Frequently Asked Questions

 

 
 
Working with Ingrain
 
What is your standard turnaround time? 
Turnaround time is completely flexible. We can provide results within 14 days, and if required in certain conditions, as fast as 7 days.

 

Does Ingrain sell software?  
No. We provide advanced rock properties analysis in our digital rock physics lab.

 

What software does Ingrain use for computing the properties?   
Ingrain uses algorithms and software developed in-house to compute properties.

 

What is the most common reason that Ingrain’s customers prefer imaging and computation instead of physical lab measurements?
Ingrain offers a completely new methodology for rock properties analysis. Physical SCAL lab measurements are time-consuming.  Ingrain evaluates drill cuttings or core material rapidly and non-destructively.  In difficult formations such as tight gas sands, shale, and oil sands, as well as for improved recovery processes, Ingrain accurately computes an assortment of essential rock properties significantly faster than laboratory methods. 

 

Can Ingrain image and analyze shales?   
Yes.  Analysis of these complex, low perm rocks requires multiple scales of imaging, including a nano-scale CT scanner with resolution of 65 nanometers per voxel and a FIB SEM (focused ion beam scanning electron microscope) with resolution a high as 3 nanometers per voxel.  This is essential for measuring porosity in shales and tight gas sands. Our technology has been successfully used to analyze both the gas and oil-bearing zones of shale reservoirs such as the Eagle Ford, as well as gas shales such as the Haynesville and Barnett.

 

Can you image the organic matter within shale and provide an analysis of total organic content (TOC)?
Yes. Understanding the connected porosity within the kerogen in place in the pore space within shales is key to developing a complete picture of porosity and permeability. 

 

Can you measure oil sands/heavy oil?
Yes. Ingrain offers distinct advantages in oil sands due to the speed of our imaging process and our ability to handle unconsolidated rocks.  Due to the non-destructive nature of our testing, we can measure properties on oil sands that could not previously be provided.

 

Can you measure bitumen percentage in oil sands? 
Yes.

 

Does Ingrain provide services for coal-bed methane? 
No.


How much confidence can we have in Ingrain’s computations when using drill cuttings?

If there is not physical damage of the sample, the computations are as good as for any other type of rock sample brought to the surface (e.g. sidewall cores).
 
In a single well, what is the recommended number of rock samples that should be scanned and analyzed for use in reservoir simulation?
If the reservoir is heterogeneous we recommend at least one core plug per foot. Another consideration is the level of detail of the reservoir model. In general, a sufficient number of rock samples should be analyzed to capture the flow units and/or lithofacies that are present in the reservoir model.
 
Can Ingrain image and compute rock samples that have been impregnated with mercury? 
Mercury is a hazardous material. Ingrain does not work with hazardous materials.


Rock Sample Preparation

 
Does Ingrain offer complete digitization of cores? 
No.


What is the minimum rock sample size Ingrain requires to be able to conduct its analyses?
Our preferred minimum is approximately one cubic inch (16.4 cubic centimeters).  The reason for having a sample of this minimum size is to be able to assess heterogeneity within the rock sample.  The actual minimum sample size depends on the grain and pore size distribution of the rock sample.

Who determines where the micro-cores or nano-cores are taken from the rock sample? 
A trained Ingrain geologist analyzes each rock sample.  The geologist determines the location from which each micro- or nano-core is taken.

 

Can Ingrain accept/handle frozen cores (such as for oil sands)? 
Yes. We minimize abrupt thermal change during the micro-coring and imaging process.

 

How do you prevent the micro-drill bit from overheating and desiccating the sample while taking a micro-core?
 The micro-drill bit is cooled using nitrogen.

 

Scanning rock samples
 
What kind of CT scanners does Ingrain use to scan the rock samples? Are they the same kind of CT scanners used in hospitals? 
Ingrain uses industrial-grade CT scanners.  Our scanners operate at much higher resolution than medical CT scanners. Our nano-scale CT scanner is the only one of its type in the world being used in the oil and gas industry.

