摘要
海侵事件是松辽盆地的重要地质事件之一，其主要特征是存在着甲藻甾烷和Ｃ３１甾烷。朝长地区长２０井原油为典型的未熟低熟油。油源对比表明：未熟低熟油的源岩与白垩系青山口组一段海侵地层有关，因而说明油气的早期生成与海侵事件密切相关。海侵地层之所以能生成油气，特别是生成低熟油气有如下原因：①伴随着海侵高水位阶段常能形成有机质丰度较高的源岩，这是油气形成的物质基础；②海侵阶段形成的生油岩和海退阶段形成的储层的有机配合，有利于油气的赋存；③海侵常能使水体的盐度增加，造成某些藻类生物的发育，形成有机质类型较好的源岩；④海侵地层中的半咸水咸水藻类具有丰富的生物类脂物，聚合程度低，在早期阶段可以形成低熟油气。
The geological event of the Cretaceous period involved important geological events
such as marine transgression The existence of high abundance of dinosterane in the mudstone
of the first section of the Qingshankou formation and member 1 and member 2 of the Nenjiang
formation indicates two periods of marine transgression The relative content of dinosterane in
the samples from the first section of the Qingshankou formation is larger than that of member 1
and member 2 of the Nenjiang formation, which implies that there is a relatively high salinity in
the sedimentation period of the first section of the Qingshankou formation C 31 sterane can
be also regarded as a marker of transgression The research result shows that early
generation of hydrocarbons is closely related to marine transgression strata Several factors
may attribute to this: (1) The excellent source rock has been formed in the high water level of
marine transgression;(2)Fluctuation of marine transgression leads to formation of source rocks,
reservoir rocks and cap rocks, which is important to oil pool formation; (3)The marine
transgression will cause the increase in salinity of water media, such that the source rocks will
have very good organic matter type; (4) Some kinds of algae such as dinoflagellates, diatoms,
prynesiophytes, rich in biological lipids and weakly polymerized, can generate hydrocarbons
in the early stage
出处
《江汉石油学院学报》
CSCD
北大核心
1999年第1期26-28,共3页
Journal of Jianghan Petroleum Institute
关键词
油气生成
海侵
白垩纪
松辽盆地
石油生成
low maturation oil
oil and gas origin
transgression
Cretaceous
period
Songliao basin
