Strongly heterogeneous gas reservoirs are commonly developed using various well types. However, traditional single-point method formulas exhibit significantly reduced applicability when addressing variations in well configurations and reservoir properties, resulting in noticeable deviations between predicted and actual productivity. Based on the productivity methodology proposed by Xi Feng’s team, a power-law relationship between the productivity coefficient and permeability was first established. Subsequently, an improved single-point method formula applicable to gas wells with diverse configurations (vertical, high-angle, and horizontal wells) was derived. The reliability and applicability of this formula were ultimately verified using test data from a gas reservoir. Results indicate that the improved single-point method formula effectively overcomes the adaptability limitations of traditional formulas in strongly heterogeneous reservoirs. For different well configurations (e.g., vertical, high-angle, and horizontal wells) and varying reservoir and permeability conditions (e.g., high-porosity/high-permeability and low-porosity/low-permeability), the predicted Absolute Open Flow of this formula has less than 5% absolute error compared with the results calculated by Xi Feng's single-point method formulas and the one derived for high-angle or horizontal wells from Xi Feng's single-point method formulas, and the error distribution meets the engineering accuracy requirements. Through the innovative transformation of the productivity coefficient and permeability, the improved single-point method formula demonstrates robust generalization capability and computational reliability in field applications. This advancement provides a more accurate quantitative tool for productivity evaluation in heterogeneous gas reservoirs.