对于水驱气藏 ,特别是比较活跃的水驱气藏 ,水侵主要维持地层压力 ,并将产量维持在初始产量 ,直到水锥突破 ,其结果直接影响到气藏的采收率 ,因此如何准确计算水驱气藏储量和水侵量大小 ,从而进行动态预测显得非常重要。通过对物质平衡方程的分析 ,提出了利用地层压力及采出量等生产数据建立目标函数 ,利用最小二乘法进行自动拟合 ,直接计算水驱气藏动态地质储量及水侵量的新方法 ,同时该方法还可以确定水驱强度指数的大小。通过实例分析对比验证说明该方法计算结果准确、可靠 ,计算简单、实用 For water-driven gas reservoirs, especially the more active water-purging gas reservoirs, the water invasion mainly maintains the formation pressure and maintains the initial production until the water cone breaks through. The result directly affects the recovery of gas reservoirs. Therefore, Accurately calculating the size of waterflooding reservoirs and water intrusion makes it very important to make dynamic prediction. Based on the analysis of the material balance equation, a new method is proposed to establish the objective function by using the production data of formation pressure and production, and automatically fit it by the least square method to directly calculate the dynamic geological reserves and water intrusion volume. At the same time, the method can also determine the size of the water flooding index. The comparison and verification of example shows that the method is accurate, reliable, simple and practical