This is an abbreviation for a well log acquired after or during drilling. You might have encountered this acronym
CBP7_SL in your log evaluation software or any (ASCII) log files provided by the logging company. The abreviatin stands for
'CMR Bin Porosity 7 - Station Log'. This log is not often acquired after (or during) drilling a well. Use this log to investigate the contribution of porosity from a given "bin" (with certain characteristics) to the total porosity; e.g., in nuclear magnetic resonance data processing, the "bins" typically correspond to different pore size ranges. At a more general level these values are measures of the apparent porosity. Better said, 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.
Furthermore, this can be explained by looking at 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 nmr logging technique and can be used to investigate the porosity of the formation. Similar logs are listed below: