DRILLING JARS

DRILLING JARS
Drilling Jars

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Performance tools for all
drilling applications
Robust tools for challenging
drilling conditions
Enhancement tools for
complex drilling
Industry leading tools for all
downhole complications
Effective tools for well
restoration and enhancement
Effective tools to bring the well
on line and manage production
Make-up and break-out tools for
efficient maintenance
Rugged testing equipment to
measure tool performance
Utilized to maintain your
downhole tools
Sharing knowledge of our tools
Minimizing risk for ultimate
dependability
Service support to ensure
client confidence
NOV Downhole is the largest independent downhole tool and equipment provider in the
world. We operate over 50 service facilities in 16 countries, delivering solutions, service,
and expertise globally.
We design, manufacture, and service the complete bottom hole assembly. In short, we
provide end-to-end solutions to meet all of your downhole needs.
With more than 450,000 square feet of manufacturing facilities and a highly skilled
and growing workforce, NOV Downhole has the capacity to produce and support the
industry’s leading selection of tools; furthermore, we have the ability to work with our
customers to design and develop their own proprietary technologies.
We take pride in our reliability and the peace of mind we bring to our customers. Our
global reach, vast range of tools, and experienced personnel enable us to support our
customers for all downhole applications.

DRILLING JARS
Creating Impact Forces to Free a Stuck Drillstring
When planning a drilling program, one must factor in the possibly of the drillstring becoming stuck. This unpredictable
event can be mitigated by placing a drilling jar in the bottom hole assembly (BHA). A drilling jar is used to create an impact
and impulse force to jar free a stuck drillstring. This is achieved by the conversion of strain energy into kinetic energy which
accelerates the “hammer” to collide with the “anvil” to create a tremendous blow.
NOV Downhole provides the most versatile range of drilling jars for drilling straight, directional, horizontal, or extended
reach wells.
NOV Downhole DrillPro and DrillTough Drilling Jars provide consistent and reliable jarring performance for extended
periods of time regardless of the bottom hole environment. Engineered with high tensile and torsional strengths, specific
types of hydraulic delay metering systems, and mechanical mandrel latches, our drilling jars can be placed in the BHA in
tension, neutral, or compression.
Hydraulic / Mechanical Drilling Jar
Combines the characteristics of
both a hydraulic upstroke jar and a
mechanical downstroke jar; features a
mechanical latch
Ideal for virtually all drilling operations
Double Acting Hydraulic/
Mechanical Drilling Jar
Hydraulic upstroke and
downstroke jar featuring a
mechanical latch
Ideal for running in the lower
BHA in compression or in the
upper BHA in tension
Build a BHA
Consider these additional products from NOV Downhole when making your equipment decisions:
Drill Bits
Drilling Motors
Reamers
Shock Tools
Non-Magnetic Drilling Tools
Stabilizers
PowerStroke Drilling Jar
Pure hydraulic upstroke and
downstroke jar; creating infinitely
variable impacts
Ideal for directional, horizontal,
and extended reach drilling
Drilling Collars
Drilling Jar Intensifiers
Drillpipe
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Hydraulic / Mechanical Drilling Jar
The NOV Downhole DrillPro Hydraulic / Mechanical Drilling Jar (HMJ) is well suited for virtually all drilling conditions. The HMJ is
engineered to overcome the limitations associated with pure hydraulic or mechanical jars, yet retain the advantages of both types.
The DrillPro HMJ is a hydraulic delay upstroke jar and mechanical downstroke jar featuring a mechanical latch which holds the
mandrel in place during tripping and drilling operations.
To jar upward, overpull is applied to the drillstring until the preset mechanical latch setting is overcome allowing the jar to enter into
the hydraulic delay sequence. The desired overpull, above free string weight, is taken up as the jar opens slowly under hydraulic
restriction (delay) after which the jar enters the free stroke and the mandrel accelerates to the fully extended position creating
the upward jarring impact. Lowering the drillstring resets the latch making the HMJ ready for another jarring cycle or to resume
drilling operations.
To jar down, the drillstring is lowered until the compressive force applied exceeds the present mechanical latch setting. Once the
latch releases, the mandrel accelerates to the fully closed position to create the downward jarring impact. Raising the drillstring until
free movement stops indicates the latch has reset and the HMJ is prepared to jar again or to continue drilling operations.
