The solution of stationary hydrodynamic task on the replacement of incompressible viscous-plastic oil with thickened water in homogeneous porous medium

Abstract

The paper reviews the stationary hydrodynamic task on the replacement of the incompressible viscous-plastic oil with the thickened water in the horizontal circular reservoir, in the centre of which a vertical oil well is operated. The formula of filtration rates in different zones, the oil recovery rate, current pressure, current pressure gradients, the pressure in the border of oil and thickened water, as well as the formula of the partial and full duration of oil motion in the reservoir have been developed using generalized Darcy filtration law. All hydrodynamic calculation formulas developed should be applied in the solution of various theoretic tasks on the development of such oil fields, as well as when planning the projects on the exploration of new oil fields. Moreover, using the well known analytical dependence between the average actual rate of fluid motion in the porous channels and filtration rate, the formulas for the time calculation of the fluid motion though the border, in one case - on its current position, in another one – from the saturation contour to the well, have been developed. The formula of the first case is applied in the isolation of the produced water flooded with the contour water (in the formation of liquid fingers) in the wells via the hydrodynamic method for the time calculation of repeated flooding after the implementation of the first cycle of corresponding measure, i.e. after the viscous oil, which is also viscous-plastic fluid in the formation conditions, is injected into the layer.