Reservoir Quality And Performance Assessment Using Well Logs From A Producing Niger Delta Field

The current investigation is focused on determining porosity and permeability, among other parameters, in a producing Niger Delta field in the Coastal Swamp Depositional Belt. Well logs like gamma ray logs, resistivity logs, caliper logs, density logs, and compressional wave logs in digital format were utilized in this study. The methodology began by filtering logs to eliminate erroneous spikes that might affect the accuracy of the outcomes. Identifying reservoir zones of interest and establishing correlations between wells were key steps in this work. These correlations revealed the consistency of shale and sand packages across the field. Finally, petrophysical characteristics were computed through empirical relationships. Results reveal that reservoirs exhibit an average gross thickness of 50 to 329 ft, a net thickness of 40 to 213, a net-to-gross ratio of 0.496 to 0.924, a shale volume of 0.054 to 0.429, an average total porosity of 0.256 to 0.407, an effective porosity of 0.202 to 0.404, water saturation of 0.036 to 0.431, and permeability of 2108 to 4932 millidarcy (md). Results also showed the reservoir units have fair-to-good porosity, exceptional permeability, and good-to-excellent net-to-gross characteristics. Overall, the comprehensive petrophysical analytical technique has increased confidence in discovering hydrocarbon by giving additional useful information into the reservoir quality distribution of the field.