Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

A Prediction Method of Orthotropic Shale Brittleness Index

An orthotropic and brittle index technology, applied in the field of drilling and completion engineering, can solve the distortion of shale brittleness index evaluation results, the inability to evaluate the brittleness anisotropy of shale formations, and the inability to apply orthotropic shale stratum and other issues, to achieve the effect of accurate reflection

Active Publication Date: 2022-03-11
SOUTHWEST PETROLEUM UNIV
View PDF14 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For deep shale, due to the significant anisotropy of shale and the development of a large number of vertical and orthogonal micro-cracks in the shale formation, the shale exhibits orthotropic characteristics, perpendicular to the bedding plane and parallel to the bedding plane. The brittleness index in the direction of the bedding plane and the direction perpendicular to the development of microcracks is usually inconsistent, and most of the current research focuses on the transversely isotropic shale, ignoring the brittle anisotropy of orthotropic shale, which has It may lead to distortion or even serious errors in the evaluation results of shale brittleness index
[0004] However, in the existing methods, the shale brittleness evaluation method based on mineral components cannot evaluate the brittle anisotropy of shale formations, while the method based on elastic parameters to evaluate the brittleness index can only evaluate the brittleness characteristics perpendicular to the bedding plane. Neither can be applied to orthotropic shale formations

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A Prediction Method of Orthotropic Shale Brittleness Index
  • A Prediction Method of Orthotropic Shale Brittleness Index
  • A Prediction Method of Orthotropic Shale Brittleness Index

Examples

Experimental program
Comparison scheme
Effect test

Embodiment

[0104] Taking the Longmaxi shale at 3171 meters in Well X1 as an example, the elastic parameter in the shale formation coordinate system: E 1 =46.07GPa,E 2 =43.43GPa,E 3 =36.59GPa, ν 12 =0.262, ν 13 =0.268, ν 21 =0.247, ν 23 =0.253, ν 31 =0.213, ν 32 = 0.213.

[0105] Now, the anisotropic brittleness index BI 3_1 , the anisotropic brittleness index BI along the y-axis 3_2 , the anisotropic brittleness index BI along the z-axis 3_3 Numerical simulation study of the influence of , the results are as follows:

[0106] (1) image 3 is the anisotropic brittleness index BI along the x-axis under different azimuths α and inclination β 3_1 The 3D graph and its corresponding section graph after polar coordinate conversion to Cartesian coordinates.

[0107] The positive and negative signs in the figure do not mean that the brittleness index is negative, but are related to the azimuth angle α and the inclination angle β. The spatial form of the figure is an irregular ellips...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a method for predicting the brittleness index of orthotropic shale, which includes measuring the longitudinal wave velocity in six directions and the shear wave velocity in three directions; calculating the anisotropic stiffness coefficient of shale; Stiffness matrix C of heterogeneous shale ORT ; Determine the anisotropic elastic modulus and Poisson's ratio of the shale; determine the flexibility matrix S of the orthotropic shale in the formation coordinates ORT ; Calculation of shale elastic modulus and Poisson's ratio under the wellbore observation coordinates; calculation of brittleness index of orthotropic shale. The invention considers the anisotropy characteristics of shale, evaluates the brittleness index of orthotropic shale formation from the perspective of actual drilling, overcomes the defect that the traditional shale brittleness index ignores the influence of anisotropy, and can more accurately reflect the shale brittleness Exponential anisotropy and its influence on well trajectory can provide scientific basis and decision-making support for shale gas horizontal well drilling and fracturing.

Description

technical field [0001] The invention relates to a method for predicting the brittleness index of orthotropic shale, belonging to the technical field of drilling and completion engineering. Background technique [0002] The brittleness of shale is one of the important properties of rock, and the shale brittleness index is an important basis for wellbore stability analysis, hydraulic fracturing segmentation and optimization. In the process of hydraulic fracturing, the brittleness index is a key parameter to evaluate the shale's compressibility. In addition to controlling the difficulty of fracture extension in the rock, it is also a factor that affects the development of fractures. [0003] For the evaluation of shale brittleness index, the commonly used methods include: shale brittleness evaluation method based on mineral components and shale brittleness evaluation method based on elastic parameters. For deep shale, due to the significant anisotropy of shale and the developm...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): G01V1/40
CPCG01V1/40G01V2210/626
Inventor 马天寿桂俊川刘阳付建红陈平
Owner SOUTHWEST PETROLEUM UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com