The Sedimentary Characteristics and Facies Model of the Upper Member of Guantao Formation of the Eocene in Xinbei Oilfield of  Shengli Petroleum Province

Key words: 
• sedimentary characteristics /
• facies model /
• the anabranched channel /
• the upper member of Guantao Formation /
• Xinbei oilfield /
• Shengli petroleum province

Abstract: The sedimentary character and facies model of the upper member of Guantao Formation in Xinbei oilfield of Shengli petroleum province were studied by core observation, granularity analysis, parameters count and well log analysis mainly. It's showed that the aim stratum in the studied area is the anabranched channel. Its granularity probability cumulation curves show similar character with the braided stream. The average channel sinuosity is more than 1.7 and duality structure develops, which is similar to meandering river. The developed burst fans can distinguish it with anastomosing river. The anabranched channel model in the studied area includes four subfacies, such as channel, bank, overflow and abandoned channel. The channel bars in abandoned channel subfacies are the most important sedimentary body. The burst fans and abandoning channels are more developed than that of natural levees. The top of the channel bars are often covered by flood plain successively. The distribution of petroleum in Xinbei oilfield is controlled by the anabranched channel mainly. The discovery of the anabranched channel facies can help Xinbei oilfield's fine sand body forecast and optimizing exploitation plan, and can be a useful geologic model for the reservoir forecast in other similar areas.