Multiple seismic signal inversion
The invention relates to methods and equipment for acquiring and processing marine seismic data are disclosed that correct source movement during inversion. By correcting source movement during inversion, multiple data sets may be acquired independently during overlapping time periods thus reducing the number of sweeps required, generating greater amounts of data, and simplifying data processing.
1. A method of recording multiple marine seismic signals comprising:
a) deploying two or more independent phase encoded vibrational seismic sources, and three or more seismic receivers spaced the same substantially common distance from one another into the water to be towed by a boat;
b) while in motion, transmitting multiple simultaneous sweep signals from the independent phase encoded seismic sources;
c) while in motion, recording multiple simultaneous phase encoded seismic signals (b);
d) inverting the recorded seismic signals in (c);
e) separating signals at each receiver into separate source specific signals; and
f) taking the source-receiver pair signals and stacking them based on a substantially common location of the respective sources and receivers at the time of the respective sweep so as to correct for the motion of the sources, receivers and common mid points.
2. The method according to claim 1 , wherein said independent phase encoded seismic sources include ZENSEIS™ seismic, vibroseis, seismic vibrators, high fidelity vibratory seismic (HFVS), cascaded HFVS, combined HFVS, slipsweep, and combinations thereof, said sources being operated independently without coordinated synchronized signals.
3. The method according to claim 2 wherein the sources are spaced at a substantially common distance from one another and the points at which the sweeps are initiated are spaced at the same substantially common distance from one another.
4. The method according to claim 1 wherein two or more streamers of receivers are laterally offset from one another to acquire three dimensional seismic data.