Water Flooding Optimization in Heterogeneous Layered Reservoirs

Water intrusion is extremely non-uniform during water flooding of layer-by-layer heterogeneous reservoir. Water breaks through to producing wells via high-permeable layers leaving not displaced oil in low-permeable low-drained zones. Massive break of water leads to high water-cut of produced liquids and eventually results in necessity of such wells shut-in. In order to calculate parameters of oil displacement by water flooding a mathematic model was built, considering joint and separate reservoir exploitation. Calculation of parameters of oil recovery from water-flooding is being done using two-dimensional with vertical cross-section numerical model of two-phase filtration in layer-by –layer heterogeneous reservoir. Development of heterogeneous formation with varying reservoir properties is undertaken by means of reservoir pressure maintenance with water injection. It is assumed that between layers there is mass exchange, liquids and formation skeleton are incompressible. With conventional water flooding approach, e.g. displacing oil by water via the most permeable layer, there is water enroachment of reservoir. In conditions of high variation in heterogeneity parameters and with the aim of the most precise identification of water-flooding efficiency several options of calculation for both joint and separate reservoir exploitation have been considered.