Navoi State Mining University, Navoi, Uzbekistan:

Zh. B. Toshov, Dean, Assistant Professor, Candidate of Engineering Sciences

Large Dzheroi-Sardara phosphorite deposit occupies vast intermountain area in the Central Kyzylkum and is developed using open pit mining method (Tashkura open pit mine, Central Mine Management, Navoi Mining and Metallurgical Company). The deposit is composed of phosphorite beds I and II mined with cutter-loaders. Overburden strata are sand clay, gravelite, clay and thin phosphatized clayey marl layer and are subjected to drilling-and-blasting together with marl parting. Clayey beds have nonuniform thickness and may be 25 m thick. The nonuniformity of the overburden in type, material constitution, hardness and other characteristics requires optimized mode of hole drilling and sustained performance of rock cutting tool. The prime influence on the efficiency and endurance of rock cutting tool during hole drilling belongs to: dynamic (impact and vibration) forces conditioned by both design of the tool and improper accommodation of drilling mode to changed properties of rocks; insufficient sealing of basic parts of bits against washwater and drilling mud; level and technological efficiency of maintenance service (selection of lubricants, cleaning and trial of bits, other scheduled operations). The author points at low performance of conventional methods of washout and removal of drilling mud and other preventive treatment under conditions of alternation of different type rocks and flimsy knowledge on packing, which is highly adversive for drilling quality, especially in weak clayey rocks. The article studies ways towards improvement of rock cutting tool in the specific conditions of blasthole drilling in overburden in Tashkura open pit mine. The algorithm (scheme) of theoretical research and laboratory and full-scale testing aimed at engineering, manufacture and use of efficient anti-packing assemblies to protect roller drill bits is proposed.

1. Liu Qingyou, Qin Hu. A New Slim-hole Drill Bit. The IADC/SPE Asia Pacific Drilling Technology Conference and Exhibition, 13–15 November 2006, Bangkok, Thailand.
2. Toshov Zh. B. Algoritm protsessa razrabotki burovykh instrumentov (Algorithm of the process of design of drilling instruments). Innovatsii, kachestvo i servis v tekhnike i tekhnologiyakh : sbornik nauchnykh trudov V Mezhdunarodnoy nauchno-prakticheskoy konferentsii (Innovations, quality and service in technics and technologies : collection of scientific proceedings of the V International scientific-practical conference). Kursk, 2015. pp. 294– 297.
3. Serikov D. Yu., Yasashin V. A., Panin N. M. Sovershenstvovanie sposobov krepleniya promyvochnykh uzlov burilnogo instrumenta (Improvement of methods of support of washing units of drilling instrument). Stroitelstvo neftyanykh i gazovykh skvazhin na sushe i na more = Construction of Oil and Gas Wells on-Land and off-Shore. 2014. No. 6. pp. 6–11.
4. Yasashin V. A. Povyshenie effektivnosti porodorazrushayushchego burovogo instrumenta konstruktorsko-tekhnologicheskimi metodami (Improvement of efficiency of rock-failure drilling instrument by design-technological methods). Trudy Rossiyskogo gosudarstvennogo universiteta nefti i gaza imeni I. M. Gubkina = Proceedings of Gubkin Russian State University of Oil and Gas. 2009. No. 1. pp. 67–78.
5. Steklyanov B. L. O zakonomernosti zatrat energii dinamicheskikh sistem v srede soprotivleniya (About the regularities of dynamic system energy consumption in resistance medium). Sovremennye tekhnologii i innovatsii gorno-metallurgicheskoy otrasli : materialy VI Mezhdunarodnoy nauchno-tekhnicheskoy konferentsii (Modern technologies and innovations of mining-metallurgical branch : materials of the VI International scientific-technical conference). Navoi, 2013. pp. 188–189.
6. Toshov Zh. B. Povysheniya effektivnosti bureniya vzryvnykh skvazhin na putyakh optimizatsii trekh sostavlyayushchikh dinamiki burovykh dolot (Increasing of efficiency of blasting hole drilling on the ways of optimization of three contents of drilling bit dynamics). Gornyy informatsionno-analiticheskiy byulleten = Mining Informational-Analytical Bulletin. 2014. No. 6. pp. 281–287.
7. Toshov Zh. B., Steklyanov B. L. Osnovnye tekhniko-tekhnologicheskie napravleniya optimizatsii dinamiki odnosharoshechnykh burovykh dolot (Basic technical and technological ways of optimization of one-roller drilling bit dynamics). Gornyy Zhurnal Kazakhstana = Mining Journal of Kazakhstan. 2014. No. 7. pp. 24–28.
8. Mohammed Jasem Al-Saeedi, Fayez Abdulrahman Al Fayez Drilling and Testing of KOC. Abu Dhabi International Petroleum Conference and Exhibition, 11–14 November 2012. Abu Dhabi, UAE, 2012
9. Zhucheng Yu, Weiguo Wang, Chaoming An. Comprehensive & Associated Drilling Technology for Ultra-deep Well Jida 4. The IADC/SPE Asia Pacific Drilling Technology Conference and Exhibition, 9–11 July, 2012. Tianjin, China.
10. Serikov D. Yu., Smorkalov D. V. Sovershenstvovanie tsentralnogo gidromonitornogo uzla trekhsharoshechnogo burovogo dolota (Improvement of central hydromonitoring unit of threeroller drilling bits). Territoriya «Neftegaz» = Oil and Gas Territory. 2014. No. 12. pp. 22–28.
11. Dina Kaniaa, Robiah Yunusa, Rozita Omara, Suraya Abdul Rashidb, Badrul Mohamad Janc. A review of biolubricants in drilling fluids: Recent research, performance, and applications. Journal of Petroleum Science and Engineering. 2015. Vol. 135. pp. 177–184.
12. Gusman A. M. Upravlenie ochistkoy zaboya skvazhiny pri burenii sharoshechnymi dolotami (Management of well cut purification during roller bit drilling). Burenie i neft = Drilling & Oil Magazine. 2005. No. 2. pp. 6–9.