Editing Steps

 

This section documents the processing steps available in the Editing Steps category.

 

Processing steps currently available are:

 

 

3D Missing Data Interpolation

Usage:

3D Missing Data Interpolation is a fast and pragmatic way to fill missing traces by means of inverse-distance weighted interpolation from near traces.

 

For 3D pre-stack interpolation of missing data, the data should be ordered as 3D common offset gathers, so that (binned) Offset is the primary key, CMP Line the secondary and record key, and CMP location the tertiary key.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

3D Missing Data Interpolation

 

Step Parameter Dialog:

 

3D Missing Data Interpolation params

 

 

Parameter Description:

 

Missing data width: Define maximum distance for interpolation and what happens to traces outside the region of interest.

 

Max interpolation distance (traces) — Enter the maximum distance in traces for the near-neighbors of a missing trace to be located.

 

Fill all missing traces — If checked, any traces that are outside the specified Max interpolation distance from live traces will be filled by using the values of the nearest trace.

 

No interpolation — If checked, no interpolation of missing data will be performed.  This flag is for test purposes only!

 

Automatic Amplitude Edit

 

Usage:

The Automatic Amplitude Edit step allows to mark traces dead or alive based on the RMS amplitude content of a group of traces.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Number of traces in running average — Enter the number of traces in the moving window where the RMS amplitude is going to be computed.

 

Percentage change in RMS amplitude — Enter the percentage change in RMS amplitude to consider the traces dead of live.

 

Editing action: Select how seismic traces are marked based on the RMS amplitude content of a group of traces within a moving window.

 

Only mark low amplitude traces as dead — If selected, low RMS amplitude traces are marked as dead.

 

Only mark high amplitude traces as dead — If selected, high RMS amplitude traces are marked as dead.

 

Mark both low and high amplitude traces as dead — If selected, both low and high RMS amplitude traces are marked as dead.

 

Automatic Trace Edit

Usage:

The Automatic Trace Edit step allows you to automatically remove invalid or noisy traces from your data set based on user-defined criteria. 

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Trace Edit Method: Select the analysis method(s) to be used to determine if a trace will be killed.

 

Spectral semblance — The spectral semblance method uses the semblance between a single trace’s power spectrum and the average power spectrum of the gather as the basis for killing a trace.

 

Power ratio — The power ratio method uses the ratio of trace energy in the upper part of a trace to that in the lower part of a trace as the basis for killing a trace.  This is often an effective means of editing traces that are contaminated with 60 Hz powerline noise, which does not decay as a function of record time.

 

Both methods — Traces will be killed only if they fail BOTH the power ratio test AND the spectral semblance test.

 

Either method — Traces will be killed if they fail EITHER the power ratio test OR the spectral semblance test.

 

Calculate spectral semblance on receiver line basis — If checked, the spectral semblance will be calculated on a receiver line basis.

 

Calculate spectral semblance using a time window — Enabled if Spectral Semblance option is selected. If checked, spectral semblance is computed within a time gate defined by its top and base in ms.

 

Spectral semblance window: Define the start and end time of the time window where the spectral semblance is calculated.

 

Start time in ms of the window — Enter the start time of the window to compute the spectral semblance. Time in ms.

 

End time in ms of the window — Enter the end time of the window to compute the spectral semblance. Time in ms.

 

Power ratio decay cutoff (dB) — If you choose the power ratio method, enter the minimum decay of trace energy in decibels that you expect between the first and second half of the trace.

 

Define top window for power ratio — Enabled if Power ratio option is selected. If checked, select parameters to define the top window where the calculation is done.

 

Top window power ratio parameters: Define the start and end time of the top time window where the power ratio is calculated.

 

Start time in ms of the window — Enter the start time of the window to compute the power ratio. Time in ms.

 

End time in ms of the window — Enter the start time of the window to compute the power ratio. Time in ms.

