Nuclear Magnetic Resonance T1–T2 Map Division Method for Hydrogen-Bearing Components in Continental Shale

There are many hydrogen-bearing components in shale, including kerogen, free oil, adsorbed oil, free water, adsorbed water, and structural water. Measuring the content and distribution of each component is important to understand the occurrence mechanism of shale oil. The nuclear magnetic resonance (NMR) T1–T2 map can be used as a non-destructive technique to distinguish hydrogen-bearing components in shale. In this paper, we examine the relaxation characteristics of kerogen, shale, and clay minerals in continental shale under different oil or water conditions using high-resolution low-field NMR instruments (frequency is 21.36 MHz, and echo time is 0.07 ms). The NMR T1–T2 map division method was established for each hydrogen-bearing component. The relaxation characteristics of each component are as follows: (1) Kerogen has the highest T1/T2 ratio; oil exhibits a higher T1/T2 ratio than that of water; and the mobility of water is greater than that of oil under saturated conditions. (2) The transverse relax...