Patent ID: 11880012
Assignee: CHINA NATIONAL PETROLEUM CORPORATION
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 2:
3. The method for extracting a downgoing wavelet and attenuation parameters from VSP data according to claim 1, wherein subtracting the downgoing wavelet log spectrum from the multi-trace downgoing P-wave log spectrum, to obtain the wavelet-corrected multi-trace downgoing P-wave log spectrum, comprising:
performing flattening processing on each current trace of the multi-trace downgoing P-wave log spectrum using the intercept and the slope to obtain flattened multi-trace downgoing P-wave log spectrum;
stacking the flattened multi-trace downgoing P-wave log spectrum to obtain a downgoing wavelet log spectrum;
subtracting the downgoing wavelet log spectrum from each current trace of downgoing P-wave log spectrum, to obtain an updated trace of downgoing P-wave log spectrum; and
replacing the current trace of downgoing P-wave log spectrum with the updated trace of downgoing P-wave log spectrum if a difference between parameters of the updated trace of downgoing P-wave log spectrum and parameters of the current trace of downgoing P-wave log spectrum is not within a preset range; iteratively performing the above steps until the difference between the parameters of the updated trace of downgoing P-wave log spectrum and the parameters of the current trace of downgoing P-wave log spectrum is within the preset range; and determining a final multi-trace downgoing P-wave log spectrum as the wavelet-corrected multi-trace downgoing P-wave log spectrum.