 

Apply moveout velocity — If selected, the normal moveout correction with a constant velocity is applied to the record before computing the power ratio. Enter the velocity for the normal moveout correction.

 

Define bottom window for power ratio — Enabled if Power ratio option is selected. If checked, select parameters to define the bottom window where the calculation is done.

 

Bottom window power ratio parameters: Define the start and end time of the bottom time window where the power ratio is calculated.

 

Start time in ms of the window — Enter the start time of the window to compute the power ratio. Time in ms.

 

End time in ms of the window — Enter the end time of the window to compute the power ratio. Time in ms.

 

 

Apply moveout velocity — If selected, the normal moveout correction with a constant velocity is applied to the record before computing the power ratio. Enter the velocity for the normal moveout correction.

 

Output kills to Trace Edit auxiliary file – If selected outputs killed traces based on the selected measurement to an auxiliary file.

 

Spectral semblance cutoff (percent) — If you choose the spectral semblance method, enter the minimum semblance value you expect for each trace’s power spectrum relative to the power spectrum for the gather.

 

Coherent Noise Attenuation

Usage:

The Coherent Noise Attenuation step edit coherent noise between adjacent traces based on variations (in percentage) of the seismic amplitudes within a time trace window.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

2)      Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Trace window length (ms) — Enter the length of the window, in ms, where the estimation of the reference amplitude is calculated.

 

Maximum trace amplitude variation (%) — Enter the maximum trace amplitude variation, in percentage, to consider a given sample noise.

 

Gap between traces to compare — Enter the number of traces to skip for trace comparison.

 

Outlier replacement options: Define what happens to seismic samples considered noise.

 

Set to average of adjacent samples — If selected, the values of the seismic samples considered noise are replaced by the average value of adjacent samples.

 

Set to zero — If selected, the value of the seismic samples considered noise are set to zero.

 

Dataset Math

Usage:

The Dataset Math step will add, subtract, multiply, divide or do adaptive subtraction between the samples of one data file from the corresponding samples of a second data file and output the result to a seismic file.

 

Input Links:

1) Seismic data in any sort order (mandatory).

2) Seismic data in any sort order (mandatory) – must match the first dataset.

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Operation: Specify the math operation to perform between the samples of the two datasets.

 

Addition — If selected, perform addition between the samples of the two datasets.

 

Subtraction — If selected, perform subtraction between the samples of the two datasets.

 

Multiplication — If selected, perform multiplication between the samples of the two datasets.

 

Division — If selected, perform division between the samples of the two datasets.

 

Adaptive subtraction — If selected, perform adaptive subtraction between the samples of the two datasets.

 

Despike

 

Usage:

The Despike step removes spikes of amplitude related with bursts of energy based on the variance estimate of a given seismic sample when compared against its neighbours.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Variance limit — Enter the number of variance allowed for a seismic sample be considered signal.

 

Window length (ms) — Enter the windown length, in ms, where the statistical measures (variance) are going to be computed and used as reference to detect spikes.

 

Replace spikes with interplated sample value — If checked, seismic samples marked as noise are going to be replaced by an interpolated sampled value from its neighbours. If unchecked, marked seismic samples are replaced by zero.

 

Dominant Frequency Edits

 

Usage:

The Dominant Frequency Edits step marks dead records based on an estimate of its dominant frequency computed within a user-defined window on a trace-by-trace basis or considering the entire records as a whole. More than one window is allowed and the failing criteria may be defined taking into consideration simultanously all windows or each window separately. A report file is automaticaly generated.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Report file: Define parameters related with the report file automatically generated by this processing step.

 

File Browse — Browse for the file where the report file is going to be written. Be default, existing report files are overwritten.

 

Send file via FTP — If checked, send the report file automatically via FTP.

 

Append to existing file — If checked, append current report file to an existing file.

 

Display report in separate window — If checked, the report file is shown in real time in a pop-up window.

 

Spatial application: Define the spatial extent where the processing step is going to be applied.

