Regimes of Displacement from an Anisotropic Formation during Injection of Fluid through a Vertical Well

The regimes of fluid displacement from a formation developed by a system of vertical wells are studied within the framework of the cross-sectional problem of flow through a porous medium. The case of an anisotropic formation in which the effect of buoyancy of the displacing fluid is significant is considered. It is shown that in the generic case the displacement process is characterized by five similarity criteria, one of them determines the intervals of fluid flow from the well to the formation. The limiting cases of the displacement regimes in which the number of constitutive similarity parameters can be reduced are described. The influence of these parameters on the recovery factor and the sweep efficiency is studied. A diagram of displacement regimes that constrains the areas of influence of the similarity criteria and the revealed limiting cases is constructed. The results of the present study may be useful in the oil and gas industry in estimating the efficiency of various field development methods.