Quantitative identification method for provenance of clastic rocks

Patent metadata

Field	Value
Publication number	US-2025277778-A1
Application number	US-202419000057-A
Country	US
Kind code	A1
Filing date	Dec 23, 2024
Priority date	Feb 29, 2024
Publication date	Sep 4, 2025
Grant date	—

Abstract

A quantitative identification method for provenance of clastic rocks is provided, which includes: determining a study area, a target horizon of the study area and potential provenances of the target horizon, and performing sampling on known wells of the target horizon and the potential provenances to obtain rock samples; measuring contents of light minerals, heavy minerals, and trace elements to obtain measurement results of the known wells and measurement results of the potential provenances, establishing standard fuzzy sets based on the measurement results of the potential provenances, and establishing to-be-identified fuzzy sets based on the measurement results of the known wells; assigning weight coefficients to three indicators; calculating weighted closenesses between the to-be-identified fuzzy sets and the standard fuzzy sets according to the weight coefficients; and determining a provenance of the target horizon according to the weighted closenesses and a principle of proximity selection.

First claim

1 . A quantitative identification method for provenance of clastic rocks, comprising the following steps:
S1, determining a study area, a target horizon of the study area and potential provenances of the target horizon, and performing sampling on known wells of the target horizon and the potential provenances to obtain rock samples; S2, measuring contents of light minerals, heavy minerals, and trace elements in the rock samples to obtain measurement results of the known wells and measurement results of the potential provenances, establishing standard fuzzy sets based on the measurement results of the potential provenances, and establishing to-be-identified fuzzy sets based on the measurement results of the known wells; S3, assigning weight coefficients related to importance in provenance discrimination to three indicators respectively corresponding to the light minerals, the heavy minerals and the trace elements; S4, calculating weighted closenesses between the to-be-identified fuzzy sets and the standard fuzzy sets according to the weight coefficients; and S5, determining a provenance of the target horizon according to the weighted closenesses and a principle of proximity selection; wherein after the provenance of the target horizon is determined, the quantitative identification method for provenance of clastic rocks further comprises: in response to a ratio of sedimentary rock debris of a parent rock of the provenance being greater than a preset threshold, exploring and developing the target horizon to obtain oil and gas from the target horizon.

2 . The quantitative identification method for provenance of clastic rocks as claimed in claim 1 , wherein the measuring contents of light minerals, heavy minerals, and trace elements in the rock samples in step S2 comprises:
performing thin-section preparation and microscopic identification on the rock samples to thereby obtain the contents of the light minerals and the contents of the heavy minerals; and performing content analysis on the trace elements by plasma mass spectrometry, to thereby obtain the contents of the trace elements.

3 . The quantitative identification method for provenance of clastic rocks as claimed in claim 1 , wherein in step S2, the light minerals comprise quartz, feldspar, rock debris, and other light minerals, and the rock debris comprises igneous rock debris, metamorphic rock debris, and sedimentary rock debris;
wherein the heavy minerals comprise heavy mineral assemblage, epidote, garnet, sphene, titanomagnetite and white titanium ore, and the heavy mineral assemblage consists of rutile, zircon and tourmaline; and wherein the trace elements comprise scandium (Sc), vanadium (V), chromium (Cr), cobalt (Co), nickel (Ni), zinc (Zn), gallium (Ga), rubidium (Rb) and zirconium (Zr).

4 . The quantitative identification method for provenance of clastic rocks as claimed in claim 1 , wherein the assigning weight coefficients related to importance in provenance discrimination to three indicators respectively corresponding to the light minerals, the heavy minerals and the trace elements in step S3 comprises:
using a pairwise comparison method to assign the weight coefficients to the three indicators.

5 . The quantitative identification method for provenance of clastic rocks as claimed in claim 4 , wherein the using a pairwise comparison method to assign the weight coefficients to the three indicators comprises:
step S31, based on geological experience, performing pairwise comparison on importance in provenance discrimination of the three indicators respectively corresponding to the light minerals, the heavy minerals, and the trace elements, to thereby construct a judgment matrix:

A
=

(

1

1
5

1
3

5

1

3

3

1
3

1

)

;

(
1
)

step S32, normalizing each column of the judgment matrix to obtain a a first matrix A 1 , expressed as follows:

A
1

=

(

1
9

3
23

1
13

5
9

15
23

9
23

3
9

5
23

Assignees

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

Inventors

• He Xinyang
• Zhang Kun
• Jiang Zhenxue
• Song Yan
• Jiang Shu
• Niu Hulin
• Jia Chengzao
• 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

• H01J49/105

  using high-frequency excitation, e.g. microwave excitation, Inductively Coupled Plasma [ICP] · CPC title

• G01N33/24 Primary

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

• G01N27/626

  using heat to ionise a gas · CPC title

• G01N21/84

  Systems specially adapted for particular applications · CPC title

• G06F17/16

  Matrix or vector computation {, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization (matrix transposition G06F7/78)} · CPC title