Stress deformed state of a drill string under off-design conditions

Proceedings of the Mavlyutov Institute of Mechanics ◽

10.21662/uim2006.1.006 ◽

2006 ◽

Vol 4 ◽

pp. 68-72

Author(s):

A.G. Khakimov ◽

Z.Z Sharafutdinov

Keyword(s):

Mechanical Characteristics ◽

Drill String ◽

Modes Of Operation ◽

Deformed State

The paper gives a methodology for calculating the drill string performance under off-design conditions, including the passage through the interface separating rocks with very different physico-mechanical characteristics, drilling of boulder rocks, and dynamic modes of operation. One of the mechanisms of the destruction of drill string elements and roller cutters is revealed.

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Influence of the mechanical characteristics of an isotropic linearly elastic system on a deformed state of the system

Soviet Applied Mechanics ◽

10.1007/bf00883056 ◽

1975 ◽

Vol 11 (12) ◽

pp. 1331-1334

Author(s):

V. V. Repyakh

Keyword(s):

Mechanical Characteristics ◽

Elastic System ◽

Deformed State

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Complex dynamics of drill-strings: Theory and experiments

MATEC Web of Conferences ◽

10.1051/matecconf/201821101002 ◽

2018 ◽

Vol 211 ◽

pp. 01002

Author(s):

Marian Wiercigroch ◽

Marcin Kapitaniak ◽

Vahid Vaziri ◽

Krishnan Nandakumar

Keyword(s):

Mechanical Characteristics ◽

Complex Dynamics ◽

Drill String ◽

Drill Bit ◽

Stick Slip ◽

Drill Bits ◽

Low Dimensional ◽

The University ◽

Experimental Rig ◽

Theory And Experiments

We investigate complex drill-string dynamics in a downhole drilling where strong nonlinear interactions between various types of vibration take place. First, we present a low dimensional model of the downhole drilling where a drill-bit cutting a rock formation has a strong coupling between torsional and axial oscillations. The model can be used to study drilling stability as an example results are given. Then we introduce a new experimental rig developed by the Centre for Applied Dynamics Research at the University of Aberdeen, capable of reproducing all major types of drill-string vibration. One of the most important features of this versatile experimental rig is the fact that commercial drill-bits, employed in the drilling industry, and real rock-samples are used. The rig operate in different configurations, which enables the experimental study of various phenomena, such as stick-slip oscillations, whirling and drill-bit bounce. It also allows to determine mechanical characteristics of the drill-bits, which are used to calibrate mathematical models.

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Method of calculating the parameters of the scraper working equipment of the trench excavator based on critical deep blocked soil cutting

Gіrnichі budіvelnі dorozhnі ta melіorativnі mashini ◽

10.32347/gbdmm2020.96.0101 ◽

2020 ◽

pp. 5-12

Author(s):

Sviatoslav Kravets ◽

Oleksandr Lukyanchuk ◽

Vladimir Suponyev ◽

Olexey Gaponov

Keyword(s):

Energy Efficient ◽

Energy Intensity ◽

Mechanical Characteristics ◽

Cutting Speed ◽

Critical Depth ◽

Modes Of Operation ◽

Increase Productivity ◽

Soil Cutting ◽

Selection Of ◽

Physical And Mechanical Characteristics

The article presents a method of calculating the parameters of the scraper working equipment of a trench excavator that performs critical depth cutting: critical depth for its cutters, number of cutting lines, pitch of cutters, height of scrapers, cutting speed, working speed, length of plowshares of cutters, necessary effort of cutting of soil, power to drive the working equipment and movement, power selection of the base machine. Methodology/approach. To solve these problems, analytical methods were used to study the parameters of multi-scraper excavators that perform critical depth cutting of soils. Findings. The developed technique allows to create energy-efficient working equipment and to determine its critical-depth modes of operation, which make it possible to increase productivity and reduce the energy consumption of multi-scraper chain trench excavators that carry out blocked cutting of soils. Research limitations/implication. The initial data for the calculation are: the width of the cutters, their cutting angle, the maximum depth of the trench, the width of the trench, the physical and mechanical characteristics of the soil. Originality/value. Managed to achieve the prerequisites for reducing the energy intensity of soil development scraper chain excavators based on critical depth cutting of soils.

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