Analysis of Changes in the Stress-Strain State and Permeability of a Terrigenous Reservoir Based on a Numerical Model of the Near-Well Zone With Casing and Perforation Channels

A finite-element scheme has been developed, including a section of reservoir rock, cement stone, casing and perforation channels. It is noted that in order to exclude the occurrence of stress concentrators at the casing – cement stone and cement stone – rock contacts, contact elements are specified in the numerical model, due to this, structural elements «slip», but at the same time, a reliable redistribution of stresses is carried out. Numerical simulation of the stress state of the near-wellbore zone using the developed model with varying depression on terrigenous reservoir for the conditions of one of the Perm Region oil field is carried out. It is shown that the safety factor of the casing is about 3–4 units, with the exception of small areas near the upper and lower areas of the perforations, where this indicator is close to one. For cement stone, the safety factor was 2-3 units and however, areas with its lowest value (1.35), also concentrated near the perforation channels, were note. To analyze the change in permeability, the dependence of this characteristic on effective stresses was used and it was found that zones of reduced stresses and an increase in permeability up to 20% of the initial value are detected in the upper and lower parts of the perforations. With an increase in depression on the reservoir, permeability decreases, especially in the lateral sections of the holes, where this parameter can decrease by 25% of the initial value. Using the Coulomb-Mohr criterion, areas of rock destruction from stretching and compression were identified. It is noted that with increasing depression, the areas of destruction under tensile stresses disappear and the areas of destruction under compression increase. An analysis of the change in the productivity coefficient depending on the depression showed that when creating a maximum depression on the 12 MPa formation, the productivity coefficient of the well can decrease by 15% due to compaction of the reservoir rock caused by an increase in effective stresses.

1. Al-Awad M.N.J., Al-Ahaidib T.Y. (2005). Estimating the amount of free sand in the yielded zone around horizontal oil wells. SPE Technical Symposium of Saudi Arabia Section, SPE-106329-MS. https://doi.org/10.2118/106329-MS

2. Araujo E.F., Alzate-Espinosa G.A., Arbeláez-Londoño A., Peña Clavijo S., Cardona Ramirez A., Naranjo Agudelo A. (2014). Analytical prediction model of sand production integrating geomechanics for open hole and cased – perforated wells. SPE Heavy and Extra Heavy Oil Conference, SPE-171107MS. https://doi.org/10.2118/171107-MS

3. Chernyshov S.E., Popov S.N., Savich A.D., Derendyaev V.V. (2023). Analysis of wells cement sheath stability during shaped charge perforating based on geomechanical modeling. Georesursy = Georesources, 25(2), pp. 245–253. (In Russ.) https://doi.org/10.18599/grs.2023.2.18

4. Chernyshov S.E., Popov S.N., Varushkin S.V., Melekhin A.A., Krivoshchekov S.N., Shaoran Ren. (2022). Scientific justificationof the perforation methods for Famennian deposits in the southeast of the Perm Region based on geomechanical modelling. Journal of Mining Institute, 527, pp. 732–743. https://doi.org/10.31897/PMI.2022.51

5. Ermolaev A.I., Efimov S.I., Pyatibratov P.V., Minixanov E.D., Dubinya N.V., Leonova A.M. (2023). Estimation of the maximum bottom-hole pressure, excluding the destruction of the bottom-hole zone of the formation, based on geomechanical core studies. SOCAR Proceedings, s1, pp. 61–69. (In Russ.) http://doi.org/10.5510/OGP2023SI100832

6. Fallahzadeh S.H., Shasizadeh S.R., Pourafshary P., Zare M.R. (2010). Modeling the Perforation Stress Profile for Analyzing Hydraulic Fracture Initiation in a Cased Hole. Nigeria Annual International Conference and Exhibition, SPE-136990-MS. https://doi.org/10.2118/136990-MS

7. Fjær E., Holt R.M., Horsrud P., Raaen A.M., Risnes R. (Eds.) (2008). Petroleum related rock mechanics. Amsterdam: Elsevier, 492 p.

8. Harlamov S.N., Dzhanxorbani M., Zajkovskij V.V. (2023). Transportation of cuttings by drilling mud in horizontal wells. Part 1. Modeling the structure of dispersed currents. Izvestiya tomskogo politexnicheskogo universiteta. Inzhiniring georesursov, 334(10), pp. 34–48. (In Russ.) https://doi.org/10.18799/24131830/2023/10/4433

9. Kashnikov Yu. A, Ashixmin S.G., Shustov D.V., Yakimov S.Yu., Kuhtinskij A.E. (2019). Increasing efficiency of hydrocarbon fields development based on complex geomechanical research. Neftyanoe xozyaystvo, 3, pp. 66–69. (In Russ.) http://doi.org/10.24887/0028-2448-2019-3-66-69

10. Kashnikov Yu. A., Ashihmin S.G. (2007). Mechanics of rocks in the development of hydrocarbon deposits. Moscow: OOO «Nedra Biznes-centr», 476 p. (In Russ.)

