US 9,285,301 B2 · Digital rock analysis systems and methods with reliable multiphase permeability determination

Abstract

The pore structure of rocks and other materials can be determined through microscopy and subjected to digital simulation to determine the properties of multiphase fluid flows through the material. To ensure reliable results, the digital rock model is first analyzed via a series of operations that, in some embodiments, include: obtaining a three-dimensional pore/matrix model of a sample; determining a flow axis; verifying that the dimension of the model along the flow axis exceeds that of a representative elementary volume (REV); selecting a flow direction; extending model by mirroring if pore statistics at a given saturation are mismatched for different percolating phases; and increasing resolution if the smallest nonpercolating sphere dimension is below a predetermined threshold. This sequence of operations increases reliability of results when measuring relative permeability using the model and displaying relative permeability measurements to user.

Claims18

Dependent claims

A multiphase permeability determination method performed by one or more computers, the method comprising:

obtaining a three-dimensional pore and matrix model of a rock formation sample based on digital imaging of the sample using a scanning microscope;
determining an axis of flow passing through said sample, wherein the determination is based on the orientation of the sample, formation pressure gradiens, or user specifications;
verifying that the dimension of the model along said axis exceeds that of a representative elementary volume (REV);
selecting a direction of the flow;
extending said model by mirroring if pore statistics at a given saturation are mismatched for different percolating phases;
increasing a resolution of digital imaging of the sample and repeating said obtaining, determining, verifying, selecting, extending, and increasing, if a smallest non-percolating sphere dimension is below a predetermined threshold;
measuring relative permeability of said sample using the model;
and
providing the relative permeability measurements to a user interface for display to a user.

6 more elements

A multiphase permeability determination system that comprises:

a user interface;
a memory having software;
and
one or more processors coupled to the memory to execute the software, the software causing the one or more processors to:
obtain a three-dimensional pore and matrix model of a rock formation sample based on digital imaging of the sample using a scanning microscope;
determine an axis of flow passing through said sample, wherein the determination is based on the orientation of the sample, formation pressure gradiens, or user specifications;
verify that the dimension of the model along said axis exceeds that of a representative elementary volume (REV);
select a direction of the flow;
extend said model by mirroring if pore statistics at a given saturation are mismatched for different percolating phases;
increase the resolution of digital imaging of the sample and repeat said obtain, determine, verify, select, extend, and increase steps if a smallest non-percolating sphere dimension is below a predetermined threshold;
measure relative permeability of said sample using the model;
and
provide the relative permeability measurements to the user interface for display to a user.

10 more elements

Dependencies are inferred from the claim text.

Digital rock analysis systems and methods with reliable multiphase permeability determination

Life of this patent

Digital rock analysis systems and methods with reliable multiphase permeability determination

Life of this patent

Abstract

Claims18