الانعكاس السيزمي Receivers source reflector

Seismic measurement: tool to obtain an image of the subsurface Source Receiver S R Measurement Processing Image Detect changes in the subsurface Detect objects

Q t t t t t t Reflection Seismics Raw data Source Receiver seismic Section geology

Seismic Imaging Data acquisititie Data processing Interpretation

Overview Fundamentals Introduction Seismic waves: Propagation Velocity and Amplitudes Seismogram Measurement systems Sources, receivers, Acquisition strategies Data processing “Pre-processing” Filter und Deconvolution Velocity anlysis and Stacking Migration Interpretation

Snapshots of wavefield propagation Source This is an example how the seismic waves propagate through a complex medium

Snapshots of wavefield propagation Source

Snapshots of wavefield propagation Source

Snapshots of wavefield propagation Source

Field of application Aim Depth of penetration Oil/Gas Exploration of layers 100 m - 5 km Engineering geophysics Groundwater Pollution Archaeological 10-500 m Earth crust seismic Composition of Earth Crust/Geodynamics -60 km Measurements in water Echo sounder, High resolution seismic ~ 0 m <100 m Georadar (GPR) Shallow investigation of earth 0.5-10 m The exploration of the subsurface using seismic waves is applied in several fields of application

Acquisition on land Seismic vibrator dynamite geophones

Receivers Source Receivers Time Example of one shot and several receivers which have a different distance to the source and thus the reflections are measured at other times.

hydrophones source Acquisition on see using a boat Acquisition on zee

Acquisitie on The seabottom Source Geophone and hydrophones Acquisition on sea using geophones and hydrophones on the seabottom Geophone and hydrophones Acquisitie on The seabottom

Seismic datacube After a lot of measurements and extensive processing we can obtain an image of the subsurface from which we can get valuable information of what is in the subsurface: for example oil or gas

Depth slice This is a depth slice of a 3D data volume we can identify different events which can be interpreted as follows

Geological interpretation

Interpretation of west-east-line 100 100 200 200 300 300 400 400 500 500 600 Interpretation of a seismic section 600 700 time [ms] 200 m depth [m]

Time slice through a 3D seismic data set Three-dimensional data volume showing a Gulf of Mexico salt dome with an associated rim syncline

Time slice through a 3D seismic data set Section at 196 ms from a three-dimensional survey in the Gulf of Thailand area, showing a meandering stream channel (from Kearey and Brooks, 1991)