生油岩定量评价中的轻烃问题

DISCUSSION ON LIGHT HYDROCARBONS IN QUANTITATIVE EVALUATION OF SOURCE BEDS

盛志纬 葛修丽

Sheng Zhiwei Ge Xiuli

石油工业部石油勘探开发科学研究院

Research Institute of Petroleum Exploretion and Development, Ministry of Petroleum Industry

生油层定量评价中,无论是使用热解法,还是烃类法,计算生油层的已生油量、残留烃量、排烃量以致聚集量时,都会遇到一个轻烃的补偿问题。所谓轻烃,我们指的是C1-C14。这种轻烃在生油岩的烃类初次运移和进入运移通道及储集层后的二次运移中最为活跃。目前实验分析中,无论是氯仿抽提还是岩样热解,大部分的轻烃都被损失掉,即使是采用吸附烃法和轻烃法,也只能回收一部分。因此,人们一直无法弄清它在生油层中的确切含量及其随埋深增加的演化规律。

This paper describes the significance of C1-C14 light hydrocarbons in quantitatve evaluation of source beds and briefly introduces the principles and analytical procedures of pyrolytical GC. According to the data from pyrolytical analyses of three types of kerogens, it is proposed the compen-sation coefficients of light hydrocarbons for the evaluation of source bed, i.e.the compensation coefficients of light hydrocarbons for the overall conversion efficiency of kerogens or organic carbon are as follows. During immature stage, 37.69-76.93% for Type I kerogen, 7.74-11.02% for Type Ⅱ kerogen and 32.66-34.72% for Type Ⅲ kerogen. In mature stage, 19.16-23.70% for Type Ⅰ kerogen, 12.27-13.72% for Type Ⅱ kerogen and 25.91-27.31% for Type Ⅲ kerogen. At the peak of oil generation, the compensation coefficients of the light hydrocarbons are as follows. 27.39-72.18% for Type I kerogen, 20.74-69.80% for Type Ⅱ kerogen and 36.60-86.96% for Type Ⅲ kerogen. Studies are carried out on the regularity of C1-C14 hydrocarbons generation during various heating stages for different types of kerogens, as well as on the retention effect of various rocks and minerals on hydrocarbons.

https://doi.org/10.11781/sysydz198602139