RXO
SchlumbergerΩ·cmFlushed Zone Resistivity
The resistivity of the flushed zone (Rxo), where mud filtrate has displaced movable fluids near the borehole. Combined with deep resistivity it reveals movable hydrocarbons and corrects for invasion.
- Property
- Flushed Zone Resistivity
- Resistivity
- Quantity
- electrical resistivity
- Ω·cm · kΩ·m · Ω·m²/m · nΩ·mm²/m · Ω·m · nΩ·mil²/ft
- Typical range
- ~0.9–108.1 ohm·m
- ohm·m, flushed-zone resistivity
Logging tool
No logging tool is associated with this curve.
Service company
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View Schlumberger mnemonics →What is the RXO curve?
How it's measured
A very shallow micro-resistivity (micro-laterolog or MSFL-type pad device) reads the zone within a few inches of the wall, essentially saturated with mud filtrate of known Rmf.
How it's used
Rxo for invasion correction, the Rxo/Rt ratio and Sxo for moved-hydrocarbon and residual-oil analysis, and a saturation check via the Rxo/Rt method that is independent of Rw.
Common gotchas
Being a shallow pad reading it fails in rugose hole and requires mudcake correction. It represents filtrate-flushed rock, not the reservoir — never substitute it for the deep curve in saturation.
In LAS files
Recorded as RXO (or MSFL, RXOZ) in ohm·m. It travels with the deep and shallow resistivity curves.
Also seen with RXO in real logs
Curves that appear alongside RXO in the same wells across the public corpus.