Karimov Tashkent State Technical University, Tashkent, Uzbekistan:

B. N. Baratov, Post-Graduate Student
Zh. B. Toshov, Dean of the Energy Department, Professor, Doctor of Engineering Sciences, j.toshov@tdtu.uz

NUST MISIS’ Division in Almalyk, Almalyk, Uzbekistan:

F. Ya. Umarov, Director, Doctor of Engineering Sciences

The process of drilling can be addressed from the points of technique and technology. Technique means engineering, design and manufacture of rock-breaking drilling tools. Technology includes selection of the optimal drill tool designs in compliance with the physical and mechanical properties of rocks at the bottomhole, and in accord with the optimal modes of drilling. Roller bit drills are used in execution of 70 % of total exploration and production drilling in the world. The drill bits of this kind can actually and greatly enhance efficiency of the whole drilling process. Extremely complex kinematics of bit work in drilling, as well as high impacts applied to the bits in drilling in rocks of different hardness, viscosity, plasticity and abrasivity make the drill bit one the most complex and high-loaded mechanisms which operate under conditions of high vibrations, in a confined space and in the medium of abrasive drilling fluid. Extremely complex conditions also exist in operation of drill bits with removal of chippings and with cooling of the tool components by feeding compressed air to the bottomhole. In recent years, as the design basis is improved, and new materials and technologies appear, designers pay much attention to the design optimization and fabricability improvement of drill bits. To this effect, it is required to take into account the axial load, rotation frequency, hole diameter, rock hardness factor, as well as physical and mechanical properties of rocks a function of drilling depth. In estimation of energy inputs, it is required to validate a more effective design of a drill bit. The authors study a few operating modes of tricone drill bits, and give recommendations on their design improvement, productivity enhancement, reliability increase and life extension.

1. Shemetov P. A., Norov Yu. D., Toshov Zh. B. Enhanced efficiency of blasthole drilling in open pit mines. Tashkent : Fan, 2009. 160 с.
2. Mendebaev T. N., Smashov N. Zh., Kuatova M. Zh. Water jet destruction of rocks in well drilling by diamond tools with independent flushing ports. Eurasian Mining. 2019. No. 2. pp. 41–43. DOI: 10.17580/em.2019.02.09
3. Trofimov A. V., Kirkin A. P., Rumyantsev A. E., Yavarov A. V. Use of numerical modelling to determine optimum overcoring parameters in rock stress-strain state analysis. Tsvetnye Metally. 2020. No. 12. pp. 22–27. DOI: 10.17580/tsm.2020.12.03
4. Zakirov N. N. Technical and technological elements of life cycle of roller bits. Tyumen : TIU, 2018. 140 p.
5. Beshenkov P. S., Polushin N. I., Gkhorbani S., Sorokin E. N. Stress distribution analysis of PDC drill bits by computer modeling. Eurasian Mining. 2017. No. 2. pp. 25–28. DOI: 10.17580/em.2017.02.06
6. Tomoya Inoue, Chang-Kyu Rheem, Masanori Kyo, Hide Sakaguchi, Matsuo M. Y. Experimental Study on the Characteristics of VIV and Whirl Motion of Rotating Drill Pipe. Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering. Nantes, 2013. Vol. 7. DOI: 10.1115/OMAE2013-10182
7. Zhao Ziqiang, Zhao Limin, Cheng Aiming, Zhang Chunlin. Non-linear dynamic analysis of the internal parallel moving gear system. Journal of Vibration and Shock. 2012. Vol. 31, Iss. 15. pp. 68–74.
8. Optimizing Drilling in Real Time using Predictive Analytics. 2016. Available at: https://analyticsindiamag.com/optimizing-drilling-real-time/ (accessed: 15.06.2021).
9. Shigemi Naganawa. Dynamics modeling of roller cone bit axial vibration. Journal of The Japanese Association for Petroleum Technology. 2005. Vol. 70, Iss. 4. pp. 333–346.
10. Niyazi Bilim, Sertaç Dündar, Bilgehan Kekeç, Arif Emre Dursun. Investigation of the Effect of Drill Bit Rotation Speed on Sustainable Drilling. Mineral Exploitation and Sustainability : Proceedings of 8^th International Conference on Sustainable in the Minerals Industry. Series: Geo-Resources Environment and Engineering. Canada, 2017. Vol. 2. pp. 206–210.
11. Toshov Zh. B. Ways towards optimization of washout components of rock cutting tools. Gornyi Zhurnal. 2016. No. 2. pp. 21–24. DOI: 10.17580/gzh.2016.02.04
12. Steklyanov B. L. Increasing efficiency of rock-breaking drilling tools based on the comparative analysis of the kinetic characteristics of their components : Dissertation … of Doctor of Engineering Sciences. Moscow, 1988. 393 p.
13. Toshniyozov L., Mamatov M. Analysis of drill bit speed in bit-rock interaction with the use of numerical simulation methods. Ukrainian School of Mining Engineering – 2020. 2020. E3S Web of Conferences. 2020. Vol. 201. 01006. DOI: 10.1051/e3sconf/202020101006
14. Steklyanov B. L., Shteynert V. A., Rakhimov R. M. Dynamic components of rock-breaking drilling tools. Stroitelstvo neftyanykh i gazovykh skvazhin na sushe i na more. 2008. No. 6. pp. 19–21.
15. Balitskiy P. V. Drill string and bottomhole interaction. Moscow : Nedra, 1975. 293 p.
16. Kricak L., Negovanovic M., Mitrovic S., Miljanovic I., Nuric S. et al. Development of a fuzzy model for predicting the penetration rate of tricone rotary blasthole drilling in open pit mines. The Journal of The Southern Africa Institute of Mining and Metallurgy. 2015. Vol. 115, Iss. 11. pp. 1065–1071.
17. Travkin V. S. Rock-breaking tool for l rook for non-core rotary drilling. Moscow : Nedra, 1982. 190 p.
18. Toshov J., Baratov B., Baynazov U. Method of calculating the gear ratios of the cones of tricone drill bits. Ukrainian School of Mining Engineering – 2020. E3S Web of Conferences. 2020. Vol. 201. 01012. DOI: 10.1051/e3sconf/202020101012