Image Gallery:
"Low Velocity Layer (LVL) model for seismic 3D survey"

This image represents 3D view of seismic survey area. Digital topography map was created from receiver and source points’ elevations only. Layers of this model are defined in terms of seismo-geological parameters like P/S-wave velocity or layer thickness/elevation. Data for subsurface model comes from borehole (upholes) and surface (shallow refraction) LVL surveys.

Picture is quite nice but more interesting is that you can use Surfer for direct and reverse calculations. First, from scattered LVL data points a continuous velocity thickness/depth model is created. Then, for series of known (x,y,elev) coordinates values of corresponding model grids (v1,h1,v2,h2,...) are assigned. Based on these values field static corrections (in terms of time, msec.) for seismic receivers/sources are calculated. These time corrections are very important part of seismic data processing flow and can have huge impact on whole project quality.

Since Surfer 7.0 version was released, it supports script automation. Thus, its possibilities are enormous. With bunch of SAX Basic and Visual Basic scripts you can change values of input model data points, recalculate whole model and get modified field statics in few minutes. That allows you multiple re-iteration of statics calculation straight on seismic crew and re-plan LVL surveying when necessary.

Maciek Pasiok 
Seismologist, 
Seismic Data Acquisition Department, 
Geofizyka Torun, 
Maciej.Pasiok@GTservices.pl 

www.GTservices.pl

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