The tight oil exploration of the Fuyu layer has achieved a significant breakthrough in southern Songliao Basin

but the tight oil charging characteristics and accumulation history are still unclear.Based on thin section observation and fluid inclusions occurrence characteristics

the growth sequence of various secondary mineral was analyzed.The time sequence of different diagenesis stages and hydrocarbon charging phases were established.According to the homogenization temperature of fluid inclusions in combination with geologic history and thermal history in the study area

the hydrocarbon accumulation phases were established in different blocks.The results show that the minerals mainly experienced compaction

cementation

metasomatism

dissolution processes in the Fuyu layer tight reservoir and the compaction runs through the whole diagenesis history.Hydrocarbon began to charge after the early calcite cementation and before the quartz overgrowth.And a large scale of hydrocarbon charging happened during the period of quartz overgrowth and feldspar dissolution.In the period of late calcite cementation

hydrocarbon charging entered the later stage.Liquid hydrocarbon continued to charge during the deposition of the Nenjiang Formation and Mingshui Formation in Changling Sag

while in Fuxin Uplift charging happened in the early period deposition of the Nenjiang Formation.There were two periods of gaseous hydrocarbon charging in uplifted area:the time of early Nenjiang Formation deposition and of Sifangtaizi-Yian Formations

respectively.