| Gamma ray || [[length::2 ft]] || [[length::12 in]] || Well-to-well correlation and estimates ''V''<sub>sh</sub> || Affected by radioactive scale near perforations
−
| [[length::2 ft]]
−
| [[length::12 in]]
−
| Well-to-well correlation and estimates ''V''<sub>sh</sub>
−
| Affected by radioactive scale near perforations
|-
|-
−
| Spectral gamma ray
+
| Spectral gamma ray || [[length::3 ft]] || [[length::16 in]] || Well-to-well correlation and estimates ''V''<sub>sh</sub> || —
−
| [[length::3 ft]]
−
| [[length::16 in]]
−
| Well-to-well correlation and estimates ''V''<sub>sh</sub>
−
| —
|-
|-
−
| Pulsed neutron
+
| Pulsed neutron || [[length::2 ft]] || [[length::18 in]] || Determines water saturation and estimates porosity || Does not work in freshwater and severely underestimates porosity in the presence of gas
−
| [[length::2 ft]]
−
| [[length::18 in]]
−
| Determines water saturation and estimates porosity
−
| Does not work in freshwater and severely underestimates porosity in the presence of gas
|-
|-
−
| Compensated neutron
+
| Compensated neutron || [[length::3 ft]] || [[length::10 in]] || Estimates porosity || Severely underestimates porosity in the presence of gas
−
| [[length::3 ft]]
−
| [[length::10 in]]
−
| Estimates porosity
−
| Severely underestimates porosity in the presence of gas