 

Applly to all data — If selected, this step is applied to the entire input seismic data.

 

Reference exclusion zone file — If selected, the application of this step is constrained spatially as defined by an auxiliary exclusion zone data file, the input seismic data is not considered entirely.

 

Apply inside exclusion zone — If checked, only the data inside the exclusion zone is considered for the calculations.

 

Apply outside exclusion zone — If checked, only the data outside the exclusion zone is considered for the calculations.

 

Calculation method: This processing step may be applied either on a record basis or trace-by-trace basis.

 

Record basis — If selected, the dominant frequency is computed for the entire record as a whole.

 

Trace by trace — If selected, the dominant frequency is computed considering each trace individually.

 

Window definition method: The estimate might be computed within a user-defined window, or windows, defined by its start and end time and offset. Seismic samples outside these windows are not considered.

 

Use all data (no window) — If selected, all seismic samples are considered. There are no constraints in terms of time or offset.

 

Enter rectangle — If selected, enables the table below where the user can define the top, bottom, start and end offset of each window considered.

 

Import rectangle — If selected, the windows are defined by an auxiliary rectangle data file.

 

Import polygon — Not yet available.

 

Record edit criteria: Define the criteria to consider a good or bad record.

 

Fails all windows — If selected, the record is considered dead if it fails in all the defined windows simultaneously.

 

Analysis only — If selected, any recorded is marked as dead. This processing step is considered just an analysis tool.

               

Fails any window — If selected, the record is considered dead if it fails in on of the defined windows.

 

Window: Define the extent of each window where the estimate of the dominant frequency is computed.

 

Start time (ms) — Enter the start time, in ms, for each window.

 

End time (ms) — Enter the end time, in ms, for each window.

 

Start offset — Enter the start offset for each window.

 

End offset — Enter the end offset for each window.

 

 

Min dominant frequency — Enter the minimum dominant frequency that a given window must have for the record to be considered good.

 

Max dominant frequency — Enter the maximum dominant frequency that a given window must have for the record to be considered good.

 

Output header — Select the header location where the flag for good/bad records is stored.

 

Add window — Select if more than one window per record is going to considered.

 

Delete window — Select to remove an existing window.

 

View window — Not yet available.

 

Export window — Not yet available.

 

Minimum live traces per analysis window — Enter the minimum number of live traces that mus exit within each window for the estimation.

 

F-X Trace Interpolation

 

Usage:

The F-X Trace Interpolation step performs a 2-to-1 f-x domain interpolation of the input gather.  Trace headers of the interpolated traces are equal to the average of their two neighbors.  The Trace Flag header field of the interpolated traces will be equal to 28 on output.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data with interpolated traces.

 

Reference:

Spitz, S., 1991 Seismic trace interpolation in the f-x domain, Geophysics, 56, p. 785.

 

Example Flowchart:

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Design widow length: parameterize window length.

 

Use whole trace — If selected, the design length is to equal the record length.

 

Specify length —  If seleceted, uses a fixed design width as defined in Length (ms).

               

Design window length (ms) — Enter the length of the design window in units of milliseconds      

 

Design widow length: parameterize window width.

 

Use full trace length — If selected, allows the window width to vary with changes in fold for pre-stack trace interpolation.

 

Specify design window length — Use this option to enter a fixed design length

       

Design window width (traces) — Enter the width of the design window in units of traces

 

Prediction filter: specify the number of traces used in the prediction filter.

 

Widht (traces) — enter the number of traces to be used by the prediction filter.

 

Frequency Trace Edits

 

The Frequency Trace Edits step marks dead records based on an estimate of its frequency computed content within a user-defined window on a trace-by-trace basis or considering the entire records as a whole. More than one window is allowed and the failing criteria may be defined taking into consideration simultanously all windows or each window separately. A report file is automaticaly generated.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Report file: Define parameters related with the report file automatically generated by this processing step.

