后生作用中膏岩对芳烃分布的影响及地化意义  

Influence of Gypsum on the Distribution of Aromatic Molecules During Catagenesis and Its Geochemical Significance

作　　者：吴嘉 王远 齐雯[4] 师生宝 姜福杰[1,2] 张春林 WU Jia;WANG Yuan;QI Wen;SHI ShengBao;JIANG FuJie;ZHANG ChunLin(National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing 102249,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Wuxi Research Institute of Petroleum Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Wuxi,Jiangsu 214216,China;Research Institute of Petroleum Exploration and Development-Northwest(NWGI),PetroChina,Lanzhou 730020,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China)

机构地区：[1]油气资源与工程全国重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214216 [4]中国石油勘探开发研究院西北分院,兰州730020 [5]中国石油勘探开发研究院,北京100083

出　　处：《沉积学报》2024年第4期1401-1410,共10页Acta Sedimentologica Sinica

基　　金：中石油集团公司直属院所基金(2018D-500804);国家自然科学基金项目(41403049,42273052);国家科技重大专项(2016ZX05007-002)。

摘　　要：【目的】硫酸盐与沉积有机质之间的反应是沉积盆地内一种典型的有机—无机相互作用类型。在后生作用早期,硫酸盐会影响沉积有机质的热演化。研究对应体系中芳烃化学组成的热演化规律,有助于理解其地球化学行为。【方法】以鄂尔多斯盆地西南缘平凉组烃源岩及其含硫干酪根为初始样品,通过含水体系热模拟实验方法研究了硫酸盐对干酪根热演化产物的影响。【结果】硫酸盐增加了早期可溶有机质产率,并使得芳烃族组分的生成高峰提前。另外,硫酸盐在后生作用阶段早期可氧化降解有机含硫化合物,减少了二苯并噻吩的生成,导致不同类型的芳烃化合物比例出现显著差异。因此,在生油高峰之前,硫酸盐和沉积有机质之间存在氧化降解反应阶段,其产物以含氧化合物等极性组分为主,二苯并噻吩均形成自有机硫化合物。【结论】该认识将硫酸盐与沉积有机质的反应范围拓展至了热应力更低的后生作用阶段含膏烃源岩。[Objective]The reactions between sulfates and sedimentary organic matter are typical organic⁃inorganic interactions in sedimentary basins.During the early stage of catagenesis,the thermal evolution of sedimentary organic matters would be influenced by the presence of sulfate.Investigations on thermal evolution of aromatic fraction compo⁃sitions in the corresponding system will improve the understanding its geochemical behaviors.[Methods]In this study,the effect of sulfate on the thermal evolution of kerogen was investigated by hydrous pyrolysis.The source rock and the corresponding sulfur-bearing kerogen were sampled from the Pingliang Formation on the southwestern margin of the Ordos Basin.[Results]Experimental results showed that the presence of sulfate promotes the yields of soluble organic matters,as well as the generation peak of aromatic fractions in the early stage.Moreover,the organosulfur compounds,might be oxidized by sulfate during the early stage of catagenesis,which led to the decreasing of genera⁃tion of dibenzothiophene.It would result in the significant discrepancies of aromatic fraction compositions between two group experiments.Therefore,there was a stage of oxidative degradation between sulfate and sedimentary organic matter before hydrocarbon generation peak.In this stage,the majority of production is polar organic compounds,such as oxygen-bearing compounds.Dibenzothiophene was derived from organosulfur compounds.[Conclusions]These understandings enlarged the reaction region between sulfate and sedimentary organic matters to the gypsumbearing source rock during catagenesis with lower thermal stress.

关 键 词：热模拟实验 有机—无机相互作用 芳烃分子标志物分布特征 热化学硫酸盐还原反应 鄂尔多斯盆地 平凉组 

分 类 号：P618.13[天文地球—矿床学]