The Seismic Picking tools in g-Space let interpreters digitise features on 2D and 3D seismic data — horizons, faults, mute zones and individual control points. Picks are tied to the active seismic view and immediately become project objects in the Data manager so they can drive downstream workflows such as velocity modelling, volumetric calculations and well-tie QC.
This guide describes the picking tools using the 3D seismic volume and 2D profiles from the Demo project. Subscribe to our channel and watch the video on how to trace horizons in g-Space on YouTube.
What can be picked
•Horizons — continuous reflector surfaces traced across seismic lines. Output is stored as a GHorizon object and used by map creation, velocity modelling and depth-conversion tools.
•Faults — fault sticks interpreted on individual lines; collected into a GFault object.
•Mutes — amplitude-masking regions used by gather-conditioning and AVO workflows.
•Checkpoint picks — individual control points used for well-tie QC and precision picking, visualised as Vista items in the current or all layers.
Starting a picking session
1.Open a Seismic view (2D) or 3D view showing the data to interpret.
2.Select the feature type from the picking toolbar: horizon, fault, mute, or checkpoint.
3.Pick interactively with the mouse — single click to add a point, drag to trace a continuous segment, double-click to close the feature.
4.Quality-control indicators (picking coverage, number of phase jumps for horizons) are updated live in the view's status area.
Quality control
Horizon picks are evaluated on two QC metrics computed automatically:
•Picking coverage — percentage of traces along the line where the horizon was actually picked.
•Phase jumps — count of 180° discontinuities, used to spot pick-to-pick mis-ties.
Tips
•Start interpretation on the most continuous line in the survey, then propagate to adjacent lines — g-Space snaps the pick to the nearest consistent reflector.
•Use the precision picking mode to force the pick onto the exact sample under the cursor when auto-snap is not desired.
•Review picks in the 3D view before building maps — cross-line consistency is easier to spot there than on individual 2D sections.
See Also