Theoretical Development of an Integrated Well Completion Optimisation Model for Tight Gas Reservoirs in the Bida Basin

Tight gas reservoirs in Nigeria's inland sedimentary basins, particularly the Bida Basin in North Central Nigeria, represent a significant underdeveloped gas resource that requires sophisticated well completion engineering approaches different from the conventional Niger Delta sandstone completions that dominate Nigerian petroleum engineering practice. This study develops an original integrated well completion optimisation model for tight gas reservoirs in the Bida Basin, addressing the absence of published completion engineering frameworks for this technically and commercially distinctive resource category. The theoretical model integrates hydraulic fracture mechanics, reservoir flow mechanics in tight porous media (Klinkenberg gas slippage and non-Darcy flow effects), and multi-objective optimisation theory to identify optimal completion configurations. The research methodology combines: petrophysical characterisation of available Bida Basin core samples and wireline log data to parameterise reservoir rock properties, three-dimensional discrete fracture network (DFN) modelling of natural fracture systems to constrain hydraulic fracture propagation geometry, and development of a semi-analytical production forecast model coupling hydraulic fracture parameters with tight gas reservoir flow equations. The multi-objective optimisation component simultaneously maximises 20-year cumulative production, minimises completion cost, and minimises environmental footprint (water usage and surface disturbance) using a Pareto frontier approach. The study's original theoretical contributions include: a Bida Basin tight gas flow mechanics model incorporating measured Klinkenberg coefficients and stress-dependent permeability, a hydraulic fracture height containment model calibrated for the basin's thin interbedded sandstone-shale stratigraphy, and a completion optimisation algorithm generating Pareto-optimal completion portfolios under geological uncertainty. Recommendations include a pilot well programme in the Bida Basin to validate the completion model under field conditions and engagement with the NUPRC for a tight gas development incentive framework. Keywords: tight gas, well completion, Bida Basin, hydraulic fracturing, completion optimisation.