Abstract:

A study of hydrocarbon charge history was carried out in JZ25 area,Liaodong Bay waters,by using homogenization temperature of fluid inclusions.The results indicate that the area had experienced two stages of hydrocarbon charge.The first one happened during the period prior to a secondary outgrowth of quartz and mainly in form of liquid-hydrocarbon inclusions of low abundance and low maturity.The second stage happened during the period after the secondary outgrowth of quart and organic inclusions of high abundance were mainly distributed along the micro-fractures that cut through quartz grains and their outgrowth rims or in the dissolution pores of feldspar grains.Hydrocarbon reservoirs in JZ25 area is considered to be formed mainly during the second stage,which is 23-21 Ma from nowadays.An analysis of excess pressure system and hydrocarbon pathway of source rocks in third member of the Shahejie Formation in the study area was then performed based on the above understanding.A model illustrating hydrocarbon migration controlled by both reservoirs and faults was also established and served as an important guidance for the exploration of large-scale hydrocarbon reservoirs in JZ25 area.

Key words: fluid inclusion, excess pressure, hydrocarbon migration model, Liaodong Bay waters