Title :
An effective method to calculate permeability based on Stoneley waves
Author :
Peng Liu ; Wenxiao Qiao ; Xiaohua Che ; Ruijia Wang ; Xiaodong Ju ; Junqiang Lu
Author_Institution :
State Key Lab. of Pet. Resources & Prospecting, China Univ. of Pet., Beijing, China
Abstract :
An algorithm of extracting formation permeability from array waveform data is specially designed for multipole array acoustic logging tool (MPAL). Purely transmitted Stoneley waves are obtained after digital filtering and waveform truncation. The corresponding amplitude curves of Stoneley waves are acquired by carrying out a Fast Fourier Transformation (FFT). Weighted spectral semblance method is used to calculate the slowness dispersion curve of Stoneley waves, and attenuation dispersion curves are obtained by using the least square fitting method. Matrix equation based on the boundary conditions at the borehole wall is applied to calculate slowness dispersion curves of Stoneley waves of equivalent elastic formation. At the end, the simplified Biot-Rosenbaum model is used to inverse formation permeability. This method is attached to log evaluation and application desktop (LEAD) of CNPC to process the logging data of oilfields. Processing results demonstrate that this method is able to calculate formation permeability fast and effectively, and the permeability obtained this way has good consistency with that of the nuclear magnetic resonance (NMR) method.
Keywords :
fast Fourier transforms; filtering theory; geophysics computing; least squares approximations; matrix algebra; nuclear magnetic resonance; permeability; Biot-Rosenbaum model; CNPC; LEAD; MPAL; Stoneley waves; array waveform data; attenuation dispersion curves; digital filtering; fast Fourier transformation; formation permeability; least square fitting method; log evaluation and application desktop; matrix equation; multipole array acoustic logging tool; nuclear magnetic resonance method; waveform truncation; weighted spectral semblance method; Acoustics; Arrays; Attenuation; Biological system modeling; Dispersion; Nuclear magnetic resonance; Permeability; Stoneley wave; acoustic logging; permeability; simplified Biot-Rosenbaum model;
Conference_Titel :
Image and Signal Processing (CISP), 2013 6th International Congress on
Conference_Location :
Hangzhou
Print_ISBN :
978-1-4799-2763-0
DOI :
10.1109/CISP.2013.6743891