A well logging system and method are disclosed for detecting the presence and estimating the quantity of gaseous and liquid hydrocarbons in the near wellbore zone. The system uses a gradient-based, multiple-frequency NMR logging tool to extract signal components characteristic for each type of hydrocarbons....http://www.google.de/patents/US6512371?utm_source=gb-gplus-sharePatent US6512371 - System and method for determining oil, water and gas saturations for low-field gradient NMR logging tools
