Determination of oil viscosity and continuous gas oil ratio from nuclear magnetic resonance logs

A system for performing operations for an oilfield having at least one wellsite with a wellbore penetrating a subterranean formation for extracting fluid from an underground reservoir therein, comprising:

• a downhole tool configured to move in the wellbore;
• a Nuclear Magnetic Resonance (NMR) module disposed in the downhole tool for obtaining a set of NMR data of a portion of the subterranean formation from inside the wellbore without acquiring formation fluid sample;
• a processor;
• and
• memory comprising instructions when executed by the processor having functionalities to:
• isolate a quantitative reservoir fluid information associated with oil from OBM using radial profiling of the set of NMR data, wherein the OBM is used for extracting fluid from the underground reservoir;
• and
• determine GOR related information associated with the portion of the subterranean formation from the quantitative reservoir fluid information associated with oil, wherein the GOR related information is determined based on a predetermined model,
• wherein operations for the oilfield is performed based on the GOR related information.

A computer readable medium comprising instructions executable by a processor to perform a method, the method comprising:

• obtaining a set of Nuclear Magnetic Resonance (NMR) data of a portion of the subterranean formation from inside the wellbore without acquiring formation fluid sample;
• isolating a quantitative reservoir fluid information associated with oil from oil based mud (OBM) using radial profiling of the set of NMR data, wherein the OBM is used for extracting fluid from the underground reservoir;
• determining gas-oil-ratio (GOR) related information associated with the portion of the subterranean formation from the quantitative reservoir fluid information associated with oil, wherein the GOR related information is determined based on a predetermined model;
• and
• performing operations for the oilfield based on the GOR related information.