According to dual-TE logging , intrinsic relaxation time T_2int and t he T_2int deviation between hydrocarbon and water can be obtained , which can be used to discriminate the formation fluid property and evaluate the hydrocarbon saturation. It is using T_2int deviation to obtain volumes of the movable hydrocarbon and movable water , and using cutoff value to determine the volume of capillary bound water . The hydrocarbon saturation could be obtained after these volumes were calibrated by hydrocarbon index. This method has been compiled to FLAN module for oil and gas identification and evaluation by nuclear magnetic resonance log. The real data of many wells are processed by this module. The result proves a good effect .