东台坳陷下第三系生油岩生物标记化合物及其地质地化意义

BIOMARKERS OF TERTIARY SOURCE ROCKS IN DONGTAI DEPRESSION AND THEIR GEOLOGICAL-GEOCHEMICAL SIGNIFICANCE

卢松年 李伟民 顾惠民 高品文

Lu Songnian Li Weimin Gu Huimin Gao Pinwen

东台坳陷是苏北-南黄海盆地的次一级构造单元。下第三系阜宁组二段和四段被认为是主要生油岩,阜宁组三段、戴南组和三垛组是主要储油层。本文根据色谱-质谱等资料,讨论了指示沉积环境、有机物类型和生油门限的生物标记化合物参数,为进一步评价生油岩的生油潜力提供了依据。

GCMS are used to analyse saturated hydrocarbon fractions of 17 argillite rock extracts of Dongtai depression so as to study the sedimentary environment,the type of organic matters and the maturity of early Tertiary source rocks with the aid of biomarkers such as sterane and terpane.Both OEP and isopre-noid distrt bution have proved that E and E are deposits under strong reducing environment in which gamma ceranes have emerged.Based on the ratio of sterane of different carbon number and that between sterane and terpane,sapropelicorganic matter(type Ⅰ and Ⅱ of kerogen)is found to distribute in regions where C sterane exceeds 30% and where the ratio between C sterane and C hopaneplus mortane exceeds 0.5.On the basis of the epimerization of sterane and terpane,it can be deduced that the depth of the threshold of oil generationis about 2,100m.

10.11743/ogg19850108