大港探区下古生界奥陶系烃源岩地化特征

RESERVOIR GEOCHEMICAL CHARACTERISTIC OF THE SOURCE ROCKS IN LOW PALEOZOIC IN DAGANG REGION

通过油源对比发现位于大港探区孔西潜山构造的孔古 3井油源来自奥陶系烃源岩 ,进一步的地球化学分析表明 ;奥陶系碳酸盐岩平均有机碳含量为 0 .14% ,平均氯仿沥青“A”含量为 0 .11% ,平均总烃含量 5 7.6 ppm ,已达到生油岩有机质丰度下限值 ,部分样品已达到好较好生油岩的有机质丰度指标 ;干酪根类型主要为Ⅱ1型、Ⅰ1型和Ⅱ2型 ;大部分样品有机质已处于高成熟～成熟演化阶段。大港探区下古生界奥陶系地层分布广泛 ,这为大港探区寻找古生界原生油气藏奠定了基础 。

Well Kong 3 is located in Kong buried ancient mountain structure in dagang exploration region, research shows that oil in the well is from source rocks of Ordovician, geochemical analysis indicates that the average organic carbon of Ordovician limestone is 0.14%, chloric bitumen A is 0.11%, total hydrocarbon is 57.6 ppm, which means bottom limits of organic richness of source rock have been reached, and data from some rocks have been ranked in good to relatively good range. The kerogen is mainly typeⅡ 1,Ⅰ 1 and Ⅱ 2, most of organic samples belongs to matured to highly matured evolution. This shows an important significance for exploration of primitive reservoir in dagong region.