Linqing Depression Eastern Part Of The Next Tertiary Petroleum Systems Analysis

Based on new theories and methods of petroleum system and organicgeochemistry, the author studied and discussed hydrocarbon-source rock of lowerTertiary in Yucheng area in several aspects, such as sedimentary organic facies,abundant of organic matter, organic type, maturity, reservoir property, andclassification of oil-gas system and their characteristics. Reservoir forming models oflower tertiary were summarized, and exploration orientation was pointed out.Based systematic sampling and analyzing, the author evaluates precisely thesource rock in lower Tertiary, and points out that source rock in Es3 and Esl aregood-better source rock, source rock in Ek, Es4 and Es2 are poor source rock. Sourcerock in Es3 is major hydrocarbon source and is mainly distributed in Yucheng subsag.Hydrocarbon generation threshold of lower Tertiary was determined by way ofRo (3100m)o Source rock of Es2 and Esl are immature, and source rock of Es3 is intransition stage of immature and mature.Hydrocarbon generation model was established according to hydrocarbon generation potential and maximum pyrolysis temperature (Tmax). Hydrocarbon generation process can be divided into two stages:①early hydrocarbon generation stage-degradation of sulphate bacteria;②matured oil generation stage.Reservoir property was studied systematically. Petrophysics in Es3 and Esl is the most favorable while that of Ek is poor. Reservoir property differs greatly in different sedimentary facies. Reservoir property of sandstone in delta front and sand bar in shore-shallow lake is favorable, while reservoir property of sand sheet in shallow lake and sandstone in turbidite fan is poor.Based on analysis and understandings above, the dissertation pointed out that there are 3 petroleum systems in lower Tertiary in Yucheng area. They are Es1-Es-petroleum system in Yucheng area, Es3-Es- petroleum system in Yucheng area, and Ek+Es4-Es-petroleum system in Yucheng area. Es3-Es-petroleum system in Yucheng area has the most favorable exploration condition among the three.Combined with analysis of hydrocarbon migration direction and accumulative rules, the dissertation summed up 3 reservoir forming models: reservoir forming model in steep lope zone, reservoir forming model in gentle slope zone, and reservoir forming model in hollow zone. Oil-gas reservoir in glutenite body in steep lope zone and lithologic reservoir in hollow zone are important exploration orientation in Yucheng area.