四川盆地晚二叠世龙潭期沉积环境及其源控作用分析

Sedimentary environment and its controlling on source rocks during late Permian in Sichuan Basin

曹清古 刘光祥 张长江 潘文蕾

Cao Qinggu Liu Guangxiang Zhang Changjiang Pan Wenlei

中国石油化工股份有限公司 石油勘探开发研究院 无锡石油地质研究所, 江苏 无锡 214126

Wuxi Research Institute of Petroleum Geology, SINOPEC, Wuxi, Jiangsu 214151, China

作为四川盆地最重要的气源岩之一,二叠系烃源岩逐渐被越来越多的研究者所重视。通过对四川盆地晚二叠世龙潭期岩相古地理的恢复,以及沉积环境对烃源岩发育的控制作用分析,指出四川盆地上二叠统优质烃源岩主要发育于浅海陆棚、潮坪-潟湖及滨岸沼泽等相带。文中引入了"有机碳厚度"的概念,即采用有机碳含量与烃源岩厚度之积综合反映烃源岩的发育特征;并结合无机地化与有机碳分析测试数据,论述了沉积环境的源控意义,为烃源岩宏观分布预测与资源量估算提供了理论参考。

As the most important source rock for gas generation in the Sichuan Basin, Permian source rocks have attracted more and more attentions. The lithofacies palaeogeography during the Longtan phase of the Late Permian in the Sichuan Basin was reconstructed, and the controlling effects of sedimentary environment on source rock generation were analyzed. In the Upper Permian of the Sichuan Basin, favorable source rocks mainly developed in the shallow shelf, tidal flat-lagoon and onshore swamp facies. The concept of "organic carbon thickness" was introduced in this article. Organic carbon content was multiplied by source rock thickness so as to illustrate the generation features of source rocks. Combined with inorganic geochemical characteristics and organic carbon analyses, the controlling effects of sedimentary environment on source rock generation were studied, providing theoretical reference for the macroscopic distribution prediction of source rocks and resource estimation.

中国石化科技部项目"四川盆地二叠系烃源岩及其资源潜力研究"(P08065)资助。

https://doi.org/10.11781/sysydz201301036