Features of Gas Cap Oil

Analyses of obtained results and comparison of curves shows that expansion of gas cap promotes decrease of formation pressure drop rates. Besides, it has direct influence on residual oil reserves withdrawal and on oil recovery increase in central zone. If there was no breakthrough of free gas into development well in the process of well operation (through interlayer with good permeability), then oil recovery factor could be much more. Expansion of gas cap and breakthrough of free gas into well cause change in definite degree of oil and gas permeability phase, additional resistance occurrence and decrease of oil withdrawal. A large volume of gas cap causes growth of gas factor during development.