DMR (Density Magnetic Resonance) Porosity

The problem of NMR measurements in gas reservoirs is that in Gas-bearing zones, total NMR porosity read much less than density-derived porosity.

Porosity derived from NMR alone suffers from the low hydrogen index of the gas and the long T1 polarization time of the gas when the data is acquired with insufficient wait time.

To provide a robust estimate of porosity, a method called Density-Magnetic Resonance (DMR) that combines density porosity and total NMR porosity was successfully applied to the  wells logged with NMR.

The DMR technique was able to produce a very good porosity estimation comparable to that measured on conventional cores.