Effective Elastic Parameters for Anisotropic Seismic Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional seismic data modeling and inversion methods assume local isotropy, which is inadequate for accurately processing anisotropic seismic data from orthorhombic and tilted transverse isotropic media, leading to errors in hydrocarbon reservoir location.
Innovation Solution
The method involves obtaining seismic data with varying azimuth angles, calculating elastic and anisotropy parameter values, and applying isotropic-type processing techniques using effective elastic parameter values to create a quantitative model of the underground formation, specifically for orthorhombic and tilted transverse isotropic media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional isotropic methods are used for seismic data processing, then processing simplicity is maintained, but accuracy of hydrocarbon reservoir location deteriorates due to inadequate handling of anisotropic effects
Solution Approach 1:
The patent transforms anisotropic elastic parameters (VTI or orthorhombic) into effective isotropic elastic parameters through mathematical transformations. This parameter change allows the use of simpler isotropic processing methods while accounting for anisotropic effects, thereby improving location accuracy without proportionally increasing processing complexity. The transformation involves calculating effective parameters from anisotropic parameters and azimuth angles, enabling isotropic-type processing to handle anisotropic data.
2Measurement precision
If anisotropic parameters are explicitly incorporated into inversion, then modeling accuracy improves, but the number of unknown values increases making inversion even harder
Solution Approach 1:
The patent extracts the essential anisotropic effects and incorporates them into effective isotropic parameters, rather than explicitly including all anisotropic parameters in the inversion. This extraction approach reduces the number of unknown values in inversion while preserving the critical anisotropic information needed for accurate modeling. The effective parameters encapsulate the anisotropic behavior in a reduced parameter set that can be handled by standard inversion algorithms.
3Ease of operation
If isotropic assumption is made for underground formation, then processing simplicity is maintained, but significant errors occur in locating hydrocarbon reservoirs in anisotropic media
Solution Approach 1:
The patent introduces effective isotropic parameters as an intermediary between the actual anisotropic formation properties and the isotropic processing algorithms. These effective parameters act as a mediator that translates anisotropic characteristics into an isotropic framework, allowing simple isotropic processing methods to accurately handle anisotropic data. The intermediary parameters bridge the gap between formation reality and processing assumptions.
Data Source
AI summary
Methods and devices for seismic exploration of an underground formation including an orthorhombic anisotropic medium or a tilted transverse isotropic medium are provided. Isotropic-type processing techniques use effective elastic parameter values calculated based on elastic parameter values, anisotropy parameter values and azimuth angle values for the orthorhombic anisotropic medium. For the tilted transverse isotropic medium, the effective elastic parameter values depend also on the tilt angle thereof.