 

File Browse — Browse for the file where the report file is going to be written. Be default, existing report files are overwritten.

 

Send file via FTP — If checked, send the report file automatically via FTP.

 

Append to existing file — If checked, append current report file to an existing file.

 

Display report in separate window — If checked, the report file is shown in real time in a pop-up window.

 

Spatial application: Define the spatial extent where the processing step is going to be applied.

 

Applly to all data — If selected, this step is applied to the entire input seismic data.

 

Reference exclusion zone file — If selected, the application of this step is constrained spatially as defined by an auxiliary exclusion zone data file, the input seismic data is not considered entirely.

 

Apply inside exclusion zone — If checked, only the data inside the exclusion zone is considered for the calculations.

 

Apply outside exclusion zone — If checked, only the data outside the exclusion zone is considered for the calculations.

 

Calculation method: This processing step may be applied either on a record basis or trace-by-trace basis.

 

Record basis — If selected, the dominant frequency is computed for the entire record as a whole.

 

Trace by trace — If selected, the dominant frequency is computed considering each trace individually.

 

Window definition method: The estimate might be computed within a user-defined window, or windows, defined by its start and end time and offset. Seismic samples outside these windows are not considered.

 

Use full trace — If selected, all seismic samples are considered. There are no constraints in terms of time or offset.

 

Enter rectangle — If selected, enables the table below where the user can define the top, bottom, start and end offset of each window considered.

 

Import rectangle — If selected, the windows are defined by an auxiliary rectangle data file.

 

Import polygon — Not yet available.

 

Record edit criteria: Define the criteria to consider a good or bad record.

 

Fails all windows — If selected, the record is considered dead if it fails in all the defined windows simultaneously.

 

Analysis only — If selected, any recorded is marked as dead. This processing step is considered just an analysis tool.

               

Fails any window — If selected, the record is considered dead if it fails in on of the defined windows.

 

Window: Define the extent of each window where the estimate of the dominant frequency is computed.

 

Start time (ms) — Enter the start time, in ms, for each window.

 

End time (ms) — Enter the end time, in ms, for each window.

 

Start offset — Enter the start offset for each window.

 

End offset — Enter the end offset for each window.

 

 

Min frequency — Enter the minimum dominant frequency that a given window must have for the record to be considered good.

 

Max frequency — Enter the maximum dominant frequency that a given window must have for the record to be considered good.

 

Output header — Select the header location where the flag for good/bad records is stored.

 

Add window — Select if more than one window per record is going to considered.

 

Delete window — Select to remove an existing window.

 

View window — Not yet available.

 

Export window — Not yet available.

 

Minimum live traces per analysis window — Enter the minimum number of live traces that mus exit within each window for the estimation.

 

Interpolate Dead Traces

Usage:

The Interpolate Dead Traces step interpolates traces marked as dead based on a simple arithmetic average of the neighbor traces not marked as dead.

 

Input Links:

1)      Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

Parameter Description:

 

This processing setp does not require any parameterization since dead traces are automatically interpolated with an arithmetic average.

 

Kill Traces

Usage:

The Kill Traces step kills traces according to specified trace header values and ranges.

 

Input Links:

1)      Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

Primary header — Select the first trace header field to use for killing traces. This is combined with the other selected header key values to determine the set of traces to kill.

 

Primary start — Enter the start value for the first selected header field.

 

Primary stop — Enter the end value for the first selected header field.

 

Secondary header — Select the second trace header field to use for killing traces. This is combined with the other selected header key values to determine the set of traces to kill.

 

Secondary start — Enter the start value for the second selected header field.

 

Secondary stop — Enter the end value for the second selected header field.

 

Tertiary header — Select the third trace header field to use for killing traces. This is combined with the other selected header key values to determine the set of traces to kill.

 

Tertiary start — Enter the start value for the third selected header field.

 

Tertiary stop — Enter the end value for the third selected header field.

