1. Comparison of Seismic and Well Data
Seismic Data
Samples area and volume
Low frequency Hz
Vertical resolution m
Horizontal resolution m
Measures seismic amplitude, phase, continuity, horizontal & vertical velocities
Time measurement
Well Data
Samples point along well bore
High frequency, 10, ,000 Hz
Vertical resolution 2 cm - 2 m
Horizontal resolution 0.5 cm - 6 m
Measures vertical velocity, density, resistivity, radioactivity, SP, rock and fluid properties from cores
Depth measurement
SLIDE 6
This slide compares different aspects of seismic and well/log data
Seismic data samples areas and volumes within the earth; wells sample points along the well bore
Seismic data is low frequency (5 to 60 Hz); a log that measures rock velocity uses frequencies that are much higher
Vertical resolution is quite different – for seismic we can resolve layers that are 15 to 100 m thick; with logs we can resolve layers 2 cm to 2 m thick
Horizontal resolution for seismic … for wells …..
Seismic data measures …… well data measures ….
And, as we have already discussed, seismic is measured in two-way travel time; well data is in depth (ft or meters)
100 m
100 m
Courtesy of ExxonMobil
L 7 – Well-Seismic 1