二连盆地赛汉塔拉凹陷烃源岩有机相与烃源灶

摘要

The study of organic facies of source rocks can contribute to characterize the source kitchen in the hy-drocarbon exploration and development.In order to assess the prospects of Saihantala Sag,Erlian Basin,the Rock-Eval data were used to classify the organic facies of source rocks and realize the evaluation of source rocks.The parameters of alkanes,biomarker and vitrinite reflectance were used to determine the organic matter maturi-ty of hydrocarbon source rocks,and the quantitative characterization of source kitchen was realized.The results show that the Lower Cretaceous source rocks mainly developed in the A'ershan Formation (K1 ba),the first member (K1 bt1) and second member (K1bt2) of Tenggeer Formation in Saihantala Sag.The source rocks in the K1 ba are mainly organic facies F,and the source rocks in K1 bt1 and K1 bt2 are mainly organic facies D/E,with a little organic facies C.The vertical distribution of source rocks shows the characteristics of organic facies F,D/E and F from bottom to top.The source rocks in the K1 bt1 is the main source rocks,and the hydrocarbon expulsion intensity ranges from 5 × 106 t/km2 to 35 × 106 t/km2,followed by K1 ba source rocks,and the hydrocarbon expulsion intensity is (2-8)× 106 t/km2.%在油气勘探过程中,有机相的研究有助于定量表征烃源灶.为了更好地分析二连盆地赛汉塔拉凹陷的勘探前景,应用大量岩石热解数据对烃源岩有机相进行划分,实现了对烃源岩的分类评价,同时结合烷烃参数、生物标志物参数和镜质体反射率标定烃源岩有机质成熟度,进而实现了对烃源灶的定量表征.研究表明:赛汉塔拉凹陷自下而上发育阿尔善组、腾一段和腾二段3套烃源岩,其中阿尔善组主要发育F相烃源岩,腾一段和腾二段主要发育D/E相烃源岩,兼有少量C相烃源岩,垂向上从阿尔善组到腾一段和腾二段下部再到腾二段上部,显示出F相—D/E相—F相的烃源岩分布特征;腾一段烃源灶为主力烃源灶,排烃强度为(500～3 500)万t/km2,阿尔善组烃源灶为次要烃源灶,排烃强度为(200～800)万t/km2.研究结果为二连盆地赛汉塔拉凹陷资源潜力分析提供了依据.