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Gorniy vestnik Uzbekistana

Article Title

MECHANISM OF FLUID MIGRATION IN reservoirs-COLLECTORS

Abstract

The mechanism of fluid migration in stratium - reservoirs is revealed. The relevance of the study of the mechanism of migration of fluids is determined by the high (up to 90%) water cut of recoverable oil. It has been established that the migration of water and oil is mainly influenced by the type, nature and parameters of their interaction with host rocks, which have different values of wettability and sorption capacity. The amount of wettability is influenced by the pH values of water and oil. It is shown that pores and capillaries often have a mixed type of wettability, depending on their diameter. It has been established that wettability indicators of host rocks are directly related to their electrical properties. It was shown that the host rock of the reservoir has pronounced hydrophilic properties, then water moves mainly along the surface of its grains and small capillaries, while oil in this case moves, as a rule, along the existing cracks and along the central part of large pores. In this case, the maximum displacement of oil by water occurs at a degree of hydrophilicity of the surface of pores and capillaries of the host rocks from 30 to 60%. The host rocks of the reservoir beds are mostly hydrophilic, i.e. in them, water selectively wets particles of minerals and rock grains better than oil does, and spontaneously spreads over the surface of the rock, replacing oil. For this reason, while drilling and killing wells, opening the reservoir, the water from the kill fluid that is filtered into the reservoir pushes oil from the near-bottom part into the reservoir and is subsequently held in the pores by capillary forces, which makes it difficult to further develop the reservoir. Two types of oil remaining in the oil reservoir after its flooding are described, as well as the conditions for the appearance of a water blockade.