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SWD data processing (Seismic While Drilling) processes pilot signals recorded during rotary drilling operations. The drill bit acts as a continuous seismic source, and the downgoing pilot signal must be extracted from a sensor at the drill pad and cross-correlated with the upgoing reflected energy recorded at the surface receivers. This cross-correlation step converts the vibrating-source seismic record into a conventional zero-phase-like gather similar to a surface-source record.
The module reads a SEG-Y file containing multi-channel SWD records, allows you to select the FFID (field file identifier) and the channel that contains the pilot (reference) trace, and computes the cross-correlation between the pilot and all other receiver channels. An optional crop window restricts which receiver channels are included in the output. Use the Read headers and Read selected FFID custom actions to inspect the dataset before processing.
The SWD seismic dataset. Connect the data item from a file reader that loads the raw multi-channel SWD records.
Handle to the SEG-Y file containing the raw SWD records. Used for random-access reading of individual FFIDs.
Trace header table for the SWD dataset. The module uses the FFID and channel number fields to identify the pilot and receiver traces within each shot record.
The Field File Identifier of the SWD record to be processed. The available FFIDs are populated automatically after using the Read headers custom action. Select the FFID corresponding to the drill segment you want to process, then use Read selected FFID to load it for inspection before running the full sequence.
Selects which channel type contains the pilot (reference) signal. Options: 1, 2, 3. Default: 1. The channel type corresponds to the sensor class recorded at the drill pad. In most SWD acquisitions channel type 1 is the vertical geophone or accelerometer placed at the pad that captures the drill-bit pilot signal. Consult the field acquisition report to determine which channel type carries the valid pilot.
Determines how the pilot trace is selected for cross-correlation. Options: From drill pad (default) or First valid.
From drill pad uses the designated pilot sensor at the drill pad location. First valid uses the nearest non-zero receiver trace, falling back to the side specified by Nearest valid trace when the drill-pad trace is absent or dead.
When Base cross-correlated trace is set to First valid, specifies the direction in which the nearest valid (non-dead) trace is searched. Options: Left (default) or Right. Select the direction that corresponds to the side of the receiver spread closest to the drill pad.
Length of the output cross-correlated trace, in seconds. Default: 0.5 s. The correlation output is truncated to this length, which determines the maximum two-way travel time that can be observed in the processed gather. Set this to exceed the expected deepest reflection time-of-interest.
Container grouping the From trace and To trace parameters for channel range selection.
First receiver channel (trace number) to include in the output gather. Default: -1 (no crop applied from the left). Set to a positive channel number to exclude near-offset receivers or auxiliary channels that should not appear in the processed output. Channel numbering starts at 1.
Last receiver channel (trace number) to include in the output gather. Default: -1 (no crop applied from the right). Set to restrict the output to a specific receiver range.
Reads the trace headers from the connected SEG-Y file and populates the FFID dropdown list with the available field file identifiers. Always run this action first after connecting the input data so that the FFID selector is populated before any other interaction.
Reads and displays the SWD record for the currently selected FFID in the interactive gather view. The pre-correlation gather and the source/receiver location maps are updated. Use this action to inspect the raw data and verify the pilot channel selection before running the full sequence.