石油源于源岩层而成于储集层

在分析现有成烃理论不足的基础上, 提出一种新的石油形成理论。新理论认为石油源于源岩层而成于储集层。也就是说, 石油是生物有机质在沉积埋藏过程的成岩作用早期, 一部分极性有机质随孔隙水一道排出源岩层, 然后在储集层中经过热力作用逐渐形成的。进一步论述了新理论与早期成因和晚期成因学说之间的差别, 及其优点:① 较好地解释低熟油成因问题; ② 没有面临后期排烃难的问题; ③ 可以解释烃源岩在“生烃死亡线”深度以下仍能生烃问题。并推测烃源岩随Ro 增大并不一定伴随大量烃类生成。

Petroleum Origination from Source Bed and Formation in Reservoir Bed

In view of the shortage of theory of petroleum genesis, this paper proposes a new theory of petroleum genesis, which considers that hydrocarbons originate from source bed and form within the reservoir bed. In the burial process of biological organic matter, at early period of diagenesis, some of the polarity organic matter was expelled from the source bed with pore water, and then gradually became hydrocarbons within reservoir by thermal action. This paper discusses the differences between this new theory and the early or late organic genesis theories. This new theory can be used to make a good explanation of genesis of immature oil, avoid the problem that late hydrocarbon expulsion is difficult, and explain that the source rocks below "depth without hydrocarbons" can still generate some hydrocarbons. Also, it is presumed that the source rocks could not generate large numbers of hydrocarbons with increase of its vitrinite reflectance (Ro).