Usher模型的特征分析及应用

CHARACTERISTIC ANALYSIS OF USHER MODEL AND ITS APPLICATION

在油气田开发中，产量、累积产量和可采储量的预测始终是油气藏工程师的一项重要任务。它直接关系到油气田中长期开发方案的编制与调整。通过对Ｕｓｈｅｒ模型微分方程式的分析，指出目前用于油气田产量预测的Ｌｏｇｉｓｔｉｃ模型和Ｇｏｍｐｅｒｔｚ模型是Ｕｓｈｅｒ模型的两种简化形式；首次推导了Ｕｓｈｅｒ模型用于油气田产量、累积产量、可采储量和最高年产量及其发生时间的预测数学模型；讨论了３个模型在实际应用中的变化特征；阐述了Ｕｓｈｅｒ模型参数的计算方法，并在具体实例中加以应用。实践结果表明，Ｕｓｈｅｒ模型比Ｌｏｇｉｓｔｉｃ模型和Ｇｏｍｐｅｒｔｚ模型具有同等或更高的预测精度。

The forecast of the production,cumulative production and recoverable reserves is an important task of reservoir engineering in oil and gas field development from beginning to end,being directly related to the compilation and adjustment of oil and gas field medium and long term development projects.Through analyzing the differential equations of Usher Model,it is pointed out that the Logistic Model and Gompertz Model used for production forecast of oil and gas fields at present are the two simplified patterns;in light of the Usher Model,the mathematical models for predicting the production,cumulative production,recoverable reserves and maximum yearly production and its appearing time of oil and gas fields are derived;the variable characteristics of the three models in practical application are discussed; and the calculation methods of the parameters in Usher Model are expounded and they are applied to the calculation for some examples.The practical results show that in comparsion with the Logistic Model and Gompertz Model,the Usher Model is of an identical or higher forecast accuracy.