1H spin-lattice relaxation time (T1) of dispersed insoluble organic matter (kerogen) as measured by NMR gives a regular increase with increasing burial depth. This evidence is indicated by 94 analytical data in the six boreholes: MITI-Hamayuchi, MITI-Wakkanai, MITI-Embetsu, Tsubetsu, Yufutsu-oki B-4 and Nishikatakai SK-1 D and in the two outcrop sections, Umanokamiyama and Oashizawa. The T1 versus vitrinite reflectance (R0) suggests a linear relationship between the two variables with a high correlation coefficient. T1 could be an evaluation parameter effective for organic maturation during burial diagenesis.
A pore size distribution of a porous medium is estimated, and using the distribution, permeability is also calculated on the basis of a two-dimensional network model. The calculated values of permeability are compared with experimental ones. The calculation agrees well with the experimental results, when the size of the network is large enough. The agreement is better than that between the experimental values and the estimation on the basis of Carman's equation.