DTHDTH
Hammer Hammer
DrillingDrilling
IntroductionIntroduction
A type of DTH hammer was patented in the US
by Royal Lee of Lee Engineering Research Company,
Milwaukee, Wisconsin.
DTH Hammer History
1928
DTH Hammer History
1954
Andre Stenuik in Belgium applied for a patent in London.
This DTH hammer is considered to be the fore-father
for the modern DTH hammer.
DTH Hammer History
1960
Several different DTH Hammer designs were
launched during this period by companies such as
Mission, Halco, Ingersoll Rand,
Atlas Copco, and Bohler & Co.
The basic design of DTH hammers has not changed much.
But operating air pressures have more than doubled…
150 psi (10 bar) to 350 psi (24 bar).
DTH Hammer History
1970
DTH Hammer History
1990
In addition to the air pressures more than doubling
so to has the number of DTH hammer manufacturers.
To stay ahead of the pack, Mission launches the
XL generation of hammers.
Mirror Impact TechnologyDeveloped by Rainer Beccu PhD.
at SRT Houston Facility
In 2000 Driltech Mission introduced the
DTH Hammer History
1999
DTH Hammer History
2003
500 psi air compressors are now entering the market
and one of our challenges is to develop tools to
withstand these pressures.
Drilling Methods and Applications
130 ft.40 M
12,000 ft.4,000 M
32000 ft.10,000 M
1 2 3 4 5 6 8 12 15 17.5 24 33 43
HOLE DIAMETER IN INCHES
Hard Rock
Hard Rock
Hard Rock
Soft Rock
Soft Rock
Soft Rock
DTH Hammer Drilling
Rotary Drilling
Top Hammer Drilling
Surface Mining
Construction
Mineral Exploration
Oil & Gas
Underground Mining
Waterwell
25 51 76 102 127 152 203 304 381 444 610 8381092
DTH and Top Hammer
Uniform penetration rate
Can drill to greater depths
Generally straighter holes
Safer in broken ground
Lower noise level
Longer drill string life
DTH
Top Hammer
20 kW
18.4
16.9
15.6
14.4
20 kW
20
20
20
20
8% loss / coupling
DTH and Rotary Drilling
• Faster drilling in hard rock
• Lower capital cost
• Capable of large diameters
• Minimum hole deviation
• Lighter drill pipe
• Lighter rig
• Less torque and pulldown
DTH
ff
PSIPSI
RotaryFFPSIPSI
Pressure – Penetration Rate
15 m /hr50 ft /hr
30 m /hr100 ft /hr
45 m /hr150 ft /hr
150 PSI 250 PSI 350 PSI
Each time the Mission 6 piston hits the bit, it is the same as being dropped 16 feet.
16 Ft. (4.9m)
40 lb. (18kg)
876 ft.lbs. (1187Nm)
Load On Bit At Impact
Piston traveling at ……..38 ft/sec (11.5 m/sec)
Blow Energy……………..876 ft.lb. (1187 Joules)(Nm)
Time of Impact is approximately only …..
0.0002 SecondsWhich is approximately the time it takes the shock wave to go to the top of the piston and back.Decelerating the piston so fast results in huge impact loads on top of the bit.
What is Important in the Drilling System
What is important in the drilling system Compressor
Air Delivery Volume CFM Maximum Operating PressureGenerally the compressor
should be sized for economical operation when drilling a particular hole size.
A larger compressor will only give better performance if the hammer can use this air efficiently
What is Important in the Drilling System Hammer
Air Consumption Maximum Operating Pressure Generally the hammer should
be selected so that all the air from the compressor is used while still maintaining the highest air pressure possible.
This will use the capacity of the compressor to it’s maximum
What is Important in the Drilling System Rig
Rod Length Control of Weight on Bit Rotary Speed
Drill Rigs can be very sophisticated but their efficiency can be greatly affected by hammer and bit selection
Their biggest contribution to productivity comes from other areas such as rod handling, set up time and ease of operation.