 

Import — Import a set of picked trace kills from a Trace Kills auxiliary dataset.

 

Export — Export the entered trace kills into a Trace Kills auxiliary dataset.

 

Add Row — Add a row to dialog.

 

Delete Row — Delete a row from the dialog.

 

Set dead trace amplitude to zero — If checked, fill dead traces with zeros.

 

Phase Rotation

Usage:

The Phase Rotation step allows you to rotate your seismic traces by a constant phase angle from –180 to +180 degrees.  Values outside this range will be wrapped back into this range (i.e. 240 degrees is equivalent to –60 degrees).

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Rotate based on header value — If checked, the phase rotation is only applied to some traces in the dataset, then a trace header value may be used to control which traces are rotated. An example of where this is useful is transition zone seismic where some receivers in a line are geophones and some are hydrophones. Rotating the hydrophone by -90 matches the data from the geophone.

 

If Component trace header — Select the trace header to be used for controlling the operation.

 

== — Select the logic operator (<, <=, ==, >, >= or !=) to be used in determining the traces to used in the operation and enter the value of the logical condition.

 

Rotate by angle stored in trace header value — If checked, does a constant phase rotation, a header value (degrees) may be used.

 

Rotation angle in trace header — Select the trace header word containing the rotation angle (degrees).

 

Phase rotation angle (degrees) — Enter the constant phase rotation angle to apply to all the seismic data traces unless Rotate by angle stored in trace header value is checked.

 

Remove DC Bias

Usage:

The Remove DC Bias step removes the average, median or mean DC bias on a trace-by-trace basis or based on a moving average window which may run per channel or gather. The calculation window may be limited within a userd-defined time gate.

 

Input Links:

1)      Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

DC calculation method: select the method to estimate the DC bias.

 

Mean — If selected, estimates the DC bias as the mean of the seismic samples considered.

 

Median — If selected, estimates the DC bias as the median of the seismic samples considered.

 

(Min+Max)/2 — If selected, estimates the DC bias as central value between the min and max of the seismic samples considered.

 

Chanel Average: DC bias may be estimated using a moving window running through channels in order to increase the reliability of the estimate.

 

Use running average across channels — If checked the DC bias is estimate taking into account a moving window computed across channels.

 

Number of channels to average — Enter the number of channels that belong to the moving window.

 

Gather Average: DC bias may be estimated using a moving window running through gathers (or records) in order to increase the reliability of the estimate.

 

Use running average across prior gathers — If checked the DC bias is estimate taking into account a moving window computed across prior gathers.

 

Number of gathers to average — Enter the number of gathers that belong to the moving window.

 

DC calculation window: define the time gate where the calculation is going to be computed.

 

Calculate DC in a window — If checked, only the entered window of each trace will be used to calculate the DC.

 

Minimum time (ms) — Enter the start time of the window to be used for calculating the DC value.

 

Maximum time (ms) — Enter the ending time of the window to be used for calculating the DC value.

 

Remove Reverberation

Usage:

The Remove Reverberation step searches for reverberations in the signal and attempts to remove these using an adaptive filtering technique.

 

Input Links:

1)      Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Minimum delay time — Enter the minimum delay time to use in searching for the reverberation.

 

Minimum offset — Enter the minimum offset to use in searching for the reverberation.

 

Maximum offset — Enter the maximum offset to use in searching for the reverberation.

 

 

Resample Seismic

 

Usage:

The Resample Seismic step creates a copy of a data set with options to (1) resample to a specified sample interval, and (2) change the start time and trace length  of the data on the fly.

 

Input Links:

1)      Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in any sort order (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Sample interval: modify the sample interval of the input seismic data.

 

Change sample interval — If checked, the traces will be resampled to the specified sample interval.         

 

                Output sample interval (ms) — Enter the new sampling interval in ms.

 

Anti-alias Filter: apply an anti-alias filter to the data after the resampling.

 

Apply anti-alias filter — If checked, apply an anti-alias filter after the resampling.

