Sedimentary Characteristics and Model of Sublacustrine Fan of Dalinghe Oil Layer of Shu2 Area in the West Sag, Liaohe Basin

Key words: 
• sublacustrine fan /
• sedimentary characteristics /
• sedimentary model /
• single gravity flow channel /
• Liaohe Basin /
• Dalinghe oil layer

Abstract: Based on cores data, geological logging data and logging data in mature exploration area, sedimentary characteristics and models of Dalinghe oil layer in Shu2 area of the West Sag has been analyzed. It shows that the gravity flow channels are widely developed in the sublacustrine fan of Dalinghe oil layer. The plane distribution, sandbody extended direction and distribution pattern of sublacustrine fan is controlled by gravity flow channels and ancient landform. The gravity flow channels and its controls on sedimentary body are banding distribution along the source direction. The main channel is gradually extended to relatively larger scale braided channel. The sides of the braided channel are the edges of the braided channel, which are banding distribution or tongue distribution. The braided channel is gradually becoming multi branched and small braided channel endings to the direction of the lake. Microfacies sequence of sublacustrine fan is the main channel→the embankment of main channel→deep lacustrine mudstone or the braided channel→the edges of the braided channel→endings microfacies→deep lacustrine mudstone. Each banded sedimentary body controlled by the braided channel is separated by deep lacustrine mudstone. And it is banding distribution or tongue distribution extending to the center of the basin far away.