3. Bumper Jars
• Release spear or overshot
• Jar down on fish
• Move work string approximately 20”
• Help get over fish
• Predetermined weight on Internal cutter
• Swage tool
5-15-2000 3
4. Lubricated/Mechanical Bumper Sub
• Use a lubricated bumper sub instead of a
mechanical bumper sub.
• More sealing elements, not as likely to
wash out.
• In hot holes, a mechanical bumper sub is
used, the heat will damage the packing
in lubricated ones.
5-15-2000 4
5. Operating Procedure
• Pick up to open stroke stretch string
• Drop string and catch abruptly
• Stop 6” from closing jar
• Spring downward; deliver a sharp blow
• Requires practice & finesse
5-15-2000 5
6. Pump Open Force
LUBRICATED BUMPER SUBS
80000
75000
70000
65000
60000
55000
50000
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
0 400 800 1200 1600 2000 2400
DIFFERENTIAL PRESSURE (psi)
PUMP OPEN FORCES (lbs.)
7 3/4” O.D.
6 1/2” O.D.
6 1/4” O.D.
4 3/4” O.D.
4 1/4” O.D.
3 3/4” O.D.
3 1/8” O.D.
2 1/4” O.D.
Pump pressure effects
cocking and down
jarring.
Reduce pump to idle
before attempting to
cork or jar down.
5-15-2000 6
7. Up Stroke Jar Types
• The two basic types of jars are mechanical and
hydraulic
• These terms refer to the method of tripping
the jar
• Hydraulic jars work by using a hydraulic fluid
cushion to delay the tripping of the jar
until the desired pull on the string is
achieved
5-15-2000 7
Shortcut (2) to Clip1.mpg.lnk
8. Hydraulic Jarring Operations
• The time delay is caused by trapped oil
slowing upward movement of the
mandrel.
• The hydraulic fluid is metered through
small jets until the mandrel enters
the large bore area, then the oil is
dumped rapidly causing the jar to fire
5-15-2000 8
9. HYDRAULIC FISHING JARS
Operating Principles
Hydraulic
Fluid
Large Bore Area Pressure Housing
5-15-2000 9
Pressure
Piston
Inner
Mandrel
10. HYDRAULIC FISHING JARS
Operating Principles
Large Bore Area Pressure Housing
Pressure
Piston
Inner
Mandrel
5-15-2000 10
11. Hydraulic Jarring Operations
• The stretch/ string produces stored energy
• When the jar trips, the energy is released
providing sudden impact
• Hydraulic jar firing delay is dependent on
pull load and time.
• A computer program is required to precisely
determine optimum jar placement
in deviated holes.
5-15-2000 11
Shortcut to Clip1.mpg.lnk
12. Hydraulic Oil Jars
Applications
• Used in vertical, directional and extended reach
wells with elevated torque and drag
• Used as lower tool when running tandem jars
• In any case with limited overpull capacity
5-15-2000 12
13. HYDRAULIC FISHING JARS
Advantages
• Variable Tripping Loads
• Unaffected by Torque
• Unaffected by Temperature
• Protected Seals & Impact Shoulders
• No Bleed-off
• Increased Overpull Limit
• Consistent Time Delay
Disadvantages
• Heat Energy Affects:
– Viscosity of the Fluid
– Decreases the Overpull Limits
– Seal Failures
5-15-2000 13
14. Pump Open Force
HYDRAULIC FISHING JARS
0 400 800 1200 1600 2000 2400
DIFFERENTIAL PRESSURE (psi)
80000
75000
70000
65000
60000
55000
50000
45000
40000
35000
30000
25000
20000
15000
10000
5000
0
5-15-2000 14
PUMP OPEN FORCES (lbs.)
7 3/4” O.D.
6 1/2” O.D.
6 1/4” O.D.
4 3/4” O.D.
4 1/4” O.D.
3 3/4” O.D.
3 1/8” O.D.
2 1/4” O.D.
1 13/16” O.D.
Pump pressure effects
cocking and down
jarring.
Reduce pump to idle
before attempting to
cork or jar down.
