Effect of capillary forces on water and oil distribution in natural traps of Kogalym field
Within the boundaries of a big Kogalymsky field there identified 54 oil deposits. The structure of many deposits gives evidence of presence of significant deviations from the principals of the prevailing anticlinal-gravitational concept of oil and gas accumulation. Basically, they are observed in oil water contact (OWC) inclined position and screening of oil accumulations along the lateral by aquifer sandy rocks. The study of the capillary reservoir-rocks characteristics proves the fact that these variations occur due to the screening of oil deposits by capillary barriers arising at the water-oil contacts in porous medium at the joints of different porous facies.