P & S-wave velocity dependence on porosity in Bahamian
carbonates
Cornelia Rasmussen
Project Purpose
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The goal was to find a measurement that describes the relationship of velocity and
porosity.
To describe the relationship of velocity and pressure.
The aim for the future is to find a well established relationship among velocity
and porosity that will allow refining the process of estimating porosity from
velocity of seismic waves.
The Bahamas
Approximately half of the world oil and gas reserves are stored in carbonates. The
Bahamas, as one of the worlds biggest exposed carbonate deposits, can provide a
representative dataset.
Project Description
Cores were drilled on Little Bahaman Bank. Out of these cores, 34 plugs were drilled for
petrophysical measurements. The porosity and the sonic velocity were measured. Finally
the relationship between velocity and porosity and velocity and pressure was reviewed.
Deliverables
The dataset shows clear that there is a relationship between sonic velocity, porosity and
pressure.
Samples with a lower porosity are faster than samples with a higher porosity.
With increasing pressure the velocity becomes faster and respectively with decreasing
pressure the velocity becomes slower.