This is a well log used in the oil and gas industry. The code
MPHEC is a unique identifier to recognize this particular log and can be found in any (ASCII) log files provided by the logging company. The full name for this log used in the industry is
'Array of partial porosities from third process'. 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. At a more general level these values are measures of the apparent porosity. In other words, 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. Better said, 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: