Seismic surveying method

• US 6,754,590 B1
• Filed: 11/16/2001
• Issued: 06/22/2004
• Est. Priority Date: 05/19/1999
• Status: Expired due to Fees

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: WesternGeco LLC (Schlumberger NV)
• Inventors: Moldoveanu, Nicolae
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): Le, Toan M.
• Application Number:
  US09/979,511
• Time in Patent Office: 949 Days
• Field of Search: 702/14, 367/56
• US Class Current: 702/14
• CPC Class Codes: G01V 1/005 with exploration systems emitting special signals, e.g. frequency swept signals, pulse sequences or slip sweep arrangements
• CPC Class Codes: G01V 1/006 generating single signals by using more than one generator, e.g. beam steering or focusing arrays G01V1/13, G01V1/3861 take precedence

Abstract

An improved method of acquiring seismic data using a plurality of vibratory seismic sources including the steps of deploying a seismic sensor deploying a plurality of vibratory seismic sources at different source points; simultaneously actuating the seismic sources; acquiring seismic data attributable to the seismic sources using the seismic sensor; redeploying at least two seismic sourc, one seismic source being thereby positioned at a source point previously occupied by the other seismic source; simultaneously actuating the redeployed seismic sources; and acquiring seismic data attributable to the redeployed seismic sources using said seismic sensor. The present invention also involves an improved method of acquiring seismic data using a plurality of vibratory seismic sources, where each seismic source is capable of producing seismic energy within given frequency ranges, including the steps of deploying a seismic sensor, deploying a plurality of vibratory seismic sources at different source points; simultaneously actuating the seismic sources in such a manner that the frequency range of the seismic energy produced by one seismic source is substantially outside the frequency range of the seismic energy produced by another seismic source; and acquiring seismic data attributable to the seismic sources using the seismic sensor.

Claims

1. A method of seismic surveying using a plurality of vibratory seismic sources, the method including the steps of:

deploying at least one seismic sensor;

deploying a plurality of vibratory seismic sources at different source points;

simultaneously actuating said seismic sources;

acquiring seismic data attributable to said seismic sources using said seismic sensor;

redeploying said seismic sources so that at least one of them is positioned at a source point previously occupied by another of them;

simultaneously actuating said redeployed seismic sources;

acquiring seismic data attributable to said redeployed seismic sources using said seismic source;

decomposing said acquired seismic data into components attributable to each said seismic source; and

stacking together components attributable to seismic sources located at a common source point.

2. A method according to claim 1, wherein said simultaneously actuating steps each comprise simultaneously actuating each seismic source M times at each source point, where M is not less than the number of seismic sources.

3. A method according to claim 1, further including the step of noise attenuating at least one of said components before said components are stacked together.

4. A method according to claim 1, wherein the respective outputs of said seismic sources are recorded and used in processing said acquired seismic data.

5. A method according to claim 1, wherein said seismic data is inverted using theoretical or optimal seismic source output.

6. A method according to claim 1, wherein each said seismic source is capable of producing seismic energy within a respective frequency range and the frequency range of the seismic energy produced by one said seismic source is substantially outside the frequency range of seismic energy produced by anon said seismic source when said seismic sources are simultaneously actuated.

7. A method according to claim 6, wherein said seismic sources have sweep tapers and a sweep taper of one said seismic source overlaps a sweep taper of another said seismic source.

8. A method according to claim 6, wherein the frequency range of one said seismic source has first order harmonics that do not overlap the frequency range of another said seismic source.

9. A method according to claim 1, wherein said redeploying step comprises shifting said seismic sources one said source point in a common direction upon a common path.