Study on thermal strength reduction of rock formation in the diamond core drilling process using pulse flushing mode

User Rating:  / 0
PoorBest 

Authors:

A.Yu.Dreus, Cand. Sc. (Tech.), Assоc. Prof., Oles Honchar Dnipropetrovsk National University, Dnipropetrovsk, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

A.K.Sudakov, Dr. Sc. (Tech.), Assоc. Prof., State Higher Educational Institution “National Mining University”, Dnipropetrovsk, Ukrainе, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

A.A.Kozhevnikov, Dr. Sc. (Tech.), Prof., State Higher Educational Institution “National Mining University”, Dnipropetrovsk, Ukrainе, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Yu.N.Vakhalin, Cand. Sc. (Tech.), Assоc. Prof. State Higher Educational Institution “Ukranian State University of Chemical Technologies”, Dnipropetrovsk, Ukrainе

Abstract:

Purpose. The study of pulse flushing impact on weakening of rock formation in the course of diamond core drilling using diamond bits.

Methodology. Theoretical research of rock formation softening processes under transient thermal impact is based on the theory of thermoelasticity. Comparative analysis of thermal stress condition of rock formation in the course of diamond core drilling using both the pulse and continuous flushing modes was carried out in the course of the research.

Findings. The process of rock formation breaking in the course of diamond core drilling using stationary and transient (pulse) flushing with drilling fluid was studied herein. Conditions for transition of rock formation fractures to movable state and strength reduction have been defined. The estimated relation between the fracture development rate and delay of rock formation decomposition are obtained herein. The study revealed that under the pulse mode of drilling fluid supply conditions appear for thermal decomposition of rock formation. Owing to a greater, as compared to the continuous flushing mode, amplitude of temperatures in the borehole working area, strength reduction of the rock formation surface occurs. When boring granitic rocks, its strength reduction is 12 % on average.

Originality. The analysis of thermal stress condition of the rock formation was carried out for the first time along with grounding of the possibility to employ the thermal cycle effect to enhance the efficiency of rock decomposition in the course of the core drilling using diamond bits. For the first time ever the characteristics of thermal decomposition of rock formation were determined as follows: minimum dimensions of fractures and minimum delay time of decomposition commencing; the evaluation of rock formation strength reduction for the diamond core drilling process. The study revealed that the technique of pulse supply of the drilling fluid stipulates for notable reduction of energy consumption of the rock formation decomposition process.

Practical value. The outcomes of the study can be applied to develop pulse techniques of wells boring, as well as to establish efficient and cost saving parameters of the process.

Список літератури / References:

1. Bezsonov, Yu.D., 1996. Drilling of exploration wells using pulse supply of drilling liquid. In: Bezsonov Yu.D., ISSN 2071-2227, Науковий вісник НГУ, 2016, № 3 9

Davidenko A.N. and Sirik, V.F., 1996 Burenie skvazhin v oslozhnenyh usloviah, Donetsk. pp. 8–9

Бессонов Ю. Д. Бурение геологоразведочных скважин с приложением импульсов промывочной жидкости / Ю.Д.Бессонов, А.Н.Давиденко, В.Ф.Сирик // Бурение скважин в осложненных условиях. – Донецк, 1996. – С. 8–9.

2. Tungusov, S.A., 2009. Increasing the productivity of drilling wells through the use of a pulsing flushing. Razvedka i okhrana nedr. No. 8. pp. 42–47.

    Тунгусов С.А. Повышение производительности бурения скважин за счет применения пульсирующей промывки / С.А.Тунгусов // Разведка и охрана недр. – 2009. – №8. – С. 42–47.

3. Li G., Shi H., Liao H., Shen Z., 2009. Hydraulic Pulsed Cavitating Jet–Assisted Drilling. Petroleum Science and Technology, No. 2, Vol. 27, pp. 197–207.

4. Iudin, M.M., 2007. About fractured rock mass. Gornyi informacionno-analiticheskij bjulleten (nauchno-tehnicheskij zhurnal), Vol. 17, No. 2, pp. 278–283.

