Geophysics lecture 08: Electric (wireline) logs - Neutron and density porosity logs.

This video lecture series on Geophysics (Undergraduate course GY 305) was made by Dr. Douglas W. Haywick from the Department of Earth Sciences at University of South Alabama.

Neutron logs

Neutron logs have a radioactive source (tritium?) that generate neutrons. As they pass into the rock, they lose energy, especially if they hit nuclei of similar weight (e.g. hydrogen). It distinguishes hydrogen concentration, the more hydrogen, the more absorption, and the more porosity.

Density logs

Density logs use a gamma ray source attached to the skid plate. It measures the bulk formation density, which is related to porosity.

See also