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Various casing perforation methods are used to ensure a hydrodynamic reservoir-to-well connection. However, perforated wells often do not perform satisfactorily during production. This is largely due to a decrease in the permeability of the near-wellbore formation as a result of casing perforation work. Studies and analysis of existing casing perforation methods have shown the effectiveness of abrasive jet perforation. The paper presents the results of numerical modeling to optimize the layout of slot channels during the abrasive jet perforation (AJP) of terrigenous productive object. Geomechanics analysis of the influence the formation scheme and orientation of the slotted channels in the productive layer during abrasive jet perforation on the permeability of terrigenous reservoirs of the oil fields in the Perm Krai was performed. The disadvantages of widespread methods of exposing perforation are described and the advantages of abrasive jet perforation based on geomechanical modeling are revealed. The calculations carried out on the placement of slotted channels showed that the distance between the systems of slotted channels is not important, since they weakly interact with each other in height with standard schemes. It was established that the best placement scheme for jet slot channels is a system of four slot channels shifted along the length of the well to the height of the slot channel with a phasing of 90°. Comparative calculations of the reservoir permeability of the near-well zone for various perforation methods have been performed.

The article presents the results of analysing geological structure of the Famennian deposits (Devonian) in the Perm Region. Numerical modelling of the distribution of inhomogeneous stress field near the well was performed for the two considered types of perforation. With regard for the geometry of the forming perforation channels, numerical finite element models of near-wellbore zones were created considering slotted and cumulative perforation. It is ascertained that in the course of slotted perforation, conditions are created for a significant restoration of effective stresses and, as a result, restoration of reservoir rock permeability. Stress recovery area lies near the well within a radius equal to the length of the slots, and depends on the drawdown, with its increase, the area decreases. From the assessment of failure areas, it was found that in case of slotted perforation, the reservoir in near-wellbore zone remains stable, and failure zones can appear only at drawdowns of 10 MPa and more. The opposite situation was recorded for cumulative perforation; failure zones near the holes appear even at a drawdown of 2 MPa. In general, the analysis of results of numerical simulation of the stress state for two simulated types of perforation suggests that slotted perforation is more efficient than cumulative perforation. At the same time, the final conclusion could be drawn after determining the patterns of changes in permeability of the considered rocks under the influence of changing effective stresses and performing calculations of well flow rates after making the considered types of perforation channels.

Introduction/purpose: The development of elastomeric materials based on synthetic polyisoprene (IR) with high green strength is a rather urgent task, because it allows to replace, completely or partially, the main ingredient - natural rubber in responsible rubber products. The aim of the work was an additional increase in the green strength values of IR and rubber mixtures based on it by its modification with high-density polyethylene of PND 277-73. Methods: The main methods of the research of the technological, physicalmechanical and operational properties were used. All tests conformed to ASTM or ISO standards. Rubber compounds were made in the Haake PolyLab rubber mixer. In parallel with the effects of modification, the influence of the mixing temperature on the main properties of IR and NR based elastomeric materials was investigated. Results: It is shown that the increase in the mixing temperature of NR and IR for 20ºC leads to significant changes in the technological properties of rubber compounds (primarily green strength), as well as the physicalmechanical and operational properties of cured rubber. It has been established that a significant increase in the green strength of the rubber compound is achieved by combining IR with 7 mass. % HDPE. Conclusion: The developed polymer composition based on IR and HDPE has a level of green strength of the rubber compound 2 times higher than that of natural rubber, while maintaining the physical-mechanical and operational characteristics of cured rubbers at the level of natural rubber. The polymer composition IR/HDPE 93/7 can be recommended for use in the manufacture of products whose manufacturing technology requires increased green strength of rubber compounds, including largesized and all-metal tires.