 

Cutoff (%Nyquist) — Enter the percentage of the Nyquist frequency at which an anti-alias filter is applied.

 

Rolloff (db/Octave) — Enter the rolloff of the filter in dB/Octave.

 

Trace length: modify the original length of the input seismic traces.

 

Change Length — If checked, the traces will be truncated or extended to the specified length.

 

Start time (ms) — Enter the start time of the trace to output in milliseconds.

 

Length (ms) — Enter the length of the trace to output in milliseconds

 

Reverse Traces

Usage:

The Reverse Traces step allows you to invert the polarity of traces according specified trace header values and ranges.

 

Input Links:

1)      Seismic data in any sort order (mandatory).

 

Output Links:

1)      Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Primary header — Select the first trace header field to use for reversing traces. This is combined with the other selected header key values to determine the set of traces to reverse.

 

Primary start — Enter the start value for the first selected header field.

 

Primary stop — Enter the end value for the first selected header field.

 

Secondary header — Select the second trace header field to use for reversing traces. This is combined with the other selected header key values to determine the set of traces to reverse.

 

Secondary start — Enter the start value for the second selected header field.

 

Secondary stop — Enter the end value for the second selected header field.

 

Tertiary header — Select the third trace header field to use for reversing traces. This is combined with the other selected header key values to determine the set of traces to reverse.

 

Tertiary start — Enter the start value for the third selected header field.

 

Tertiary stop — Enter the end value for the third selected header field.

 

Import — Import a set of picked trace reversals from a Trace Reversals auxiliary dataset.

 

Export — Export the entered trace reversals into a Trace Reversals auxiliary dataset.

 

Add Row — Add a row to dialog.

 

Delete Row — Delete a row from the dialog.

 

 

Revive Dead Traces

Usage:

The Revive Dead Traces step modifies marked seismic traces into live traces given a minimum adjacent dead traces.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Minmum number adjacent traces — Enter the minimum number of adjacent dead traces that must exist to be modified into live traces.

 

 

S/N Based Record Edits

Usage:

The S/N Based Record Edits step marks dead records based on an estimate of its signal-to-noise ratio computed within a user-defined window on a trace-by-trace basis or considering the entire records as a whole. More than one window is allowed and the failing criteria may be defined taking into consideration simultanously all windows or each window separately. A report file is automaticaly generated.

 

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

Report file: Define parameters related with the report file automatically generated by this processing step.

 

File Browse — Browse for the file where the report file is going to be written. Be default, existing report files are overwritten.

 

Send file via FTP — If checked, send the report file automatically via FTP.

 

Append to existing file — If checked, append current report file to an existing file.

 

Display report in separate window — If checked, the report file is shown in real time in a pop-up window.

 

Spatial application: Define the spatial extent where the processing step is going to be applied.

 

Applly to all data — If selected, this step is applied to the entire input seismic data.

 

Reference exclusion zone file — If selected, the application of this step is constrained spatially as defined by an auxiliary exclusion zone data file, the input seismic data is not considered entirely.

 

Apply inside exclusion zone — If checked, only the data inside the exclusion zone is considered for the calculations.

 

Apply outside exclusion zone — If checked, only the data outside the exclusion zone is considered for the calculations.

 

Amplitude Definition: Select the type of amplitude to be computed during this editing processing step.

 

Average power — If selected, compute the average power of the input seismic amplitudes.

 

Average RMS — If selected, compute the average RMS of the input seismic amplitudes.

 

Average absolute value — If selected, compute the average of the absolute value of the input seismic amplitudes.

 

Calculation method: This processing step may be applied either on a record basis or trace-by-trace basis.

 

Record basis — If selected, the dominant frequency is computed for the entire record as a whole.

 

Trace by trace — If selected, the dominant frequency is computed considering each trace individually.

 

Window definition method: The estimate might be computed within a user-defined window, or windows, defined by its start and end time and offset. Seismic samples outside these windows are not considered.

