Abstract To evaluate the evolution and significance of organic pores in marine shales, samples with high organic matter and low thermal maturity were collected from the Mesoproterozoic Xiamaling Formation in the Xiahuayuan region, Hebei province, northern China. Samples underwent a thermocompression simulation experiment. Scanning electron microscope (SEM) observations, N2/CO2 gas adsorption analyses, and statistical calculations assured the qualitative and quantitative characterization of organic pores during kerogen maturation. Results demonstrated that pores largely evolve from macro- and meso-sizes to meso- and micro-sizes along with increasing pore volumes. As the total proportion of organic pores reached over 50% from the maturation (345 °C and 375 °C) to high maturation stages (440 °C), they provided the main space for gas storage. Organic pore types changed from hydrocarbon shrinkage cracks to hydrocarbon bubble pores and hydrocarbon dissolution pores. Additionally, organic porosity sharply increased initially followed by as low decrease as the samples were heated to the post maturation (500 °C) stage.

中文翻译：

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海相页岩热压缩有机质孔隙演化：生排烃模拟实验

摘要 为评价海相页岩有机质孔隙演化及其意义，在河北省下花园地区中元古代下马岭组采集了有机质含量高、热成熟度低的样品。样品进行了热压缩模拟实验。扫描电子显微镜 (SEM) 观察、N2/CO2 气体吸附分析和统计计算确保了干酪根成熟过程中有机孔隙的定性和定量表征。结果表明，随着孔隙体积的增加，孔隙在很大程度上从宏观和中观尺寸演变为中观和微观尺寸。从成熟阶段（345℃和375℃）到高成熟阶段（440℃），有机孔的总比例达到50%以上，为储气提供了主要空间。有机孔隙类型由烃类收缩裂缝向烃类气泡孔和烃类溶蚀孔转变。此外，有机孔隙率最初急剧增加，然后随着样品加热到成熟后 (500 °C) 阶段而降低。