3D modeling method for cementing hydrate sediment based on CT image

Patent metadata

Field	Value
Publication number	US-11694338-B2
Application number	US-202017415621-A
Country	US
Kind code	B2
Filing date	Jul 23, 2020
Priority date	Jul 3, 2020
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

The present invention belongs to the technical field of petroleum exploitation engineering, and discloses a 3D modeling method for cementing hydrate sediment based on a CT image. Indoor remolding rock cores or in situ site rock cores without hydrate can be scanned by CT; a sediment matrix image stack and a pore image stack are obtained by gray threshold segmentation; then, a series of cementing hydrate image stacks with different saturations are constructed through image morphological processing of the sediment matrix image stack such as dilation, erosion and image subtraction operation; and a series of digital rock core image stacks of the cementing hydrate sediment with different saturations are formed through image subtraction operation and splicing operation to provide a relatively real 3D model for the numerical simulation work of the basic physical properties of a reservoir of natural gas hydrate.

First claim

The invention claimed is:

1. A 3D modeling method for cementing hydrate sediment based on CT image, comprising steps of:
step 1, scanning remolding or in situ rock cores without natural gas hydrate by CT to obtain digital rock core image stacks;
step 2, adjusting the gray threshold of the digital rock core image stacks, conducting binarization segmentation to obtain a sediment matrix and a pore, and respectively saving as the image stacks;
step 3, firstly dilating a sediment matrix image stack obtained in step 2 at x pixel and then eroding at x pixel;
step 4, performing image subtraction; and subtracting the sediment matrix image stack obtained in step 2 from the sediment matrix image stack obtained in step 3 to obtain a cementing hydrate image stack;
step 5, performing image subtraction again; and subtracting the cementing hydrate image stack obtained in step 4 from the pore image stack obtained in step 2 to obtain a new pore image stack corresponding to the cementing hydrate image stack obtained in step 4;
step 6, splicing and combining the sediment matrix image stack obtained in step 2, the cementing hydrate image stack obtained in step 4 and the new pore image stack obtained in step 5 to form a digital rock core image stack with the sediment matrix, the cementing hydrate and the pore, which is the digital rock core image stack of the cementing hydrate sediment;
step 7, repeatedly executing step 3 to step 6, and adjusting x value to obtain the digital rock core image stacks of the cementing hydrate sediment with different hydrate saturations.

Assignees

• Univ Dalian Tech

Inventors

• Song Yongchen
• Li Yanghui
• Wu Peng
• Sun Xiang
• Liu Weiguo
• Zhao Jiafei
• Yang Mingjun
• Yang Lei
• Ling Zheng

Classifications

• G06V10/467

  Encoded features or binary features, e.g. local binary patterns [LBP] · CPC title

• G06T2207/20036

  Morphological image processing · CPC title

• G06T7/155 Primary

  involving morphological operators · CPC title

• G06T17/10

  Constructive solid geometry [CSG] using solid primitives, e.g. cylinders, cubes · CPC title

• G06T2207/10081

  Computed x-ray tomography [CT] · CPC title