Иудин М.М. О трещиноватости массива горных пород / М.М.Иудин // Горный информационно-аналитический бюллетень (научно-технический журнал). – 2007. – Т. 17. – №. 2. – С. 278–283.

5. Zhang, L., Mao, X., and Lu, A., 2009. Experimental study on the mechanical properties of rocks at high temperature. Science in China Series E: Technological Sciences, 52(3), pp. 641–646.

6. Ischenko, K. S., 2012. Studying the mechanism of the rock breaking and structural changes in the rocks under thermal loading. In: K. S. Ischenko and V. Ya. Osenniy, 2012 Geotehnicheskaya mehanika: Mezhved. sb. nauch. tr. Dnepropetrovsk: IGTM NANU, 2012. Vol. 107. pp. 115–130.

Ищенко К.С. Исследование механизма разрушения и структурные изменения в горных породах при их термическом нагружении / К.С.Ищенко, В.Я.Осенний // Геотехническая механика. – Днепропетровск: ИГТМ НАНУ, 2012. – Вип. 107. – С. 115–130.

7. Brodov, G.S., 2001. Osnovy termomehanicheskogo kolonkovogo bureniya [Basics of thermomechanical exploration drilling]. Saint Petersburg: VITR, Russia.

Бродов Г.С. Основы термомеханического колонкового бурения / Бродов Г.С. – СПб.: ВИТР. – 2001. – 55 с.

8. Yermakov, S.A., Fedorov, L.N., Vashchenko, D.S., and Skriabin, R.M., 2010. Experimental study of strength reduction of hard rock under heated by friction friction element of the thermomechanical core bit. Gornyi informacionno-analiticheskij bjulleten (nauchno-tehnicheskij zhurnal), No. 7, pp 151–155.

Экспериментальные исследования разупрочнения крепких горных пород при нагреве трением фрикционных элементов термомеханической коронки / С.А.Ермаков, Л.Н.Федоров, Д.С.Ващенко, Р.М.Скрябин. // Горный информационно-аналитический бюллетень. – 2010. – № 7. – C. 151–155.

9. Kozhevnikov, A.A., Krysan, V.V., Vakhalin, Yu.N. and Livak, O.V., 2011. Razrushenie gornykh porod pri termotsyklicheskom vozdeistvii [Rock formation decomposition under shocking cooling]. Dnipropetrovsk: LizunovPress.

Разрушение горных пород при резком охлаждении / [Кожевников А.А., Крысан В.В., Вахалин Ю.Н. и др.] – Днепропетровск: ТОВЛiзуновПрес‟. – 2011. – 152 с.

10. Kozhevnikov, A.A., Goshovskiy, S.V., Dreus, A.Yu., and Martynenko, I. I., 2007. Thermal field of a diamond bit in the course of drilling using non-stationery mode of borehole flushing. Dopovidi Natsionalnoy akademii nauk Ukrainy, No. 2, pp. 62–67.

Тепловое поле алмазной коронки при бурении с нестационарным режимом промывки скважины / А.А.Кожевников, С.В.Гошовский, А.Ю.Дреус, И.И.Мартыненко // Доповіді Національної академії наук України. – 2007. – №2. – С. 62–67.

Files:
03_2016_Dreus
Date 2016-07-29 Filesize 404.54 KB Download 384

Visitors

3478678
Today
This Month
All days
14
40326
3478678

Guest Book

If you have questions, comments or suggestions, you can write them in our "Guest Book"

Registration data

ISSN (print) 2071-2227,
ISSN (online) 2223-2362.
Journal was registered by Ministry of Justice of Ukraine.
Registration number КВ No.17742-6592PR dated April 27, 2011.

Contacts

D.Yavornytskyi ave.,19, pavilion 3, room 24-а, Dnipro, 49005
Tel.: +38 (056) 746 32 79.
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
You are here: Home Archive by issue 2016 Contents No.3 2016 Mining Study on thermal strength reduction of rock formation in the diamond core drilling process using pulse flushing mode