岩石物理岩石孔喉结构特征对核磁T2谱影响的数值模拟

We built a three-dimensional irregular network model which can adequately describe reservoir rock pore-throat structures. We carried out numerical simulations to study the NMR T2 distribution of water-saturated rocks. The results indicate that there is a good correlation between T2 distribution and the pore radius frequency histogram. The total T2 distribution can be partitioned into pore body and pore throat parts. The effect of parameters including throat radius, pore-throat ratio, and coordination number of the micro- pore structure on the T2 distribution can be evaluated individually. The result indicates that： 1 ） with the increase of the pore throat radius, the T2 distribution moves toward longer relaxation times and its peak intensity increases; 2） with the increase of the pore-throat ratio, the T2 distribution moves towards longer T2 with the peak intensity increasing and the overlap between pore body T2 and pore throat T2 decreasing; 3） With the increase of connectivity, the short T2 component increases and peak signal intensity decreases slightly.

Numerical simulation of rock pore-throat structure effects on NMR T2 distribution

We built a three-dimensional irregular network model which can adequately describe reservoir rock pore-throat structures. We carried out numerical simulations to study the NMR T2distribution of water-saturated rocks. The results indicate that there is a good correlation between T2distribution and the pore radius frequency histogram. The total T2distribution can be partitioned into pore body and pore throat parts. The effect of parameters including throat radius, pore-throat ratio, and coordination number of the micro-pore structure on the T2distribution can be evaluated individually. The result indicates that 1) with the increase of the pore throat radius, the T2distribution moves toward longer relaxation times and its peak intensity increases; 2) with the increase of the pore-throat ratio, the T2 distribution moves towards longer T2with the peak intensity increasing and the overlap between pore body T2and pore throat T2decreasing; 3) With the increase of connectivity, the short T2component increases and peak signal intensity decreases slightly.