Sub-layer Correlation of Quantou IV Formation of the Lower Cretaceous in Haituozi Area of Songliao Basin

Abstract

Fluvial-flood plain facies are developed at lower-mid Quantou Ⅳ Formation, and delta front - shallow lake facies are developed at the upper formation in Haituozi area of Southern Songliao Basin. Channel sand bodies are good oil and gas reservoirs, but the distribution of sand is not clear, which has become a key factor restricting oil and gas development. No less than 100 wells data of logging, some data of drilling, cores and testing are collected and used in correlation, firstly 5 roughly provenance direction and 5 crosscutting provenance direction sections were selected in the area, with high resolution sequence stratigraphic analysis, Quantou Ⅳ Formation is subdivided into 4 sequences (corresponding to the fifth order cycle sequence, are respectively called cycle A, B, C and D), sequence stratigraphic framework were established. Then the similarity of facies association characteristics in base level change, consistency of reservoir fluid properties, isochronous maximum flooding surface in a certain area, different stages of overlay channels are took full account in the operation of sub-layer correlation. In the end 3 sub-layers are divided from cycle A , 3 sub-layers divided from cycle B, 5 sub-layers from cycle C, and cycles D corresponds to a sub-layer, Quantou Ⅳ Formation is divided into 12 sub-layers, which lays good foundation for the production and development. Key words : High resolution sequence stratigraphy; Sub-layer correlation; Songliao basin; Haituozi area; Quantou Ⅳ Formation