Seismic workshop

Presentation: Jacques Jenny PhDW_GeoSoft / Geo2X Switzerland

Type of seismic waves

Average P and S velocities- P waves velocity: 1000 to 5000 m/s- S wave velocity: 300 to 1000 m/s

Seismic waves propagation

Seismic method overviewMethod Equipment Depth Use Processing

Refraction 12 -24 channels

1-50 m EngineeringLandslide

Easy to complex

Reflection 48 – 96 channels

50 – x00 m EngineeringOil water prospect.

Difficult to very complex

Surface waves

24 – 48 channels

10 – 50 m Engineering Complex

DownholeCrosshole

Triaxial geophone

1-100 m Engineering Complex

Refraction versus reflection

refraction.swf reflexion.swf

Processing result

Refraction seismic

Reflection seismic

Surface waves

Downhole seismic

Equipment• Recording equipment• Seismic source• Processing software

Recording equipment

Seismic source

SN388

Seismic source

Buffalo gun

Drop weight 300 kg

Processing softwareRefraction: WinSism,Plotrefa,RayfractReflection: Visual SUNT, ReflexSurface wave: WinMASW, SurfSEIS, SeisImagerDownhole: WinDownHole