Abstract:Based on the integrated analysis of high-resolution seismic data (2D/3D), four structure styles, gas chimneys (fluid diapirs), large-scale faults, normal faults in submarine fan, and detachments faults in slide, could be identified in Shenhu Area in northern continental slope of the South China Sea. On the seismic profiles, gas chimneys displayed as the obviously vertical courses, which were composed of chaotic reflector zone, misty reflector zone and top high-amplitude reflector zone. The large-scale faults were located at the northwest and northeast of the study area, which would control the sedimentation of the deep strata. The normal faults showed the closed relationship with the progradation character of the Pliocene submarine fan, especially in the west of the gas hydrate drilling area. In the Quaternary, the detachments faults were widely distributed in the slide with the echelon pattern on the seismic profiles. The results shows that the large-scale faults could not control the formation of gas hydrate in the drilling area considering the long distances, whereas the gas chimneys and small-scale faults, including the normal faults in submarine fan and detachments faults in slide, would act as the migration pathways for the fluid/gas. So in the Shenhu gas hydrate drilling area, the gas chimneys associated with the faults could be regarded as the gas-bearing fluid influx system. Once the methane-bearing fluid migrating through the vertical and lateral pathways entered the gas hydrate stability zone and captured by the favorable deposits, the gas hydrate would be formed and stored. Further, the tectonic setting in the Shenhu gas hydrate drilling area could lead to the differences of the fluid influx system between the western and the eastern, which might be a crucial factor for the distribution of gas hydrate.