Page 105 - Basic Well Log Analysis for Geologist
P. 105
ia 6 en alin inca
POURS EE
PARC ITT LOGS
DENSITY LS. POROSITY
20 to °
1 iL 1
GR API UNITS
NEUTRON LS. POROSITY
20 10 °
HIGH POROSITY
NO INVASION
|
| LOW POROSITY
| NO INVASION
-
| en >70
! NO INVASION
HIGH POROSITY
INVADED
4 | LOW POROSITY
INVADED
1
SHALY SAND
* @, HYDROCARBON DENSITY
Figure 36. Schematic illustration of neutron-density responses in gas-bearing sandstones (modified after Truman et al, 1972).
Generalized neutron-density log responses show how gas effect varies with depth of invasion, porosity, hydrocarbon
density, and shale content.
90