 

Use all data (no window) — If selected, all seismic samples are considered. There are no constraints in terms of time or offset.

 

Enter rectangle — If selected, enables the table below where the user can define the top, bottom, start and end offset of each window considered.

 

Import rectangle — If selected, the windows are defined by an auxiliary rectangle data file.

 

Import polygon — Not yet available.

 

Record edit criteria: Define the criteria to consider a good or bad record.

 

Fails all windows — If selected, the record is considered dead if it fails in all the defined windows simultaneously.

 

Analysis only — If selected, any recorded is marked as dead. This processing step is considered just an analysis tool.

               

Fails any window — If selected, the record is considered dead if it fails in on of the defined windows.

 

Window: Define the extent of each window where the estimate of the dominant frequency is computed.

 

Start time (ms) — Enter the start time, in ms, for each window.

 

End time (ms) — Enter the end time, in ms, for each window.

 

Start offset — Enter the start offset for each window.

 

End offset — Enter the end offset for each window.

 

 

Min dominant frequency — Enter the minimum dominant frequency that a given window must have for the record to be considered good.

 

Max dominant frequency — Enter the maximum dominant frequency that a given window must have for the record to be considered good.

 

Output header — Select the header location where the flag for good/bad records is stored.

 

Add window — Select if more than one window per record is going to considered.

 

Delete window — Select to remove an existing window.

 

View window — Not yet available.

 

Export window — Not yet available.

 

Minimum live traces per analysis window — Enter the minimum number of live traces that mus exit within each window for the estimation.

 

Trace Header Calculation

Usage:

The Trace Header Calculation step allows calculate a selected trace header from existing trace headers.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Select trace header to calculate: select the trace header to be calculated.

 

Offset — If checked, calculates the offset and updates the corresponding trace header.

 

Azimuth — If checked, calculates the azimuth and updates the corresponding trace header.

 

Midpoint coordinates — If checked, calculates the midpoint coordinates and updates the corresponding trace header.

 

Trace Header Logic

Usage:

The Trace Header Logic step allows you modify the trace header values of a seismic trace using the relational operators and logic conditions characteristic of an If - Then – Else statement.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

 

 

Parameter Description:

if — Select the relational and logic conditions for which the then statement will be executed.

 

                Header Field — Select the primary trace header field to be tested.

 

                Relation — Select the primary relational operator

 

                Header Field — If selected, the primary trace header field will be evaluated against the chosen header field using the primary relational operator.

 

                Constant — If selected, the primary trace header field will be evaluated against the user-supplied constant using the primary relational operator.

               

                Logic — If checked, the Logic option allows selection of a secondary header field using and|or logic. 

 

                Header Field — Select the secondary trace header field to be tested.

 

                Relation — Select the secondary relational operator

 

                Header Field — If selected, the primary trace header field will be evaluated against the chosen header field using the secondary relational operator.

 

                Constant — If selected, the primary trace header field will be evaluated against the-user supplied constant using the secondary relational operator.

 

 

then — Define the trace header operation to be performed in the case that the if conditions are satisfied.

 

                Header Field — Select the trace header field to be modified in the case that the if conditions are satisfied.

 

                Header Field — If selected, the header field selected above will be set equal to the chosen header field.

 

                Constant — If selected, the header field selected above will be set equal to the user-supplied constant.

 

 

else — Define the trace header operation to be performed in the case that the if conditions are not satisfied.

 

                Header Field — Select the trace header field to be modified in the case that the if conditions are not satisfied.

 

                Header Field — If selected, the header field selected above will be set equal to the chosen header field.

 

                Constant — If selected, the header field selected above will be set equal to the user-supplied constant.

 

 

Example:  If the source-receiver azimuth is greater than or equal to zero, set the User Def 1 field equal to +1.   Otherwise, set the User Def 1 field equal to -1.