What Features Most AffectHammer Performance
1. Suitable compressor (flow give pressure)
2. Piston diameter
3. Piston impact energy and frequency
4. Piston & Bit energy transfer
5. Correct diameter of drill pipe
Comparing Hammers
ProductivityPenetration rateReliability
Hammer life
Hammer cost per meter
Total Drilling Cost per meter
DT
H C
ost Calculator.xls
Matching Titon & Mission
Drilling Parameters1. Rock Type
2. Feed Pressure
3. Rotation Speed
4. Flushing
5. Air pressure
Characteristics of the rock to be drilled
namely :-
- DRI – Drilling Rate Index
- Compressive strength
- Silica Content
- Competency – solid, broken, faulted
Rock Type
Drilling Rate Index
Most accurate means of comparing rock drillability
for percussive drilling.
Considers brittleness of rock.
More accurate than using crushing strength (UCS).
High DRI = Easy to drill Low DRI = Hard to drill
Rock is the leading cause of Hammer & Bit problems
Rock Type
ANORTHOSITE GRANITE GNEISS
AMPHIBOLITE
MICA GNEISS
QUARTZITE LIMESTONE MARBLE
DIABASE PHYLLITE
SANDSTONE PEGMATITE
DIORITE
GABRO SLATE SHALE
MONTSONITE
GREYWACKE NORITE
GNEISS GRANITE MICA SCHIST
GNEISS
TACONITE GRANITE
Drilling Rate Index
10 20 30 40 50 60 70 80 90
Location Alachua Tamrock testmine, Finland
Rock Type Texas PinkGranite
MyllypuroGranodiorite
Drilling Rate Index 49 43Cerchar Abrasivity Index, CAI 6.0 6.0Vickers Hardness Number,VHNR
821 820
Density (g/cm3) 2.59 2.65Brittleness Value, S 20 53 41Sievers J value, SJ 6.2 12.0
For example a Mission6 hammer tested in Alachua at 350psi (24bar) anda 6-1/2” (165mm) bit would drill at 192 ft/hr (58.5m/hr). In the Tamrock TestMine we could expect a penetration rate of:-192 ft/hr * (49/43) .8 = 175 ft/hr58.5 m/hr * (49/43) .8 = 53.3 m/hr
For further reference to these numbers see pages 10-17 of Tamrock’sUnderground drilling handbook.
Drilling Rate Index
Penetration Rate vs. Bit Diameter
Rate of Penetration "A" = ROP "B" x
Dia. "B”
( )Dia. “B”
= 126.8 feet/hr.
( )
3
3
Penetration rates for different bit diameters may be calculated using the following formula.
Assume:
Dia. “B” = 6.5”Dia. “A” = 6.125”
ROP “A” = 116 x 6.66.125
Bit Dia vs ROP Calculator.xls
-Compressive Strength 12,000 – 60,000 psiUsually called “hardness”
-Tensile Strength indicates brittlenessNot normally considered except where rock is reluctant to break apart such
as a recrystallyzed shale
-Silica Content – 0% - 100%A higher silica content the faster the carbide and steel wear
-Competency – solid, broken, faultedBroken & Faulted tends to ‘lead’ the drill string and cause “I’m Stuck” and
“The bit just shanked”
Rock Type
COMPRESSIVE STRENGTHSof
COMMON ROCK TYPESDiorite
Gabbro
Gniess
Granite
Limestone
Marble
Quartzite
Sandstone
Slate
Shale
Taconite
psi '000 10 20 30 40 50 60
mPa 69 138 207 276 345 414
Diorite
Gabbro
Gniess
Granite
Limestone
Marble
Quartzite
Sandstone
Slate
Shale
Taconite
% Silica 10 20 30 40 50 60 70 80 90 100
AVERAGE SILICA CONTENTSof
COMMON ROCK TYPES
GOLDEN RULE OF THUMB
HARDER ROCK requires more impact
energy and higher torque
SOFTER ROCK requires higher feed rates
and better flushing
MORE ABRASIVE ROCK requires
more consumables $$
FeedPressure
Feed Pressure
Keeping the bit closed against the driver sub to transfer most energy
Influenced by - Operating Air pressure
-Rock type
Also known as Hold Down or Pull Down
Feed PressureInsufficient Weight on Bit
Unable to Hold Constant Air PressureRattling or Erratic DrillingDrop in Rate of PenetrationDamage to Bit and Hammer
Excessive weight on bit:Does Not Increase Penetration RateAccelerates Bit WearRaises Rotation Motor LoadCan cause deviation in hole
Weight on Bit needs to be monitored and adjusted by the Driller
RotationSpeed
The distance the buttons on the bit are moved
between each blow of the piston. The optimum
distance generates the biggest chips or cuttings
and gives the most efficient drilling.
