含铁矿物对高成熟有机质有水体系热解生气的影响  

Effect of iron-bearing minerals on gas generation from pyrolysis of high-mature organic matter in hydrothermal conditions

作　　者：张文军 何坤[3,4] 李贤庆[1,2] 米敬奎[3,4] 胡国艺[3,4] ZHANG Wen-jun;HE Kun;LI Xian-qing;MI Jing-kui;HU Guo-yi(State Key Laboratory of Coal Resources and Sofe Mining,China Univeristy of Mining and Technology,Beijing 100083,China;Collega of Geoscience and Surveying Engineering,China University of Mining and Technology,Beijing 100083,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China;State Key Laboratory of Petroleum Geochemistry,China National Petroleum Corporation,Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [3]中国石油勘探开发研究院,北京100083 [4]中国石油天然气集团公司油气地球化学重点实验室,北京100083

出　　处：《天然气地球科学》2020年第9期1316-1325,共10页Natural Gas Geoscience

基　　金：国家自然科学基金(编号:41973068,U1810201);国家科技重大专项(编号:2016ZX05007-001);中国石油勘探开发研究院科学研究与技术开发项目(编号:2018ycq01)联合资助。

摘　　要：为了探讨含铁矿物对水—有机质生气的影响,基于黄金管热模拟装置,选用了高熟干酪根样品开展了3组有水体系(干酪根+水、干酪根+黄铁矿+水、干酪根+磁铁矿+水)的恒温热解实验。气体产物的定量分析结果表明,黄铁矿和磁铁矿的加入均导致干酪根在有水体系下气态烃产率一定程度的降低。比如,水—黄铁矿体系和水—磁铁矿体系在Easy%RO=3.08%时CH4产率相比单独有水体系分别降低8.5 mL/gTOC和13.3 mL/gTOC。水—黄铁矿体系CO2产率及碳稳定同位素值明显高于单独有水体系和水—磁铁矿体系,含铁矿物(尤其是磁铁矿)加入的热解体系的H2S产率明显低于单独有水体系。气体组成分析结果表明,含铁矿物的加入明显提高了烃类气体的干燥系数,同时导致异构烷烃相对含量的降低。水—磁铁矿体系气体产物氢同位素值相对低于单独有水体系,表明磁铁矿的加入促进了早期H2的生成而与有机质之间发生了加氢作用。这些结果表明,含铁矿物的加入可能抑制了碳正离子的反应,水—有机质的加氢生气可能主要是自由基反应。In order to ascertain the effect of iron-bearing minerals on gas generation from water-organics reactions,three groups of isothermal pyrolysis involving a high-mature kerogen(kerogen+water,kerogen+pyrite+water,kerogen+magnetite+water)were conducted in hydrothermal conditions by a gold-tube system.Through determination of the yields of gas products,it is indicated that the presence of pyrite and magnetite both led to a certain decrease in the yields of hydrocarbon gases.For instance,the methane yields at Easy%RO of 3.08%in hydrothermal experiments with pyrite and magnetite are about 8.5 and 13.3 mL/gTOC lower than that in pyrolysis with only water.The yield and carbon isotopic ratios of CO2 in pyrolysis involving water and pyrite are evidently higher than those in pyrolysis involving only water and involving water and magnetite.The H2S yields in hydrothermal experiments with Fe-bearing minerals(especially magnetite)are much lower compared with those without minerals.The analysis of gas compositions shows that the presence of pyrite apparently resulted in the increase of gas dryness and the decrease of relative content of isomeric hydrocarbons.The hydrogen isotope of the gas product of the water-magnetite system is relatively lower than that of the water-only system,indicating that the addition of magnetite promoted the formation of early H2 and hydrogenation occurred with the organic matter.These results indicate that the addition of iron-bearing minerals may inhibit the carbocation reaction,and the hydrogenation of water-organic matter may be mainly a radical reaction.

关 键 词：干酪根 黄铁矿 磁铁矿 催化抑制作用 有机—无机作用 

分 类 号：TE122.11[石油与天然气工程—油气勘探]