The invention discloses an oil and
water layer recognition method suitable for a volcanic reservoir. The oil and
water layer recognition method comprises the following steps of performing inversion
processing on an echo string by using nuclear magnetic
logging data in a dual
waiting time mode to obtain a long
waiting time T2 spectrum and a short
waiting time T2 spectrum; then performing
differential spectrum processing to obtain a difference spectrum reflecting oil and gas information; performing integral
processing on the difference spectrum to obtain difference spectrum
porosity (Diff_Por); determining sensibility of various
hydrocarbon components on an oil and
water layer by gas
logging data establishing a
hydrocarbon characteristic ratio (Ratio_C); establishing a
cross plot of the difference spectrum
porosity and the
hydrocarbon characteristic ratio according to existing oil testing data and determining a distinguishing boundary of the oil and water layer; extracting the difference spectrum
porosity and the hydrocarbon
characteristic ratio of a stratum of which oil and water are about to be recognized according to the previous steps; and effectively recognizing the oil and water layer by using the established
cross plot. On the basis of nuclear magnetic
differential spectrum processing, processing is carried out further to obtain the difference spectrum porosity, the
cross plot is established by the difference spectrum porosity and the hydrocarbon characteristic ratio obtained by the gas
logging data, and then the oil and water layer of the volcanic reservoir can be recognized.