焉耆盆地侏罗系包裹体与油气运聚期次的关系

RELATIONS BETWEEN JURASSIC INCLUSIONS AND OIL & GAS MIGRATION & ACCUMULATION IN YANQI BASIN

陈文学 李永林 张辉 赵得力

Chen Wenxue Li Yonglin Zhang Hui Zhao Deli

焉耆盆地侏罗系砂岩储层中的流体包裹体主要分布于三工河组和八道湾组,其均一温度多为101～110℃和121～130℃,组分中的正构烷烃碳数呈双峰态,前主峰为18或20,后主峰为26或27。这些特征指示焉耆盆地在侏罗纪中晚期发生两次成藏作用,即晚侏罗世以八道湾组低成熟油气的生成、运移和聚集为主的第一期成藏作用和侏罗纪末期以成熟油气的生成、运移和聚集为主的第二期成藏作用。根据生烃史分析,该区还应存在第三纪末的油气聚集,但因成岩作用不活跃,包裹体丰度低而未检测到。

Inclusions in Jurassic sandstone reservoirs in Yanqi basin are mainly distributed in Jianghe Formation and Badaowang Formation, their homogeneous temperature is between 101℃～110℃ and 121℃～130℃,carbon numbers of n-alkane appear in double- peaks state, main front peak with 18 or 20 carbon numbers, Main back peak with 26 or 27 carbon numbers. These features indicate that accumulations of oil and gas took place twice in the basin during the middle-late Jurassic, namely, the first phase is believed to be mainly for low matured oil & gas generation, migration and accumulation in Badaowang Formation in the late Jurassic, and the second phase is for the maturation of oil & gas in end Jurassic. It is believed by analyzing the history of hydrocarbon generation that the accumulation of oil and gas should have taken place once more in this region by the end Tertiary, this event has not been detected because of the inactive diagenesis and low abundance of the inclusions.

10.11743/ogg20020308