Video: High Resolution Imaging Using Sea Surface Related Multiples
- Shaoping Lu (PGS) | Dan Whitmore (PGS) | Jack Kinkead (PGS) | Alejandro Valenciano (PGS) | Ruben D. Martinez (PGS)
- Document ID
- Offshore Technology Conference
- Publication Date
- Document Type
- 2014. Offshore Technology Conference
- Geohazard, High resolution, Illumination, Multiples, Depth imaging
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In marine oil and gas exploration of seismic data acquisition, both primary and multiple reflections are recorded at the streamers. In seismic data processing, primaries are usually used as signal to image the subsurface; multiples are regarded as noise to be removed (SRME) (Verschuur, 1991). Multiples can also be treated as useful information to image the earth. The idea of using sea surface related multiples as valuable information for depth migration has been discussed by Berkhout and Verschuur (1994), Guitton (2002) and Whitmore et al. (2010). Lu et al. (2011) presents the first 3D example of imaging sea surface related multiples using towed streamer acquisition geometry.
Conventional shot domain migration constructs a subsurface image by combining the forward extrapolated down-going wavefield from a source location and reverse extrapolated up-going wavefield originating at the surface receiver positions. Similarly, sea surface related multiples can also be used for imaging the subsurface where the boundary data for the down-going and up-going wavefields are generated at the receiver locations via up-down wavefield separation. After up-down separation, the down-going and up-going wavefields act as the source and receiver surface wavefields and exist at the receiver positions.
Compared to primaries imaging, multiples imaging can help to enhance subsurface illumination in depth migration; because the source wavefield (down-going wavefield) of multiples imaging is more broadly distributed than the source wavefield of primaries imaging. More significantly, multiples imaging improves angular illumination by using additional source wavefield coverage.
In this paper, 3D field data examples are used to compare imaging of primaries and imaging of multiples. A shallow water field data example shows the successful application of the technology to mitigate the acquisition footprint and generate very high resolution images. A deep water field data example demonstrates the opportunity of the technology to improving subsurface illumination and angular illumination when applied to wide azimuth acquisition. By enhancing subsurface illumination in depth migration, the technology has the potential of improving quality of subsurface reservoir characterization and reducing drilling hazard risks.