Method for determining rock matrix and fracture permeability by using poroelastodynamics and density averaging schemes

Patent metadata

Field	Value
Publication number	US-2023383648-A1
Application number	US-202217804273-A
Country	US
Kind code	A1
Filing date	May 26, 2022
Priority date	May 26, 2022
Publication date	Nov 30, 2023
Grant date	—

Abstract

A method of determining rock matrix and fracture permeability to perform a reservoir fluid flow simulation. The method includes: obtaining a petrophysical characterization of a formation sample, measuring a first and second elastic wave velocity of the formation sample at a first and second frequency, calculating an average rock matrix density and an average porosity of the formation sample, determining a set of calculated elastic wave velocities for the first and second frequencies over a range of candidate permeabilities, and determining a rock matrix permeability and a fracture permeability based on the set of calculated elastic wave velocities at the first and second frequency respectively. The method further including performing a reservoir fluid flow simulation based, at least in part, on at least one of the rock matrix permeability and the fracture permeability.

First claim

What is claimed:

1 . A method, comprising:
obtaining a petrophysical characterization of a formation sample; measuring a first elastic wave velocity of the formation sample at a first frequency and measuring a second elastic wave velocity of the formation sample at a second frequency, wherein the first frequency is lower than the second frequency; calculating, based at least in part on the petrophysical characterization, an average rock matrix density and an average porosity of the formation sample; determining a set of calculated elastic wave velocities for the first frequency over a range of candidate permeabilities and a set of calculated elastic wave velocities for the second frequency over the range of candidate permeabilities; determining a rock matrix permeability based, at least in part, on the set of calculated elastic wave velocities at the first frequency for the average rock matrix density and the average porosity; determining a fracture permeability based, at least in part, on the set of calculated elastic wave velocities at the second frequency for the average rock matrix density and the average porosity; and performing a reservoir fluid flow simulation based, at least in part, on at least one of the rock matrix permeability and the fracture permeability.

2 . The method of claim 1 , further comprising determining a location of a wellbore based, at least in part, on the reservoir fluid flow simulation.

3 . The method of claim 1 , wherein calculating an average rock matrix density and an average porosity comprises calculating a plurality of averages of rock matrix density and calculating a plurality of averages of porosity.

4 . The method of claim 3 , wherein the average rock matrix density and the average porosity comprises an arithmetic mean, a geometric mean, or a harmonic mean.

5 . The method of claim 1 , wherein:
a measured elastic wave velocity comprises a measured P-wave phase velocity; a set of calculated elastic wave phase velocities at the first frequency comprises a set of calculated P-wave phase velocities; and a set of calculated elastic wave phase velocities at the second frequency comprises a set of calculated P-wave phase velocities.

6 . The method of claim 1 , wherein obtaining a petrophysical characterization of a formation sample comprises obtaining a core sample and determining at least one petrophysical characteristic of the core sample.

7 . The method of claim 1 , wherein the petrophysical characterization of the formation sample comprises a density of a mineral grain and a volume fraction of the mineral grain, a density of an organic material and a volume fraction of the organic material, a porosity of the formation sample, and a volume fraction of a fracture.

8 . A system, comprising:
a core sample analyzer configured to determine:
a petrophysical characterization of a formation sample, and
a measured elastic wave velocity at a first frequency and a second frequency for the formation sample wherein the first frequency is lower than the second frequency; and
a computer processor, configured to:
receive a petrophysical characterization of a formation sample;
receive a first measured elastic wave velocity of the formation sample at a first frequency and a second measured elastic wave velocity of the formation sample at a second frequency, wherein the first frequency is lower than the second frequency;
calculate, based at least in part, on the petrophysical characterization, an average rock matrix density and an average porosity of the formation sample;
determine a set of calculated elastic wave velocities for the first frequency over a range of candidate permeabilities and a set of calculated elastic wave velocities for the second frequency over the range of candidate permeabilities;
determine a rock matrix permeability based, at least in part, on the set of calculated elastic wave velocities at the first frequency for the average rock matrix density and the average porosity;
determine a fracture permeability based, at least in part, on the set of calculated elastic wave velocities at the second frequency for the average rock matrix density and the average porosity;
perform a reservoir fluid flow simulation based, at least in part, on at least one of the rock matrix permeability and the fracture permeability; and
determine a wellbore path based, at least in part, on the reservoir fluid flow simulation.

9 . The system according to claim 8 , further comprising a drilling system configured to drill a wellbore guided by the wellbore path.

10 . The system according to claim 8 , wherein the average rock matrix density and the average porosity comprise a plurality of averages of rock matrix density and calculating a plurality of averages of porosity.

11 . The system of claim 8 , wherein calculating an average rock matrix density and an average porosity comprises calculating a plurality of averages of rock matrix density and calculating a plurality of averages of porosity.

12 . The system according to claim 8 , wherein:
a measured elastic wave velocity comprises a measured P-wave phase velocity; a set of calculated elastic wave phase velocities at the first frequency comprises a set of calculated P-wave phase velocities; and a set of calculated elastic wave phase velocities at the second frequency comprises a set of calculated P-wave phase velocities.

13 . The system according to claim 8 , wherein obtaining a petrophysical characterization of a formation sample comprises obtaining a core sample and determining at least one petrophysical characteristic of the core sample.

14 . The system according to claim 8 , wherein the petrophysical characterization of the formation sample comprises a density of a mineral grain and a volume fraction of the mineral grain, a density of an organic material and a volume fraction of the organic material, a porosity of the formation sample, and a volume fraction of a fracture.

15 . A non-transitory computer readable medium storing a set of instructions executable by a computer processor, the set of instructions comprising functionality for:
receiving a petrophysical characterization of a formation sample; receiving a first measured elastic wave velocity of the formation sample at a first frequency and a second measured elastic wave velocity of the formation sample at a second frequency, wherein the first frequency is lower than the second frequency; calculating, based at least in part, on the petrophysical characterization, an average rock matrix density and an average porosity of the formation sample; determining a set of calculated elastic wave velocities for the first frequency over a range of candidate permeabilities and a set of calculated elastic wave velocities for the second frequency over the range of candidate permeabilities; determining a rock matrix permeability based, at least in part, on the set of calculated elastic wave velocities at the first frequency for the average rock matrix density and the average porosity; determining a fracture permeability based, at least in part, on the set of calculated elastic wave velocities at the second frequency for the average rock matrix density and the average porosity; and performing a reservoir fluid flow simulation based, at least in part, on at least one of the rock matrix permeability and the fracture permeability.

16 . The non-transitory computer readable medium of claim 15 , wherein the computer processor is further configured to determine a wellbore path based, at least in part, on the reservoir fluid flow simula

Assignees

• Aramco Services Co

Inventors

• Liu Chao
• Kazei Vladimir
• Phan Dung T
• Abousleiman Younane N

Classifications

• E21B49/088 Primary

  combined with sampling · CPC title

• G01N33/241

  for hydrocarbon content · CPC title

• G01V1/306 Primary

  for determining physical properties of the subsurface, e.g. impedance, porosity or attenuation profiles · CPC title

• E21B49/005

  Testing the nature of borehole walls or the formation by using drilling mud or cutting data · CPC title

• E21B2200/20

  Computer models or simulations, e.g. for reservoirs under production, drill bits · CPC title