歧口凹陷沙一段低熟烃源岩评价

摘要

This paper evaluates the immature hydrocarbon source rocks in the Qikou sag of Bohai Bay by studying the organic matter abundance of source rocks, the hydrocarbon-generating and-exhausting characteristics,the depositional environment,the organic petrology characteristics,and the characteristics of crude oil.The purpose is to provide the theoretical basis for the evaluation and exploration and development of the immature oil resources in the Qikou sag.The results show that the organic matter of the immature source rocks in the Qikou sag is abundant and good type.Thus, these source rocks have the characteristics of concentratedly generating hydrocarbon and efficiently exhausting hydrocarbon.The hydrocarbon source rocks mainly deposit in a salty environment under a droughty climate.The algae and the mineral bituminous matrix in macerals make a great contribution to the formation of immature petroleum.A large number of immature and low-mature oils are found in the Qikou sag.%利用烃源岩有机质丰度、生排烃特征、发育古环境、有机岩石学及原油特征等手段，探讨歧口凹陷沙一段低熟烃源岩生烃、排烃特征。研究结果表明，歧口凹陷沙一段低熟烃源岩有机质丰度高、类型好，具有集中排烃、高效排烃的特点。沙一下段烃源岩发育的环境主要为干旱气候下的咸水环境。藻类及显微组分中的矿物沥青基质是低熟烃源岩形成低熟油气的物质基础。歧口凹陷存在大量未熟－低熟的原油。