The researchers studied the sedimentary evolution of the Nenjiang Formation in the Southern Songliao Basin. They used data from well logging, mud logging, rock core, and seismic data to explore the types and characteristics of sedimentary facies in the area. The study revealed that the sediment in the Nenjiang Formation comes from river systems in the north and southwest. Four main types of sedimentary subfacies were identified, showing a progression from deep lake to shallow lake to delta front. The basin's sedimentary processes shifted from deep lake to shallow lake to delta front over time.