Quantitative Analysis of Reservoir Connectivity Using Production Data and Pressure Transient Analysis in the Eastern Niger Delta

Compartmentalisation of Niger Delta sandstone reservoirs by sealing faults and stratigraphic barriers critically controls drainage efficiency and ultimate recovery, yet identifying and quantifying inter-reservoir connectivity from production data alone presents significant analytical challenges in fields with limited appraisal drilling. This study quantifies reservoir connectivity in selected reservoir intervals of an eastern Niger Delta field using an integrated analysis of well test pressure transient data, inter-well tracer test results, and production decline analysis. Pressure build-up tests at six wells were analysed using Bourdet derivative plots and radial composite models to identify transmissibility barriers and their effective distances from the tested wells. Tracer test breakthrough times and concentration histories were modelled using analytical stream-tube methods to estimate inter-well permeability and effective flow volume. Material balance calculations using pressure-production history data provided independent estimates of connected reservoir pore volume for comparison with volumetric estimates from the static model. The study integrates findings using a connectivity matrix relating individual well pairs to their estimated degree of dynamic communication. Results challenge the original geological interpretation of a single connected reservoir body, demonstrating that two sub-units separated by a thin shale interval act as hydraulically distinct compartments during production. Revised development recommendations based on the connectivity analysis are presented. Keywords: reservoir connectivity, pressure transient analysis, material balance, Niger Delta, tracer test.