鄂尔多斯盆地杭锦旗地区上古生界烃源岩热演化特征模拟研究

Thermal evolution modeling of Neopaleozoic source rocks in Hangjinqi region, Ordos Basin

赵桂萍

Zhao Guiping

中国科学院 计算地球动力学重点实验室, 北京 100049 2. 中国科学院大学 地球科学学院, 北京 100049

Key Laboratory of Computational Geodynamics, Chinese Academy of Sciences, Beijing 100049, China 2. School of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China

以表征烃源岩热演化程度的实测镜质组反射率（Ro）为标定值，以PetroMod盆地模拟软件为工具，在剥蚀厚度恢复、古大地热流值选取的基础上，利用鄂尔多斯盆地杭锦旗地区70余口探井的录井、测井资料确定了不同地层的岩性组成，建立了相应的单井地质模拟，对上古生界太原组和山西组山1段、山2段烃源岩的演化历史进行了模拟。结果表明，研究区西部、南部的新召、十里加汗、阿镇和浩饶召区带Ro值达到0.65%进入生烃门限的时间为晚三叠世中晚期，北部的公卡汗和什股壕区带Ro值达到0.65%进入生烃门限的时期为早侏罗世早期。平面上，烃源岩热演化程度总体表现为自西南向东北方向逐渐降低的趋势：西部、南部的新召区带、十里加汗区带南部现今Ro值最大为1.43%和1.46%，达到了过成熟演化阶段；北部、东部的什股壕、阿镇区带现今Ro值为0.85%~1.0%，处于生烃高峰期的早期阶段。

Taking the measured Ro values which reflected the characteristics of thermal evolution degree of source rocks as calibration, the thermal evolution history of source rocks of the Taiyuan Formation and members 1 and 2 of the Shanxi Formation in Neopaleozoic was modeled through erosion thickness restoration and the selection of ancient heat flow. We analyzed well logging data of different strata from more than 70 wells, and established a corresponding geological model. Source rocks reached the threshold of hydrocarbon generation (Ro>0.65%) during the mid-late stage of Late Triassic in Xinzhao, Shilijiahan, Azhen and Haoraozhao areas in the western and southern Hangjinqi region and during the early stage of Early Jurassic in Gongkahan and Shiguhao areas in the northern Hangjinqi region. The thermal evolution degree of source rocks decreases from southwest to northeast in the study area. The maximum Ro values in Xinzhao and southern Shilijiahan are 1.43% and 1.46% respectively, reaching the over-mature stage of evolution. However, the Ro values in Shiguhao and Azhen areas in the northern and eastern Hangjinqi region range from 0.85%-1.0%, showing that the source rocks are still in the early stage of hydrocarbon generation peak.

中国科学院知识创新工程重要方向项目（Y225014EA2）资助。

https://doi.org/10.11781/sysydz201605641