Wyniki wyszukiwania - BazTech

1

Numerical approach in recognition of selected features of rock structure from hybrid hydrocarbon reservoir samples based on microtomography

Kaczmarek Ł. D., Zhao Y., Konietzky H., Wejrzanowski T., Maksimczuk M.

Studia Geotechnica et Mechanica

|

2017

|

Vol. 39, nr 1

13--26

EN

The study employs numerical calculations in the characterization of reservoir sandstone samples based on high-resolution X-ray computed microtomography. The major goals were to determine porosity through pore size distribution, permeability characterization through pressure field, and structure impact on rock strength by simulation of a uniaxial compression test. Two Miocene samples were taken from well S-3, located in the eastern part of the Carpathian Foredeep. Due to the relation between sample size and image resolution, two X-ray irradiation series with two different sample sizes were performed. In the first approach, the voxel side was 27 µm and in the second it was up to 2 µm. Two samples from different depths have been studied here. Sample 1 has petrophysical features of conventional reservoir deposits, in contrast to sample 2. The approximate grain size of sample 1 is in the range 0.1–1.0 mm, whereas for sample 2 it is 0.01–0.1 mm with clear sedimentation lamination and heterogenic structure. The porosity, as determined by µCT, of sample 1 is twice (10.3%) that of sample 2 (5.3%). The equivalent diameter of a majority of pores is less than 0.027 mm and their pore size distribution is unimodal right-hand asymmetrical in the case of both samples. In relations to numerical permeability tests, the flow paths are in the few privileged directions where the pressure is uniformly decreasing. Nevertheless, there are visible connections in sample 1, as is confirmed by the homogenous distribution of particles in the pore space of the sample and demonstrated in the particle flow simulations. The estimated permeability of the first sample is approximately four times higher than that of the second one. The uniaxial compression test demonstrated the huge impact of even minimal heterogeneity of samples in terms of micropores: 4–5 times loss of strength compared to the undisturbed sample. The procedure presented shows the promising combination of microstructural analysis and numerical simulations. More specific calculations of lab tests with analysis of variable boundary conditions should be performed in the future.

2

High-resolution computed microtomography for the characterization of a diffusion tensor imaging phantom

Kaczmarek Ł., Wejrzanowski T., Skibiński J., Maksimczuk M., Krzyżak A.

Acta Geophysica

|

2017

|

Vol. 65, no. 1

259--268

EN

This paper addresses the issue of the quantitative characterization of the structure of the calibration model (phantom) for b-matrix spatial distribution diffusion tensor imaging (BSD-DTI) scanners. The aim of this study was to verify manufacturing assumptions of the structure of materials, since phantoms are used for BSD-DTI calibration directly after manufacturing. Visualization of the phantoms’ structure was achieved through optical microscopy and high-resolution computed microtomography (µCT). Using µCT images, a numerical model of the materials structure was developed for further quantitative analysis. 3D image characterization was performed to determine crucial structural parameters of the phantom: porosity, uniformity and distribution of equivalent diameter of capillary bundles. Additionally calculations of hypothetical flow streamlines were also performed based on the numerical model that was developed. The results obtained in this study can be used in the calibration of DTI-BST measurements. However, it was found that the structure of the phantom exhibits flaws and discrepancies from the assumed geometry which might affect BSD-DTI calibration.

3

The use of X-ray computed microtomography for graptolite detection in rock based on core internal structure visualization

Kaczmarek Ł., Kozłowska A., Maksimczuk M., Wejrzanowski T.

Acta Geologica Polonica

|

2017

|

Vol. 67, no. 2

299--306

EN

This paper presents for the first time X-ray computed microtomography (μCT) analysis as a technique for Silurian graptolite detection in rocks. The samples come from the Jantar Bituminous Claystones Member of the Opalino core, Baltic Basin, northern Poland. Images were obtained with spatial resolution of 25 μm, which enabled the authors to create a 3-D visualization and to calculate the ratio of fissure and graptolite volume to the total sample volume. A set of μCT slices was used to create a 3-D reconstruction of graptolite geometry. These μCT slices were processed to obtain a clearly visible image and the volume ratio. A copper X-ray source filter was used during exposure to reduce radiograph artifacts. Visualization of graptolite tubaria (rhabdosomes) enabled Demirastrites simulans to be identified. Numerical models of graptolites reveal promising applications for paleontological research and thus for the recognition and characterization of reservoir rocks.

4

Wykorzystanie wysokorozdzielczej mikrotomografii komputerowej oraz analizy ultradźwiękowej w charakterystyce struktury paleozoicznych gazonośnych łupków z basenu bałtyckiego

Kaczmarek Ł., Maksimczuk M., Wejrzanowski T., Łukasiak D.

