This is a log of measurements along a well bore (a well-log). The code
MPHS is a unique identifier to recognize this particular log and can be found in any (ASCII) log files provided by the logging company. The official name for this log is
'MRIL total porosity'. This log is very common in the industry. This log helps to evaluate the apparent formation porosity as measured with an nuclear magnetic logging device.
In general this log thus reflects units 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. At a more general level these values are measures of the volume fraction. This can be explained as being 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: