gscienceMining Science and Technology (Russia)Горные науки и технологии2500-0632The National University of Science and Technology MISiIS (NUST MISIS)10.17073/2500-0632-2018-2-9-12gscience-106Research ArticleMINERAL RESOURCES EXPLOITATIONРАЗРАБОТКА МЕСТОРОЖДЕНИЙ ПОЛЕЗНЫХ ИСКОПАЕМЫХEffect of hole shape on roughness friction factor in perforated and slotted horizontal boreholes used for opencast mine dewateringEffect of hole shape on roughness friction factor in perforated and slotted horizontal boreholes used for opencast mine dewateringTranDuc HuanTranDuc Huan

Germany

Hanoi, Vietnam

6, Akademischestrafte, Freiberg, Germany, D-09596

18, Pho Vien Street, Duc Thang Ward, Bac Tu Liem District, Hanoi, Vietnam

DrebenstedtC.DrebenstedtCarsten

6, Akademischestrafte, Freiberg, Germany, D-09596

Freiberg University of Mining and Technology Hanoi Univer-sity of Mining and GeologyВьетнамFreiberg University of Mining and Technology Hanoi University of Mining and GeologyViet NamFreiberg University of Mining and TechnologyГерманияFreiberg University of Mining and TechnologyGermany20180908201802913Copyright © Tran D., Drebenstedt C., 20182018Tran D., Drebenstedt C.Tran D., Drebenstedt C.This work is licensed under a Creative Commons Attribution 4.0 License.https://mst.misis.ru/jour/article/view/106

Horizontal boreholes were adapted for using in mine dewatering systems. Efficient and economically sound application of this new method of dewatering requires using perforated or slotted pipes as filters when installing casing. Pressure drop along a horizontal borehole is a major factor that affects the borehole performance. The pressure drop is caused by four separate effects: wall friction, perforation roughness, inflow acceleration, and mixing effects. This paper is devoted to studying the effects of these two former factors in perforated or slotted pipes. Numerical analysis was carried out using different types of perforation holes and slots. The simulation model was constructed using ANSYS Fluent 14.5 software. The results showed that at high Reynolds number, roughness friction factor values in perforated pipes with circular holes are significantly higher than those in slotted pipes with axially elongated slots and slotted pipes with perpendicular (to pipe axis) slots.

Horizontal boreholes were adapted for using in mine dewatering systems. Efficient and economically sound application of this new method of dewatering requires using perforated or slotted pipes as filters when installing casing. Pressure drop along a horizontal borehole is a major factor that affects the borehole performance. The pressure drop is caused by four separate effects: wall friction, perforation roughness, inflow acceleration, and mixing effects. This paper is devoted to studying the effects of these two former factors in perforated or slotted pipes. Numerical analysis was carried out using different types of perforation holes and slots. The simulation model was constructed using ANSYS Fluent 14.5 software. The results showed that at high Reynolds number, roughness friction factor values in perforated pipes with circular holes are significantly higher than those in slotted pipes with axially elongated slots and slotted pipes with perpendicular (to pipe axis) slots.

perforation roughnesshorizontal filtersdewateringopencast mines.perforation roughnesshorizontal filtersdewateringopencast mines.ReferencesEichler R.A., Drebenstedt C. Innovative De-watering Concepts for Open Cast Mines Using Horizontal Wells (HDD-Wells), Mine Planning and Equipment Selection, 2014, pp. 697-706.Eichler R.A., Drebenstedt C. Innovative Dewatering Concepts for Open Cast Mines Using Horizontal Wells (HDD-Wells), Mine Planning and Equipment Selection, 2014, pp. 697-706.Mansel H., Drebenstedt C., Jolas P., Blank-enburg R. Dewatering of Opencast Mines using Horizontal Wells, International Mine Water As-sociation, 2012.Mansel H., Drebenstedt C., Jolas P., Blankenburg R. Dewatering of Open-cast Mines using Horizontal Wells, International Mine Water Association, 2012.Tran D.H., Drebenstedt C. Challenges during Horizontal Directional Drilling (HDD) Wells Installation for Dewatering Opencast Mines, Scientific Reports on Resource Issues, Freiberg, Germany, 2014.Tran D.H., Drebenstedt C. Challenges during Horizontal Directional Drill-ing (HDD) Wells Installation for Dewatering Opencast Mines, Scientific Re-ports on Resource Issues, Freiberg, Germany, 2014.Tran D.H., Drebenstedt C. Considerable As-pects to Select Filter Wells for Dewatering, Sci-entific Reports on Resource Issues, Freiberg, Germany, 2015.Tran D.H., Drebenstedt C. Considerable Aspects to Select Filter Wells for Dewatering, Scientific Reports on Resource Issues, Freiberg, Germany, 2015.Jiang W., Sarica C., Ozkan E., Kelkar M. Investigation of the Effects of Completion Geometry on Single-Phase Liquid Flow Behavior in Horizontal Wells, Journal of Energy Resources Technology, Bd. Vol. 123, 2001, pp. 119-126.Jiang W., Sarica C., Ozkan E., Kelkar M. Investigation of the Effects of Completion Geometry on Single-Phase Liquid Flow Behavior in Horizontal Wells, Journal of Energy Resources Technology, Bd. Vol. 123, 2001, pp. 119-126,.Su Z., Gudmundsson J.S. Perforation Inflow reduces Frictional Pressure Loss in Horizontal Wellbores, Journal of Petroleum Science and Engineering, Bd. 19, 1998, pp. 223-232.Su Z., Gudmundsson J.S. Perforation Inflow reduces Frictional Pressure Loss in Horizontal Wellbores, Journal of Petroleum Science and Engineering, Bd. 19, 1998, pp. 223-232,Su Ze, Gudmundsson J.S. Friction Factor of Perforation Roughness in Pipes, Society of Pe-troleum Engineers, 1993.Su Ze, Gudmundsson J.S. Friction Factor of Perforation Roughness in Pipes, Society of Petroleum Engineers, 1993.Su Ze, Gudmundsson J.S. Pressure Drop in Perforated Pipes: Experiments and Analysis, Society of Petroleum Engineer, Melbourne, Aus-tralia, 1994.Su Ze, Gudmundsson J.S. Pressure Drop in Perforated Pipes: Experiments and Analysis, Society of Petroleum Engineer, Melbourne, Australia, 1994.Abdulwahid M.A., Dakhil S.F., Injeti N.K. Numerical Investigation of the Turbulent Flow Parameters Distribution in a Partly Perforated Horizontal Wellbore, European Scientific Jour-nal, Bd. Vol. 9, 2013, pp. 372-387.Abdulwahid M.A., Dakhil S.F., Injeti N.K. Numerical Investigation of the Turbulent Flow Parameters Distribution in a Partly Perforated Horizontal Wellbore, European Scientific Journal, Bd. Vol. 9, 2013, pp. 372-387.

The authors declare that there are no conflicts of interest present.