Post-Injection
Interwell Porosity Distribution &
Difference Image
(from Shear & Compressional Interwell Velocities)
Replacement of Pore Fluid by CO2 in this Reservoir Induces a Change in
Apparent Porosity on the Order of Two to Six Percent.
This Change is Not Readily Interpreted from
the Post-Injection Porosity Image alone (Figure 1 Below),
but is Easily Detected when the Difference in Apparent Porosity
between Post-Injection and Pre-Injection Surveys is
Computed (Figure 2 Below).

