Development of a Geophysical Monitoring Network Design Framework for Nigeria’s Induced Seismicity Risk from Petroleum and Mining Operations

Nigeria's expanding petroleum production and mineral extraction operations involve high-pressure injection and reservoir depletion activities that, in tectonically sensitive geological settings, may induce or trigger seismicity at magnitudes potentially damaging to infrastructure and communities, yet no formal framework for induced seismicity monitoring network design has been developed within the Nigerian regulatory context. This research develops a probabilistic seismic network design framework optimised for detecting, locating, and characterising induced seismic events associated with petroleum and mining operations in Nigeria, applying it to three priority operational areas representing different geological and seismic noise environments. The framework employs a network sensitivity analysis based on the concept of minimum detectable magnitude as a function of station spacing, local noise levels, and the velocity model at each site. Optimal network designs for the Agaie-Lapai (petroleum injection), Plateau State tin mines, and Warri petrochemical complex operational areas are derived using a genetic algorithm that minimises the minimum detectable magnitude while satisfying cost and logistical constraints. The Niger Delta operational area, characterised by high-amplitude cultural noise from processing facilities, requires a specialised borehole sensor network strategy to achieve a minimum detectable magnitude of 0.5, whereas the Plateau State area achieves the same sensitivity with surface sensors at wider spacing. The research develops an induced seismicity regulatory framework proposal for the Nigerian Upstream Petroleum Regulatory Commission, incorporating monitoring thresholds, traffic light protocols, and incident response procedures aligned with international best practice. Keywords: induced seismicity, monitoring network, seismic hazard, Nigeria, traffic light protocol