This process calculates shift volume from RMO picks. RMO picks can be made using the RMO picking process (see Residual Moveout chapter). The calculated shift volume can be applied to input gather data using Trace shift, type= Volume-based shift.
The recommended workflow is:
- In the Imaging tab, pick RMO (parabolic or non-parabolic) on volumes and/or horizons. You can create multiple separate sets of picks, if necessary, with different parameters. It is important that pick spacing and maximum moveout be managed, to avoid picks overlapping in time/depth.
- Use this process in the Calculate Shifts mode to create a volume of shifts. To make realistic updates, this should be somewhat sparse. We recommend starting with an IL/CL or CMP spacing of 50m, offset spacing of 500m, vertical sampling of 10ms or 10m.
- Use the Volume Smoothing process on the volume of shifts (see Volume Smoothing). The results should be very smooth — we recommend starting at 500m to 1000m laterally, and 100ms/100m vertically.
- Use Trace Shift to apply the volume based shift.
- Turn all volumes off except RMO correction and original volume. Use Insight's Hotkey Page Up/Page Down, or middle mouse scroll between the two volumes for QC.
Parameters (Calculate Shifts mode)
- In the Process tab, click the Add icon and select New Process.
- Select RMO Correction and type a name for the process.
- In the Details Panel, at Mode, select Calculate shifts.
- Click the blue + icon to add any number of RMO Picking items from the Imaging tab. You can mix any number and type of picks. However, they must all be in the vertical domain of the seismic volume to which you will eventually apply the shifts (i.e. all TWT or all TVD).
Input the following Shifts volume extents:
- IL/CL (or CMP) spacing — Note that this is specified as a distance, not a trace count.
- Offset — Min/Max/Increment sequence. We recommend 500m spacing as a starting point.
- TWT/TVD — Min/Max/Increment sequence. We recommend 10ms/10m as a starting point.