A new determining porosity method based on four detectors and D-T neutron source

Summary The sensitivity of D-T neutron porosity logging to formation porosity change is lower than that of Am-Be neutron porosity logging.In order to improve the sensitivity of porosity measurement, based on a measurement system consisting of four detectors and D-T neutron source, The Monte Carlo simulation method was used to establish the numerical calculation model , the effects of density and hydrogen index on the thermal neutron count ratio and inelastic gamma count ratio are studied . A new method to correct the influence of density in porosity measurement by inelastic gamma count ratio is proposed. The data in the model well was processed using this method, and the processed results showed better accuracy and sensitivity to porosity than the unprocessed values.