Abstract:

Based on the theory of high accuracy sequence stratigraphy, this paper reconstructs the sublayer units deposition model of the Putaohua oil layer group PI332a-PI11 thin layer of Yaojia Formation 1st section from Xingshugang area of Daqing Changyuan in Songliao basin, which comprehensively uses various data such as core analysis, seismic data, well logs and analysis test data. Our analysis suggests that there is a “panting uplift action” (the socalled panting is a phenomenon that the underlying uplift center migrates wavelike) in Xingbei oilfield, which is the internal dynamic factor of meandering composite belt swings regularly. Guided by this theory, the plane distribution patterns of every sublayer sedimentary microfacies units were rebuilt in this area. There are 2 sub facies and 14 microfacies types were recognized from main oil layers PI1-PI3 in plane. Comprehensive research shows that the PI332a-I22 thin layer units of Xingshugang oilfield are the upper distributary plain subfacies, where high bending distributary channel sand is the main part and the point bar relatively develop. PI212 thin layer is the lower distributary plain subfacies, where low bending distributary channel sand is the main part. PI11-PI211 thin layer is the dendritic inner front delta deposition. The detailed study of sedimentary facies in this area laid a foundation for oil and gas exploration and development.

Key words: panting uplift action, wave overlap concept, Xingshugang oilfield, Putaohua oil layer group