HYDROCARBON CHARGING HISTORY AND POOL-FORMING MODEL OF THE ARCHEOZOIC-MESOZOIC METAMORPHIC-VOLCANIC RESERVOIRS, XINGLONGTAI BURIED HILL, LIAOHE BASIN

One of the uses of fluid inclusion enclaves analysis in petroleum geology is to utilize inclusion enclaves in diagenic minerals in inferring hydrocarbon migration path,calculating injection time and determin-ing injection direction.The patterns of homogeneous temperature of hydrocarbon inclusion enclaves in the Xinglongtai reservoir,as a whole,are characterized by normal unimodal or asymmetric unimodal distributions,and the major peak temperatures range from 80℃ to 100℃,which reflect that,the hydrocarbon inclusion enclaves in different samples are of the similar formation process.In addition,inclusion homogeneous temperatures in a few wells display a bimodal distribution pattern,which may imply that,there exist at least 2 stages of inclusion formation.Studies on the burial-heat evolution history shows that,hydrocarbon injection period in the Xinglongtai reservoir is 3-35 Ma ago,which can be divided into 2 major stages:27-35Ma and 3-24Ma,and the former is the main hydrocarbon injection stage.Researches also show that,the direction of hydrocarbon injection is from the east to the west.There are 3 pool-forming stages:a)A small amount of hydrocarbon migrates into the embryonic trap in the late Es³,after which the temporary uplift in the end of Es³ results in oxidation for part of the hydrocarbon in the incipient reservoir,forming black asphalt;b)The Es²-Ed stage is the major hydrocarbon accumulation period;c)Hydrocarbon gene-(ration) intensity is relatively weak since the late Tertiary.Hydrocarbon in the reservoir is preserved,which is attributed to the excellent mudstone cap of the overlying Es³⁺⁴.