Evaluating the production potential of new wells is paramount in devising effective reservoir development strategies. This study introduces a novel methodology tailored for the West African faulted block sandstone reservoirs, specifically Chad's D Field, to accurately estimate new well productivity. Utilizing Drill Stem Test (DST) data from wells D-1 and D-2 in the P reservoir, we derived initial productivity indexes ranging from 0.8 to 11.0 bbl/(d.psi) based on perforation intervals of 4.6–66.2 m. The optimal drawdown pressure, calculated using advanced reservoir engineering techniques, ranged between 18 and 1101 psi, closely mirroring actual field performance. Our approach also involved adjusting the productivity index based on real-time production data, revealing an average production rate of 750 bbl/d for single well, with individual well rates spanning from 400 to 3500 bbl/d. The integration of DST results with actual production data has demonstrated high accuracy, validating the efficacy of our methodology. This approach provides a robust scientific foundation for productivity assessment and development planning in analogous reservoirs, significantly enhancing reservoir management and optimization practices.