V-int to V-avg (depth)

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V-int to V-avg (depth)

 

Description

The V-int to V-avg (depth) module converts an interval velocity field defined in the depth domain into its corresponding average velocity field, also in the depth domain. Average velocity at a given depth is defined as total depth divided by one-way travel time to that depth, and is related to interval velocity by integration over depth. This conversion is commonly required when preparing velocity models for depth-domain imaging, well-to-seismic ties, or time–depth conversion using a depth-based velocity representation.

The module requires no additional user parameters. It reads the input interval velocity gather, applies the depth-domain Vint-to-Vavg conversion to each trace, and writes the resulting average velocity field to the output gather. The conversion uses the relationship Vavg(z) = z / integral(dz/Vint(z)) integrated from the surface to depth z.

Input data

Input DataItem

The sorted index item that controls the order in which input gathers are processed. This is the standard sequence control input inherited from the ISequenceNoDiff base class.

Input SEG-Y data handle

A handle to the SEG-Y file or in-memory data store containing the input interval velocity traces in the depth domain.

Input trace headers

The trace header collection associated with the input velocity gather. Spatial coordinates from these headers are propagated unchanged to the output.

Input gather

The input interval velocity gather in the depth domain (Vint-Z). Each trace represents the interval velocity as a function of depth at one CMP or grid node location.

Input stack line

Optional 2D stack line geometry associated with the input data. Used when processing 2D line-based velocity models.

Input crooked line

Optional crooked line geometry. Used when the 2D seismic line follows a non-straight surface path.

Input bin grid

Optional 3D bin grid definition that maps inline/crossline numbers to surface coordinates. Used when processing 3D velocity volumes.

Input sorted headers

The sorted index controlling gather assembly order, passed through from the standard sequence infrastructure.

Parameters

This module has no user-configurable parameters. The conversion from depth-domain interval velocity to depth-domain average velocity is performed automatically using the standard Vavg(z) = z / integral(dz/Vint(z)) relationship. All output sampling and spatial attributes are inherited from the input gather.

Settings

Auto-connection

When enabled, the module automatically connects to compatible upstream and downstream modules in the processing flow.

Bad data values option { Fix, Notify, Continue }

Controls how the module responds when bad or undefined sample values are encountered in the input velocity data. Fix replaces bad values before processing; Notify logs a warning and continues; Continue silently proceeds without correction.

Execute on { CPU, GPU }

Selects whether processing is performed on the CPU or GPU. For this lightweight conversion module, CPU execution is typically sufficient.

Distributed execution

When enabled, distributes processing across multiple compute nodes in a cluster environment. Useful for large 3D velocity volumes.

Bulk size

The number of gathers sent to each compute node per batch when running in distributed mode. Larger values reduce scheduling overhead but require more memory per node.

Limit number of threads on nodes

Sets the maximum number of CPU threads used per node when processing in distributed mode.

Job suffix

An optional text label appended to the distributed job name to help identify this processing step in cluster job queues.

Set custom affinity

When enabled, allows manual specification of the CPU core affinity mask for this module's threads.

Affinity

Specifies the CPU core affinity mask when Set custom affinity is enabled. Leave at default unless optimizing for NUMA architectures.

Number of threads

The number of parallel CPU threads used for processing. Set to match the available CPU cores on the processing machine for optimal throughput.

Skip

When enabled, this module is bypassed and input data is passed through unchanged. Use during testing to temporarily disable the conversion without removing the module from the flow.

Output data

Output DataItem

The output sequence control item passed downstream.

Output SEG-Y data handle

A handle to the output data store containing the computed depth-domain average velocity traces, ready for use by downstream modules.

Output trace headers

Trace headers for the output average velocity gather, with spatial coordinates and bin assignments preserved from the input.

Output gather

The computed average velocity gather in the depth domain (Vavg-Z). Each output trace contains the average velocity as a function of depth, derived from the corresponding input interval velocity trace.

Output stack line

The output 2D stack line geometry, passed through unchanged from the input.

Output crooked line

The output crooked line geometry, passed through unchanged from the input.

Output bin grid

The output 3D bin grid definition, passed through unchanged from the input.

Output sorted headers

The output sorted index, passed through to downstream modules.

Information

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