断陷盆地深层是中国东部老油田勘探的新领域.前人的研究主要集中于松南地区梨树断陷深层油藏的成藏期次研究,而缺乏对深层油藏油气成藏地球化学的整体研究.本文对松南地区梨树断陷深层原油进行了色谱与色谱-质谱分析,并结合储层流体包裹体分析技术,剖析了梨树断陷油气成藏地球化学特征.结果表明,梨树断陷深层油藏主要存在3种不同成因类型原油,分别来源于2套烃源层.不同类型原油纵向上分布特征明显.梨树断陷深层油气藏主要经历了3期油气成藏过程,登娄库期早期生成的原油主要汇聚于洼陷周边的后五家户和八屋地区;泉头期大规模生成的油气,主要聚集于断陷周缘斜坡与构造高部位;泉头期末-嫩江期,油气持续充注,主要在双龙地区聚集成藏.原油含氮化合物分子组成表明,不同类型原油基本呈相似的油气运聚途径与方向,均指示油气自洼陷区向周缘斜坡带,北东向运移.
Oil and gas in the deep of fault depressions is a new field of the hydrocarbon exploration in eastern China.The previous studies focused on accumulation period of deep oil reservoir in the Lishu fault depression,and the research of oil reservoir geochemistry of oil and gas accumulation is limit.Base on analyses of GC and GC-MS for crude oil and reservoir fluid inclusions,geochemistry of oil and gas reservoir in the Lishu fault depression has been analyzed.Three oil types,which derived from two sets of source rocks,were found in the deep oil reservoir of the Lishu fault depression.The different oils show a notable vertical distribution pattern.The deep oil reservoir of the Lishu fault depression underwent three forming periods:oil and gas were charged and accumulated in the sag and the nearby areas in the Denglouku period,large scale oil and gas accumulations were occurred and were distributed in slope and structural highs in the Quantou period,and oil and gas were kept filling and were accumulated in the Shuanglong area at the end of Quantou and Nengjiang periods.The molecular compositions of nitrogenous compounds in the oils indicated that all the oils were charged in a direction of SW-NE.