IP Library › Granted Patent US 12,529,639
Granted Patent B2
US 12,529,639 · App. 17/999,990 · Granted Jan 20, 2026

Method for estimating hydrocarbon saturation of a rock

Inventors: Nishank Saxena (Houston, TX); Faruk Ömer Alpak (Houston, TX); Amie Marie Hows (Houston, TX); John Justin Freeman (Houston, TX); Matthias Appel (Houston, TX); Ronny Hofmann (Houston, TX); Bochao Zhao (Houston, TX)
Assignee: SHELL USA, INC.
G01N15/088E21B49/00G01N23/046G01N23/083G01N33/24G01N33/241G06T7/0002G06T7/11G01N2015/0846G01N2223/401G01N2223/419G01N2223/616G01N2223/649G06T2200/04G06T2207/10081G06T2207/20081G06T2207/30181
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Quick Facts
Patent No.
US 12,529,639
App. No.
17/999,990
Granted
Jan 20, 2026
Kind
B2
Abstract

The present invention provides a method for estimating hydrocarbon saturation of a hydrocarbon-bearing rock from a measurement for an electrical property a resistivity log and a rock image. The image is segmented to represent either a pore space or solid material in the rock. An image porosity is estimated from the segmented image, and a corrected porosity is determined to account for the sub-resolution porosity missing in the image of the rock. A corrected saturation exponent of the rock is determined from the image porosity and the corrected porosity and is used to estimate the hydrocarbon saturation. A backpropagation-enabled trained model can be used to segment the image. A backpropagation-enabled method can be used to estimate the hydrocarbon saturation using an image selected from a series of 2D projection images, 3D reconstructed images and combinations thereof.

Claims (18)

1 . A method for estimating hydrocarbon saturation of a hydrocarbon-bearing rock from a resistivity log and a rock image, comprising:

obtaining a measurement for an electrical property for a field having a hydrocarbon-bearing formation;

obtaining a 3D image of a rock from the hydrocarbon-bearing formation in the field, wherein the 3D image is comprised of a plurality of voxels and the 3D image has a resolution;

processing the 3D image to segment the 3D image by selecting each voxel of the 3D image to represent either a pore space in the rock or solid material in the rock;

estimating an image porosity of the rock from the segmented 3D image, the image porosity lacking a sub-resolution porosity of the rock;

determining a corrected porosity adapted to account for the sub-resolution porosity of the rock;

estimating a corrected saturation exponent of the rock from the image porosity and the corrected porosity of the rock; and

estimating the hydrocarbon saturation of the hydrocarbon-bearing rock using the corrected saturation exponent and the electrical property measurement.

2 . The method of claim 1 , further comprising the steps of:

obtaining a measurement of formation porosity along a well bore for the field; and

converting the electrical property measurement to a continuous saturation profile using the estimated hydrocarbon saturation and the formation porosity measurement.

3 . The method of claim 1 , wherein the 3D image of the rock is obtained by x-ray computer tomography.

4 . The method of claim 1 , wherein the step of estimating the hydrocarbon saturation comprises determining a formation water conductivity and a cementation exponent.

5 . The method of claim 1 , wherein the rock is obtained from a hydrocarbon-bearing formation comprised of sandstone, carbonate, shale and combinations thereof.

6 . The method of claim 1 , wherein the corrected porosity of the rock is determined by laboratory measurement.

7 . The method of claim 1 , wherein the corrected porosity of the rock is determined by deriving a non-wetting liquid capillary pressure curve from the segmented 3D image of the rock; and determining the corrected porosity from the segmented 3D image and the non-wetting liquid capillary pressure curve.

8 . The method of claim 7 , wherein the non-wetting liquid capillary pressure curve is derived from the segmented 3D image of the rock at pressures of up to an image-limited pressure, where the image-limited pressure is the minimum pressure that can be applied on the non-wetting liquid to overcome the capillary pressure of the narrowest pore throat distinguishable from the segmented 3D image of the rock.

9 . The method of claim 1 , wherein the 3D image is obtained from a cloud-based tool adapted to store and process 2D projection images from a pore-scale imaging technology.

Assignments (2)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 18, 2025
From: SAXENA, NISHANK; ALPAK, FARUK ÖMER; HOWS, AMIE MARIE; FREEMAN, JOHN JUSTIN; APPEL, MATTHIAS; HOFMANN, RONNY; ZHAO, BOCHAO
To: SHELL USA, INC.
Reel/Frame 071760/0875 →
CHANGE OF NAME Recorded Dec 1, 2022
From: SHELL OIL COMPANY
To: SHELL USA, INC.
Reel/Frame 062034/0110 →
Continuity (3)
Provisional Application 63046063 · Jun 30, 2020
Related Publication 20230221236A1 · Jul 13, 2023
Related Publication 20240044768A2 · Feb 8, 2024
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