Features
Hydraulic delay upstroke jar and mechanical downstroke jar
Mechanical latch – adjustable release settings
Jet type metering device for the hydraulic delay
Jar placement can be in tension, neutral, or compression
Hydraulic/Mechanical Drilling Jars
Benefits
Outside Diameter inches 4-3/4 6-1/4 6-1/2 6-3/4 7 8 9 9-1/2
(mm) (121) (159) (165) (171) (178) (203) (229) (241)
Inside Diameter inches 2-1/4 2-1/4 2-3/4 2-1/2 2-1/2 2-13/16 2-13/16 2-13/16
(mm) (57) (57) (70) (64) (64) (71) (71) (71)
Assembly Number 380 447 474 340 450 336-20 354 381
Maximum Hole Diameter* inches 7-7/8 9-7/8 12-1/4 12-1/4 12-1/4 17-1/2 26 26
(mm) (200) (251) (311) (311) (311) (445) (660) (660)
Maximum Jar Load [Up/Down lbf 75,000 160,000 180,000 190,000 190,000 220,000 250,000 250,000
(N) (333,600) (711,700) (800,600) (845,100) (845,100) (978,600) (1,112,000) (1,112,000)
Tensile Yield Strength lbf 354,000 755,000 865,000 828,000 828,000 965,000 1,225,000 1,225,000
(N) (1,574,600) (3,358,400) (3,847,700) (3,683,100) (3,683,100) (4,292,500) (5,449,000) (5,449,000)
Torsional Yield Strength** lbf-ft 16,000 41,000 41,000 40,000 40,000 68,000 110,000 112,000
(N-m) (21,600) (55,500) (55,500) (54,200) (54,200) (92,100) (149,100) (151,800)
Total Stroke inches 12 15 16 15 15 14 15 15
(mm) (292) (381) (406) (381) (381) (366) (381) (381)
Up Latch Setting, Standard lbf 40,000 90,000 90,000 90,000 90,000 95,000 100,000 100,000
(N) (177,900) (400,300) (400,300) (400,300) (400,300) (422,500) (444,800) (444,800)
Maximum lbf 55,000 140,000 140,000 140,000 140,000 150,000 155,000 155,000
(N) (244,600) (622,700) (622,700) (622,700) (622,700) (667,200) (689,400) (689,400)
Down Latch Setting, Standard*** lbf 18,000 40,500 40,500 40,500 40,500 42,750 45,000 45,000
(N) (80,000) (180,100) (180,100) (180,100) (180,100) (190,100) (200,100) (200,100)
Maximum lbf 24,750 63,000 63,000 63,000 63,000 67,500 69,750 69,750
(N) (110,000) (280,200) (280,200) (280,200) (280,200) (300,200) (310,200) (310,200)
Pump Open Area in² 6.5 9.6 11.0 11.0 11.0 14.2 15.9 15.9
(mm²) (4,200) (6,200) (7,100) (7,100) (7,100) (9,170) (10,260) (10,260)
Length [Latched Position] feet 12.7 16.3 18.5 15.0 15.0 15.5 15.0 15.0
(m) (3.9) (5.0) (5.6) (4.6) (4.6) (4.7) (4.6) (4.6)
Weight lb 0550 1,300 1,500 1,400 1,600 2,200 2,700 3,000
(kg) (250) (590) (690) (640) (730) (1,000) (1,300) (1,400)
* Hole openers not recommend
** Torsional Yeild Strength rating is based on the yeild of the body connections independent of tool joint connections
*** Down Latch Setting is 45% + or - 5% of the Up Latch Setting
Simple to operate; requires no torque application
in the jarring procedure
No unexpected jarring while making connections
or drilling
Continuous and consistent jarring performance

DRILLING JARS
Double-Acting Hydraulic/Mechanical Drilling Jar
The NOV Downhole DrillTough Double-Acting Hydraulic / Mechanical Drilling Jar is a hydraulic delay upstroke and downstroke
jar featuring a mechanical latch making it a versatile drilling jar for complex drilling programs.
The DrillPro Double-Acting HMJ is similar to the HMJ in design and operation; however, it has the benefit of a hydraulic delay
downstroke jar making it effective for directional, horizontal, and extended reach drilling. This jar is ideal for compression
placement in the drillstring because there is no “bleed through” operation required when tagging or picking up off bottom.
