Method and device of identifying fracture

Patent metadata

Field	Value
Publication number	US-10845495-B2
Application number	US-201815878254-A
Country	US
Kind code	B2
Filing date	Jan 23, 2018
Priority date	Aug 7, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A method and device of identifying a fracture are provided in the embodiments of the present application. The method comprises: determining three components of structure quantification for each data point in a seismic data volume; constructing a structure quantification matrix of the data point according to the three components of structure quantification for each of the data points; determining feature value and feature vector of the structure quantification matrix of each of the data points; determining fracture attribute value of the data point according to the feature value and feature vector of the structure quantification matrix of each of the data points; constructing a data volume of the fracture attribute according to the fracture attribute values of respective data points; and performing a fracture extraction for the data volume of the fracture attribute according to the feature vectors of the structure quantification matrix of the respective data points. The embodiments of the present application can improve the accuracy of identifying a minor fracture, so as to realize an effective identification of the minor fracture.

First claim

What is claimed is:

1. A method of identifying a fracture of a stratum, comprising:
obtaining a seismic data volume regarding the stratum;
determining three components of structure quantification for each data point in the seismic data volume;
constructing a structure quantification matrix of the data point according to the three components of structure quantification for each of the data points;
determining feature value and feature vector of the structure quantification matrix of each of the data points;
determining fracture attribute value of the data point according to the feature value and feature vector of the structure quantification matrix of each of the data points, the fracture attribute value indicating a degree of the fracture of the stratum;
constructing a data volume of the fracture attribute according to the fracture attribute values of respective data points; and
performing a fracture extraction for the data volume of the fracture attribute according to the feature vectors of the structure quantification matrix of the respective data points so as to identify a position of a fracture.

2. The method according to claim 1 , wherein the step of determining three components of structure quantification for each data point in the seismic data volume comprising:
convolving each of the data points in the seismic data volume and a first order derivative of Gaussian function to obtain three components of structure quantification for the data point.

3. The method according to claim 2 , wherein convolving each of the data points in the seismic data volume and the first order derivative of Gaussian function according to the following equations:
d ( x )= E ( u ( x,y,z )⊗ G ( x ,σ)′);

d ( y )= E ( u ( x,y,z )⊗ G ( y ,σ)′);

d ( z )= E ( u ( x,y,z )└ G ( z ,σ)′);

where d(x), d(y) and d(z) are the three components of structure quantification for the data points, respectively; u(x,z) is a data amplitude of the data points; E( ) is a weighted range control function; and G(x,σ)′, G(y,σ)′ and G(z,σ)′ are the first order derivatives of the Gaussian function in x, y and z directions, respectively.

4. The method according to claim 3 , wherein the weighted range control function comprises:

σ
=

α
×

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where σ is a weighted scope control coefficient; α is a constant coefficient; and f is a primary frequency of the data points.

5. The method according to claim 1 , wherein constructing the structure quantification matrix of each of the data points according to the following equation:

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Assignees

• Petrochina Co Ltd

Inventors

• Feng Chao
• Teng Tuanyu
• Yao Qingzhou
• Ma Delong
• Zhang Han
• Yin Lu
• Huang Linjun

Classifications

• E21B47/005

  Monitoring or checking of cementation quality or level · CPC title

• G01V2210/63

  Seismic attributes, e.g. amplitude, polarity, instant phase · CPC title

• G01V2210/642

  Faults · CPC title

• G01V1/307

  for determining seismic attributes, e.g. amplitude, instantaneous phase or frequency, reflection strength or polarity · CPC title

• G01V1/50 Primary

  Analysing data · CPC title