迪北气藏侏罗系阿合组烃包裹体特征及成藏分析

Hydrocarbon Inclusion Characteristics of Jurassic Ahe Formation and Analysis on Petroleum Accumulation in Dibei Gas Reservoir of Kuqa Depression

迪北气藏侏罗系阿合组储集层共见到2期烃包裹体:Ⅰ期发黄色荧光的烃包裹体和Ⅱ期发蓝白色荧光的烃包裹体。根据包裹体光性特征和组分分析:Ⅰ期烃包裹体为成熟的中质油,Ⅱ期烃包裹体为成熟—过成熟的轻质凝析油。油源对比认为,形成这2期烃包裹体的主力烃源岩是阳霞凹陷三叠系湖相烃源岩。通过包裹体测温、捕获深度计算及埋藏史恢复,Ⅰ期烃包裹体形成于中新统康村组沉积早—中期(17—10 Ma),Ⅱ期烃包裹体形成于中新统康村组沉积晚期—库车组沉积中期(10—5 Ma)。迪北气藏所在的依奇克里克构造带自中新世以来快速沉积,快速沉降,导致其具有多期连续成藏的特点,先后形成Ⅰ期和Ⅱ期油气的聚集。

Two periods of hydrocarbon inclusions are observed in the Jurassic Ahe formation of Dibei gas reservoir,including the hydrocar?bon inclusions of periodⅠwith yellow fluorescence and the inclusions of periodⅡwith blue fluorescence.The analysis on the optical characteristics and components of the inclusions shows that the inclusions of periodⅠare mature intermediate oil and those of period II are mature-over mature light condensate oil.On the basis of oil?source rock correlation,it is considered that the major source rocks of the two periods of hydrocarbon inclusions are the Triassic lacustrine source rocks in Yangxia sag.The results of temperature measurement,cap?ture depth calculation and burial history restoration for the conclusions indicate that the inclusions of periodⅠformed during the earlymedium deposition period(17-10 Ma)of the Miocene Kangcun formation,and the inclusions of periodⅡformed in the late deposition pe?riod of the Miocene Kangcun formation to the medium deposition period of the Kuche formation(10-5 Ma).The Yiqikelike tectonic belt deposited rapidly since Miocene,resulting in the multi?period and continuous reservoir accumulation.