Features
Hydraulic delay upstroke jar and mechanical
downstroke jar
Mechanical latch – adjustable release settings
Jet type metering device for the hydraulic delay
Jar placement can be in tension, neutral, or
compression
Double-Acting Hydraulic/Mechanical Drilling Jars
Benefits
Outside Diameter inches 4-3/4 6-1/4 6-1/2 6-3/4 7 8 9-1/2
(mm) (121) (159) (165) (171) (178) (203) (241)
Inside Diameter inches 2-1/4 2-1/4 2-1/4 2-1/2 2-1/2 2-13/16 3
(mm) (57) (57) (57) (64) (64) (71) (76)
Assembly Number 431 442 428 440 480 411 437
Maximum Recommended Hole Diameter* inches 7-7/8 12-1/4 12-1/4 12-1/4 12-1/4 17-1/2 26
(mm) (200) (311) (311) (311) (311) (445) (660)
Maximum Jar Load [Up/Down] lbf 84,000 160,000 160,000 190,000 190,000 300,000 350,000
(N) (373,600) (711,700) (711,700) (845,100) (845,100) (1,334,400) (1,556,800)
Tensile Yield Strength lbf 362,000 755,000 755,000 823,000 1,000,000 1,000,000 1,225,000
(N) (1,610,300) (3,358,400) (3,358,400) (3,660,900) (4,448,200) (4,448,200) (5,449,100)
Torsional Yield Strength** lbf-ft 11,500 37,500 37,500 44,500 70,000 73,500 95,000
(N-m) (15,500) (50,800) (50,800) (60,300) (94,900) (99,600) (128,800)
Total Stroke inches 19 22 22 20 20 21 21
(mm) (470) (546) (546) (518) (518) (533) (533)
Up Latch Setting Standard lbf 40,000 90,000 90,000 90,000 90,000 95,000 100,000
(N) (177,900) (400,300) (400,300) (400,300) (400,300) (422,500) (444,800)
Maximum lbf 55,000 140,000 140,000 140,000 140,000 150,000 155,000
(N) (244,600) (622,700) (622,700) (622,700) (622,700) (667,200) (689,400)
Down Latch Setting*** Standard lbf 18,000 40,500 40,500 40,500 40,500 42,800 45,000
(N) (80,000) (180,100) (180,100) (180,100) (180,100) (190,300) (200,100)
Maximum lbf 27,000 63,000 63,000 63,000 63,000 67,500 69,800
(N) (120,100) (280,200) (280,200) (280,200) (280,200) (300,200) (310,400)
Pump Open Area in² 6.5 9.6 9.6 11.0 11.0 14.2 15.9
(mm²) (4,200) (6,200) (6,200) (7,100) (7,100) (9,170) (10,260)
Length [Latched Position] feet 19.8 22.5 22.5 23.0 23.0 22.5 23.0
(m) (6.0) (6.9) (6.9) (7.0) (7.0) (6.9) (7.0)
Weight lb 850 2,000 2,100 2,300 2,500 3,100 5,200
(kg) (390) (910) (960) (1,100) (1,200) (1,500) (2,400)
* Hole openers not recommend
** Torsional Yeild Strength rating is based on the yeild of the body connections independent of tool joint connections
*** Down Latch Setting is 45% of the Up Latch Setting and a tolerance of -+5
Simple to operate; requires no torque application
in the jarring procedure
No unexpected jarring while making connections
or drilling
Continuous and consistent jarring performance
Effective in high friction directional, horizontal, or
extended reach wells
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PowerStroke Drilling Jar
The DrillTough Powerstroke Drilling Jar has raised the industry standard for drilling jars. The PowerStroke is a double
acting hydraulic jar with infinitely variable trip loads up to the maximum rating of the tool. Only a minimal load
is required in both the up and down jarring directions, which is crucial when drilling directional, horizontal, and
extended reach wellbores. Every aspect of its rugged design is engineered to withstand the rigors and long hours of
today’s demanding drilling and fishing operations.
The DrillTough PowerStroke has an extra long stroke to allow the operator to deliver exceptional impact and impulse
forces during jarring operations. Both the up and down impact surfaces are located internally to the PowerStroke,
and by isolating them from the wellbore fluid provides reliable and consistent operation.
The NOV Downhole DrillTough PowerStroke will satisfy all of your demanding drilling jar requirements, providing
control, power, and flexibility for extended drilling periods.
