渗流-自由流动耦合试井模型

Coupling Well Test Model of Percolation Flow and Free Flow

建立了耦合流动试井数学模型,在溶洞自由流动区,考虑流体的流体力学性质,在溶洞外的区域考虑地层渗流性质。对模型进行了数值和解析联合求解,得到了耦合流动模型压降、压恢试井曲线特征,分析了耦合流动模型流动规律,确立溶洞直径及体积、渗流区渗透率和溶洞边缘渗流区的表皮系数作为该试井模型参数体系,通过求解反问题可以确定溶洞大小等特征。

Coupling flow mathematical model for well test is established.In solution cavity free flow area,hydromechanics feature is considered,and in the area outside solution cavity,percolation feature is considered.Solving this mathematical model with combination of numerical and analytical methods,pressure drawdown and pressure buildup of the coupling flow model and their features are obtained;analyzing the flow rule of the coupling flow model,the diameter and volume of the solution cavity,and permeability of the percolation area and skin factor of the edge area of the solution cavity are all determined and to be used as parameters of the well test model,then solving the reverse problem to get some characteristics,for example,the size of the solution cavity etc.