16. MECHANICAL DRILLING
JARS
Applications
• Vertical Wells
• Directional Wells with Less Than 30º Hole Angle
• Geothermal Wells
5-15-2000 16
17. Mechanical Jarring Operations
• Mechanical jars have a preset pull load
that causes the jar to trip
• They are dependent on pull load only
• Upper tool when running jars in tandem
5-15-2000 17
18. SLINGERS
Applications
Fishing Slingers
• Vertical and Directional Wells
• Horizontal Wells
• Very Deep Wells
• Very Shallow Wells
• Any Time Higher Impact Forces required
5-15-2000 18
19. Accelerator-Booster-Intensifier-Slinger
Applications
• Allows optimum jar placement
• Accelerates the BHA mass
• Protects the drill string and surface equipment
• Compensates for drag in high angle holes
• Compensates for insufficient stretch in shallow
holes
5-15-2000 19
21. Jarring Operations
• How long to jar? 4-5 hours w/no progress
• Got stuck coming up? Jar down
• Got stuck going down? Jar up
• Differentially stuck? Little effect
5-15-2000 21
22. Four Elements of Effective Jarring
In any jarring operation, make sure you have met each of the four elements or
you are not effectively jarring at the stuck point. This addresses the up-jar only.
1. Restricted Pull:
> Stuck situation
> Restricted Pull Device, i.e. Oil Jar
2. Multiplier: Drill Collars
> If you do not run drill collars or hevi-weight, the multiplier is less than 1
3. Transition Area:
> Change in mass from drill collars to tubing or D.P. can also be the
transition area.
> Jar Accelerator/Intensifier is the perfect transition area.
4. Stored Energy:
> Jar Accelerator/Intensifier
> Jarring work string
5-15-2000 22
23. Jarring While WO O
• Arrive on rig @ noon; 11-20-97
• Offshore from Cameron, Louisiana
• Stuck in 12-1/4² hole 9¢ off bottom @ 5949
• 13-3/8² casing set at 1500².
5-15-2000 23
24. Stuck B.H.A.
• 12-1/4² bit
• 8²O.D. mud motor
• Float sub
• 12² O.D. stabilizer
• C.D.R. tool
• M.W.D. drill collar
• Orientation sub
• Monel drill collar
• x-over sub
• two 6-1/8² drill collars
• 9-5/8² stabilizer
• 10 joints 4-1/2² hevi-weight drill pipe
• Daily drilling jars
• 20 more joints hevi-weight drill pipe
5-15-2000 24
25. Free point, Back-off & Jar
• Determined pipe is stuck at 2,000¢.
• Backed off at 1898¢, and POH
• TIH with jarring assembly
• Screw into fish
• Jar 4 hours with no results
5-15-2000 25
26. Running Free Pt. & Jar
• Ran free point again
• 50% free at 1930; 40% free at 2,000
• Continue to jar 4 more hours
• Ran free point again
• 60% free @ 1955; 40% free @ 2,000
5-15-2000 26
27. Jarring on Fish
• Continue to jar on fish 4 more hours
• Ran free point again; same results
• Fired string shot @ 1995 w/no results
• Made a back-off @ 1962 (2 joints) on
3rd. attempt
• Made wiper trip, screwed into fish
5-15-2000 27
28. Jarring on Fish
• Continue jarring on fish 6 hours
• Ran free point; stuck @ 2058, 50% free
with torque @ 2024
• Made a back-off with string shot @ 2024
(2 more joints)
• Made short trip, Circ. out, screw into fish
@ 2024
5-15-2000 28
29. Jarring on Fish
• Continue jarring on fish 4 more hours
• Ran free point; 50% free @ 2152
• Fired shot @ 2152 with no results
• Fired 2nd. shot @ 2118 with no results
• Fired 3rd. Shot and backed off @ 2118
(3 more joints)
5-15-2000 29
30. Jarring on Fish
• Made short trip, Circ. Out, screw into
fish @ 2118.
• Jar down on fish 4 hours
• Ran free point; 80% free @ 2218
• Made a back-off @ 2218 (3 more Jts.)
• Circ. Out & P.O.H.; recovered 10 Jts.
5-15-2000 30
31. Trip # 2 @ 5:00 a.m. 11-25-97
• Jarring assembly with new jars; Acc.
• Screw into fish @ 2218; jar 4 hours
• Ran free point; 60% free @ screw in point
• Jar down 4 hours
• Ran free point; 50% free w/torque @ 2284
5-15-2000 31
32. Jarring on Fish
• Made a back-off with string shot @2284
(2 more joints)
• Made short trip, Circ. Out, screw into
fish @ 2284
• Jar on fish 4 more hours
• Ran free point; 40% free @ 2316
5-15-2000 32
33. Jarring on Fish
• Continue jarring 6 hours while WOO
• Fired string shot @ 2284; no success
• Fired 2nd. Shot @ 2284; no success
• Fired 3rd. Shot @ 2252/ made a BO
• P.O.H. recovered 1 jt. 7 days jarring;
recovered 13 Jts. P. & A. well
5-15-2000 33
35. Fishing in Lateral Wells
Generally, you can use the same attachment
tools:overshots, spears screw in sub etc.
