生油岩干酪根腐泥化作用的镜下特征及其对类型划分的意义

MICROSCOPIC CHARACTERISTICS ON THE SAPROFICATION OF KEROGEN IN SOURCE ROCKS AND THEIR SIGNIFICANCE IN THE CLASSIFICATION OF ORGANIC TYPES

殷沫 祝幼华

Yin Mo Zhu Youhua

胜利石油地质科学研究院 山东东营

Geoscience Research Institute in Shengli Oilfield, Dongying, Shandong

应用透射光和反射荧光对济阳坳陷48口井160块生油岩进行了系统观察。发现干酪根中的无定形体有来自于低等浮游群体藻类、高等植物的表皮细胞(角质体)和草本植物三类不同的先质,它们具有不同的生烃潜力,这为正确划分干酪根类型提出了新的依据。文章还重点研究了低等浮游藻类降解成无定形体的演化过程依次形成藻质体、腐化藻体和无定形体,并伴随有烃类的形成。作者指出藻类在未成熟阶段以微生物降解为主并形成低熟原油,进入成熟阶段则以热降解占主导而形成成熟原油。

160 source rock samples taken from 48 wells in the Jiyang Depression are systematically studied using transmitted and reflected fluorescent lights. Amorphous solids discovered in kerogens may derive from three different types of precursors, i.e. lower planktonic astogenetic algae, cutinites of higher plants and herbaceous plants, which can have certain hydrocarbon potential and provide new evidences for the classification of kerogen types. This paper also focuses on the degradative evolution of lower planktonic algae into amorphous solids and suggests that microbial degradation prevails over algae during undermaturation, generating crude oil of low maturity; while matured oil generates during the maturation stage dominated by thermal degradation.

https://doi.org/10.11781/sysydz199103287