在利用核磁共振测井资料评价南海东部低孔渗轻质油层过程中，普遍存在渗透率高估的现象．为提高核磁共振渗透率的计算准确性，需深入分析其偏高成因并建立相应的校正方法．本文系统开展了不同饱和状态（包括饱含水、束缚水、饱含油及残余油状态）下的核磁共振横向弛豫时间（T₂）谱实验．通过对比同一岩心在饱含水和含油状态下的T₂谱，发现轻质油会使T₂谱中大孔分布明显右移，而小孔部分基本保持不变，表明轻质油是引起T₂谱异常及核磁共振渗透率偏差的主要原因．基于此，通过岩心分类确定了不同类型储层的T₂截止值，建立了针对大孔孔隙组分进行校正的T₂谱校正方法．结果表明，该方法能够将含轻质油层的T₂谱有效校正到饱含水状态，显著提高了核磁共振渗透率的准确性．

In the eastern oil fields of the South China Sea, when using nuclear magnetic resonance(NMR) logging to calculate the permeability of low porosity, low-permeability light oil reservoirs, the measured permeability values tend to be overestimated. To enhance the computational accuracy of nuclear magnetic resonance permeability, it is necessary to conduct an in-depth analysis of the causes of overestimation and establish corresponding correction methods. This paper systematically conducted NMR transverse relaxation time (T₂) spectroscopy experiments under different saturation states, including water-saturated, bound water, oil-saturated, and residual oil conditions. By comparing the T₂ spectra of the same core sample in water-saturated and oil-containing states, it was found that light crude oil causes a significant rightward shift in the distribution of macropores within the T₂ spectrum, while the distribution of micropores remains largely unchanged. This indicates that light oil is the primary cause of T₂ spectrum anomalies and NMR permeability deviations. Based on this, T₂ cutoff values for different reservoir types were determined through core classification, and a T₂ spectrum correction method calibrated for macropore components was established. Results demonstrate that this method can effectively correct T₂ spectra from light oil-bearing reservoirs to fully water-saturated conditions, significantly enhancing the accuracy of NMR permeability measurements.