Running Zap on SuperSeisworks:

 

(reference Landmark SuperSeisWorks box 1, ZAP! pgs. 135-158)

 

What is ZAP!? Zap is a program in seisworks that autotracks between

specified lines/traces in a horizon, following either a peak or trough to give

a contour map of a horizon in a 3-D survey. It can track along either an

amplitude, phase or value.

 

Zap is actually a very easy program to run, and the Landmark ZAP! book

is pretty self-explanatory, but here is a quick rundown of the steps

necessary to ZAP! an amplitude horizon:

 

1. In Seisworks/Seismic View, interpret a horizon along various traces and

lines in a 3-D survey, the density determined by how coherent the

reflector is. It's best to interpret along both traces and lines.

2. In the Seisworks/Seismic View window, select the 'Horizons' pull down menu

and ZAP!. A small ZAP! window will appear in the screen selected.

3. In the ZAP! window, select 'Controls' and then 'Volume Selection'. This

brings up a box that allows you to pick the volume over which ZAP! will

track. ZAP! prefers a cube data file, but will allow you to track over

a 3dv file. Click the appropriate circle on the left (likely 3dv File)

and select the file by clicking on the list button. Specify the volume

you want below.

NOTE: Pick your volume carefully, ZAP! doesn't like very large areas.

4. Click initialize. The window should stay open, and the little ZAP! window

should now show a progress bar. If the windows disappeared, the volume

selected was likely too large (and ZAP! crashed). This process creates

a temporary cube data file from a 3dv file.

5. After it finishes interpreting, select Horizon Selection in the Control

window. If the horizon you'd like Zapped is the active one, click

'Active Horizon'. The defaults should be okay. If you want to ZAP

an inactive horizon, select 'Selected Horizon' and input the names

of the input and output files.

6. The defaults for 'Snap/Confidence' worked for me, so I did not change

anything in that window.

Constant Shift: shifts all seedpoints by particular Z value

The Confidence section applies only if you would like a confidence

map to evaluate the results of a tracking job. (pg. 149)

7. Click Apply or OK.

8. In the Zap window, click 'Zap and/or Track'. A window pops open.

9. This shows you your input and output horizons and allows you to tell it

what to track.

Score - indicates how similar amplitudes must be, 100 equals perfect

match, etc. Page 84 details the meaning of various values.

Maximum Jump - maximum value for allowable jumps between traces.

See page 91 in ZAP! for discussion of Simple, Standard, Complex etc.

tracking. Standard was good enough for me.

'Snap then Pick' - if on (default) references the values in the

'Snap/Confidence' panel in the Controls box. This option only

effects seedpoints picked in Point mode.

10. Run ZAP! A Zap! Results status box posts the results of the job

to let you know how well it ran.

 

Hopefully this will work. If it doesn't, go back and interpret along more

traces on your 3-D survey or play with the Score, Maximum Jump and

Tracking Mode parameters.

 

Any other questions email jlupa@geosc.psu.edu