How do you find the porosity of a well log?
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Beside this, how do you calculate the effective porosity of a log?
Total porosity minus clay-bound water (CBW). Log effective porosity. In essence, total porosity minus shale water, where solid minerals and the volume of shale (Vsh) constitute the matrix (non-effective porosity) and the remaining volume constitutes the effective porosity.
Similarly, what is porosity log? Neutron logs are porosity logs that measure the hydrogen ion concentration in a formation. In clean formations (i.e. shale-free) where the porosity is filled with water or oil, the neutron log measures liquid-filled porosity. Neutrons are created from a chemical source in the neutron logging tool.
Keeping this in view, how do you find the porosity of a density log?
Obtaining porosities from a density log
- Φ = porosity.
- ρma = matrix density (see table below)
- ρb = formation bulk density (log value)
- ρf = density of the fluid saturating the rock immediately surrounding the borehole—usually mud filtrate (use 1.0 for freshwater and 1.1 for saltwater mud)
How do you determine porosity?
There are two basic equations used to calculate porosity. The first equation uses the total volume and the volume of the void. Porosity = (Volume of Voids / Total Volume) x 100%. The second equation uses the total volume and the volume of the solid.