3D Image Data in CAD/CAE
Working as PR and Marketing Officer for Simpleware, with specialties in: marketing communications, social media, press, quality management, copywriting.
3D Image Data and Digital Rock Physics
October 5th, 2015 by Gareth James
Researchers and analysts working in oil and gas can use 3D image data and digital rock physics techniques to characterise rock samples. Using image data from modalities such as micro-CT and FIB-SEM to analyse rock properties can complement experimental testing and enables non-destructive evaluation. Given the complexity of rock image data, it’s important to have an integrated software toolkit for going from scan data through to simulation-ready models – our software at Simpleware has been developed to solve this challenge.
Digital rock physics workflows typically begin with the collection of volume images from scans, with images containing different material phases that can be segmented and used as the basis for analysing grain structure, porous networks and other characteristics. Scanning rock samples at different length scales also means that flow and transport properties can be simulated for very small porous networks.
In Simpleware software, a stack of images can be converted from 2D pixels into 3D pixels (voxels), and segmented to identify different material phases, such as solid and fluid regions, as well as pores. Image processing filters can be used to reduce scan noise, and measurement and statistics tools used to obtain quantified data; this includes surface area, tortuosity, connectivity and pore sizes.
One of the main challenges of working with rock image data involves going from segmented images of multi-phase materials through to meshes that can be used in simulations. Our image-based meshing techniques enable multi-part models with conforming interfaces and shared nodes to be created, taking into account partial volume effects and preserving topology and volume. Image data can also be adaptively remeshed in order to reduce mesh size without compromising the original geometry. These meshes can be imported directly to leading FE/CFD solvers for realistic simulations.
The effective material properties of samples can similarly be obtained using finite element-based homogenisation techniques. A complex heterogeneous material, such as a rock sample, can be substituted with a homogeneous material and used to calculate effective properties by post-processing fields induced in a cuboidal material sample by a sequence of appropriate boundary conditions. Example properties can include effective stiffness tensor and elastic moduli, as well as absolute permeability and electrical conductivity/permittivity, thermal conductivity and molecular diffusivity.
With these approaches, it is possible to obtain valuable qualitative and quantitative information from rock samples. We’ve worked on making complex or at-times intractable digital rock physics workflows more straightforward in our software, with options available for scripting and user customisation. Digital rock physics has a great deal of promise for everything from reservoir characterisation to oil recovery and hydrocarbon production, and having this toolkit and workflow in place in crucial to accurate image-based modelling and simulation.
Want to learn more? Visit http://simpleware.com/industries/materials/rock-physics/ and request a free trial of the software.