Seismic exploration using non-impulsive vibratory sources activated by stationary, Gaussian codes to simulate an impulsive, causal generating, recording and pre-processing system and processing the results into distortion-free final records

Claim 1

A method of seismic surveying using non-impulsive vibratory sources that recovers all the essential information of full-waveform recording in a distortion-free manner whereby operations in accordance with an impulsive, causal exploration system are simulated, which comprises: A. injecting non-impulsive, seismic vibrations into the earth by activating at least one vibratory source with a driving code of minimum phase, Gaussian, zero-mean, stationary characteristics; B. recording the seismic vibrations that have propagated through the earth from said at least one vibratory source to at least one receiver within said wellbore; and C. cross-correlating a full-waveform preserved representation of a precursor Gaussian, zero-mean, stationary code, unfiltered, with said received seismic vibrations; the result of said cross-correlation being a seismic survey record that is essentially distortion-free and single-sided with time simulating results obtainable in accordance with said impulsive causal exploration system.

Claim 2

A method of seismic surveying using non-impulsive vibratory sources that recovers all the essential information of full-waveform recording in a distortion-free manner whereby operations in accordance with an impulsive, causal exploration system are simulated, which comprises: A. injecting non-impulsive, seismic vibrations into the earth by activating at least one vibratory source with a driving code of minimum phase, Gaussian, zero-mean, stationary characteristics; B. recording the seismic vibrations that have propagated through the earth from said at least one vibratory source to at least one receiver within said wellbore; and C. cross-correlating a full-waveform preserved representation of a precursor Gaussian, zero-mean, stationary code, unfiltered, with said received seismic vibrations; the result of said cross-correlation being a seismic survey record that is essentially distortion-free and single-sided with time simulating results obtainable in accordance with said impulsive causal exploration system.

Claim 7

A method of seismic surveying using non-impulsive vibratory sources whereby operations in accordance with an impulsive, causal exploration system, is simulated, which comprises: A. generating a Gaussian, zero-mean, and stationary precursor code; B. filtering said precursor code through a minimum-phase band-pass filter; C. driving at least one substantially linearly-responding seismic vibratory source with the resultant filtered code to inject non-impulsive signals into the earth for a time interval longer than the recording interval of the resultant seismic waves; D. recording the full-wave seismic signals detected by at least one receiver positioned in said wellbore to detect said resultant seismic waves; E. recording a waveform-preserved representation of said precursor Gaussian, zero-mean, stationary code without filtering thereof; and F. cross-correlating said waveform-preserved representation of said precursor code with the full-wave detected seismic signals; the result of said cross-correlating being a seismic record that is essentially distortion-free and single-sided with time) simulating results obtainable in accordance with said impulsive causal exploration system.

Claim 8

A method of seismic surveying using non-impulsive vibratory sources whereby operations in accordance with an impulsive, causal exploration system, is simulated, which comprises: A. generating a Gaussian, zero-mean, and stationary precursor code; B. filtering said precursor code through a minimum-phase band-pass filter; C. driving at least one substantially linearly-responding seismic vibratory source with the resultant filtered code to inject non-impulsive signals into the earth for a time interval longer than the recording interval of the resultant seismic waves; D. recording the full-wave seismic signals detected by at least one receiver positioned in said wellbore to detect said resultant seismic waves; E. recording a waveform-preserved representation of said precursor Gaussian, zero-mean, stationary code without filtering thereof; and F. cross-correlating said waveform-preserved representation of said precursor code with the full-wave detected seismic signals; the result of said cross-correlating being a seismic record that is essentially distortion-free and single-sided with time) simulating results obtainable in accordance with said impulsive causal exploration system.

Claim 10

A method of seismic surveying using at least one non-impulsive vibratory source that recovers all essential information of full-waveform recording, in which operations in accordance with an impulsive, causal exploration system are simulated, which comprises: A. injecting non-impulsive, seismic vibrations into the earth by activating at least one vibratory source with a driving code of minimum-phase, Gaussian, zero-mean, stationary characteristics; B. recording a full-wave unfiltered representation of said code; C. recording a waveform-preserved representation of the seismic vibrations that have propagated through the earth from said at least one vibratory source to at least one receiver in said wellbore in an up-going direction; and D. cross-correlating said full-wave representation of said unfiltered Gaussian, zero-mean, stationary code with said waveform-preserved representation of the recording of said propagated seismic vibrations by said receiver; the result of said cross-correlation being a seismic survey record essentially distortion-free and single sided with time, simulating results obtainable by said impulsive causal exploration system.

Claim 11

A method of seismic surveying using at least one non-impulsive vibratory source that recovers all essential information of full-waveform recording, in which operations in accordance with an impulsive, causal exploration system are simulated, which comprises: A. injecting non-impulsive, seismic vibrations into the earth by activating at least one vibratory source with a driving code of minimum-phase, Gaussian, zero-mean, stationary characteristics; B. recording a full-wave unfiltered representation of said code; C. recording a waveform-preserved representation of the seismic vibrations that have propagated through the earth from said at least one vibratory source to at least one receiver in said wellbore in an up-going direction; and D. cross-correlating said full-wave representation of said unfiltered Gaussian, zero-mean, stationary code with said waveform-preserved representation of the recording of said propagated seismic vibrations by said receiver; the result of said cross-correlation being a seismic survey record essentially distortion-free and single sided with time, simulating results obtainable by said impulsive causal exploration system.