An application of NMR logging to calculating permeability in low porosity and low permeability reservoir

For the low porosity and permeability reservoir in HZ area,the eastern South China Sea,there is a poor corrclation between porosity and permeability,and it is not accurate to calculate permeability by conventional methods.Therefore,the pore structure is analyzed,and the correlation between integrated petrophysical paramctcrs and rock pore structure parameters is studicd for the low porosity and permeability reservoir.By using the ability for NMR T2 distribution to characterizc microscopic pore structure of rocks,a quantitative relationship to calculate permeability of the tight reservoir rocks has been established on a basis of measured NMR data of core samples form these rescrvoir rocks in laboratory.Finally,the reliability is verified for this relationship by some examples.