未熟—低熟油流体特征——以济阳坳陷古近系为例  

Characteristics of Immature to Low Mature Oil Fluids as Examplified by the Lower Tertiary of the Jiyang Depression

作　　者：施继锡[1] 余孝颖[1] 

机构地区：[1]中国科学院地球化学研究所矿床地球化学重点实验室,贵州贵阳550002

出　　处：《矿物岩石地球化学通报》2003年第4期314-318,共5页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：中国科学院知识创新工程项目(KJCX2 5W NO 3)资助

摘　　要：对济阳坳陷古近系储层中流体包裹体的研究进一步证明,其油气属未熟—低熟油气。除了油藏埋深浅、地层时代新、为自生自储同生油藏外,还具下列特征:油气生成温度低,包裹体均一温度范围为53～115℃;处于低演化阶段,储层中主要的包裹体类型是纯液态烃包裹体及纯液体盐水溶液包裹体。包裹体烃类成分中重烃及丁烷含量高,重烃平均占总烃的52.14%,丁烷平均占总烃的14.46%;流体压力高,估算的流体压力范围是10.0～40.5MPa;盐度较高;还原环境;古地温梯度高,为3.830℃/100m等流体特征。研究结果为该坳陷油气成因及识别未熟—低熟油成油物理化学条件等提供了信息。Studies of fluid inclusions from the Lower Tertiary reservoir strata of the Jiyang Depression confirm that the oil and gas are immature to low mature. The Lower Tertiary reservoirs in the Jiyang Depression are characterized by shallow burial depth, young geological ages, and authogenesis-authopreservation-syngenesis in origin. The oil and gas have a low formation temperature(53-115℃)and are of low mature evolution. The fluid inclusions in the reservoirs are dominated by pure liquid hydrocarbons and pure saline solutions.Among the total hydrocarbons of fluid inclusions,hydrocarbon and butane constitute 52.14% and 14.46% on the average,respectively.The fluid has a high pressure(10.0～40.5MPa),relatively high salinity (3.3%) and is reduced in character.The paleogeothermal gradient is estimated to be 3.83℃/100m.This study has provided much information about the origin of oil and gas in the Jiyang Depression and the physical and chemical formation conditions of immature to low mature oils.

关 键 词：未熟-低熟油 济阳坳陷 古近系 流体包裹体 

分 类 号：P618.13[天文地球—矿床学]