Affected by :-
-Rock Type
-Air Pressure (piston blow energy)
-Bit Design (face shape & button size)
Rotation Speed
Rotation Speed
Approximate Blows per Minute
at Maximum Operation Conditions
Pressure Blows Per
Hammer (PSIG) Minute
M30 300 2375
M40B 350 2000
M50/55 350 1920
SD-6 350 1520
M60/M65 350 1890
SD-8 350 1589
SD-10 250 1335
SD-12 250 1501
Rotation Formula:
RPM = PM x f
D x 3.1416 (
PM = Peripheral Movement (mm)F = Piston FrequencyD = Bit Diameter (mm)
PM must vary according to the formation being drilled and design of bit.The harder and more mineralized the rock, the smaller the value of PM.Example:
165 mm (6-1/2”) bitM65 @ 350 psi - 1890 BPM35000 psi (250MPa) Granite - PM = 8 mm
RPM = 29 RPM ORRotation Calculator.xls
Rotation Speed
Adjust rotation speed so
the RIG doesn’t shake, rattle and roll,
the cuttings are as big as possible
and
rotation is not jerky
Flushing
Getting cuttings out of the hole…..
Affected by
-Annulus size
-Bit design
-Hole depth
-Water in the hole
Flushing
Recommended minimum
up-hole velocity
is
5,000-7,000 ft/minute
(25-35 m/s)
Flushing
Where AA is the annular area = .785 x (Dh2 – Dp2)
Annular velocity should be 5,000 Ft/Min or more.
Excessive annular velocity accelerates wear. To calculate annular velocity, use this formula:
Annular Velocity = SCFM x 144 (Ft/Min)AA
Dh = Hole Diameter (inches)Dp = Drill Pipe Diameter (inches)
Velocity Calculator.xls
Make sure that you’ve got
cuttings coming out of the hole
while you’re drilling.
Otherwise…..
Flushing
YOUR STUCK !!
Just like a gardener,you planted your hammer and bit!
