沾化凹陷烃源岩地球化学特征分析

The Geochemical Characteristics of Hydrocarbon Source Rocks in Zhanhua Depression

研究对比沾化凹陷区各个层段烃源岩的地球化学特征。从有机质丰度来看,沾化凹陷以沙一段、沙二段、沙三段岩样有机质丰度高,东营组和沙四段次之,馆陶组最差;其干酪根类型以腐泥型为主,混合型次之,以腐殖型最少;其源岩母质输入以低等水生生物为主。从有机质成熟度来看,沾化凹陷沙三段、沙四段有机质演化程度较高,干酪根的缩聚程度较高。综合以上因素,认为沾化凹陷沙三段烃源岩最好,沙一段、沙四段和东营组则相对较好,次为沙二段,馆陶组则为非烃源岩。

There are many sets of source reservoir roof with good accumulation conditions in Zhanhua depression,especially in Shahejie formation,and it is rich in oil and gas resources.This paper studied geochemical characteristics about each layer by using the standard of Organic carbon abundance,organic type and organic matter maturity.Judging from the organic matter abundance,source rocks in the 1st member and the 2nd member and the 3rd member of the Shahejie formation have high organic matter abundance;but Dongying formation and the 4th member of the Shahejie formation both are poorer;Guantao formation is the worst.The main kerogen type is sapropelic-type,then is mixed type,the humic-type kerogen is the least;lower aquatic organisms is the dominant in the organic matter.Judging from the organic matter maturity,source rocks in the 4th member and the 3rd member of the Shahejie formation have high Organic evolution degree,and the kerogen is high degree of condensation.According to the above factors,source rocks in the 3rd member of the Shahejie formation is the best,then is source rocks in the 1st member and the 4th member of the Shahejie formation and Dongying formation,then is source rocks in the 2nd member of the Shahejie formation,source rocks in Guantao formation is not hydrocarbon source rocks.