澳大利亚北波拿巴盆地Plover组烃源岩特征及热演化

Characteristics and Thermal Evolution of Source Rocks of Plover Formation in the Northern Bonaparte Basin,Australia

北波拿巴盆地油气资源丰富,是澳大利亚重要的含油气盆地。下-中侏罗统Plover组烃源岩分布广,厚度大,是北波拿巴盆地的主力烃源岩。基于地质和地球化学等资料,采用有机地球化学方法和盆地模拟技术,分析了Plover组烃源岩的分布、有机质丰度、类型及成熟度等静态特征,并定量模拟恢复了其热成熟演化历史。研究表明,Plover组烃源岩有机质丰度高,整体达到较好—好级别;有机质类型以偏腐殖型为主,决定了研究区以寻找天然气为主要勘探方向;Malita地堑和Calder地堑的Plover组烃源岩进入成熟生烃门限的时间早,现今多处于高成熟阶段,为研究区的主力生烃灶;Sahul台地的Plover组烃源岩进入生烃门限的时间相对较晚,现今仍处于低成熟阶段。

The northern Bonaparte Basin,rich in oil and gas resources,is one of the most important petroliferous basins in Australia.As the main source rock i n the northern Bonaparte Basin,the Lower-Middle Jurassic Plover Formation is wi dely distributed with large thickness.This paper analyses the static characteri stics as the abundance,type and maturity and the dynamic thermal maturation his tory of the Plover Formation by the data of geological and geochemical,the meth od of organic geochemistrys and the technique of basin modelling.It is shown th at the Plover Formation source rock has abundant organic matter,which reaches a preferable-good level generally and contains humic organic matter,indicating t hat gas is the main exploration target in the study area.The Plover Formation s ource rock in the Malita and Calder grabens reached oil threshold in earlier tim e with a high maturity now,and is the main hydrocarbon kitchen,whereas that in the Sahul platform reached oil threshold at later,and is still in low maturati on stage today.