异常高压气藏动态预测模型及应用

针对异常高压气藏具有压降图异常和定容封闭的特征,基于体积平衡原理,导出了异常高压气藏的压降方程,并结合气井的二项式渗流方程和气体的井筒流动方程,建立了异常高压气藏动态预测基本模型,在模型中考虑了储气层的压实和岩石颗粒的弹性膨胀作用,以及地层束缚水的弹性膨胀作用.应用该模型对实际异常高压气藏进行生产动态预测的结果表明,所建立和提出的模型可靠,预测方法正确,能较好地预测异常高压气藏稳产期和产量递减期的生产动态.

Application of Dynamic Prediction Model for Overpressure Gas Reservoir

The pressure drop equation was derived from the volume balance principle in allusion to the characterization with abnormity of pressure-drop plot and constant-volume in overpressure gas reservoir. And by combining the binomial seepage equation of gas wells with the well-bore flow equation, the basic performance prediction model was established. The model gives consideration to the compaction of gas-bearing reservoir, the elastic expanding of rock grains and the elastic expanding of formation irreducible water. And with the model, the detailed dynamic prediction has been conducted on the actual overpressure gas reservoir. The calculation results show that the methods presented in this paper are reliable and correct. The model can preferably predict the production performance in the stable production period and the production decline period of overpressure gas reservoir.