11. Li W., Chen L., Wang X., Fan Q., Xu G., Xiao W., Li X., Ye Zh. (2024). Acid fracturing technology and effect evaluation of carbonate horizontal well in Fuman oilfield. Journal of Physics: Conference Series, 2679, 012010. https://doi.org/10.1088/1742-6596/2679/1/012010

12. Liu F., Fan Y., Li L., Li J., Chen Y., Lv Z., He T. (2022). Case study of successfully staged acid fracturing on the ultra-deep horizontal well for the Qixia fm HTHP tight carbonate gas reservoir in China. Frontiers in Energy Research, 10, 917740. https://doi.org/10.3389/fenrg.2022.917740

13. Lukin S.V., Esipov S.V., Zhukov V.V., Ovcharenko Yu.V., Xomutov A.Yu., Shevchuk T.N., Suslyakov I.V. (2016). Borehole stability prediction to avoid drilling failures. Neftyanoe xozyaystvo, 6, pp. 70–73. (In Russ.)

14. Musaed N.J. Alawad, Talal Y. AlAhaidib. (2005). Estimating the amount of free sand in the yielded zone around horizontal oil wells. SPE conference paper, SPE 106329-MS, pp. 1–14.

15. Popov S., Chernyshov S., Gladkikh E. (2023). Experimental and numerical assessment of the influence of the bottommhole pressure drawdown on terrigenous reservoir permeability and well productivity. Fluid Dynamics & Materials Processing, 19(3), pp. 619–634. https://doi.org/10.32604/fdmp.2022.021936

16. Popov S.N. (2019). Development of 3D geomechanical model of the Achimov deposits of one of the fields of the Far North. Aktualnye problemy nefti i gaza, 2(25), pp. 1–17. (In Russ.) http://doi.org/10.29222/ipng.2078-5712.2019-25.art3

17. Popov S.N., Chernyshov S.E, Krivoshhekov S.N. (2023a). Comparative analysis of the analytical and numerical methods for calculating the stressstrain state of the near-wellbore zone based on the elastic model taking into account the main structural elements of the well. Izvestiya Tomskogo politexnicheskogo universiteta. Inzhiniring georesursov, 334 (5), pp. 94–102. (In Russ.) https://doi.org/10.18799/24131830/2023/5/3961

18. Popov A.N., Ismakov R.A., Popov M.A. (2023b). Forecasting hydraulic fracturing of porous rocks in the process of drilling a well. Stroitelstvo neftyanyh i gazovyh skvazhin na sushe i na more, 5(365), pp. 20–24. (In Russ.)

19. Popov S.N., Chernyshov S.E. (2023). Development of a geomechanical model and determination of the drilling fluid “density window” in the interval of famennian productive deposits (on the example of a site of one of the Timano-Pechora oil and gas province oilfield). Geologiya, geofizika i razrabotka neftyanyh i gazovyh mestorozhden, 11, pp. 32–39. (In Russ.) Safari R., Smith C., Fragachan F. (2017). Improved recovery of carbonate reservoir by optimizing acidizing strategy: coupled wellbore, reservoir, and geomechanical analysis. Abu Dhabi International Petroleum Exhibition & Conference, SPE-188683-MS. https://doi.org/10.2118/188683-MS

20. Vashkevich A.A., Zhukov V.V., Ovcharenko Yu.V., Bochkov A.S. (2016). Development of integrated geomechanical modeling in Gazprom Neft PJSC. Neftyanoe xozyaystvo, 12, pp. 16–19. (In Russ.)

21. Wang L. Shen X., Wu B., Shen T., Shi J. (2023). Integrated analysis of the 3D geostress and 1D geomechanics of an exploration well in a new gas field. Energies, 16(2), 806. https://doi.org/10.3390/en16020806

22. Yang Y., Liu Z., Sun Z., An S., Zhang W., Liu P., Yao J., Ma J. (2017). Research on stress sensitivity of fractured carbonate reservoirs based on CT technology. Energies, 10(11), 1833. https://doi.org/10.3390/en10111833

23. Zhang J., Moridis G., Blasingame Th.A. (2022). Message passing interface (MPI) parallelization of iteratively coupled fluid flow and geomechanics codes for the simulation of system behavior in hydrate-bearing geological media. Part 1: methodology and validation. SPE Reservoir Evaluation & Engineering, 25(03), pp. 600–620. https://doi.org/10.2118/206161-PA

24. Zoback M.D. (2007). Reservoir Geomechanics. Cambridge, U.K.: Cambridge University Press, 505 p.