致密气井动态储量计算方法讨论

针对延长气田延北区块主力气藏山23层单井动态储量认识不清，产能评价不确定性大等问题，通过调研目前石油行业计算气藏动态储量较为成熟的各类方法，对比不同方法的计算原理和典型井计算结果的合理性和适用性，对产能贡献大的Ⅰ类储层气井、Ⅱ类储层气井筛选出最优动态储量计算方法。研究结果表明：生产初期物质平衡法计算的动态储量偏低，但是对于定点测压关键井，根据年度测压数据和累采量及时更新物质平衡法曲线图，可逐步校正动态储量；生产初期产量递减法计算的动态储量也偏低；不稳定生产拟合法，因整合了多种递减法和特征图版，能高效提供更准确的动态储量结果。认为延北区块应以不稳定生产拟合法(Topaze法)为主，物质平衡法、产量递减法等为辅进行单井和气藏动态储量的评估和预测。以上成果认识，对合理配产、调整开发方案具有一定指导意义。

Discussion on calculation method of dynamic reserves in tight gas wells

In view of the problems such as unclear understanding of the dynamic reserves of Shan23 single well in Yanbei block of Yanchang gas field,large uncertainty of productivity evaluation and so on,by investigating various kinds of mature methods for calculating the dynamic reserves of gas reservoirs in the petroleum industry at present,comparing the calculation principles of different methods and the rationality and applicability of the results of typical well calculation,the calculation methods for selecting the optimal dynamic reserves of class I and class II gas wells,which contribute greatly to productivity.The research results show that the dynamic reserves calculated by material balance method are low at the beginning of production,but the dynamic reserves can be corrected step by step for the key wells with fixed-point pressure measurement.The dynamic reserves calculated by the decline method in the initial production stage is also low.The unstable production fitting method can efficiently provide more accurate dynamic reserves results by integrating various decline methods and characteristic plates.It is considered that unstable production fitting method(Topaze method)should be the main method in Yanbei block,material balance method and production decline method should be used to evaluate and predict the dynamic reserves of single well and gas reservoir accessorially.The understanding of the above achievements has certain guiding significance for rational allocation of production and adjustment of development program.