METHOD FOR DETERMINING PERSPECTIVE SITES AND OPTIMUM TECHNOLOGICAL PARAMETERS FOR USE OF CYCLIC WATER FLOODING Russian patent published in 2018 - IPC E21B43/20 E21B43/32 

FIELD: oil industry.

SUBSTANCE: invention relates to the field of geological and hydrodynamic modeling of the development of oil fields. It can be used for the automated selection of the optimal area of application of the cyclic waterflooding technology, and also for the automated selection of the optimum period of the water injection cycle. Said method includes calculating the relative increase in oil production by applying a cyclic waterflood using such parameters, as permeability, well position, borehole pressure, viscosity of reservoir fluids, compressibility of fluids and rocks. It involves calculating the current density of oil reserves using the initial stock density, the accumulated volume of produced oil. It is followed by calculating the complex criterion for the efficiency of cyclic waterflooding. To increase the accuracy of determining the prospective areas for cyclic flooding, in calculating the relative increase in oil production, porosity and the distance between the wells are additionally factored in. Using analytical dependencies a complex criterion for the efficiency of cyclic waterflooding is calculated. Current oil reserves are calculated on the basis of Voronoi cells. For this, a Voronoi grid is constructed on the basis of the coordinates of the active wells. Then, the area of each cell is calculated. Accumulated volume of produced oil from each cell is calculated based on the wells coordinates, which have ever been present in the cell – active and inactive. After that, the current density of oil reserves is calculated using analytical expression. Calculation of the relative increase in oil is carried out for each pair of injection and production wells and for each pair of adjacent layers of interlayers of the accepted geological and hydrodynamic model based on the coordinates of the active wells. Further, the porosity and distance between the wells are taken into account when determining the accumulated oil production for stationary and cyclic waterflooding for each pair of adjacent interlayer layers. And the relative increase in oil production is calculated using a cyclic waterflood according to analytical expression.

EFFECT: technical result is an increase in the efficiency of cyclic waterflooding.

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