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US 11,960,043 B2Granted
Data driven method to invert for the formation anisotropic constants using borehole sonic data
AssigneeSchlumberger Technology Corporation
InventorsTing Lei, Romain Prioul
Life of this patent
Estimating the term…
Abstract
A method is presented wherein inversion for formation anisotropic constants is achieved using borehole sonic data.
Claims14
A method, comprising:
- obtaining a waveform;
- processing the obtained waveform to obtain at least one of a Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersion;
- at least one of performing a computation and obtaining a library computation for interpolated theoretical dispersions of the Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersions;
- performing an initial estimate of mud slowness using both the processing of the obtained waveform and the interpolating the theoretical dispersions;
- calculating a mismatch between the processed waveform obtaining the at least one Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersion and the theoretical dispersions of the Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersions;
- estimating at least one DTmud value as a vertical depth profile;
- calculating a second mismatch between the theoretical dispersion and the processed waveform using the at least one estimated DTmud value;
- estimating at least one parameter by minimizing the second mismatch;
- using regression, calculating the at least one parameter over multiple depths;
- updating values for the at least one parameter based upon the regression;
- calculating a third mismatch between the theoretical and measured dispersions based upon the updated values for the at least one parameter based upon the regression;
- and
- estimating a final value of the at least one parameter by minimizing a mismatch between the theoretical and measured dispersions.
10 more elements
A method, comprising:
- obtaining a waveform from a sonic borehole device in a formation;
- processing the obtained waveform from the sonic borehole device to obtain at least one value of a Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersion;
- performing a computation to produce a theoretical dispersion of the Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersions for the waveform;
- performing an initial estimate of mud slowness using both the processing of the obtained waveform and the theoretical dispersion;
- calculating a first mismatch between the processed waveform obtaining the at least one Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersions and the theoretical dispersions of the Stoneley, flexural, quadrupole and Pseudo-Rayleigh dispersions;
- estimating at least one DTmud value as a vertical depth profile;
- calculating a second mismatch between the theoretical dispersion and the processed waveform using the at least one estimated DTmud value;
- estimating at least one Thomson parameter for the formation by minimizing the second mismatch;
- using regression, calculating at least one revised Thomson parameter over multiple depths;
- calculating a third mismatch between the theoretical and measured dispersions based upon the updated values for Thomson parameter based upon the regression;
- and
- estimating a final value of the at least one Thomson parameter by minimizing a mismatch between the theoretical and measured dispersions.
9 more elements
Dependencies are inferred from the claim text.