METHOD OF EVALUATION OF SPACE DISTRIBUTION OF OIL SATURATED REGIONS IN WATERED BEDS Russian patent published in 2009 - IPC E21B43/00 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to development and operation of oil deposits under water drive mode, particularly to methods of increasing oil withdrawal from bed. Method includes charting of deposit maps by means of isochrones of flooding. According to invention by means of hydrodynamic investigations of water flooded wells there is obtained a dependence of production flooding on yield of extracted fluid. Oil saturated regions in water flooded, non-uniform by permeability beds are evaluated by the character of change of the above said dependence and by the time of existence of positive effect of decreased production water flooding. Monotonous decrease of production flooding at increase of liquid yield and its constancy at the set mode of operation testify of presence of patches of regions with residual oil saturation washed up with water during operation. Monotonous increase of production water flooding at increase of liquid yield testify of presence of regions stretched for tens and hundreds of meters and distributed uniformly along the whole bed including regions with primary oil saturation not participating in filtration. Also variations of flooding values in time testify of non-uniform in stretching distribution of oil-saturated regions. Abrupt decrease of flooding of production at increase of liquid yield, achieving maximum water flooding and following abrupt increase of flooding tell of presence of space stretched regions with intermediary oil saturation - they are transitive regions of hydrodynamic capillary displacement.

EFFECT: increased oil withdrawal from bed.

1 tbl, 1 dwg