中文摘要：

针对A区块的实际情况，通过压汞数据得出的毛管压力曲线。分析了表征二类油层与主力油层孔隙结构特征的各项参数。研究了不同孔隙半径区间的孔隙体积、孔喉比及渗透率贡献分布特点。给出了二类油层与主力油层孔隙结构的差异。研究结果表明，与主力油层相比，二类油层除具有低孔低渗的特点之外，其它主要差异为：平均孔隙半径较小、中值压力较大、60％以上的孔隙体积分布在小孔道中；孔喉比为4．8—64．8，是主力油层孔喉比的4倍以上，最大达20倍以上，孔喉分布不均匀。

英文摘要：

According to actual situation of a block, by the capillary pressure curve which is obtained from the mercury penetration data, the pore structure characteristics parameters of second-class reservoirs and major reser- voirs are analyzed and the pore volume, pore-throat ratio and permeability contribution distribution of different pore radius interval are studied. The differences of pore structure between second-class reservoirs and major reservoirs in a block are given. The result shows that, compared with the major reservoirs, besides the characteristics of low po- rosity and low permeability the second-class reservoirs have the other characteristics. The average pore radius is smaller, the median pressure is high, more than 60% of the second-class reservoirs pore volume distributes in small pore channel, the pore-throat ratio is 4. 8 to 64.8, which is more than four times of the major reservoirs, up to 20 times. The pore throat distribution is uneven.