Furong Wu

Identification of subtle seismic sequence boundaries by all-reflector tracking method

Summary Seismic sequence analysis presented by Vail et al. (1977) is based on the identification of reflection terminations on regional seismic profiles. It is difficult to be used in small 3D surveys with reflection terminations not so straight to be identified. In this paper, we present a method, which labeled as ‘all-reflector tracking’, for identifying subtle seismic sequence stratigraphic boundaries in small 3D seismic surveys. It has been used in the late Triassic Xujiahe Formation of a 180 km 2 3D seismic survey in middle Sichuan Basin, southwest China. As a result, five seismic sequence boundaries and three transgressive surfaces were recognized in Xujiahe Formation, which subdivided the formation into four seismic sequences and seven seismic systems tracts, and therefore the seismic sequence stratigraphic framework for the survey was successfully constructed. It is suggested that all-reflector tracking is an efficient approach to seismic sequence stratigraphy in small 3D seismic surveys.