Rock penetration

1. 16/08/2022
Fundamentals
of Rock
Penetration
Agha S. M. Pathan
Drilling as a Process
• Rock Penetration
• First Operation
o Exploratory and/or development phase
• Unit Operation
o Production drilling
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Types (Modes of Energy Application)
• Mechanical: Percussion, rotary, rotary-percussion
• Thermal: Flame, plasma, hot fluid, freezing
• Hydraulic: Jet, erosion, cavitation
• Sonic: High frequency vibration
• Chemical: Micro blast, dissolution
• Electrical: Electric arc, magnetic induction
• Seismic: Laser ray
• Nuclear: Fusion, fission
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UNDERGROUND DRILL RIGS AND BOLTERS
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2. 16/08/2022
Surface DTH
Drill Rig
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Drill Rig is the drilling
equipment, either crawler
or wheel mounted; self-
propelled or towable. The
Rig Operator can
operate and control
drilling operation
Parameters.
Drilling in Mining
• In the context of Mining Engineering drilling refers to making holes into
a rock mass for various purposes, i. e. drilling shot holes for blasting,
sinking exploratory boreholes etc.
• Drilling is one of the primitive and common operations in rock
excavation industry, starting from exploration to exploitation.
• Rocks are drilled for several purposes, such as:
oGeological Exploration
oBlast Hole For Mineral Production
oRock Bolting
oRock Cores for Determining Geotechnical Parameters
oRock Excavation for Civil Construction.
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Drilling in Mining
• Bench Drilling
• Drilling for Drifting and Tunnelling
• Production Drilling
• Drilling for Raises
• Drilling Rocks with Overburden
• Rock Supports
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3. 16/08/2022
Classification of Drill Rigs
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• Assignment (as per previous slide)
Planning a Drilling Operation
• Following requirements are necessary for accomplishment of
a drilling process (Gokhale, 2003)
o The drilling bit meant for disintegrating the formation
must be sufficiently hard so that it can disintegrates the
formation for a longer period.
o The cuttings formed in the process of formation
disintegration must be taken out of the hole as soon as
possible. One should avoid crushing and grinding of the
drilled chips inside the hole.
o Drilling tool must be advanced in the intended direction
of the drilled hole.
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Planning a Drilling Operation (cont.)
o The hole walls must be competent to avoid collapsing and
blinding of the hole.
o After completing the drillhole the drilling components
and the drill should be removed from the place.
o The dust and noise generated during the drilling should
be contained as far as practicable.
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Rockmass Properties that Affect Drilling
Operations
1) Hardness
2) Strength
3) Elasticity
4) Plasticity
5) Abrasiveness
6) Texture
7) Structure
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4. 16/08/2022
Drilling Mechanism
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Modes of Fragmentation
• The drilling process involves three forms of energy while
penetrating any rockmass:
A. Mechanical
Crushing, Impact Crushing and Scratching
B. Thermal
Spalling, Fusion and Vaporization
C. Chemical
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Fragmentation under Mechanical Energy
1) Crushing
Rotary only
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Fragmentation under
Mechanical Energy
2) Impact Crushing
Percussion and Rotary percussion
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5. 16/08/2022
Fragmentation under Mechanical Energy
3) Scratching
Rotary and
Rotary percussion
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Fragmentation under Thermal Energy
1) Spalling
> Different mineralogical compositions
> Coefficient of Thermal Expansion: Coefficient of Linear
Expansion (also superficial and cubical expansions)
2) Fusion and Vaporization
> Melting of low melting point mineral compositions
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Fragmentation under Chemical Energy
• Chemical reaction of some mineral compositions with
formation fluid (water) and/or drilling fluid.
• Solubility in water
• Reactivity with acidic water
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Assignment
• Types of Drill bits used in any mining project
for:
1) Exploratory drilling
2) Development drilling
3) Production drilling
Submission ends:
2nd Day of June, 2021
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