 

 

Trace Header Math

Usage:

The Trace Header Math step allows you modify the trace header values of a seismic trace using standard mathematical operations.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

 

Parameter Description:

 

Trace header value to modify — Select trace header location to be modified.

 

Add to index — I checked, changed trace header is automatically updated in the index file.

 

The rest of the parameters are just like a regular calculator.

 

Example:  Add 40 to the existing value of the Uphole time.

 

 

 

Trace Header Resequencing

Usage:

The Trace Header Resequencing step is used to modify trace header values based on changes in other trace header values.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data file containing the duplicated trace (mandatory).

 

Reference:

-

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Trace Header to Modify — Select the trace header field that will be modified.

 

Monitor Trace Header — Select the monitor trace header field.  A change in value of the Monitor Trace Header will result in a change in value of the Trace Header to Modify based on the following two values:

 

Restart value — This value will be placed in the Trace Header to Modify whenever there is a change in the Monitor Trace Header.

 

Increment value — This value will be added to the Restart value for each trace header in which the Trace Header to Modify does not change.

 

Trace Sample Math

Usage:

The Trace Sample Math step allows you operate at the trace seismic samples using some pre-defined mathematical operations and two user-defined values.

 

Input Links:

1) Seismic data in any sort order (mandatory).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Math operation: Select pre-defined mathematical operations to be applied to the trace seismic samples of the input seismic file.

 

Value of a — Enter a value to be used in the selected mathematical operation replacing a.

 

Value of b — Enter a value to be used in the selected mathematical operation replacing b.

 

Vibroseis Correlation

Usage:

The Vibroseis Correlation step cross correlates uncorrelated seismic data acquired with the Vibroseis™ method with the corresponding vibroseis sweep. The correlated output data should be considered zero phase.

 

Input Links:

1.       Seismic data in any sort order (mandatory).

2)    Seismic data — Vibroseis™ pilot sweeps (optional).

 

Output Links:

1) Seismic data in same sort order as the input (mandatory).

 

 

Example Flowchart:

 

 

Step Parameter Dialog:

 

 

Parameter Description:

 

Signature Input Options: Select the method of accessing the Vibroseis pilot sweep.

 

One pilot per dataset from an auxiliary file — Select the seismic file that contains the Vibroseis pilot.

 

One pilot per record from an auxiliary file — This option inputs one pilot trace in sequential order from an auxiliary file and crosscorrelates that pilot signature with the respective sequential record.  Therefore, number of pilot traces should equal the number of input records.

 

One pilot per trace from an auxiliary file — This option inputs one pilot trace in sequential order from an auxiliary file and crosscorrelates that pilot signature with the respective sequential trace. Therefore, number of pilot traces should equal the number of input traces.

 

One pilot from auxiliary seismic using trace header — This option inputs one pilot trace based on the selected traced heder from an auxiliary file and crosscorrelates that pilot signature with the respective sequential trace. Therefore, number of pilot traces should equal the number of input traces.

 

                Trace header — Select trace header to be used to select the pilot.

 

One pilot per record from intput data file — This option uses one trace from the each of the uncorrelated input records as the pilot trace for that record.

               

Sweep trace number — Enter the trace number to use as the pilot sweep.

 

First trace to kill — If you demultiplexed the data set with the auxiliary traces to recover the pilot sweep, you may wish to kill these auxiliary traces so that the do not appear on output. Enter the first trace number to kill.

 

Last trace to kill — If you demultiplexed the data set with the auxiliary traces to recover the pilot sweep, you may wish to kill these auxiliary traces traces so that the do not appear on output. Enter the last trace number to kill.

 

 

Pilot length (ms) — Enter the length of the pilot sweep in milliseconds.

 

Minimum phase compensate data —If checked, a minimum phase compensation filter will be calculated and applied so that the correlated data will be minimum phase on output.

 

Extended Correlation — If checked, an extended correlation will be done using the entered trace output