海相优质烃源层评价与形成条件研究

在对全球范围内不同类型海相烃源岩对比分析的基础上,通过筛选出百余块不同类型烃源岩和含油储集岩的热压加水生排油气模拟实验,结合大中型油气田形成的地质条件,对我国海相优质烃源岩的形成条件进行了综合研究,认为海相优质烃源岩主要形成条件有:1)台内盆地及近滨潟湖、台地斜坡、前缘斜坡及前礁等沉积相带,浮游生物发育,水体稳定且较深,处于还原-强还原环境;2)较高的有机质含量,总有机碳含量TOC≥2%;3)Ⅰ-Ⅱ型干酪根,低成熟阶段形成的大量稠油可以沿富有机质页理面以油相网状传递式连续不断地长距离运移,很容易形成大油田;4)烃源转化过程中古油藏及分散在烃源岩和储集岩中的可溶有机质也是优质再生气源,高成熟-过成熟储集岩中的TOC>0.20%时就属优质气源岩,由其原始"油"生成的总生气量与TOC>2%且为Ⅰ-Ⅱ₁型干酪根的烃源岩生成的总生气量基本相当. 

Study of forming condition on marine excellent source rocks and its evaluation

Forming condition of the marine excellent source rocks was studied by the simulation experiment on hydrocarbon generation and expulsion from a mass of different types source rocks and oiliness reservoir rocks,and comparative analysis on geological setting of global large oil and gas field and its marine source rocks.The main forming condition of the marine excellent source rocks form:1)advantage sedimentary environment including intraplatform depression/basin,lagoon,platform slope,anterior border slope and fore reef etc,where have exuberance planktons,tranquilization and deep seawater and reducing environment;2) rich organic matters,total organic carbon content TOC≥2%;3) Ⅰ-Ⅱ type of kerogen;4)paleo-petroleum pool and the dispersed soluble organic matter of the source rocks and reservoir rocks in course of hydrocarbon generation are excellent regenerative gas source during the organic carbon content is large than 0.2%.