A Novel Framework for Integrating Microseismic Monitoring and Geomechanical Modelling to Optimise Hydraulic Fracturing in the Gombe Sandstone Gas Plays, North East Nigeria

Tight sandstone gas reservoirs in the Gombe Sandstone of the Benue Trough, North East Nigeria, require hydraulic fracturing to achieve commercial flow rates, but the absence of a calibrated geomechanical model and microseismic monitoring framework has prevented rigorous fracture design optimisation for this formation. This study develops a novel integrated framework for combining real-time microseismic monitoring data with geomechanical model updating to optimise hydraulic fracture design in the Gombe Sandstone gas play. A one-dimensional mechanical earth model is constructed from wireline log data, calibrated by core mechanical tests and leak-off test data, and extended to three dimensions using seismic impedance volumes. The mechanical earth model provides input to the fracture propagation simulator FraCMan for predicting fracture geometry under specified injection conditions. A downhole microseismic monitoring array is deployed during a multi-stage hydraulic fracture treatment to record seismic emissions generated by fracture growth and shear activation of natural fractures. Moment tensor inversion of microseismic events characterises the failure mechanisms and stress orientations in the vicinity of the treatment zone. An iterative Bayesian model updating algorithm is developed to ingest microseismic observations in near-real-time and update mechanical property distributions in the geomechanical model, enabling adaptive redesign of subsequent fracture stages. The framework is validated against post-treatment production logs. Keywords: hydraulic fracturing, microseismic monitoring, geomechanical model, Gombe Sandstone, tight gas.