自生伊利石K-Ar、Ar-Ar测年技术对比与应用前景展望——以苏里格气田为例  

Perspective on the K/Ar and Ar/Ar geochronology of authigenic illites:a case study from the Sulige gas field,Ordos Basin,China

作　　者：张有瑜[1,2,3] Horst Zwingmann 刘可禹[1,2,3,4] 罗修泉[1] 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油天然气集团公司盆地构造与油气成藏重点实验室,北京100083 [3]提高石油采收率国家重点实验室,北京100083 [4]Earth Science and Resource Engineering,Commonwealth Scientific and Industrial Research Organization Bentley,Australia P.O.Box 1130

出　　处：《石油学报》2014年第3期407-416,共10页Acta Petrolei Sinica

基　　金：中国石油天然气股份有限公司科技攻关项目"油气勘探新领域;新理论;新方法;新技术"(2011A-0207)资助

摘　　要：以苏里格气田为例,对自生伊利石K-Ar法、Ar-Ar法年龄测定的技术特点、应用效果和应用前景进行了系统对比和深入研究。苏里格气田自生伊利石(I/S有序间层)发育较好,主要呈丝状,具有典型的自生成因特征,其K-Ar年龄、未真空封装Ar-Ar总气体年龄和真空封装Ar-Ar总气体年龄分别为141~145 Ma、171~237Ma和130~152 Ma。K-Ar年龄表明主要为晚侏罗世晚期—早白垩世早期成藏,其分布规律很好地反映了成藏特征和成藏过程;未真空封装Ar-Ar总气体年龄明显偏老,不能代表自生伊利石的形成年龄,更不能反映成藏时代,"^(39)Ar核反冲丢失"现象是导致其偏老的主要原因;真空封装Ar-Ar总气体年龄与K-Ar年龄基本接近,可能反映自生伊利石的形成年龄并代表成藏时代。本次对比研究表明,对于利用自生伊利石同位素测年技术探讨砂岩油气藏成藏时代,K-Ar法测年技术简便快捷、经济成熟、稳定可靠,是第一选择并具有较好的应用前景;未真空封装Ar-Ar法测年技术很难获得理想的年龄数据和较好的应用效果,如果没有其他特殊目的,可以不予考虑;真空封装Ar-Ar法测年技术,如果运用得当,有可能获得相对较好的年龄数据和相对较好的应用效果,但技术复杂、环节多、周期长和费用高等将会严重制约其发展和应用。This paper makes a systematic comparison of and a deep study on the technical features,application prospective and effects of the K-Ar,vacuum-encapsulated Ar-Ar,and non encapsulated Ar-Ar dating of authigenic illites from petroleum reservoirs by taking the Sulige gas field as an example.Authigenic illite,or the ordered mixed layer illite/smectite （I/S） is well developed in reservoirs of the Sulige gas field.It is mainly presented in filamentous form,with typical authigenic origin.The corresponding K-Ar ages,vacuum encapsulated Ar-Ar total gas ages,and non-encapsulated Ar-Ar total gas ages are 141-145 Ma,130-152 Ma,and 171-237 Ma,respectively.The K Ar ages indicate that the hydrocarbon accumulations mainly occurred during the period from the late phase of the Late Jurassic to the early phase of the Early Cretaceous,reflecting the accumulation features and processes by their distributions.The non-encapsulated Ar-Ar total gas ages are older due to 39Ar recoil loss,and can＇t represent the forming ages of authigenic illites,or the accumulation times,both of which may be represented by the vacuum-encapsulated Ar-Ar total gas ages that are basically close to the K-Ar ages.The comparative results show that the K-Ar isotopic dating of authigenic illites is most applicable to exploring the hydrocarbon accumulation time in sandstone,with the advantages of easy-operation,low-cost,celerity and reliability,and better application prospect.The non-encapsulated Ar-Ar dating method will not be adopted unless for some special purposes,due to the difficulties in obtaining desirable age data and achieving good application prospect.The vacuum encapsulated Ar-Ar dating method may yield reasonable age data if performed properly.However,the complex technical procedures,long analytical duration and high cost present a huge challenge for its development and routine application in studying petroleum reservoir chronology.

关 键 词：苏里格气田 下石盒子组八段砂岩储层 自生伊利石 K-AR测年 未真空封装Ar-Ar测年 真空封装Ar-Ar测年 39Ar核反冲丢失 成藏年代 

分 类 号：TE122.14[石油与天然气工程—油气勘探]