Study on Sedimentary Facies of Ledong Formation in Yinggehai Basin Based on Seismic Facies Analysis

Objectives: The sedimentary distribution of Ledong formation in Yinggehai basin is not clear. The combination of seismic data and seismic forward modeling can clarify the sedimentary distribution in this area. Methods: The seismic facies boundary is characterized by seismic configuration, and the seismic subfacies boundary is characterized by seismic attribute structure. The sand body thickness of Ledong formation is characterized by seismic forward modeling and well logging sand body statistics of relevant well sections. Finally, the plane distribution of sedimentary facies is summarized. Results and conclusions: (1) The overall seismic attributes of the Ledong Formation in the Yinggehai Basin are favorable, characterized primarily by moderate to strong reflections on both sides. However, the middle section is severely disrupted by faults, exhibiting weak reflection characteristics. (2) The Ledong Formation represents a shallow marine beach-dam depositional environment, with extensive sand body development. A significant beach-dam complex is developed in the central part of the study area. The core of the sand bodies is relatively pure in texture and possesses excellent physical properties, making it a promising reservoir for oil and gas. (3) Based on seismic facies, two gas-water models are summarized: sheet sand bodies and multiple sets of sand bodies.