平庄凹陷烃源岩有机质成熟度评价

平庄凹陷盖层中发育九佛堂组、沙海组和阜新组3套烃源岩,虽然以往围绕煤矿生产展开了大量的煤田地质勘探工作,但石油、天然气勘探工作较少,研究程度较低。为了客观评价平庄凹陷的油气资源,需对烃源岩有机质成熟度进行评判。在对平庄凹陷烃源岩岩石热解、镜质组反射率、生物标志物参数分析的基础上,对平庄凹陷九佛堂组、沙海组烃源岩有机质热演化特征及演化阶段进行了系统研究。结果表明：平庄凹陷烃源岩各参数随埋藏深度的增加变化明显,具有纵向上的连续性和横向上的不均匀性;平庄洼陷烃源岩有机质成熟度处于未成熟—低成熟—成熟阶段,其中,九佛堂组烃源岩是盆地的主要成油岩系;四龙洼陷烃源岩有机质成熟度较低,对盆地成烃贡献不大。

Maturity Evaluation of the Organic Matter of Source Rock in Pingzhuang Depression

In the coverage of Pingzhuang depression,there are three sets of source rocks named Jiufotang formation,Shahai formation and Fuxin formation.Although much coalfield geological exploration work had been done earlier,the exploration work on petroleum and gas is few up to now.In order to objectively assess the oil and gas resources in Pingzhuang depression,the maturity of organic matter source rock must be judged.In this paper,the thermal evolution characteristics and stages of organic matter in the source rock of Jiufotang formation and Shahai formation in Pingzhuang depression are systemacally studied based on the the analysis of thermal decomposition,vitirnite reflectance and biomarker parameters.It is found that,parameters of source rock in the Pingzhuang depression vary obviously with the variation of burial depth which is characterized by longitudinal continuity and transversal nonuniformity.The maturity of organic matter of source rock in Pingzhuang depression is at the immature-low mature-mature stage,and the source rock of Jiufotang formation is the main rock series creating oil in the basin.Maturity of organic matter of source rock in Silong depression is lower,which has little contribution to the generation of hydrocarbon in the depression.