Method of Calculating Secondary Porosity of Reef Limestone Reservoir by Casting Thin Section Calibrating Nuclear Magnetic T 2 Spectrum

Secondary pores are the main reservoir space and transportation channel of oil gas in reef limestone reservoir. At present, method calculating secondary porosity is restricted by morphological characteristics spectrum, regional artificial influence, accuracy calculation. We present a new for nuclear magnetic resonance T 2 spectrum which calibrated casting thin section. begin with analyzing determining high correlation between surface section total porosity. The objective confirming feasibility using thin-section information calibrate. Then, we use as calibrating data find id="M3"> relaxation time corresponding to best section, that is, id="M4"> cutoff value porosity, through Monte Carlo method. Finally, calculate functional relationship statistical analysis shows effectively improves calculation results have productivity.