三塘湖盆地上古生界烃源岩镜质组反射率异常研究

The Vitrinite Reflectance Anomalies of Upper Paleozoic Source Rocks in Santanghu Basin

马安来 钟宁宁 李贤庆 包建平

MA An-lai ZHONG Ning-ning LI Xian-qing BAO Jian-ping

江汉石油学院 分析测试研究中心, 湖北 荆州 434102; 石油大学, 北京 昌平 102200

Jianghan Petroleum University, Jingzhou Hubei 434102; Petroleum University, Changpin Beijing 102200

镜质组反射率是评价有机质成熟度的重要指标,然而由于地质因素和测试技术的原因,镜质组反射率测量值常与预计值有一定的偏差。在三塘湖盆地上古生界烃源岩中,可以观察到镜质组反射率的局部增强和镜质组反射率的抑制。局部增强多分布在上二叠统的烃源岩中,主要与火山活动有关。这种反射率的增强在平面上分布广泛,但纵向上影响范围较小。反射率的抑制是在上古生界烃源岩含有较高含量的腐泥组分背景下产生的。用氢指数模板方法对抑制进行了校正,抑制的幅度最大可达0.3%。

The vitrinite reflectance is the most important maturity indicator. Due to the geological factors and measurement technique, the measured vitrinite reflectance is different from that of expected. In upper Paleozoic source rock from Santanghu Basin, both of the vitrinite reflectance enhancement and suppression can be observed. The vitrinite reflectance enhancement is caused by the volcanic activity which was widespread laterally but effected vertically only in a small scope. The vitrinite reflectance suppression resulted from high content of sapropelinite. Using hydrocarbon index, the correction was made and the maximum suppression is about 0.3%.