Deterministic phase correction and application
AssigneeConocoPhillips Company
InventorsPeter M. EICK, Joel D. BREWER, Shan SHAN
Life of this patent
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Abstract
A method of more accurate phase encoding of phase offset vibrators used in simultaneous-multiple-sourcing 3D seismic mapping. The method measures the actual input energy and the proxy energy thereby determining a bulk error and a frequency-dependent error, both to be applied to correct the proxy energy. The corrected proxy energy is then used to perform actual seismic survey, and the inversion is then performed using the corrected proxy energy to source separate each vibe where the error is minimized.
Claims17
A method of source separating composite seismic data that includes signals from two or more seismic sources, said two or more seismic sources operating at the same time but in offset phases and delivering source seismic energy signals into the earth, and at least one seismic receiver receiving seismic data from said two or more seismic sources and recording the seismic energy received by said seismic receiver as the composite seismic data, and wherein proxy aux channels are used to generate the source seismic energy signals, the method comprises:
- a) obtaining a baseline measurement of source seismic energy signal at each frequency for each of said seismic sources;
- b) obtaining a simultaneous proxy measurement of the source seismic energy signal at each frequencies for each of said seismic sources;
- c) measuring a bulk sweep-to-sweep phase variation between the baseline measurement of step (a) and the proxy measurement of step (b) of the output source seismic energy to determine the bulk phase error;
- d) measuring a frequency dependent sweep-to-sweep phase variation between the baseline measurement of step (a) and the proxy measurement of step (b) to determine the frequency dependent phase error;
- e) applying the bulk and frequency dependent phase errors to the proxy source signal as an aux channels to create a corrected aux channel for each of the two or more seismic sources for each sweep;
- f) inputting the corrected proxy aux channels for the seismic sources and receiving and recording the composite seismic data with the at least one seismic receiver into an inversion program;
- g) performing an inversion on the revised composite seismic data to source separate the revised composite seismic data.
A method of source separating composite seismic data that includes signals from two or more seismic sources, said two or more seismic sources operating at the same time but in offset amplitude and delivering source seismic energy signals into the earth, and at least one seismic receiver receiving seismic data from said two or more seismic sources and recording the seismic energy received by said seismic receiver as the composite seismic data, and wherein proxy aux channels are used to generate the source seismic energy signals, the method comprises:
- a) obtaining a baseline measurement of source seismic energy signal at each frequency for each of said seismic sources;
- b) obtaining a simultaneous proxy measurement of the source seismic energy signal at each frequencies for each of said seismic sources;
- c) measuring a bulk sweep to sweep amplitude variation between the baseline measurement of step (a) and the proxy measurement of step (b) of the output source seismic energy to determine the bulk amplitude error;
- d) measuring a frequency dependent sweep to sweep amplitude variation between the baseline measurement of step (a) and the proxy measurement of step (b) to determine the frequency dependent amplitude error;
- e) applying the bulk and frequency dependent amplitude variations to the proxy aux channels to create a corrected aux channel for each of the two or more seismic sources for each sweep;
- f) inputting the corrected proxy aux channels for the seismic sources and receiving and recording the composite seismic data with the at least one seismic receiver into an inversion program;
- g) performing an inversion on the revised composite seismic data to source separate the revised composite seismic data.
An improved method of source separating composite data for a seismic survey by acquiring receiver data corresponding to reflected phase encoded vibratory signals simultaneously generated by multiple sources and inverting said receiver data to separate said phase encoded vibratory signals;
- the improvement comprising first measuring a bulk phase shift error and a frequency-dependent phase shift error at least once for a particular ground condition, acquiring receiver data corresponding to reflected phase encoded vibratory signals simultaneously generated by multiple sources, and compensating for said bulk phase shift error and said frequency-dependent phase shift error before said inverting step, and inverting said receiver data to separate said phase encoded vibratory signals.
A method of source separating composite seismic data, comprising:
- a) measuring a bulk sweep-to-sweep phase variation to determine a bulk phase error;
- b) measuring a frequency dependent sweep-to-sweep phase variation to determine a frequency dependent phase error;
- c) correcting acquired seismic data to account for said bulk phase error and said frequency dependent phase error to create revised composite seismic data;
- d) performing an inversion on said revised composite seismic data to source separate the revised composite seismic data into source separated seismic data.
Dependencies are inferred from the claim text.