Virtual 3D geometry by common shot

Theory

Regularization in 3D seismic processing reorganizes irregularly sampled field data into a uniformly spaced 3D grid (inline, crossline, and time/depth). This ensures data compatibility with processing algorithms (e.g., migration, inversion) that assume regular sampling. Midpoint consistency ensures that traces sharing the same midpoint (midway between source and receiver) are grouped and interpolated spatially and azimuthally without bias. T

This procedure creates regularized geometry based on common shot. For each given common shot, creates virtual regularized geometry.

Input data

Input bin grid

connect/reference to Output bin grid. This bin grid information is used for creating regularized geometry.

Parameters

Enable GUI

By default, FALSE (Unchecked).

Receiver line length

specify the receiver line length in meters.

Distance between receivers

this is the distance between two adjacent receivers. Also known as Receiver Interval.

Distance between receiver lines

specify the distance between two adjacent receiver lines.

Count of receiver lines

provide the total number of receiver lines in the survey area.

Direction of receiver line

specify the receiver line direction i.e., angle in degree of receiver lines.

1st receiver line - X coordinate of 1st receiver

specify the 1st x-coordinate of 1st receiver of the 1st receiver line

1st receiver line - Y coordinate of 1st receiver

specify the 1st y-coordinate of 1st receiver of the 1st receiver line

Source line length

specify the source line length in meters.

Distance between sources

specify the distance between two adjacent shot points. This is also known as Shot point interval.

Distance between source lines

specify the distance between two adjacent source lines.

Count of source lines

specify the total number of source lines.

Direction of source line relative to receiver line { 90, 270 } - specify the direction of shooting of shot line with respect to receiver line. By default, 90. Angle between source and receiver lines, for orthogonal acquisition system the values are 90 or 270.

1st source line - X coordinate of 1st source

specify 1st x-coordinates of 1st source of the 1st source line

1st source line - Y coordinate of 1st source

specify 1st y-coordinates of 1st source of the 1st source line

Trace Selection

this section deals with the trace selection, offset and azimuth information

Offset limitation type { Ellipse, Rectangle }

select the offset limitation by Ellipse or Rectangle. By default, Ellipse.

Trace Selection Mode { None, By Offset, By Offset / Azimuth }

no decimation will be used, the coverage depends on acquisition" parameters only

Trace Selection Mode - By Offset

decimation by offset with preserved azimuth distribution

Offset increment

Offset step used for decimation

Decimation factor for min offset

Decimation factor that will be used for near offset decimation

Decimation factor for max offset

Decimation factor that will be used for far offset decimation

Trace Selection Mode - By Offset / Azimuth

decimation by offset and azimuth distribution

Offset increment - see above

Azimuth increment

Azimuth step used for decimation

Maximum offset

maximum offset for active spread

Maximal fold of source gather (non positive number: do not use)

Maximum number of traces for shot gather, decimation with preserved offset and azimuth distribution

Narrow azimuth maximal distance

Maximum distance in crossline direction fro active spread

Narrow azimuth { disable, along receiver line }

Turn on / off offset limitation in crossline direction for active spread

Cut off fold map - This will  produce output geometry only for bins with non zero fold according to the "Bin grid for input data"

Max distance to valid bin

Constant topography value - Constant topography value for output geometry, -999 use values from "Bin grid for input data"

Datum position { Constant, On topography }

choose the datum position from the drop down menu. By default, On topography.

Constant datum

if datum position is Constant, specify the constant datum value.

Write output trace vector to disk

this allows the user to write the output trace vector into a file

Output seismic file name

specify the output file name.

Settings

Number of threads

One less than total no of nodes/threads to execute a job in multi-thread mode. Limit number of threads on main machine.

Skip

By default, FALSE(Unchecked). This option helps to bypass the module from the workflow.

Output data

Trace headers

generates the output trace headers as a vista

Information

Number of source gathers

displays total number of source gathers of the survey area

Minimal source fold

displays minimum source fold

Source fold - 1st quartile

displays 1st quartile source fold

Source fold - median

displays median source fold

Source fold - 3rd quartile

displays 3rd quartile source fold

Maximal source fold

displays maximum source fold

Examples

In this example workflow, the user has to define the survey geometry parameters like source and receiver intervals, source and receiver lines, offsets and coordinates etc in the parameters field.

In case the user wants to use the parameters of the input data, click on the action items option "Get parameters from binning". It will automatically fills the parameters however the user MUST pay attention to the automatically filled parameters. It is the user's responsibility to input the correct parameters for creating a virtual surface consistent regularization scheme.

Actions

Get parameters from binning

this allows the user to get all the parameters required for binning. Click this option and it will automatically fills the parameters information from the trace headers.

Video lesson

YouTube video lesson, click here to open [VIDEO IN PROCESS...]

Related articles

Yilmaz. O., 1987, Seismic data processing: Society of Exploration Geophysicist

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