Abstract: This study provides a quantitative analysis of features associated with tectonic activity in the north-western margin of the Bozhong Sag, with the aim of clarifying the relationship between reservoirs and tectonic activity. Using data from drilling, logging, three-dimensional seismic survey, and laboratory analysis, with related materials and the fault activity rate, the control of tectonic activity over the reservoir with respect to settlement rate, reservoir distribution, and physical characteristics is determined. The results show that, for the same period, fault activity varied in different locations. Es3 and Ed3 were characterized by strong fault activity, corresponding to a period of strong fault basin subsidence, and as the distance between settlement center and the boundary faults was short, they mainly developed into fan deltas with thick and coarse granularity. Es1 and Es2 had weak fault activity, corresponding to a weak rift basin, and as the distance between the boundary faults and subsidence center was relatively great, they mainly developed into braided river deltas with thick and coarse granularity. Ed2 had strong fault activity, corresponding to the transition stage, was less affected by the late boundary fault and more by distant provenance, and developed into braided river deltas with fine granularity, low thickness, and greater extension. Ed1 was characterized by very weak fault activity, and developed into braided river deltas with low thickness and long extension, mainly regulated by secondary fault activity. Border faulting controls the location of clastic sediment input to the basin, while secondary fault activity plays a regulatory role in the spread of clastic sediments. Regional tectonic uplift significantly improves the fan delta tight reservoir. This finding provides a reference for reservoir prediction in areas of low exploration with a similar tectonic setting.

Key words: Bozhong Sag, Paleogene, fault activity, sediment, settlement center, reservoir