Features
Hydraulic delay upstroke and downstroke jar
Patented, self cleaning seal cone metering system
Exceptional tensile and torsional strength ratings
BHA placement – tension or compression
Large inner diameter
PowerStroke Drilling Jars
Benefits
Driller control - infinitely variable impact intensity
Continuous and consistent jarring performance
Creates superior jarring forces
Ideal for directional, horizontal, and extended reach drilling
Low pressure drop through the tool allows for high flowrates
Outside Diameter inches 3-1/8 3-3/8 4-3/4 6-1/4 6-1/2 6-3/4 7 7-3/4 8 9-1/2
(mm) (79) (86) (121) (159) (165) (171) (178) (197) (203) (241)
Inside Diameter inches 1-1/4 1-1/2 2-1/4 2-3/4 2-3/4 2-3/4 2-3/4 3-1/16 3-1/16 3-1/16
(mm) (32) (38) (57) (70) (70) (70) (70) (78) (78) (78)
Assembly Number 503734 504413 156353 155790 155790 503348 503348 156426 156426 504398
Maximum Jar Load lbf 50,000 50,000 90,000 170,000 170,000 230,000 230,000 300,000 300,000 550,000
[Up/Down] (N) (222,400) (222,400) (400,300) (756,100) (756,100) (1,023,000) (1,023,000) (1,334,400) (1,334,400) (2,446,500)
Tensile Yield Strength lbf 240,000 250,000 482,000 848,000 848,000 1,237,000 1,237,000 1,472,000 1,472,000 2,550,000
(N) (1,067,500) (1,112,000) (2,144,000) (3,772,000) (3,772,000) (5,502,400) (5,502,400) (6,547,700) (6,547,700) (11,342,900)
Torsional Yield Strength* lbf-ft 5,700 6,300 16,200 42,000 42,000 63,300 67,800 72,800 72,800 200,000
(N-m) (7,700) (8,500) (21,900) (56,900) (56,900) (85,800) (91,900) (98,700) (98,700) (271,100)
Total Stroke inches 24 24 24 28 28 28 28 30 30 30
(mm) (610) (610) (610) (711) (711) (711) (711) (762) (762) (762)
Pump Open Area in² 2.8 3.7 7.1 12.2 12.2 12.2 12.2 16.8 16.8 21.1
(mm²) (1,810) (2,390) (4,590) (7,880) (7,880) (7,880) (7,880) (10,840) (10,840) (13,620)
Length [Open Position] feet 30.5 30.5 30.0 32.0 32.0 32.0 32.0 33.0 33.0 33.0
(m) (9.3) (9.3) (9.1) (9.8) (9.8) (9.8) (9.8) (10.1) (10.1) (10.1)
Weight lb 550 630 1,500 2,400 2,500 2,800 3,000 4,500 4,800 6,000
(kg) (250) (290) (690) (1,100) (1,200) (1,300) (1,400) (2,100) (2,200) (2,800)
* Torsional Yeild Strength rating is based on the yeild of the body connections independent of tool joint connections

DRILLING RELIABILITY JARS
Drilling Jar Placement Program
The NOV Downhole Windows-based jar placement program determines the optimum jar placement in
the drillstring, as well as the effects of hole angle, hole curvature, and frictional drag. This successful field
proven placement program is suitable for straight, directional, and horizontal hole analysis.
The effectiveness of jarring depends not only on the jar design, but also on;
Placement of the jar in the drillstring
Drillstring design
Hole conditions
The difference in jar performance between proper and improper placement can be a factor of as much
of 4. Because the analysis of the mechanics of jarring is complex, a computer program is needed to
precisely determine optimum jar placement.
Stress Wave Theory
The energy for jarring comes from the spring effect of
the drillstring when it is either stretched or compressed.
When the jar trips, the sudden release of energy does not
instantaneously go to the stuck point. Rather, the energy
is transmitted by stress waves that travel at the speed of
sound in metal.
The Impact Impulse Factor
To be effective, the jarring force (impact load) must exceed
the sticking force. How far the stuck object moves depends
on the duration of the impact load. The combined effect of
impact load and duration is called impulse. Optimum jar
placement occurs with the largest impulse for an impact
load greater than the sticking force.
