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The problem of cost-effective oil production from carbonate reservoirs becomes more and more important every year due to a decrease in oil reserves in terrigenous reservoirs. Oil extraction from carbonate reservoirs is always associated with the low filtration properties of the rock matrix and the dense fracture network presence. One of the most effective methods at this development stage for carbonate reservoirs is the non-stationary drainage technology. The development of non-stationary deposit drainage technology by determining the effective action time with different work periods and well accumulation, due to deformations in the fracture system, will allow reducing wells watering percentage. As a result of fluid flows redistribution in the formation, unprocessed areas are attracted by capillary impregnation. An important stage in the application of non-stationary action is the study of oil optical properties. To assess the quality of the reserves involved in the development, laboratory studies of the deposit non-stationary production efficiency of the Romashkinskoye oil field were carried out. The investigations were carried out using a spectrophotometer and a chromatograph. The influence of non-stationary selection on the wells operation dynamics and on the final ORC was determined.

Currently, main light hydrocarbon reserves are being depleted across the world, which is why more and more petroleum companies pay attention to the possibility of developing unconventional reservoirs and hard-to-recover reserves. It is obvious that at this development stage of technologies for oil field exploitation, cost-effective development of unconventional reservoirs is impossible, and therefore there is a need for new oil production methods. Herewith, accurate setting and conducting of laboratory experiments plays an important role, since the decisions taken based on the experimental results affect the technological and economic factors. Such studies include filtration tests for determining the oil displacement ratio from core in laboratory. When carrying out filtration tests, the important point is accurate formulation of the experiment, which is impossible without a well-developed methodology and specification. To date, the tests to determine the oil displacement ratio are regulated by IST-39-195-86, which was approved in 1986. In a detailed investigation of the document, it was established that most of the points in the document need to be changed and refined in connection with the improvement of equipment and methods for preparing the core material in order to reduce errors at various stages of the experiment and to estimate the displacement ratio more accurately in determining the effectiveness of the technologies being developed.

The article discusses the results of physical laboratory modeling of nonisothermal oil displacement by formation water on model composite core samples of the Akansky field, performed on a VINCI CFS-700 filtration unit. In the work, the influence of the permeability of composite core samples on the results of nonisothermal oil displacement by formation water was studied. An analysis of the performed experiments shows that the influence of the temperature regime on the displacement coefficient manifests itself to varying degrees on samples of different permeabilities. The change in the displacement coefficient at various temperature conditions occurs most strongly in low-permeability rock samples, in high-permeability rocks the changes are less significant. Use for displacing produced water with a temperature below the initial formation water (within 2-5ºС) provokes a greater decrease in the displacement coefficient than the use of slightly heated water (within 7ºС). The presence of highly differentiated rock samples by permeability revealed when drilling productive formations significantly complicates the processes of oil displacement. The local highly permeable sections available in the context of productive formations can act as intensifying the process of displacing the zone with the right choice of temperature and exposure technology.