百色盆地第三系烃源岩热模拟特征研究

百色盆地第三系百岗组和那读组湖相烃源岩为混合型。通过2个典型未成熟暗色泥岩样品加水热压模拟实验的液态烃、气态烃产率及组成等对比分析，发现两者存在明显的差异。那读组样品在低成熟～成熟阶段（模拟温度为230～350℃）以液态烃产出为主，其中低熟油的累积产率约占60%的比例。百岗组样品在低成熟阶段液态烃产率略大于气态烃产率，到成熟阶段则以气态烃产出为主。在热模拟的气相产物组成中，那读组样品的气态烃含量随模拟温度升高具有明显的双峰特征。在热模拟液态烃中，C₂₇、C₂₈、C₂₉规则甾烷呈“V”字型分布，C₂₇／C₂₉甾烷比值、姥/植比值和伽马蜡烷含量随模拟温度增加的变化较小，Ts/Tm比值随模拟温度增加的变化幅度较大。

Study on Characteristics of Source Rock by Thermosimulation in Tertiary of Baise Basin

Baigang Formation and Nadu Formation in Tertiary of Baise Basin are lacustrine source rocks. After contrasting and analyzing the results of liquid hydrocarbon and gaseous hydrocarbon productivity and component from hydrous pyrolysis of two typical immature samples of black mudstone, it is discovered that their differences are still remarkable. The hydrocarbon analysis result of the samples from Nadu Formation shows it is basically liquid in low mature-mature stage(simulating temperature between 230 to 350℃),accumulative productivity of low mature oil takes up some 60%. Liquid hydrocarbon productivity is little bigger than gaseous hydrocarbon at low mature stage in samples of Baigang Formation, but at mature stage, the hydrocarbon is basically gaseous one. In the component of thermal simulation gaseous matter, the content of gaseous hydrocarbon in the samples of Nadu Formation is significantly double peak with the increase of simulating temperature. In the thermal simulation liquid hydrocarbon，the distribution of C₂₇,C₂₈,C₂₉regular steranes is in the form of letter "V", the steranes ratio of C₂₇/C₂₉, pristane／phytane and the content of gammacerane changes in a small range with the increase of simulating temperature, but the ratio of Ts/Tm changes in a great range with the increase of simulating temperature.