Targeted activation parameters for marine seismic sources
AssigneePGS Geophysical AS
InventorsStig Rune Lennart Tenghamn, Manuel Beitz, Christian Strand
Life of this patent
Estimating the term…
Abstract
Techniques are disclosed relating to marine geophysical surveys. Various output characteristics of a vibratory source may be modified based on whether a source is targeting an identified portion of a survey area. The portion of the survey area may be detected during the survey or may be pre-identified. In some embodiments, a survey system drives a vibratory source using digital codes having different lengths based on whether the source is targeting an identified portion of a survey area. The disclosed techniques may improve imaging of geology under certain types of formations or may reduce environmental impact, in various embodiments.
Claims13
A system, comprising:
- one or more processors;
- and
- one or more non-transitory computer readable media or memories having program instructions stored thereon that are executable by the one or more processors to:
- during a marine geophysical survey being performed in a body of water over a survey area:
- tow a survey system comprising a set of one or more vibratory signal sources;
- while the survey system is moving, detect when the survey system is targeting a portion of interest in the survey area, wherein the detecting step is based on one or more of:
- geodetic positions of the vibratory signal sources and of seismic sensors located in the survey area;
- characteristics of one or more survey traces generated by the seismic sensors responsive to seismic energy that is reflected from one or more reflectors disposed below a water bottom in the survey area;
- and
- depth of the water bottom in the targeted area;
- cause the set of one or more vibratory signal sources to exhibit a first output characteristic when the survey system is targeting the portion of interest;
- and
- cause the set of one or more vibratory signal sources to exhibit a second output characteristic, different than the first output characteristic, when the survey system is not targeting the portion of interest;
- wherein the causing steps comprise varying at least one output parameter configured to control the one or more vibratory signal sources.
A system, comprising:
- one or more processors;
- and
- one or more memories having program instructions stored thereon that are executable by the one or more processors to:
- during tow, through a body of water, of a set of one or more vibratory signal sources for a marine geophysical survey over a survey area:
- identify a portion of the survey area based on signals emitted from at least a portion of the one or more vibratory signal sources, reflected from the portion of the survey area, and measured by one or more seismic sensors, wherein the identifying is performed based on stacking survey traces and detecting a change in amplitude that meets a threshold;
- drive at least a portion of the set of signal sources using a first value of an output parameter when targeting the identified portion of the survey area;
- and
- drive at least a portion of the set of vibratory signal sources using a second value of the output parameter when targeting another portion of the survey area;
- wherein the detecting the change in amplitude is performed based on determined amplitudes from multiple monitoring windows at different depths.
Dependencies are inferred from the claim text.