Laboratory modeling and study of the process of oil penetration into the gas cap, followed by its displacement by water or gas, is relevant for most oil and gas and gas-oil fields, including fields containing almost 10% of the current oil reserves of Rosneft Oil Company. One of the possible ways to increase the efficiency of development and reduce technological and economic risks is advanced (or simultaneous) development of the gas cap and oil reservoir. However, according to many scientists, a decrease in pressure in the gas cap due to gas extraction causes the penetration of oil into gas-saturated intervals and, as a result, irreversible losses of this oil, a decrease in the total oil recovery for the deposit. This approach to the development of oil objects in contact with the gas cap was formed because there was no purposeful laboratory study of the process, the formation of residual oil saturation in the gas cap after the penetration of oil into it. And the residual oil saturation in the gas cap was taken on the basis of the results of traditional experiments on the displacement of oil by water (or gas) for extremely oil-saturated core samples. The Tyumen Petroleum Research Center have developed and certified a method for measuring residual oil saturation in a gas-saturated reservoir after oil has been penetration into it, followed by its displacement by water or gas. The technology of physical modeling and determination of residual oil saturation in gas caps is based on many years of experience in conducting filtration experiments using a specialized stand, a distinctive feature of which is the use of two sources of gamma radiation from the radioactive isotope 241Am. A series of test experiments on core samples of a weakly consolidated reservoir of the Pokur suite, carried out at the bench, confirmed that the values of residual oil saturation after the penetration of oil into the gas cap are significantly lower than for extremely oil-saturated core samples of similar properties. This paper continues the discussion of the features of the technology of physical modeling of residual oil saturation in a gas cap after the penetration of oil into it. The results of the experiment on core samples from the BT formation of one of the Rosneft Oil Company fields in Eastern Siberia are presented.
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