【摘要】 利用南海西沙周缘地震资料,进行了地震相研究,并结合邻区地质资料,进行了南海西沙周缘新生代沉积相分析,讨论了盆地的充填演化历史。研究认为,南海西沙周缘盆地充填断陷期以陆相和海陆过渡相沉积为主;坳陷期以海陆过渡相和海相沉积为主,自下而上充填了一套冲积相-湖相(始新统)-海陆交替相(渐新统)-滨浅海台地相(中-下中新统)-浅海、半深海相(上新统-第四系)沉积序列,盆地的充填历史反映了南海西沙周缘沉积环境由陆相向海相逐渐过渡的过程。通过对油气地质条件分析,认为始新世-渐新世早期是重要的烃源岩发育期;渐新世晚期-中新世中期是储层发育期;中新世晚期后是区域该层发育时期。更多还原

【Abstract】 Under the domination of Shenhu movement,Nanhai movement and Dongsha movement in Tertiary,Xisha area developed typical two-layered sediment pattern of rifting-depression,and the tectonic framework expresses Northeast oriented character.Using the seismic data,we discussed the seismic phase of investigated area.The sediment facies in this area was analyzed combining with the research result of adjacent areas.Furthermore,we discussed the sediment history in this area.As a result,the sediment in rifting stage was mainly terrestrial deposition.On the other hand,the sediment in depression stage was mainly transitional-marine deposition.From lower layer to the upper interval,the sediment evolution was mainly followed: fluvial-lacustrine facies in Eocene,transitional facies in Oligocene,shallow marine-coastal facies in Miocene,and shallow marine-bathyal facies in Pliocene to Quaternary.The deposition in this area reflected the transition of continent to marine facies.On the basis of petroleum system analysis,it can be concluded that source rocks developed in Eocene to early Oligocene;reservoirs developed in late Oligocene to middle Miocene;and regional seal rocks mainly developed after late Miocene.更多还原