Micropore size analysis in oil-well cement by proton nuclear relaxation.

The durability of cement depends mainly on cement microstructure parameters such as pore size distribution. In this study, we have observed pore size distribution in a Class G oil-well cement immersed for 1 year in brine at T = 293 K, P = 10(5) Pa and in a down-hole condition at T = 353 K, P = 7.10(6) Pa by proton nuclear magnetic spin-lattice relaxation (1H-NMR). After 4 months of immersion at T = 293 K, P = 10(5) Pa, the distribution of discrete relaxation rates reveals the fractal feature of the pore size distribution, whereas after 1 year at T = 353 K, P = 7.10(6) Pa, a dispersed distribution is still observed.