MSFL
SchlumbergerΩ·cmMicro Spherically Focused Log
A shallow, pad-mounted micro-resistivity that reads the flushed zone (Rxo). Combined with a deep resistivity it drives invasion correction and movable-hydrocarbon analysis.
- Property
- Micro Spherically Focused Resistivity
- Micro Resistivity
- Quantity
- electrical resistivity
- Ω·cm · kΩ·m · Ω·m²/m · nΩ·mm²/m · Ω·m · nΩ·mil²/ft
- Typical range
- ~1.8–128.3 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 MSFL curve?
How it's measured
A small focused electrode array on a pad measures resistivity a few inches into the formation — essentially the mud-filtrate-flushed zone Rxo — while riding the borehole wall.
How it's used
Rxo for invasion correction of the deep logs, the Rxo/Rt ratio for moved hydrocarbons, and mudcake and permeable-bed indication. A key companion to laterolog suites.
Common gotchas
Being a pad tool, it fails in washed-out or rugose hole and needs mudcake correction. It reads Rxo, not Rt — never use it directly for saturation without the deep curve.
In LAS files
Recorded as MSFL (or RXO, MLL) in ohm·m. It travels with the deep and shallow resistivity curves and the caliper.
Also seen with MSFL in real logs
Curves that appear alongside MSFL in the same wells across the public corpus.