考虑变井筒存储的双重介质凝析气藏气井压力动态分析

PRESSURE BEHAVIOR ANALYSIS FOR GAS WELLS IN DUAL-POROSITY CONDENSATE GAS RESERVOIRS UNDER CONSIDERATION OF VARIABLE WELLBORE STORAGE

以前的试井分析方法虽然考虑了井筒存储的影响,但没有考虑井筒存储变化对压力动态的影响。然而由于凝析气自身的特性,如不考虑此因素将会对凝析气压力动态产生较大的影响。为此,首次建立了考虑变井筒存储的双重介质凝析气井气藏试井分析数学模型,通过Laplace变换和Stehfest数值反演进行求解,绘制其压力及压力导数曲线,并分析研究了各参数对压力和压力导数动态的影响。该方法采用的新模型更符合凝析气藏的开采过程中的真实情况,对凝析气藏开采分析研究有指导意义。

Well test analysis methods used before only consider the effect of wellbore storage on well pressure behavior but not the effect of its variation, which greatly affect pressure performance due to the characteristics of condensate gas reservoirs. Therefore, a mathematical model considering this factor was built in this paper for well test analysis of gas producers in dual-porosity condensate gas reservoirs. It was solved through Laplace transformation and Stehfest numerical inversion to plot the type curves of pressure and pressure derivative. In addition, effect of various parameters on pressure and its derivative was studied. This new model is more applicable for recovery analysis of condensate gas reservoirs.