Micro-CT in geosciences: Getting the inside story. Wesley De Boever

Transcription

1 Micro-CT in geosciences: Getting the inside story Wesley De Boever November 24, 2016

2 Bruker microct Micro-CT scanner manufacturer Life science and material science Hardware and software Headquarters in Kontich, Belgium Part of Bruker group Worldwide supplier of analytical equipment 6000 employees November 24,

3 Introduction What is (micro)-ct? Computed tomography is a non-destructive 3D imaging and analysis technique Study the internal structure of all types of samples Organic material to metals Living organisms to fossils Sample diameters from 1 mm to 20 cm Micro-CT X-rays from an X-ray tube with a spot size of a few micrometres November 24, 2016

4 Introduction What is micro-ct? X-rays can penetrate matter Differential absorption reveals internal structure 2D projections = radiographies Sample X-ray source X-ray source November 24, 2016

5 Introduction What is micro-ct? X-rays can penetrate matter Differential absorption reveals internal structure 2D projections = radiographies X-ray source X-ray source November 24, 2016

6 Introduction What is micro-ct? X-rays can penetrate matter Differential absorption reveals internal structure Computed tomography 100s to 1000s of radiographies over many angles November 24, 2016

7 Introduction What is micro-ct? Laboratory micro-ct Source and detector are fixed. Sample rotates X-ray source X-ray source R d 1 1 M M s M SDD SOD R: Voxel size d: resolution detector s: spot size X-ray source M: magnification November 24, 2016

8 Introduction What is micro-ct? Laboratory micro-ct Resolutions down to ± 400 nm Most systems rely on geometric magnification. X-ray source X-ray source R d 1 1 M M s M SDD SOD R: Voxel size d: resolution detector s: spot size X-ray source M: magnification November 24, 2016

9 Introduction What is micro-ct? Laboratory micro-ct Resolution depends on sample size X-ray source X-ray source R d 1 1 M M s M SDD SOD R: Voxel size d: resolution detector s: spot size X-ray source M: magnification November 24, 2016

10 Introduction What is micro-ct? Laboratory micro-ct Resolution depends on sample size But region of interest scanning is possible X-ray source X-ray source R d 1 1 M M s M SDD SOD R: Voxel size d: resolution detector s: spot size X-ray source M: magnification November 24, 2016

11 Introduction What is micro-ct? Laboratory micro-ct Take 1000s of projections Backprojection into virtual space November 24, 2016

12 Introduction What is micro-ct? Fe oxides Reconstructed slices grey values represent differences in attenuation density and atomic number. Quartz (SiO 2 ) Feldspars (Ca,Na)Al 2 Si 2 O 8 Pores 2 mm 500 µm Vosges Sandstone 2 mm sample size 1 µm voxel size November 24, 2016

13 Introduction What is micro-ct? Reconstructed slices grey values represent differences in attenuation density and atomic number. November 24, mm Estaillades limestone 4 mm sample size 5 µm voxel size

14 Introduction What is micro-ct? Reconstructed slices Stack of slices forms a 3D volume 1 mm November 24, 2016

15 Applications Micro-CT in geosciences Mature technology applications already 20 years ago. Throughout all fields of geosciences Oil and gas Sedimentology Structural geology Construction materials Geochemistry Paleontology November 24,

16 Applications Micro-CT in geosciences Review papers on the technology Ketcham & Carlson (2001). Acquisition, optimiziation and interpretation of {X}-ray computed tomography imagery: applications to the geosciences. Computers & Geosciences, 27, Mees, Swennen, Van Geet, Jacobs (2003). Applications of X-ray computed tomography in the Geosciences. Geological society, London, Special Publications Volume 215. Wildenschild & Sheppard (2013). X-ray imaging and analysis techniques for quantifying porescale structure and processes in subsurface porous medium systems. Advances in Water Resources, 51, Cnudde & Boone (2013). High-resolution X-ray computed tomography in geosciences: A review of the current technology and applications. Earth-Science Reviews, 123, Noiriel (2015). Resolving time-dependent evolution of Pore-Scale Structure, Permeability and Reactivity using X-ray Microtomography. Reviews in Mineralogy and Geochemistry, 80, Similar papers can be found for each sub-domain of geosciences. November 24,

17 Micro-CT Systems November 24,

18 Micro-CT Systems Desktop micro-ct systems Small footprint Maintenance free High ease of use Laboratory micro-ct systems Large cabinet High flexibility Best resolution Differences between systems: X-ray energy Resolution (pixel size and X-ray spot size) Maximum sample size November 24,

19 Micro-CT Systems Desktop micro-ct systems Skyscan1272 High resolution Skyscan1173 High energy Skyscan1275 Automated, high throughput Laboratory micro-ct systems Large cabinet High flexibility Best resolution Voxel size down to 0.4 µm X-ray energy 100 kev November 24,

20 Micro-CT Systems Desktop micro-ct systems Skyscan1272 High resolution Skyscan1173 High energy Skyscan1275 Automated, high throughput Laboratory micro-ct systems Large cabinet High flexibility Best resolution X-ray energy 130 kev Voxel size down to ~5 µm November 24,

21 Micro-CT Systems Desktop micro-ct systems Skyscan1272 High resolution Skyscan1173 High energy Skyscan1275 Automated, high throughput Laboratory micro-ct systems Large cabinet High flexibility Best resolution X-ray energy 100 kev Voxel size down to 4.5 µm November 24,

22 200 cm Micro-CT Systems Desktop micro-ct systems 1272 High resolution 1173 High energy 1275 Automated, high throughput Laboratory micro-ct systems SkyScan2211 X-ray energy up to 190 kev Voxel size down to 0.1 µm X-ray spot size 500 nm 2 X-ray detectors November 24,

23 Results Quantitative 3D analysis Acquisition and reconstruction Image processing filtering Segmentation Dividing images into different phases Determination of parameters of interest in 3D Porosity and pore network properties Amount of mineral phase X Grain size shape orientation sphericity Results November 24,

24 Results Quantitative 3D analysis November 24,

25 Micro-CT Main advantages for geological applications November 24,

26 Micro-CT Main advantages for geological applications 3D structural information Porosity analysis Pore networks connectivity flow paths 3D mineral distribution 3D analysis of shape and morphometries Grains, sedimentary patterns, fossils, etc. November 24,

27 Application examples 3D structural information - porosity Rocks can be segmented into binary pore vs. solid models. Reconstructed slice Binarized image 1275 November 24,

28 Application examples 3D structural information - porosity Rocks can be segmented into binary pore vs. solid models. At each point, 3D pore network properties are known November 24,

29 Application examples 3D structural information - porosity Rocks can be segmented into binary pore vs. solid models. At each point, 3D pore network properties are known. Local thickness of the pore network 2211 November 24,

30 Application examples 3D structural information - porosity 2 mm microplug - 1 µm resolution SkyScan mm microplug - 1 µm resolution SkyScan November 24,

31 Application examples 3D structural information - porosity Rocks can be segmented into binary pore vs. solid models. At each point, 3D pore network properties are known. Local thickness of the pore network Open versus closed porosity 2211 November 24,

32 Application examples 3D structural information - porosity Based on 3D imaging, direct modelling of transport properties can be done. Permeability Multiphase flow properties Capillary pressure curves Resistivity index Etc. For conventional reservoirs simulated values are very close to laboratory measured values. More and more methods available for unconventional reservoirs Simulation and image created with November 24,

33 Application examples Grain size analysis 1275 November 24,

34 Application examples Grain size analysis 1275 November 24,

35 Application examples 3D mineral distribution If sufficient contrast rocks can be segmented into different mineral fractions. November 24,

36 Application examples 3D mineral distribution ore geology Gold deposit 9 µm pixel size 29 minutes scan time 1275 November 24,

37 Application examples 3D mineral distribution ore geology Cu-ore 5 cm sample size 25 µm resolution 1275 Original sample Volume render November 24,

38 Application examples 3D mineral distribution ore geology Cu-ore 5 cm sample size 25 µm resolution 57 % 34 % 7.5 % 1.5 % 1275 November 24,

39 Application examples No sample preparation fast results 10 mm microplug 6 µm resolution SkyScan1275 Scanned in 30 minutes 1275 November 24,

40 Application examples No sample preparation fast results 5 mm microplug 5 µm resolution SkyScan minutes per scan 5 vertical scans stitched together 1275 November 24,

