Digital Rocks

Instructors: Dr. Michael Myers & Dr. Lori Hathon

Discipline: Geoscience and Engineering

Course Duration: 5 days

Teaching Mode: In-person

Introduction: Digital Rock Physics (DRP) is an emerging technique that uses high-resolution X-rays to penetrate solid rock and reveal the minerals and elements hidden in it. Digital Rock offers a faster, better, and lower-cost analysis of minerals and organic matter within the rock. CT images can reveal mud invasion, core heterogeneities, and the extent of core damage.

Who Should Attend: Geoscientists, Petropysicists Petroleum Engineers, Production engineers/technologists, Asset managers, and technical professionals interested in the knowledge of the reservoir rocks and its.

Course Description: This course is designed to provide participants with a comprehensive knowledge of Digital Rock Physics (DRP). This course covers the application of whole-core imaging, micro-CT imaging, Thin Section Imaging, Scanning Electron Microscopy (SEM), and Multi-Scale modal imaging and image analysis.

Course Content:

Day 1: Applications of Whole Core Imaging

One of the applications of whole-core CT scanning is to provide quantitative data for correlation with well logs. CT images can reveal mud invasion, core heterogeneities, and the extent of core damage. CT data are used to correctly orient the core for core plug drilling and measurement. Integrated CT, white light, UV, and Hyper Spectral Imaging aid in selecting locations for core plug measurements.

1.1 – Whole Core CT

1.2 – Dal Energy Scanning – Bulk Mineralogy

1.3 – Dual Energy Scanning – Estimating Geomechanical and Acoustic Properties

1.4 – Interpretation of Depositional Environment

1.4 – Flow Visualization and Saturation Monitoring (Core Flood)

1.5 – Fracture density and characterization

1.6 – Hyper Spectral Imaging

1.7 – Exercises/Workshop

Day 2: Applications of Micro-CT Imaging

Micro-CT imaging (as well as medical CT) is performed to assess core plug quality for measurement (low-resolution images) and for performing Digital Rock Physics (DRP) studies (high-resolution images). DRP results are a function of image resolution, signal-to-noise ratio, and segmentation techniques employed, among other parameters. The sensitivity of results to these user-controlled parameters will be investigated.

2.1 – Image Acquisition – Optimizing Phase Contrast and Signal-to-Noise Ratio

2.2 – Imaging Tools and Image Resolution (Micro- and Nano-CT)

2.3 – What is an REV?

2.4 – Image Segmentation Techniques

2.5 – Extracting Pore Body and Pore Throat Size Distributions

2.6 – Pore Network Modeling – Absolute Permeability

2.7 – Pore Scale Imaging of Fluid Distribution

2.8 – Developing Models for Relative Permeability

2.7 – Modeling Acoustic Properties

2.8 – Modeling Electrical Properties

2.9 – Exercises/Workshop

Day 3: Applications of Thin Section Imaging

2D imaging and image analysis are much less costly than 3D techniques. Further, they allow the identification of mineralogy and the relative proportion of detrital and authigenic phases. Small volumes of authigenic phases like quartz cement can dramatically influence geomechanical and acoustic properties. 2D imaging and image analysis can provide porosity/permeability/velocity estimates from images that agree as well as plug measurements as 3D estimates at a fraction of the cost.

3.1 – Quantitative Image Analysis versus Standard Point Counting

3.2 – Particle Size Measurement – Comparison with Standard Sieve and LPSA Data

3.2 – Pore Body Size Distribution – Influence of Thin Section Orientation

3.3 – Conversion of 2D pore body size to 3D equivalent

3.4 – Estimating NMR T2 distributions from thin section estimates of pore body size

3.5 – Estimating Surface Relaxivity

3.6 – Grain Contact Analysis

3.7 – Acoustic Properties and Acoustic Anisotropy

3.8 – Image Processing Workflows

3.9 – Modeling Absolute Permeability

3.10 - Exercises

Day 4: Scanning Electron Microscopy

Scanning electron microscopy has evolved from relatively qualitative applications to quantitative estimates of rock properties, particularly in shale reservoirs. Various imaging modalities and their primary applications are discussed.

4.1 – Imaging Modalities – Backscattered and Secondary Electrons

4.2 – Imaging Modalities – Energy Dispersive X-ray Spectroscopy

4.3 – Imaging Modalities - Cathodoluminescence

4.4 – Focused Ion Bean (FIB) SEM

4.5 – Helium Ion Microscopy – Porosity in Clay Mineral-Rich Samples

4.6 – Image Analysis Results as a Function of Imaging Modality

4.7 – Exercises

Day 5: Integration and Upscaling

Multi-Scale/Multi-Modal Imaging and Image Analysis can be used to estimate rock properties at the pore and core scales. Linking Micro-CT from core plugs to whole core CT can be used to upscale from the core plug to the whole core scale. Relating core plug measurements to core descriptions can be used to upscale from the core plug to the whole core and log scales.

5.1 – Sampling for Upscaling: Facies-Based versus Statistical Sampling

5.2 – 2D and 3D Image Analysis Results Compared to Core Plug Measurements

5.3 – Registered Multi-Scale/Multi-Modal Imaging

5.4 – Leverett J Functions and Other Averaging Techniques

5.5 – Exercises