Many factors, both natural and anthropogenic, can influence the seismogenic pattern of injection-induced earthquakes (IIE). With an enhanced earthquake catalog and a comprehensive fluid injection database compiled for the southern Montney play in northeast British Columbia, we explore the relative significance of the potential controlling factors of IIE. We first show that hydraulic fracturing (HF) operations are most likely responsible for the increased seismicity in the region. For areas with comparable HF activities, the regional structural geology could be one primary factor correlating with the distribution of IIE. Our investigations further reveal that the stratigraphic formation for HF is the next important factor deciding the level of IIE. Specifically, the number of HF stages targeting the Upper Montney is about five times of that targeting the Lower-Middle Montney (LMM), yet the latter ones are responsible for the majority of IIE. The elevated seismic response with LMM may be attributed to two possible mechanisms, 1) the proximity to deeper permeable formations and subvertical graben faults that facilitates the downward migration of injected fluid and stress perturbation to reactivate pre-existing faults in the basement, and 2) the geomechanical heterogeneity of the two newly recognized geological units (Altares Member and Pocketknife Member) along the upper and lower boundaries of the LMM that enhances the seismogenesis of IIE. Our results provide an important framework of constructively mitigating the injection-related seismic hazard.