This is an acronym for a well log used in the oil and gas industry. You might have encountered this acronym PO6B
in your log evaluation software or any (ASCII) log files provided by the logging company. The code stands for 'Partial porosity from MRIL (single element)'
. This log is very common in the industry. This log displays readings of 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. 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.
Simply said, this is a log that describes the pore volume per unit gross volume. Porosity is determined from measurements on cores or interpreted from logs. In general this log therefore displays units 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.
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: