Characterizing rock properties with optical energy sources in a wellbore

Patent metadata

Field	Value
Publication number	US-12487075-B2
Application number	US-202418639393-A
Country	US
Kind code	B2
Filing date	Apr 18, 2024
Priority date	Apr 18, 2024
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A downhole tool system includes a bottom hole assembly that includes a connector; a laser head; a light source; a sensing assembly; and a controller. The connector is configured to couple to a downhole conveyance run into a wellbore to a reservoir rock formation. The laser head is configured to emit a laser beam toward the reservoir rock formation at a fixed frequency. The light source emitter is configured to emit a light beam toward the reservoir rock formation. The sensing assembly includes at least one optical receiver configured to (1) receive a reflected laser beam and a reflected light beam, and (2) interfere the reflected laser beam with the reflected light beam. The controller is configured to perform operations including generating a speckle interferogram based on the interference; and determining an angular displacement and an axial displacement of the wellbore based on the speckle interferogram.

First claim

What is claimed is:

1 . A downhole tool system, comprising:
a bottom hole assembly, comprising:
a connector configured to couple to a downhole conveyance run into a wellbore from a terranean surface to a reservoir rock formation;
a laser head configured to emit a laser beam toward the reservoir rock formation at a fixed frequency;
at least one light source emitter configured to emit a light beam toward the reservoir rock formation; and
a sensing assembly comprising at least one optical receiver configured to (1) receive a reflected laser beam from the reservoir rock formation and a reflected light beam from the reservoir rock formation, and (2) interfere the reflected laser beam with the reflected light beam; and
a controller communicably coupled to the sensing assembly and configured to perform operations comprising:
generating at least one speckle interferogram based on the interference between the reflected laser beam and the reflected light beam; and
determining an angular displacement and an axial displacement of the wellbore based on the at least one speckle interferogram.

2 . The downhole tool system of claim 1 , wherein the emitted light beam has a wavelength at a long IR spectrum.

3 . The downhole tool system of claim 2 , wherein the wavelength is at 1500-1600 nanometers.

4 . The downhole tool system of claim 1 , wherein the laser head is configured to emit the laser beam toward the reservoir rock formation to induce a thermal change on the reservoir rock formation and change a stress state of the reservoir rock formation.

5 . The downhole tool system of claim 1 , wherein the emitted light beam is tuned to transmit through a wellbore fluid in the wellbore.

6 . The downhole tool system of claim 1 , wherein the at least one light source emitter comprises:
a single light source; and a plurality of optical fibers configured to emit a plurality of light beams from the single light source; an optical array configured to radially illuminate the reservoir rock formation with the plurality of light beams.

7 . The downhole tool system of claim 6 , wherein the sensing assembly is configured to interfere the reflected laser beam with the plurality of reflected light beams with an optical-fiber-based beam splitter.

8 . The downhole tool system of claim 1 , wherein the at least one light source emitter comprises an array of light source emitters radially arranged around the BHA and configured to radially illuminate the reservoir rock formation with a plurality of light beams.

9 . The downhole tool system of claim 8 , wherein the at least one optical receiver comprises two optical receivers, each receiver comprising a photodetector array, and the sensing assembly is configured to direct a first portion of the reflected light beams on the photodetector array and a second portion of the reflected light beams on a spectrometer.

10 . The downhole tool system of claim 1 , wherein the reflected light beam comprises spectral reflectance information, and the operations comprise:
determining a rock type of the reservoir rock formation based on the spectral reflectance information.

11 . The downhole tool system of claim 1 , wherein the operations comprise:
generating a plurality of speckle interferograms based on the interference between the reflected laser beam and the reflected light beam, each of the speckle interferograms generated at a particular time instant; and recording the plurality of speckle interferogram into a time-lapse interferogram.

12 . The downhole tool system of claim 11 , wherein the operations comprise:
determining a wellbore roughness for each of the plurality of speckle interferogram in the time-lapse interferogram; determining a change of wellbore roughness over the time-lapse interferogram; and determining the angular displacement and the axial displacement of the wellbore based on the change of wellbore roughness.

13 . A method of determining one or more wellbore characteristics, comprising:
positioning a bottom hole assembly (BHA) on a downhole conveyance at a reservoir rock formation in a wellbore, the BHA comprising:
a laser head;
at least one light source emitter; and
a sensing assembly comprising at least one optical receiver;
operating the laser head to emit a laser beam toward the reservoir rock formation at a fixed frequency; operating the at least one light source emitter to emit a light beam toward the reservoir rock formation; sensing, with the at least one optical receiver, a reflected laser beam from the reservoir rock formation and a reflected light beam from the reservoir rock formation; interfering, with the sensing assembly, the reflected laser beam with the reflected light beam to generate an interferogram; generating, with a controller communicably coupled to the sensing assembly, generating at least one speckle interferogram based on the interference between the reflected laser beam and the reflected light beam; and determining, with the controller, an angular displacement and an axial displacement of the wellbore based on the at least one speckle interferogram.

14 . The method of claim 13 , comprising operating the at least one light source emitter to emit the light beam toward the reservoir rock formation with a wavelength at a long IR spectrum.

15 . The method of claim 14 , wherein the wavelength is at 1500-1600 nanometers.

16 . The method of claim 13 , comprising operating the laser head to emit the laser beam toward the reservoir rock formation to induce a thermal change on the reservoir rock formation and change a stress state of the reservoir rock formation.

17 . The method of claim 13 , comprising operating the at least one light source emitter to emit the light beam toward the reservoir rock formation at a frequency or wavelength that is tuned to transmit through a wellbore fluid in the wellbore.

18 . The method of claim 13 , wherein the at least one light source emitter comprises a single light source, a plurality of optical fibers, and an optical array, and operating the at least one light source emitter to emit the light beam toward the reservoir rock formation comprises:
operating the single light source to emit a plurality of light beams, through the plurality of optical fibers, toward the reservoir rock formation; and operating the optical array to radially illuminate the reservoir rock formation with the plurality of light beams.

19 . The method of claim 18 , wherein the sensing assembly is configured to interfere the reflected laser beam with the plurality of reflected light beams with an optical-fiber-based beam splitter.

20 . The method of claim 13 , wherein the at least one light source emitter comprises an array of light source emitters radially arranged around the BHA, the method comprising:
operating the array of light source emitters to radially illuminate the reservoir rock formation with a plurality of light beams.

21 . The method of claim 20 , wherein the at least one optical receiver comprises two optical receivers, the method comprising:
operating the sensing assembly to direct a first portion of the reflected light beams on the photodetector array and a second portion of the reflected light beams on a spectrometer.

22 . The method of claim 13 , wherein the reflected light beam comprises spectral reflectance information, the method comprising:
determining, with the controller, a rock type of the reservoir rock formation based o

Assignees

• Saudi Arabian Oil Co

Inventors

• San Roman Alerigi Damian Pablo
• Alghamdi Safiyah
• Batarseh Sameeh

Classifications

• G01V8/02

  Prospecting · CPC title

• G01B11/303

  using photoelectric detection means · CPC title

• G01B9/02094

  Speckle interferometers, i.e. for detecting changes in speckle pattern · CPC title

• E21B49/006

  Measuring wall stresses in the borehole · CPC title

• E21B47/0228

  using electromagnetic energy or detectors therefor · CPC title