1. Purposes for Well-Seismic Ties & Quality
Business Stage
Accuracy Required
Seismic Quality Required
Example Application
Regional Mapping
Within a few cycles
Within ~½ cycle
Wavelet character match
Poor/fair
Good
Very good
Mapping and tying a regional flooding surface across a basin
Exploration
Comparing a lead to nearby wells
Exploitation
Seismic attribute analysis
Inversion
SLIDE 4
The purpose and required accuracy of a well-seismic tie varies with the stage of our studies
If we are doing regional mapping, e.g., mapping a significant erosional unconformity or a flooding surface, then our tie does not need to be very precise, within 1 or 2 seismic cycles (peaks or troughs) – and the seismic data quality does not have to be very good
In the exploration stage, we would like to tie well data, e.g., the top of a stratigraphic horizon/marker within ½ a cycle
This requires good seismic data quality
In the exploitation stage (development & production), we need to not only know the seismic event within ½ a cycle, but the shape of the real and modeled seismic trace should be quite similar
For this, we need very good seismic data quality
If we obtain a good character (shape) tie between the real and synthetic traces, then:
We would then be able to extract various seismic attributes (measures of the seismic wavelets) to predict rock and fluid properties
We may also be able to use a process called inversion to transform the seismic data into an estimate of the rock properties in cross-section views or as a 3D volume (if we have 3D seismic data)
Courtesy of ExxonMobil
L 7 – Well-Seismic 1