The dynamic material balance methodology can be used to estimate gas initially-in-place using only production and PVT data. With this methodology, reservoir pressure is obtained without requiring the well to be shut in; it is therefore superior to the static material balance method since there is no loss of production. However, the technique requires iterative calculations and numerical integration of gas pseudotime and is quite complex to implement in practice. A simpler and equally accurate methodology is proposed in this study. It requires only production and PVT data and also does not rely on a shut-in pressure survey. In addition, it requires neither iterative calculations nor numerical integration of gas pseudotime. The results of the analysis include gas initially-in-place and gas productivity index, and can easily be extended to production forecasting. Gas initially-in-place is evaluated with a high degree of reliability. The methodology is successfully tested with two simulated cases and one field case, giving high-accuracy results.

动态物料平衡方法可用于仅使用生产和 PVT 数据来估计气体初始就地。使用这种方法，无需关井即可获得储层压力；因此，它优于静态物料平衡方法，因为没有生产损失。然而，该技术需要迭代计算和气体伪时间的数值积分，并且在实践中实施起来非常复杂。本研究提出了一种更简单且同样准确的方法。它只需要生产和 PVT 数据，也不依赖关井压力调查。此外，它既不需要迭代计算，也不需要气体伪时间的数值积分。分析结果包括天然气初始就位和产气指数，并且可以很容易地扩展到生产预测。气体初始就地评估具有高度的可靠性。该方法通过两个模拟案例和一个现场案例成功测试，给出了高精度的结果。