field geometry for multichannel seismic (mcs) profiles
DESCRIPTION
Introduction to Seismic Reflection Imaging: Pt 2. FIELD GEOMETRY FOR MULTICHANNEL SEISMIC (MCS) PROFILES. Layouts for a comon-shot gather; a cmmon mid-point gather; and a common receiver gather. - PowerPoint PPT PresentationTRANSCRIPT
FIELD GEOMETRY FOR
MULTICHANNEL SEISMIC (MCS) PROFILES
Introduction to Seismic Reflection Imaging: Pt 2
Layouts for (A) a comon-shot gather; (B) a cmmon mid-point gather; and(C) a common receiver gather.
Sequence of survey layouts to acquire a 6-fold coverage; S indicates the source and G a geophone (or hydrophone).
Fold = N/2n whereN = total number of receiver groups;n = number of group intervals moved between shots
Results of common mid-point (CMP) stacks showing improvement in imaging for summations of 6, 18 and 48 shot-receiver pairs.
A. Composite shallow reflection record made up of five separate 12-channel records, each of which was recorded with a different time delay between the shot instant and the start of recording.
B. Corresponding time-distance graph identifying the major seismic events on the record. The optimum window is that range of source-receiver separations that allows the target reflection to be observed without interference from other events.
Example of a common mid-point gather
Some Examples of Shot Gathers
The application of a time-varying gain function to a waveform exhibiting spherical divergence, in order to recover signal amplitudes at later travel times. Gain functions are applied in discrete windows(labelled 1 to 5 as shown).
Types of filters: (A) bandpass; (B) low-cut (high-pass); (C) high-cut (low-pass); (D) notch.
filtered
unfiltered