 

How does Ingrain acquire the digital images?
Imaging takes place in several steps. We take digital photographs of each rock sample. We may use a lower resolution CT scanner to assess heterogeneity in a rock sample to help determine where to take the micro-cores that are scanned in the micro-scale CT scanner. We also use the micro-scale CT scanner to help determine where to take the nano-cores for scanning in the nano-scale CT scanner.
Do you use the same size micro-cores in both the micro-scale and the nano-scale CT scanners?   
No. For the nano-scale scanner, we use much smaller sizes – we refer to them as “nano-cores.”  The size of a typical micro-core is 2.5 mm, while the size of a typical nano-core is 0.5 mm.

 

How long does it take to acquire the scans?  
Tighter rocks require more time than more porous rocks.  Scanning times for micro-scale CT scanner run from 1 to 8 hours depending on the size and heterogeneity of the micro-core.  Scanning times for the nano-scale CT scanner run from 24 to 72 hours, again depending on the size and heterogeneity of the nano-core.

 

Do we receive the image data as part of the results?
Yes. We provide scanned images of a single axial slice, axial slices in 3 directions, and a rendering of the 3D volume.  We also provide renderings of the rock volume and pore volume pictures.
 

Preparing images for computation 

 
How many 2D slices do you image from each micro-core? 
As many as 1024 2D slices are produced during the scanning process. These slices are stacked to create a 3D volume.  Each 3D volume is then put through a process called image segmentation as the final step before computations are done.

 

Image segmentation: What exactly does that mean?
 Segmentation is a process performed on each digital 3-dimensional rock in the X, Y, and Z planes. It involves transforming the 3D image that contains information about its black, white and shades of gray intensity into a digital file containing pixels associated to grains and pores.

 

Do you convert your images to network models for simulations?
No, Ingrain does not use network models.  We create a high-resolution 3D digital image of the actual grains and pores of the rock sample from a large number of 2D tomographic slices.
 


Physical properties computation

 
Why should we care about having reservoir rock properties information if we already have well log data? 
Porosity can be inferred from Neutron, Sonic and Density logs, but permeability is the only crucial property that cannot be immediately inferred from well log data.

 

Do you capture the connections between the pores that characterize the transport properties?  
Yes, with Ingrain’s technology we reveal the pore space, including connected and isolated porosity. We do not use models.

 

What kind of permeability measurement does Ingrain provide?   
We provide absolute permeability in three directions.   We also provide relative permeability curves, usually in one direction.

 

Does ingrain focus primarily on low perm rocks?
No, we provide advanced rock properties analysis on sandstones, carbonates, oil sands, tight gas sands, and shales.
Can Ingrain quantify isolated porosity and connected porosity?
Yes.

 

How does Ingrain compute elastic properties?
The segmented 3D image of the rock sample (called the vRock) is digitally deformed with prescribed strain to calculate the resulting stress using FEM (Finite Element Method). By relating stress to strain, we obtain the elastic moduli of the rock sample.
Does Ingrain compute bulk modulus and Poisson ratios?
Yes.

 

Does Ingrain take into account the different mineral moduli when calculating elastic properties?
Yes.

 

Since Ingrain imaging is done at ambient conditions, can you simulate reservoir stress conditions like compressibility?
Yes.

 

How does Ingrain characterize grain cementation? 
Cementation is resolved by our imaging process.
 


Relative permeability computation

 
Does Ingrain compute fluid flow characteristics or just the physical properties of the rock?
Both.  Elastic properties are computed in the “dry” rock. The porosity framework is the input for the fluid flow simulation.
Could Ingrain use the in-situ fluid properties in the flow simulation?
Yes, if the in-situ parameters like temperature, pressure, salinity, GOR, etc are known, we can simulate the corresponding fluid.

 

Is there flexibility in setting the fluid saturation parameters when running permeability analysis? This is important in tight gas sands, where oil saturation can dramatically affect gas permeability.
Yes.

 

What kind of fluid does Ingrain use for permeability?
We use gas, oil and water.