油页岩有机碳的演化模式与评价方法

EVOLUTION MODEL AND EVALUATION METHOD OF ORGANIC CARBON IN OIL SHALE

秦匡宗 劳永新 黄醒汉

Qin Kuangzong Lao Yongxin Huang Xinghan

从干酪根的结构特性和有机碳的化学构成出发,来研究干酪根的演化与评价,能够深入地揭示油气生成过程的本质,可靠地进行生油岩油气生成量的估测。基于这一考虑,人们提出了“有效碳”、“有潜力碳”等概念。七十年代后期发展起来的固体样品 C-13核磁共振波谱分析新技术——交叉极化与幻角自旋(cross polarization and magic angle spinning,CP/MAS),可以直接测定固体试样中芳构碳与脂构碳的含量,从而为研究干酪根有机碳的构成及其演化提供了新的有效手段。

Thermal evolution of Fushun and Maoming oil shales is studied by Fischer Assay and Rock-Eval,and aromaticities of pyrolysis products are measured by nuclear magnetic resonance and fixed carbon ratio.In respect to the behavior of aromatic carbon and aliphatic carbon during thermal evolution,the authors found that the aromatic carbon pyrolysis residue remains unchanged,and the carbon contained in oil and gas are primarily originated from aliphatic car-bon.Thus an evolution model of organic carbon fractions of kerogen is sug-gested.In consideration of the mass balance of aromatic carbon and aliphatic carbon during evolution,an equation relating oil and gas yield P,to the orga-nic carbon content C and the“quality parameter”of organic carbon K isderived as follows:P=1.2 CKWhere K is equal to(f/f)-1,f and f are the aromaticities of samples after and before the evolution respectively.The calculated values are checked by Rock-Eval experimental results,the average error is less than 10%.

10.11743/ogg19850310