
Biological Structure ◽  
Electron Microscopic ◽  
Thin Sections ◽  
Resolution Electron ◽  
Discrete Structures ◽  
Large Phase ◽  
Biological Substrates ◽  
High Resolution Electron Micrographs

High resolution electron microscopic study of negatively stained macromolecules and thin sections of tissue embedded in a variety of media are difficult to interpret because of the superimposed phase image granularity. Although all of the information concerning the biological structure of interest may be present in a defocused electron micrograph, the high contrast of large phase image granules produced by the substrate makes it impossible to distinguish the phase ‘points’ from discrete structures of the same dimensions. Theory predicts the findings; however, it does not allow an appreciation of the actual appearance of the image under various conditions. Therefore, though perhaps trivial, training of the cheapest computer produced by mass labor has been undertaken in order to learn to appreciate the factors which affect the appearance of the background in high resolution electron micrographs.

The ultrastructure of the double membrane-bound bodies and endoplasmic reticulum in serial sections of wheat spot mosaic-affected wheat plants

1990 ◽  
Vol 48 (3) ◽  
pp. 694-695
Author(s):  
M. H. Chen ◽  
C. Hiruki
Keyword(s):  
Endoplasmic Reticulum ◽  
High Resolution ◽  
Membrane Structure ◽  
Mosaic Disease ◽  
Serial Sections ◽  
Thin Sections ◽  
Double Membrane ◽  
Southern Alberta ◽  
Membrane Bound ◽  
Scanning Em

Wheat spot mosaic disease was first discovered in southern Alberta, Canada, in 1956. A hitherto unidentified disease-causing agent, transmitted by the eriophyid mite, caused chlorosis, stunting and finally severe necrosis resulting in the death of the affected plants. Double membrane-bound bodies (DMBB), 0.1-0.2 μm in diameter were found to be associated with the disease.Young tissues of leaf and root from 4-wk-old infected wheat plants were fixed, dehydrated, and embedded in Spurr’s resin. Serial sections were collected on slot copper grids and stained. The thin sections were then examined with a Hitachi H-7000 TEM at 75 kV. The membrane structure of the DMBBs was studied by numbering them individually and tracing along the sections to see any physical connection with endoplasmic reticulum (ER) membranes. For high resolution scanning EM, a modification of Tanaka’s method was used. The specimens were examined with a Hitachi Model S-570 SEM in its high resolution mode at 20 kV.

scholarly journals PTU-151 High Resolution Manometry Profile of Hiatal Hernia in Patients before and after Fundoplication: Abstract PTU-151 Table

Gut ◽  
2013 ◽  
Vol 62 (Suppl 1) ◽  
pp. A109.2-A110 ◽  
Author(s):  
K Bilnik ◽  
E Klimacka-Nawrot ◽  
J Kurek ◽  
B Blonska-Fajfrowska ◽  
A Stadnicki
Keyword(s):  
High Resolution ◽  
Hiatal Hernia ◽  
High Resolution Manometry ◽  
Before And After

scholarly journals High-resolution Manometry in Patients with Gastroesophageal Reflux Disease Before and After Fundoplication

2017 ◽  
Vol 23 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Katarzyna Rerych ◽  
Józef Kurek ◽  
Ewa Klimacka-Nawrot ◽  
Barbara Błońska-Fajfrowska ◽  
Antoni Stadnicki
Keyword(s):  
High Resolution ◽  
Gastroesophageal Reflux Disease ◽  
Gastroesophageal Reflux ◽  
Reflux Disease ◽  
High Resolution Manometry ◽  
Before And After

scholarly journals Dynamics of Erosion and Deposition in a Partially Restored Valley-Bottom Gully

Land ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 62
Author(s):  
Alberto Alfonso-Torreño ◽  
Álvaro Gómez-Gutiérrez ◽  
Susanne Schnabel
Keyword(s):  
High Resolution ◽  
Sediment Deposition ◽  
Aerial Images ◽  
Valley Bottom ◽  
Erosion And Deposition ◽  
Channel Dynamics ◽  
Check Dams ◽  
Before And After ◽  
Multi Temporal ◽  
Spatio Temporal

Gullies are sources and reservoirs of sediments and perform as efficient transfers of runoff and sediments. In recent years, several techniques and technologies emerged to facilitate monitoring of gully dynamics at unprecedented spatial and temporal resolutions. Here we present a detailed study of a valley-bottom gully in a Mediterranean rangeland with a savannah-like vegetation cover that was partially restored in 2017. Restoration activities included check dams (gabion weirs and fascines) and livestock exclosure by fencing. The specific objectives of this work were: (1) to analyze the effectiveness of the restoration activities, (2) to study erosion and deposition dynamics before and after the restoration activities using high-resolution digital elevation models (DEMs), (3) to examine the role of micro-morphology on the observed topographic changes, and (4) to compare the current and recent channel dynamics with previous studies conducted in the same study area through different methods and spatio-temporal scales, quantifying medium-term changes. Topographic changes were estimated using multi-temporal, high-resolution DEMs produced using structure-from-motion (SfM) photogrammetry and aerial images acquired by a fixed-wing unmanned aerial vehicle (UAV). The performance of the restoration activities was satisfactory to control gully erosion. Check dams were effective favoring sediment deposition and reducing lateral bank erosion. Livestock exclosure promoted the stabilization of bank headcuts. The implemented restoration measures increased notably sediment deposition.

scholarly journals Rip current evidence by hydrodynamic simulations, bathymetric surveys and UAV observation

2017 ◽  
Author(s):  
Guido Benassai ◽  
Pietro Aucelli ◽  
Giorgio Budillon ◽  
Massimo De Stefano ◽  
Diana Di Luccio ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Numerical Simulations ◽  
Current System ◽  
Current Evidence ◽  
Rip Current ◽  
Rip Currents ◽  
Transport Pathways ◽  
Fine Sediments ◽  
Scientific Challenge

Abstract. The prediction of the formation, spacing and location of rip currents is a scientific challenge that can be achieved by means of different complementary methods. In this paper the analysis of numerical and experimental data, including UAV observation, allowed to detect the presence of rip currents and rip channels at the mouth of Sele river, in the Gulf of Salerno, southern Italy. The dataset used to analyze these phenomena consisted of two different bathymetric surveys, a detailed sediment 5 analysis and a set of high-resolution wave numerical simulations, completed with satellite and UAV observation. The grain size trend analysis and the numerical simulations allowed to identify the rip current system, forced by topographically constrained channels incised on the seabed, which were detected by high resolution bathymetric surveys. The study evidenced that on the coastal area of the Sele mouth grain-size trends are controlled by the contribution of fine sediments, which exhibit suspended transport pathways due to rip currents and longshore currents. The results obtained were confirmed by satellite and UAV 10 observations in different years.

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