Abstract: On the basis of oil-water two-phase percolation theory and factual materials,the compact-expulsion characteristics of source rocks were studied in the upper forth member and the lower third member of Shahejie Formation in Dongying Depression.The variation curves of oil expulsion concentration in source rocks were given,which indicated that oil expulsion concentration was controlled by viscosity of oil,saturation and relative permeability of oil and water in the source rocks.The critical oil saturation for oil expulsion of source rocks was related to those factors.In the early stage,oil expulsion concentration was much less than oil saturation of source rock.The expulsion material was mainly water,despite of the fact that oil saturation was rather high.Oil concentration increased with the burial depth of source rocks.When the burial depth of source rock reached a certain depth,the water saturation in source rocks was nearly equal to the irreducible water saturation,and the oil expulsion concentration was close to 1.The main oil expulsion stage could appear.

Key words: Dongying Depression, two-phase percolation, source rock, hydrocarbon expulsion, oil expulsion concentration, water saturation

摘要： 根据两相渗流原理,用实际资料研究了东营凹陷沙四上亚段和沙三下亚段烃源岩压实排液过程中排油浓度的变化特点,并建立了该烃源岩排油浓度变化剖面。排油浓度受烃源岩内原油黏度、油水相对渗透率、含油和含水饱和度等因素的控制,烃源岩排油临界饱和度也与上述参数有关。在早期阶段,尽管烃源岩含油饱和度较高,但排油浓度远低于烃源岩含油饱和度,为主要排水阶段。排油浓度随烃源岩埋深的增加而增加,当埋深达到一定深度时,含水饱和度接近束缚水饱和度,排油浓度接近于1,进入主要排油阶段。

关键词: 东营凹陷, 两相渗流法, 烃源岩, 排烃, 排油浓度, 含水饱和度