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Corporate
Headquarters
7909 Parkwood Circle Drive
Houston, Texas 77036
United States
Phone: 713 375 3700
Fax: 713 346 4560
California
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Bakersfield, California 93308
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Toll Free: 800 328 0038
Louisiana
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Bossier City, Louisiana 71111
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Phone: 318 747 4890
108 Nova Drive
Broussard, Louisiana 70518
United States
Phone: 337 839 2400
Toll Free: 800 585 5697
190 Thompson Road
Houma, Louisiana 70363
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New Mexico
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Farmington, New Mexico 87401
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Phone: 505 326 4303
North Dakota
3202 1st Avenue West
Williston, North Dakota 58801
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Phone: 701 774 0091
Oklahoma
3800 South Thomas Road
Oklahoma City, Oklahoma 73179
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Phone: 405 677 2484
Toll Free: 877 760 1711
Texas
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Alice, Texas 78332
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Kilgore, Texas 75662
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10720 West Interstate 20 East
Odessa, Texas 79765
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Phone: 432 563 1173
30444 Highway 59 South
Rosenberg, Texas 77471
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Phone: 281 341 5365
Toll Free: 800 248 8665
Utah
4971 South 4625 East
Vernal, Utah 84078
United States
Phone: 435 789 0670
West Virginia
Route 2 Murphy Run Road
Clarksburg, West Virginia 26301
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Phone: 304 622 4303
Wyoming
778 Circle Drive
Casper, Wyoming 82601
United States
Phone: 307 237 3100
Canada
Suite 1010, 540 5th Avenue SW
Calgary, Alberta T2P 0M2
Canada
Phone: 403 294 5748
93 Panteluk Street
Kensington Avenue North
Estevan, Saskatchewan S4A 2A6
Canada
Phone: 306 634 8828
Canada
11501 89th Avenue
Grande Prairie, Alberta T8V 5Z2
Canada
Phone: 780 532 8115
Toll Free: 866 782 5752
1505 4th Street
Nisku, Alberta T9E 7M9
Canada
Phone: 780 955 8828
China
No. 499 Danjiang Road
Tanggu, Tianjin 300451
China
Phone: 86 22 6061 9581/82/83
Germany
Im Bulloh 29
Lachendorf 29331
Germany
Phone: 49 5145 93952 0
Indonesia
Cilandak Commercial Estate, Unit 105
Jalan Raya Cilandak KKO
Jakarta 12560
Indonesia
Phone: 62 21 782 6088
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Manggar, Balikpapan 76166
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Phone: 62 542 722 114
Malaysia
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Mexico
Calle Laurel Lote 37 Manzana 19
Ciudad Industrial Bruno Pagliai
Veracruz, Veracruz CP 91697
México
Opening in 2008
United Arab Emirates
M13 plot 35, Mussafah Industrial Area
Abu Dhabi
United Arab Emirates
Phone: 971 2 554 8959
P. O. Box 61490
Plot S 50601 South Jebel Ali Free Zone
Jebel Ali Free Zone, Dubai
United Arab Emirates
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United Kingdom
Unit 10, Kirkton Avenue
Pitmedden Road Industrial Estate
Dyce, Aberdeen
Scotland, United Kingdom AB21 0BF
Phone: 44 1224 334800
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Rawmarsh Road
Rotherham, South Yorkshire S60 1RU
England, United Kingdom
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Russia
Shamotnaya Street 5
Podolsk, Moscow Region 142100
Russian Federation
Phone: 7 495 5425115
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Arabian Established for Trade
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New Khaldiya
Dammam, Saudi Arabia
Phone: 966 3 847 3930
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Al Lado del Lagobar
Ciudad Ojeda, Estado Zulia 4019
Venezuela
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www.nov.com
d o w n h o l e @ n o v . c o m
Manufacturing and
Engineering Centers
Barrio California
Ave San Martín de Porres Nº 150
Santa Cruz, Bolivia
Phone: 591 3 352 4107
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Broussard, Louisiana 70518
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Phone: 337 232 3475
Bay 20, 4216 54th Avenue SE
Calgary, Alberta T2C 2E3
Canada
Phone: 403 279 4040
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Edmonton, Alberta T6E 5N3
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Toll Free: 877 955 7311
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Houston, Texas 77032
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Phone: 281 272 7700
103 Guernsey Lane
Youngsville, Louisiana 70592
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Phone: 337 856 5300
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Holton Health Trading Estate
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Phone: 44 1202 631817
© 2008 National Oilwell Varco
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