莺琼盆地中新统海相烃源岩地球化学特征及生烃潜力评价
Geochemical Characteristics and Hydrocarbon Generation Potential of Miocene Marine Source Rocks in the YingQiong Basin

摘要： 通过有机碳测定、岩石热解分析、显微组分定量分析、饱和烃色谱、色谱-质谱等实验分析，对莺琼盆地中新统海相烃源岩的地球化学特征进行了研究，探讨了不同层位烃源岩的生烃潜力。结果表明：莺琼盆地中新统海相烃源岩有机质丰度总体较低，大部分烃源岩为中等烃源岩，有机质类型以Ⅱ2型和Ⅲ型为主，有机质热演化主要处于成熟阶段。烃源岩显微组分组成具有富含镜质组、壳质组+腐泥组次之、贫含惰性组的特征。烃源岩沉积环境主要为弱氧化-弱还原环境，具有陆生高等植物和低等水生生物生源混合输入的特征。莺歌海盆地梅山组烃源岩综合评价为中等烃源岩，生烃潜力相对较好，三亚组烃源岩综合评价为较差—中等烃源岩，具有一定的生烃潜力。琼东南盆地梅山组和三亚组烃源岩综合评价为中等烃源岩，具有相当的生烃潜力。
Abstract: Based on the analysis of organic carbon，rockeval pyrolysis，maceral identification，saturated hydrocarbon chromatography and chromatographymass spectrometry，geochemical characteristics of the Miocene marine source rocks in the YingQiong Basin were studied. The hydrocarbon generation potentials of different source rocks were discussed. The results indicate that the organic matter abundance of the Miocene marine source rocks are generally low, most of which are medium source rocks. Organic matters comprise mainly type Ⅱ2 and Ⅲ, and their thermal evolution is mainly in the mature stage. The maceral composition of the studied samples is dominated by vitrinites, and the inertinite contents are relatively low. Sedimentary environment of the source rocks was weakly oxidizing to weakly reducing, and the organic matter may have be originated from terrestrial higher plants and lower aquatic algae. Comprehensive source rock evaluation on the Meishan Formation in the Yinggehai Basin indicates that they are medium source rocks with relatively high hydrocarbon generation potential, whereas source rocks of the Sanya Formation are poormedium ones and have minor hydrocarbon generation potential. The Meishan and Sanya formations in the Qiongdongnan Basin contain medium source rocks, and have certain hydrocarbon generation potential