呼和湖凹陷中低煤阶煤系烃源岩地球化学特征及生烃潜力评价

Middle-low Rank Coal-series Source Rock Geochemistry Characteristics and Evaluation of Hydrocarbon Generation Potential of Huhehu Depression

通过有机地球化学和有机岩石学方法,结合热模拟试验,探讨了呼和湖凹陷煤系烃源岩的生烃潜力。研究结果表明:该区煤系烃源岩有机质丰度总体达到中等-好烃源岩标准;有机质类型以腐殖型为主,镜下显微组分以基质镜质体为主;大部分烃源岩处于中低煤阶,煤与煤系泥岩地球化学特征相似,生物标志化合物显示煤层主要来源于高等植物。分别应用高温-高压釜和Rock-Eval生油岩评价仪进行热模拟试验和开放体系生烃动力学研究,热模拟试验总产烃量与热解生烃潜量基本一致,而生烃过程反映了煤系源岩多阶段生烃的特点,表明该区煤系烃源岩具较大的生烃潜力。

Through the methods of organic geochemistry and organic petrology and in combination with the thermal simulation experiment,the hydrocarbon generation potential of coal-series source rock in Huhehu Depression was discussed.The research results showed that the coal-series source rock organic matter abundance in the area was totally in the standard of medium-good hydrocarbon source rock;organic matter type was main of humic type,the microscopic composition was mainly desmocollinite;the most of hydrocarbon source rocks were in middle-low coal rank.Geochemical characteristics of coal and coal-seam mudstone were similar,biomarker compounds displayed that coal was mainly derived from higher plants.A thermal simulation experiment and open system hydrocarbon generation kinetics are studied by using high pressure and high temperature stove and Rock-Eval instrument respectively,the total hydrocarbon production of thermal simulation experiment and hydrocarbon generation potential of pyrolysis is basically the same,and the hydrocarbon generation process reflects that the coal-series source rock having multi stage hydrocarbon generation characteristics,showing the coal-series source rock has great potential of hydrocarbon generation.