This is the name of a log measured along a well bore (a well-log). You could have found the code
DPDM in your log evaluation software or your corporate datastores. The full name for this log used in the industry is
'Density Porosity Dolomite, Memory'. This log is very common in the industry. Use this log to investigate the porosity derived from a neutron logging measurement, assuming that the rock matrix material is dolomite.
So basically this is a measure of the porosity as measured with an neutron logging device.
Furthermore, this can be explained by looking at 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.
In general this log thus reflects units 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.
Note: This log is kept in the memory of the tool until it is recovered from the well.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: