Our study interval is the Paleogene Pinghu Formation, which comprises the main hydrocarbon-bearing strata and source rock interval in the Xihu Depression. Despite the existence of only three wells (W1, W2, and W3) in Block B and two wells (W4 and W5) in Block A, the availability of stacked and migrated 3-D seismic data throughout the study area, makes it possible to conduct a sedimentary facies analysis of the Pinghu Formation using sequence stratigraphy and seismic sedimentology.