杨彧爽 毛治超 李阳

摘      要： 通过对沧东凹陷古近纪孔二段部分取样井的岩心的进行观测与取样，对沧东凹陷古近系孔二段烃源岩的地层厚度与分布特征进行分析研究;并对泥岩烃源岩样品进行有机地球化学的分析测试，其中分别包括对总有机碳（TOC）测试、镜质体反射率（Ro）测定、岩石热解分析、全岩有机显微组分分析、氯仿沥青“A”抽提、族组分分离等分析方法进行分析，完成了对沧东凹陷古近系孔二段烃源岩的有机质丰度、有机质类型以及有机质成熟度的研究，从而对沧东凹陷古近系孔二段烃源岩进行评价。研究结果表明，研究区烃源岩有机质丰度普遍较高，型以Ⅱ1、Ⅱ2为主，部分为Ⅰ型有机质，没有Ⅲ型有机质。有机碳（TOC）值为0.12%～76%，平均值为2.23%，大部分超过生烃门限（0.2%）;镜质组反射率为0.627%～0.888%，总体上处于成熟阶段。

关  键  词：沧东凹陷;孔二段;烃源岩;烃源岩评价

中图分类号：TE122       文献标识码：A       文章编号： 1671-0460（2020）02-0480-04

Abstract： Through the observation and sampling of the core of Cangdong sag， the stratigraphic thickness and distribution characteristics of the source rocks of the second member of Kongdian formation of the Paleogene in Cangdong sag were studied. The organic geochemical analysis and testing of the mudstone source rock samples were carried out， including total organic carbon（TOC）test， rock pyrolysis analysis， analysis of whole rock organic microscopic composition， vitrinite reflectance（Ro）measurement， chloroform asphalt "A" extraction， group component separation， etc. The study on the organic matter abundance， organic matter type and organic matter maturity of the source rocks of Kong2 member of the Paleogene in Jidong Sag was finished， and the source rocks of Kong2 member of the Paleogene in Jidong Sag were evaluated. The results show that the organic matter abundance of source rocks in the study area is generally high， the TOC value is 0.12%～76%， the average value is 2.23%， exceeding the hydrocarbon generation threshold （0.2%）; the vitrinite group reflectivity is 0.627%～0.888%， overall at a mature stage. The organic matter type is mainly composed of II1 and II2， and some of it is type I organic matter.

Key words：  Cangdong sag; the second member of Kongdian formation; source rocks; source rock evaluation

沧东凹陷是中国渤海湾盆地黄骅亚盆地中含油最多的地区之一，已发现7个常规油田，包括两个巨型油田。沧海凹陷面积为1.5×103 km2，位于渤海湾盆地黄骅亚盆地南部。这条东北向的凹陷以东部的徐西断裂，西部的沧东断裂，北部的孔店隆起和南部的东莞隆起为界。沧东凹陷可划分为五个不同的构造单元，即：孔店构造带;舍女寺断裂带;孔东坡;孔西坡和南皮斜坡。

关于沧东凹陷孔二段形成的石油勘探擴展为研究该地层的油气潜力和详细的生物标志物分布提供了难得的机会，以证明有机质来源和沉积特征。……