POTA
Schlumberger%Potassium
Potassium concentration from spectral gamma ray — a clay-typing and mineral indicator. It is elevated in illite, mica, feldspar, and glauconite; the potassium and thorium channels together fingerprint clay mineralogy.
- Property
- Potassium Concentration
- Concentration
- Quantity
- dimensionless
- % · GEuc · ppm · mEuc · cEuc · MEuc · nEuc · pEuc · kEuc · ppk · fEuc · µEuc · dEuc · EEuc · TEuc · Euc
- Typical range
- ~0–2.6 PU
- weight percent (%)
Logging tool
No logging tool is associated with this curve.
Service company
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How it's measured
From the potassium emission window (1.46 MeV, potassium-40) of the spectral gamma tool, reported as weight-percent potassium.
How it's used
Clay mineral typing via the Th/K crossplot, detection of potassium-feldspar hot sands, and evaporite or mica identification. It refines shale volume beyond total GR.
Common gotchas
Potassium-feldspar-rich sands read high potassium without being shale — the classic GR hot-sand pitfall this curve helps explain. Spectral statistics require adequate logging speed.
In LAS files
Recorded as POTA (or K, KTH) in percent (sometimes fractional). It comes with THOR and URAN from spectral runs.
Also seen with POTA in real logs
Curves that appear alongside POTA in the same wells across the public corpus.