41 Application examples Sedimentology 50 mm sediment core 35 µm resolution SkyScan November 24,

42 Application examples Sedimentology 80 mm clay core 50 µm resolution SkyScan November 24,

43 Application examples Imaging of fossils Arthropod larva Leanchoilia illecebrosa (fossil length: 2 mm) SkyScan1272 Voxel size 1.5 µm 1272 Courtesy of Dr. Yu Liu Yunnan Key Laboratory for Paleobiology Yunnan University - China November 24,

44 Application examples Imaging of fossils insect in amber Mosquito in amber Voxel size 7 um Scan time 20 minutes 1275 November 24,

45 Micro-CT Main advantages for geological applications 3D structural information Porosity analysis Pore networks connectivity flow paths 3D mineral distribution 3D analysis of shape and morphometries Grains, sedimentary patterns, fossils, etc. Non-destructive imaging Multi-scale analysis Monitoring of dynamic processes / changing samples Imaging (and digital preservation) of precious samples November 24,

46 Application examples Multi-scale analysis Multi-scale analysis Large samples at low resolution Small samples at high resolution Region of interest scanning No physical subsampling 10 mm sample 5.5 µm resolution Zoom in scan (4 mm FOV) 2 µm resolution 2211 November 24,

47 Application examples Multi-scale analysis Very high resolutions on reasonable sample sizes. 4 mm 1 µm resolution 2 mm 500 nm resolution 2211 November 24,

48 Application examples Monitoring of dynamic processes November 24,

49 Application examples Monitoring of dynamic processes Compression test of a Noyant limestone using SkyScan MTS November 24,

50 Application examples Monitoring of dynamic processes Compression test of a Noyant limestone using SkyScan MTS3 SkyScan MTS2 - Compression / tensile up to 440 N SkyScan MTS3 - Compression up to 4400 N Custom design / third party 1275 November 24,

51 Application examples Monitoring of dynamic processes Crystallization in porous media Time-lapse CT Salt crust formation on Bentheimer sandstone Scanned after each absorption drying cycle SkyScan µm voxel size - 30 minutes per scan 1275 November 24,

52 Application examples Monitoring of dynamic processes Moisture transport in porous media Real-time CT Liquid displacement in Bentheimer sandstone. 1 scan = 80 seconds Pixel size = 10 µm SkyScan November 24,

53 Micro-CT Main advantages for geological applications 3D structural information Porosity analysis Pore networks connectivity flow paths 3D mineral distribution 3D analysis of shape and morphometries Grains, sedimentary patterns, fossils, etc. Non-destructive imaging Multi-scale analysis Monitoring of dynamic processes / changing samples Imaging (and digital preservation) of precious samples Complementary to traditional methods E.g. optical or electron microscopy, XRF, XRD November 24,

54 Application examples Data-fusion with traditional research methods X-ray fluorescence imaging SEM / EDS FIB Nanotomography X-ray diffraction Optical microscopy November 24,

55 Application examples Data-fusion with traditional research methods Data fusion combination of micro-ct with EDS / XRD / XRF X-ray MicroCT in Conjunction with Other Techniques for Core Analysis I.V. Yakimchuk 1, A.S. Denisenko 1, B.D. Sharchilev 1, and I.A. Varfolomeev 1, 2 1 Schlumberger, , 13 Pudovkina str., Moscow, Russia, 2 Moscow Institute of Physics and Technology, , 9 Institutskiy per., Dolgoprudny, Russia 1272 November 24,

56 Application examples Data-fusion with traditional research methods A drill core was scanned using the 1275 and an XRF mapping was performed using the Bruker M4 Tornado From left to right: - XRF data - µ-ct data - Overlay of XRF on µ-ct November 24,

57 Application examples Data-fusion with traditional research methods A drill core was scanned using the 1275 and an XRF mapping was performed using the Bruker M4 Tornado Image registration allows 3D alignment of both image modalities and inspection of the sample. November 24,

58 Conclusions Micro-CT provides 3D information on Porosity Mineral distribution Structure All kinds of samples Sample sizes from mm to full core Mature and accepted method Complementary method to traditional analysis techniques November 24,

59 Q & A session Thank you for your attention More information: Wesley De Boever Applications.bmct@bruker.com Phone: +32 (0) November 24,

60 Copyright Bruker Corporation. All rights reserved. Innovation with Integrity