Success is determined by:
• Where to back-off
• In Jar placement
• String design
5-15-2000 35
36. Friction/ Inverted Strings
• Sliding friction drag is high in extended
reach wells.
• Inverted drill strings are used whereas
drill collars are kept in the vertical
section.
• Spiral weight drill pipe is used in the
angle building section/drill pipe is
used in horizontal section.
5-15-2000 36
37. Jarring Most Common
• Most fishing in lateral wells will be in the
jarring mode.
• Before a jarring operation is started, a free
point and back off must first be made.
• After locating the free point, study the well
plot checking for the true dog legs, then
decide the depth to back off that offers the
best chance of connecting to the fish.
5-15-2000 37
38. Tip on Torque Setting
• Rely on torque readings rather than
stretch.
• To take a torque reading, set the weight at
slightly less than the neutral weight.
• This tends to reduce hole drag around the
curve while rotating to get a torque
reading.
5-15-2000 38
39. Experience Counts
• Carefully work the torque down, one
round at the time, using a long snub
line, with a torque guage.
• Fire the shot on the run to prevent line
creeping.
• The process of getting a successful free
point and back off could take
several hours, so be patient.
5-15-2000 39
40. Do Not Be Discouraged
• When a string shot is fired, no effect
may be felt at the surface.
• Pull the WL out, to see if the shot fired
• Work pipe with torque until you get it
backed off or determine it won’t
• You may have to fire another shot using
a higher grains per foot shot.
5-15-2000 40
41. Example Job
• Given: 7-5/8² casing with 6-1/2² hole and
the B.H.A. is stuck at 8690 (60¢up from bit).
• Drill collars - No - Length - lb/ft
2 30 50
• The fish is differentially stuck.
• Where is the best place to back-off?
5-15-2000 41
43. Fishing String
Component No. Length (lb/ft)
drill pipe 33 30 13.30
intensifier
hevi - weight 12 30 25.30
jar
3-1/2 D.P. 1 30 13.30
bumper
3-1/2 cs hy. tbg. 1 30 9.3
5-3/4 o.s. (may use right hand wicker grapple) if
back reaming required.
5-15-2000 43
44. Tensile/ Torque/ 3-1/2² CS Hy. Tubing
• Tension yield for P110 x 9.3# is 285,000
• Max. torsional yield is 3,800 ft/lbs.
• Stiffness is called “section modulus”
• The higher this number, the stiffer the pipe
5-15-2000 44
46. Section Modulus/ DP verses Tubing
Stiffness of 3-1/2² x 13.30# DP is: 2.44
Stiffness of 3-1/2² x 9.3# Tbg. Is: 1.86
5-15-2000 46
.58
.58 2.44 = .2377 rounded to .24
Conclusion: The tubing is 24% more limber
47. One Jt. Tbg. In B.H.A.
Pull load (lb) = 100,000 Weight Jts. = 2 HWDP
% of peak 1 JT. 3-1/2 PH 4
impact No.
Length Impact Impulse
5 2 60 382,629 2,794
10 2 60 382,629 2,794
20 3 90 339,162 3,247
5-15-2000 47
48. One Jt. Tbg. In B.H.A.
Pull load (lb) = 60,000 Weight Jts. = 12 HWDP
% of peak 1 JT. 3-1/2 PH 4
impact
Pull Load Impact Impulse
5 60,000 274,604 8,435
10 60,000 274,604 8,435
20 60,000 274,604 8,435
By reducing the pull load from 100,000 to 60,000,
the impulse is greater.
5-15-2000 48
49. Top Fish Inside Casing
Pull load (lb) = 100,000 Weight Jts. = 2 HWDP
% of peak 8 Jts. Hevi-weight below jars
impact Pull Load
Impact Impulse
5 100,000 398,100 2,863
10 100,000 398,100 2,863
20 100,000 352,417 3,408
By leaving the top of fish inside the casing, the
possibility of connecting to it is retained, while the
impact is good using 8 joints of HW below the jars.
5-15-2000 49
50. Jars in Vertical Section
Pull load (lb) = 100,000 Weight Jts. = 2 HWDP
% of peak 23 Jts. Drill pipe below jars
impact Pull Load
Impact Impulse
5 100,000 152,053 1,087
10 100,000 152,053 1,087
20 100,000 134,081 1,150
Poor impact and impulse is the results of placing the
jars in the vertical section of the hole.
5-15-2000 50
