About Ingrain's Digital Rock Physics Lab
Ingrain's digital rock physics lab computes the physical properties and
fluid flow characteristics of oil and gas reservoir rocks. We provide advanced rock properties
analysis for sandstones, shales, carbonates, tight gas sands and oil sands.
Using
core plugs or even drill cuttings, Ingrain can deliver accurate results
as fast as 14 days. Ingrain can even provide accurate results using
samples from core repositories that have been altered by drilling
fluids.
The digital rock physics workflow includes three major steps:
- Sample selection, preparation and 3-D imaging of a rock fragment
- Image processing (segmentation) to discriminate pores from solid matrix and identify minerals within this matrix
- Accurate simulation of physical processes under precise experimental conditions.
The sample material for imaging can come from core, sidewall plugs, or drill cuttings. To cover the variability of scale-related properties, the first two sources are recommended.
The process begins with a team of trained geologists evaluating rock samples and preparing them for imaging with industrial-grade CT scanners. These scanners produce a 3-D reconstruction from hundreds of tomographic slices. Most conventional samples are imaged using a Micro CT system that functions at resolutions down to one micron. For microporous carbonates, Ingrain uses a Nano CT system which delivers resolution to 0.05 microns.
The Nano CT machine cannot resolve the very small and very important
features of shales, which are rapidly becoming a major source of
hydrocarbons. This is where a new imaging technique called FIB- SEM
(focused ion beam combined with scanning electron microscope) comes in. The
FIB–SEM tool allows users to physically slice materials and to view
them at very high magnification. The FIB system directs a high-energy
focused beam at the mounted rock sample and cuts away material in a
precise manner. The removed layer can be as thin as 2.5 nanometers.
After a slice is removed, the SEM is used to acquire a high-resolution
image of the newly exposed material. These consecutive slices comprise
a 3-D image.
The reconstructed 3D images are then subjected to proprietary segmentation routines that differentiate pores from minerals and, within the mineral matrix, identify different mineralogy such as pyrite, calcite or clay. The final result is a vRock digital reservoir rock. A vRock digital reservoir rock preserves the pore space in its complete intricacy and makes it ready for computational experiments.
The final step includes computational experiments where fluid flow, electrical current, and elastic deformation are simulated in a segmented sample at desired conditions and selected transport agents. The results describe permeability, electrical conductivity, and elastic properties of the rock. They are then compared to one another and also to the mineralogy and porosity of the sample to understand and quantify relations among these different attributes of rock.
Ingrain's multiphase flow simulations provide relative permeability and capillary pressure. These algorithms handle fluid phases of drastically different viscosity and surface tension.
