Determination of Fluid Saturation in Shale Reservoirs Using NMR

摘要

A method of estimating fluid saturations includes obtaining amplitude values of nuclear magnetic resonance (NMR) data for a material, with each amplitude value being associated with a longitudinal magnetization recovery (T1 relaxation) time and a transverse magnetization decay (T2 relaxation) time. A mean is calculated as a function of the amplitude values and the T1 and T2 relaxation times for the amplitude values. Hydrocarbon saturation of pore space of the material is estimated as a function of the deviation of the mean from a threshold hydrocarbon saturation indicator and a threshold water saturation indicator, using the processor. Water saturation of the pore space of the material is estimated as a function of the deviation of the mean from the threshold hydrocarbon saturation indicator and the threshold water saturation indicator, using the processor.