Method for quantitative evaluation of self-sealing property of organic-rich shale

Patent metadata

Field	Value
Publication number	US-12436141-B1
Application number	US-202519054931-A
Country	US
Kind code	B1
Filing date	Feb 17, 2025
Priority date	May 31, 2024
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

A method for quantitative evaluation of self-sealing property of organic-rich shale includes: S1, selecting geological parameters for evaluating the self-sealing property of the organic-rich shale; S2, taking organic-rich shale samples, and measuring the geological parameters of each sample; S3, calculating a weight coefficient w; of each geological parameter; S4, calculating a self-sealing evaluation coefficient S, and correcting the S to obtain a corrected self-sealing evaluation coefficient S′; S5, establishing a self-sealing evaluation standard of the organic-rich shale according to the S′, wherein if S′≥0.6, the self-sealing grade is excellent, if 0.45≤S′<0.6, the self-sealing grade is good, if 0.3≤S′<0.45, the self-sealing grade is medium, and if S′<0.3, the self-sealing grade is poor. According to the method, the self-sealing property of the shale is quantitatively evaluated, and the preservation condition of the shale gas in the shale formation can be more accurately predicted.

First claim

What is claimed is:

1. A method for quantitative evaluation of self-sealing property of organic-rich shale, comprising:
S1, selecting geological parameters for evaluating the self-sealing property of the organic-rich shale, wherein the geological parameters comprise five geological parameters of adsorption gas content, overlying pressure, connectivity difference A, connectivity difference B and bound water content;
wherein the connectivity difference A is a difference between connectivity of shale itself and connectivity of roof strata;
wherein the connectivity difference B is a difference between the connectivity of the shale itself and connectivity of floor strata;
S2, taking a plurality of organic-rich shale samples, measuring the adsorption gas content, the overlying pressure, the connectivity difference A, the connectivity difference B and the bound water content of each of the plurality of organic-rich shale samples, and then carrying out standardization processing on each of the five geological parameters to obtain standardized geological parameters Zx ij , wherein the standardized geological parameter for the j-th geological parameter is denoted as P j , and a formula of the standardization processing is as follows:

Z
⁢

x

i
⁢
j

=

x

ι
˙

⁢
j

-

min
⁢

{

x

1
⁢
j

,

x

2
⁢
j

,
…

,

x
nj

,

}

max
⁢

{

x

1
⁢
j

,

x

2
⁢
j

,
…

,

x
nj

,

}

-

min
⁢

{

x

1
⁢
j

,

x

2
⁢
j

,
…

,

x
nj

,

}

,

where x ij is a value of an i-th sample of a j-th geological parameter before the standardization processing; Zx ij is a value of the i-th sample of the j-th geological parameter after the standardization processing; min {x 1j , x 2j , . . . , x nj } is a minimum value of all sample data of the j-th geological parameter, max {x 1j , x 2j , . . . , x nj } is a maximum value in all sample data of the j-th geological parameter; and j=1, 2, 3, 4, 5;
S3, calculating a weight coefficient ω j′ of each of the five geological parameters to obtain five weight coefficients respectively corresponding to the five geological parameters, where ω j′ =t j ;
S4, sorting the five weight coefficients in descending order to obtain an ordered sequence: t 1 >t 2 >t 3 >t 4 >t 5 , wherein a standardized geological parameter corresponding to the weight coefficient t 1 is P 1 , a standardized geological parameter corresponding to the weight coefficient t 2 is P 2 , a standardized geological parameter corresponding to the weight coefficient t 3 is P 3 , a standardized geological parameter corresponding to the weight coefficient t 4 is P 4 , and a standardized geological parameter corresponding to the weight coefficient t 5 is P 5 ;
S5, calculating a self-sealing evaluation coefficient S, wherein a formula of the self-sealing evaluation coefficient S is as follows:

S
=

t
1

×

P
1
3

+

t
2

×

P
2
2

+

t
3

×

P
3

+

t
4

×

P
4

Assignees

• Univ Southwest Petroleum
• Univ China Geosciences Wuhan
• Univ China Petroleum Beijing

Inventors

• Zhang Kun
• He Xinyang
• Jiang Shu
• Song Yan
• Niu Hulin
• Jia Chengzao
• Jiang Zhenxue
• Jiang Lin
• Wang Xueying
• Ding Xiong
• Shu Yi
• Zhang Yi
• Qiao Yiting
• Liu Jiayi
• Peng Jun
• Li Bin
• Liu Jinhua
• Zheng Binsong
• Chen Lei
• Yang Xuefei
• Han Fengli
• Tang Weishi
• Ruan Jingru
• Gou Hengfeng
• Xiao Yi
• Li Lintao
• Liu Yipeng
• Liu Ping
• Wu Meijia
• Lu Lu
• Wang Zeyun
• Ye Laiting

Classifications

• G01N24/081

  Making measurements of geologic samples, e.g. measurements of moisture, pH, porosity, permeability, tortuosity or viscosity · CPC title

• G01N2015/0866

  Sorption · CPC title

• G01N15/08

  Investigating permeability, pore-volume, or surface area of porous materials · CPC title

• G01N33/24

  Earth materials (G01N33/42 takes precedence) · CPC title

• G01N33/246 Primary

  for water content · CPC title