This is the name of a log measured along a well bore (a well-log). The acronym SPLF can be found in any (ASCII) log files provided by the logging company. Smoothed CNP (Limestone Matrix-Fixed Hole Size) is the full name for this log. This log is not used too often in the industry.

This log helps to evaluate the porosity derived from a neutron logging measurement, assuming that the rock matrix material is calcite.

Concluding, this is a measure of the porosity as measured with an neutron logging device. In general this is a measurement of the apparent porosity. This can be explained as being the initial estimate of porosity, normally from logs, not corrected for the (often large) effects of clays, gas, etc. Such estimates should only be used for qualitative interpretation of clean, gas-free intervals. At a higher level, this can be seen as a measure of the volume fraction. In other words, the ratio of the volumes occupied by two components, or by one component to the total volume of the system.

This log usually has the unit 'Porosity'. This is the pore volume per unit gross volume. Porosity is determined from measurements on cores or interpreted from logs.

Data for this log is produced by a tool that uses a neutron logging technique and can be used to investigate the porosity of the formation. Similar logs are listed below:

• High-resolution Classic Neutron Porosity (HNPH)
• APS Near/Far Corrected Dolomite Porosity (FPMC)
• High Resolution Thermal Neutron Porosity (Ratio Method) in Selected Lithology (HTNP)
• Density Porosity Dolomite, Transmitted (DPDX)
• Smoothed CNP (Limestone Matrix-Caliper Corrected) (SPLC)
• APS High Resolution Near/Array Corrected Dolomite Porosity (HADC)
• Neutron Porosity Dolomite, Borehole Corrected, Transmitted (NPDX)
• APS Near/Array Corrected Limestone Porosity (APLC)
• Smoothed Far Detector ONLY Porosity (Sandstone Matrix-Fixed Hole Size) (SFSF)
• Neutron Porosity Sandstone (NPHS)