Nafta-Gaz

|

2015

|

R. 71, nr 12

1017--1023

PL

W artykule przedstawiono metodykę badań próbek z horyzontów perspektywicznych dla eksploatacji łupków gazonośnych z polskiej części basenu bałtyckiego. Do badań wykorzystano wysokorozdzielczą mikrotomografię komputerową (µCT) oraz pomiar czasu przejścia fal ultradźwiękowych przez próbki. Uzyskany rozmiar piksela obrazu µCT dla próbek o większych rozmiarach wynosił 25 µm, natomiast dla niewielkich fragmentów próbek było to 5 µm. W badaniach ultradźwiękowych czynnikiem o dominującym wpływie na uzyskiwane wyniki okazała się szczelinowatość, która oddziaływała tłumiąco na propagację fal. Na podstawie analizy µCT określono procentowy udział szczelin w próbkach (średnia 0,82%) oraz przekroje przedstawiające strukturę wewnętrzną próbek z morfologią szczelin. Na podstawie prędkości propagacji fal ultradźwiękowych przez próbki obliczono dynamiczne parametry modułu Younga (zakres wyników 22÷57 GPa) oraz współczynnika Poissona (0,21÷0,40). Otrzymane wyniki wskazują na wysoką przydatność stosowania analiz ultradźwiękowych oraz wysokorozdzielczej tomografii komputerowej jako badań uzupełniających się.

EN

The article presents the methodology of characterization research of samples from prospective horizons for the exploitation of shale gas from Polish part of the Baltic Basin. High-resolution computed microtomography (μCT) and ultrasonic technique were used for the analysis. The resulting pixel size of μCT image for larger samples were 25 microns, while for small fragments of samples pixel size were 5 microns. In ultrasonic tests, fissures had a dominant impact on acoustic waves propagation. Extensive fissures surface resulted in attenuation of ultrasonic waves. Based on the μCT analysis, percentage content of fissures in the samples (average 0.82%) were determined. Furthermore a cross-section of specimens revealed the internal structure and morphology of fissures. Dynamic parameters of Young’s modulus (range 22÷57 GPa) and Poisson’s ratio (0.21÷0.40) were calculated, by converting the process of propagation velocity of ultrasonic waves through the samples. Results indicate the suitability of the use of ultrasonic analysis and μCT as complementary tests.

5

Strukturalna analiza mioceńskich piaskowców z zapadliska przedkarpackiego za pomocą wysokorozdzielczej mikrotomografii komputerowej

Kaczmarek Ł., Machowski G., Maksimczuk M., Wejrzanowski T.

Nafta-Gaz

|

2015

|

R. 71, nr 9

647--654

PL

Artykuł przedstawia wyniki wykorzystania wysokorozdzielczej mikrotomografii komputerowej w analizie strukturalnej oraz ilościowej przestrzeni porów i szczelin w piaskowcach mioceńskich. Dodatkowo wykonano badanie przepuszczalności analizowanych skał. Próbki zostały pobrane z odwiertu S-3, zlokalizowanego we wschodniej części zapadliska przedkarpackiego. W celu przeprowadzenia badania wykonano dwie serie naświetlania rentgenowskiego próbek. Pierwszy zestaw próbek został wytypowany dla uzyskania przestrzennego rozkładu ziaren, porów oraz szczelin. Długość boku woksela (tzn. najmniejszego elementu objętości) w tym etapie badań wynosiła około 26 μm. Drugi zestaw naświetlania został wykonany dla zobrazowania elementów strukturalnych o wielkościach od około 3 μm do 26 μm oraz cech petrofizycznych. Wynikiem przeprowadzonych badań jest charakterystyka analizowanych skał, która umożliwia podział próbek na dwie grupy. Pierwsza grupa próbek posiada cechy strukturalne oraz petrofizyczne typowe dla skał złóż konwencjonalnych, natomiast druga grupa – dla skał złóż typu niekonwencjonalnego. Właściwe rozpoznanie parametrów petrofizycznych każdego typu złoża stanowi kluczowy element optymalizacji procesu jego udostępniania.

EN

The article presents results of high-resolution computed microtomography use in the structural analysis and quantification of pores and fractures in Miocene sandstones. Furthermore, the permeability studies of rocks were performed. Miocene samples were taken from well S-3, located in the eastern part of the Carpathian Foredeep. For the aforementioned analysis two series of X-ray irradiation were performed. The first set of samples was selected to obtain the spatial distribution of grains, pores and fractures. At this stage of the study, the length of the voxel side amounted to approx. 26 μm. The second set of X-ray exposure was performed to reveal structural elements and petrophysical characteristics of sizes ranging from approx. 3 μm to 26 μm. The result of performed characteristics is the division of samples into two groups. The first group of samples has structural and petrophysical features of rocks typical for conventional reservoir deposits, while the second – for the unconventional type. Appropriate identification of petrophysical parameters of the formation is a key element for the optimization of the reservoir development.