Water InjectionAdvantages Reduce Dust Reduce Operating Temperature Stabilize Hole Wall Better Control Cuttings Removal
Disadvantages May Increase Need for Oil Injection Can Cause Corrosion May Cause Solid Contamination
FoamAdvantages
Improves flushing Dissipates water (aerates) Stabilizes hole Reduces annular velocity requirements
Disadvantages
Cannot use oil injection – kill foam Will Cause Corrosion – dissolves oil Solid Contamination Added Maintenance – strip hammer after use
November2003
April2001
May2003
Feb2000
June2004
Mission Hammer Introduction Schedule
New Shank New Shank
XL32 - December ‘98RC5 - December ‘00XL5.5 - December ‘02SD4 - December ‘02XL4 - December ‘02XL3 - March ’04XL5 - September ‘04SD5 - December ‘04XL6 - June ‘04XL8 - June ‘04SD6 - December ‘05SD8 - December ‘05SD10 - December ‘05SD12 - December ‘05XL12 - June ‘05
Obsolescence Schedule
HAMMERS OBSOLESCENCE SCHEDULE TO DECEMBER 2005
Item Jun '03 Sep '03 Dec '03 Mar '04 Jun '04 Sep '04 Dec '04 Mar '05 Jun '05 Sep '05 Dec '05XL3 Hammers Discontinued - upgrade to M30
Parts Parts built to customer order only DiscontinuedBits Bits remain available for customers using other hammers with IR3.5 Shank
Guide Devices Guide devices remain available for customers using other hammers with IR3.5 ShankSD4 Hammers Discontinued - upgrade to M40B
Parts Discontinued - upgrade to M40BBits Bits remain available for customers using other hammers with SD4 Shank
Guide Devices Guide devices remain available for customers using other hammers with SD4 ShankXL4 Hammers Discontinued - upgrade to M40B
Parts Discontinued - upgrade to M40BBits Discontinued - upgrade to M40B
Guide Devices Discontinued - upgrade to M40BSD5 Hammers Discontinued - upgrade to M50/M55
Parts
Bits Bits remain available for customers using other hammers with SD5 ShankGuide Devices Guide devices remain available for customers using other hammers with SD5 Shank
XL5 Hammers Discontinued - upgrade to M50/M55Parts Parts built to customer order only
Bits Bits built to customer order onlyGuide Devices Bits built to customer order only
XL5.5 Hammers Discontinued - upgrade to M50/M55Parts Discontinued - upgrade to M50/M55
Bits Discontinued - upgrade to M50/M55Guide Devices Discontinued - upgrade to M50/M55
SD6 Hammers Current Product - Only model available is 32-SD6/4Parts Current Product
Bits Current ProductGuide Devices Current Product
XL6 Hammers Only model available in 32-XL6HD/4C/BC Discontinued - upgrade to M60/M65Parts
Bits
Guide Devices
Parts
Bits Current ProductGuide Devices
Parts
Bits Current ProductGuide Devices
Parts Current ProductBits Current Product
Guide Devices
Parts
Bits Bits remain available for customers using other hammers with SD8 ShankGuide Devices
Parts Current ProductBits Current Product
Guide Devices
Parts Current ProductBits Current Product
Guide Devices
Parts
Bits
HAMMERS OBSOLESCENCE SCHEDULE TO DECEMBER 2005
Parts
Bits Bits remain available for customers using other hammers with IR3.5 ShankGuide Devices
Parts Discontinued - upgrade to M40BBits Bits remain available for customers using other hammers with SD4 Shank
Guide Devices
Parts Discontinued - upgrade to M40BBits Discontinued - upgrade to M40B
Guide Devices
Parts
Bits Bits remain available for customers using other hammers with SD5 ShankGuide Devices
Parts
Bits
Guide Devices
Parts Discontinued - upgrade to M50/M55Bits Discontinued - upgrade to M50/M55
Guide Devices
Parts Current ProductBits Current Product
Guide Devices Current ProductXL6 Hammers Only model available in 32-XL6HD/4C/BC Discontinued - upgrade to M60/M65
Parts Parts built to customer order only DiscontinuedBits Bits built to customer order only Discontinued
Guide Devices Bits built to customer order only DiscontinuedMission6 Hammers Discontinued - order new M60/M65 Hammer or upgrade with rebuild kit
Parts Rebuild kit only DiscontinuedBits Current Product
Guide Devices Current ProductMission6W Hammers Discontinued - order new M60/M60W Hammer or upgrade with rebuild kit
Parts Rebuild kit only DiscontinuedBits Current Product
Guide Devices Current ProductSD8 Hammers Current Product
Parts Current ProductBits Current Product
Guide Devices Current ProductXL8 Hammers Discontinued - upgrade to M85
Parts Parts built to customer order only DiscontinuedBits Bits remain available for customers using other hammers with SD8 Shank
Guide Devices Guide devices remain available for customers using other hammers with SD8 ShankSD10 Hammers Current Product
Parts Current ProductBits Current Product
Guide Devices Current ProductSD12 Hammers Current Product
Parts Current ProductBits Current Product
Guide Devices Current ProductXL12 Hammers Current Product Discontinued - Replace with SD12
Parts Current Product Parts built to customer order onlyBits Current Product Bits (IR112) built to customer order only
HAMMERS OBSOLESCENCE SCHEDULE TO DECEMBER 2005
Item Jun '03 Sep '03 Dec '03 Mar '04 Jun '04 Sep '04 Dec '04 Mar '05 Jun '05 Sep '05 Dec '05
What is
Mirror
Impact
Technology?
