中国石油大学学报（自然科学版）2026，Vol.50Issue(2)：55-63,9.DOI:10.3969/j.issn.1673-5005.2026.02.006
基于高能中子自补偿校正的D-T源确定中子孔隙度改进方法
An improved method for determining porosity by D-T source based on fast neutron self-compensated correction
摘要
Abstract
D-T source neutron porosity logging exhibits low sensitivity in high-porosity formations,and its response character-istics differ from those of conventional compensated neutron logging across various lithologies and in shaly formations.This study proposes a novel method that utilizes thermal neutron counts within a pulsed time window to characterize a self-compen-sated correction factor for high-energy neutrons,combined with a thermal neutron count ratio to determine porosity.Monte Carlo simulations were conducted to construct wellbore-formation models,simulating the distributions of fast and thermal neu-trons under varying porosity and shale content for both D-T and Am-Be sources.The self-compensated correction factor for high-energy neutrons and neutron porosity logging responses were systematically analyzed and validated using field logging da-ta.The results show that the thermal neutron count ratio increases with porosity.After applying the fast neutron self-compen-sated correction,the relative sensitivity improves by a factor of 1.85 to 2.69(for limestone formations with porosity ranging from 20%to 40%),and the porosity deviation is reduced to 49%-52%of the original value.In particular,the porosity ac-curacy decreases from 1.55%to 0.80%in limestone formations with 30%porosity.In sandy shale formations with 13%-22%porosity,the absolute error of the calculated porosity is reduced to within 2%compared with conventional compensated neutron logging.This method effectively addresses the low sensitivity of D-T neutron sources in high-porosity formations and provides a promising approach for neutron porosity evaluation in cased-hole wells.关键词
D-T中子源/热中子计数比/孔隙度/中子自补偿校正/蒙特卡罗模拟Key words
D-T neutron source/thermal neutron count ratio/porosity/neutron self-compensated correction/Monte Carlo simulation分类
天文与地球科学引用本文复制引用
谢冰,张辉,张慧,张锋,王青川..基于高能中子自补偿校正的D-T源确定中子孔隙度改进方法[J].中国石油大学学报（自然科学版）,2026,50(2):55-63,9.基金项目
国家自然科学基金项目(42474155,42174147) （42474155,42174147）
国家科技重大专项(2025ZD1402105,2025ZD1401104) （2025ZD1402105,2025ZD1401104）
