Abstract: So far, the exploration of the Pearl River Mouth Basin located in the eastern part of the South China Sea has encountered problems related to the determination of low relief structures. We used broadband velocity modeling under multiple-well constraints to create a velocity model for the region and to ascertain the objective structures. The concept, technical details, and application procedure of this method are discussed and compared with the depth-structure map obtained through the PSDM method. The data processing results show that the broadband velocity modeling technology under multiple-well constraints is affected by the existence of faults and the significant absolute error exists; however, the relative error for the same layer is smaller. A more accurately characterized velocity of the research area can produce better diagrams of low relief structures. A specific method of analysis for the broadband velocity modeling of low relief structures of the Pearl River Mouth Basin located in the eastern part of the South China Sea was explored.

Key words: Pearl River Mouth Basin, low relief structure, fault, broadband velocity modeling technology, velocity analysis