20 kg
20 kg
It is the optimumTransfer of Energy
“Too little” energyis not
productive
“Too much”energy
is wasted
“Just right” energyis optimum results
Imagine two balls on a snooker table
Heavy HeavyLight Light
Both balls continue Bounce back
Stop Continue
1.Top Sub
2. Piston Case
3. Feed Tube Assembly
4. Piston
5. Guide Sleeve
6. Bit Retainer
7. Driver Sub
8. Button Bit
Simple Design
1.
2.
3.
4.
5.6.
7.8.
Check valve
M65 Features & Benefits
Thicker Piston CaseM6 new diameter 5.75”M65 new diameter 5.9”
Results inLonger Wear Life
Longer Driver SubM6 = 1.5”
M65 = 2.5”Results in
Longer Wear Life
Plazma Nitride SurfaceResults in
Stronger Piston
Longer Top Sub andSmaller Wrench Flats
Results inLonger Wear Life
Choke in the Feed TubeSuits wider range of
compressor sizes
Hammer32-M65/04C
32 = Hammer
M30 = Mission30M40B = Mission40BM50 = Mission50M55 = Mission55M60 = Mission60M60W = Mission60WM65 = Mission65M80 = Mission80M85 = Mission85
Top Sub Configuration16 = 2-7/8 API04 = 3-1/2 API Reg55 = 3-1/2 Beco77 = Cubex Number 2419 = 4-1/2 API17 = Blank
C = Retrac Buttons
Hammer Part Numbers
Top Sub33-48001/16A
33 = Top Sub
48 = Mission40B Series58 = Mission 50 Series68 = Mission 60 Series88 = Mission 80 Series 001= Standard Duty
002= Heavy Duty
A = Assemblywith O-RingThread Type
16 = 2-7/8 API04 = 3-1/2 API55 = 3-1/2 Beco19 = 4-1/2 API77 = Cubex #2417 = Blank
Hammer Part Numbers
Piston Case35-48001A
35 = Piston Case
48 = Mission40B Series58 = Mission 50 Series68 = Mission 60 Series88 = Mission 80 Series
001= Standard Duty002= Heavy Duty
A = Assembly with Piston Retaining Ring
Hammer Part Numbers
Driver Sub34-48001A
34 = Driver Sub
48 = Mission40B Series58 = Mission 50 Series68 = Mission 60 Series88 = Mission 80 Series
001= Standard Duty002= Heavy Duty
A = Assembly with O-ringNew Mission Hammers being designed
without o-ring!
Hammer Part Numbers
Piston36-48081
36 = Piston
48 = Mission40B Series58 = Mission 50 Series68 = Mission 60 Series88 = Mission 80 Series
Heat Treatment Method041= Salt Bath Nitride081= Plazma Nitride
Hammer Part Numbers
Feed Tube37-48001A
37 = Feed Tube
48 = Mission40B Series58 = Mission 50 Series68 = Mission 60 Series88 = Mission 80 Series
001= Blast Hole301= Water Well
A = Assembly with Retaining Pin
Hammer Part Numbers
EZ Help Part Number Guide
32- Hammers
33- Top Subs
34- Driver Subs
35- Piston Cases
36- Pistons
37- Feed Tubes
38- Various minor parts
39- Check Valve Guides
42- Bits
47- Foot Valve
56- Tuning Ring
80- Guide Devices
81- Pilot Bits
82- Reamers
84- Casing Shoes