NPOR
Schlumberger%Enhanced Neutron Porosity
An enhanced-processing thermal neutron porosity — the ratio-method neutron log with additional corrections applied for a cleaner porosity in known lithology. A processed sibling of NPHI and TNPH.
- Property
- Thermal Neutron Porosity
- Neutron Porosity
- Quantity
- dimensionless
- % · GEuc · ppm · mEuc · cEuc · MEuc · nEuc · pEuc · kEuc · ppk · fEuc · µEuc · dEuc · EEuc · TEuc · Euc
- Typical range
- ~0.1–37.4 pu
- porosity units, limestone-calibrated
Logging tool
No logging tool is associated with this curve.
Service company
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How it's measured
Derived from the dual-detector thermal neutron measurement with enhanced environmental and lithology corrections applied, reported as apparent porosity.
How it's used
A drop-in neutron porosity for the neutron-density crossplot and gas detection, preferred where the enhanced corrections improve accuracy over raw NPHI.
Common gotchas
Like all neutron porosities it reflects hydrogen index, not porosity — gas and shale bias it, and the matrix calibration must match the formation. Confirm which corrections the 'enhanced' processing includes.
In LAS files
Recorded as NPOR (or NPHI, TNPH) in v/v or %. Watch the calibration lithology.
Also seen with NPOR in real logs
Curves that appear alongside NPOR in the same wells across the public corpus.