Quartz School for Well Site Supervisors
Schlumberger Private
Module – 11
Drilling Problems
& Solutions
Section – 3
Fishing Operations
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
1/87
Fishing Concepts
Fish
Any object dropped or stuck in a well that interferes with normal operations.
Schlumberger Private
Fishing Job
The operation of removing these objects – specialized field of expertise
• Open Hole
• Cased Hole
Fishing Tools
Specially designed tools for engaging down hole tubulars and recovering them to the
surface
Fishing Economics
Most effective way for determining optimum fishing time and cost
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
2/87
Optimum Fishing Time Calculator
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
3/87
Optimum Fishing Time Calculator
OFT (days)
1.9
Using the equation found from the trendline approximation relating OFT and Cost Ratio:
OPTIMUM FISHING TIME = 0.4003 x (COST RATIO)
Minimum OFT (days)
Maximum OFT (days)
0.0500
0.0450
Optimum
Fishing Time
0.0400
0.0350
Probability
100% confidence will
display a 10% default
range!
1.7
2.1
Schlumberger Private
The curve shows the
Optimum Fishing Time.
The red and yellow bars
display the range for
minimum and maximum
OFTs dependant on the
confidence level entered.
-0.7847
0.0300
0.0250
0.0200
0.0150
0.0100
0.0050
0.0000
0.0
0.5
1.0
1.5
2.0
2.5
Time (days)
3.0
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
3.5
4.0
4.5
4/87
Decision Tree Examples for Fishing Operations
RECOVERY: PROB. OF SUCCESS
FISHING COST FOR:
116.3 K
FISHING
= % SUCCES + % FAILURE
=
11.6 K +
306.2 K
=
317.8 K
NOT RECOVERY: PROB. OF SUCCESS
FISHING COST FOR:
= COSTO OF FISHING + SIDETRACK COST
= FISHING COST + SIDETRACK COST
74.9 K
Schlumberger Private
STUCK PIPE
ACUMM COST
10%
5 Days
90%
5 Days
340.2 K
SIDETRACK
= COSTO OF FISH + SIDETRACK PLUG AND TIME
224.0 K
CONCLUSION: SIDE TRACK
Plan after 5 days
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
5/87
Fishing Operations
PREVENTION is the first important step to avoid fishing jobs from happening.
“The most economical method of fishing is to develop a plan that precludes factors
and operations that may result in fishing”. C.S Adkins – Economics of Fishing
There is a set of fishing rules that apply every time:
• Get as much information as possible of well condition (status)
• BHA information (lengths, OD, ID, fishing neck, etc.)
• Casing (Depth, OD, ID, Weight)
• Open Hole (Size, depth)
• Well trajectory (surveys)
• Tight spots / Washout (Caliper log)
•
Sketches are very important - mean the success or failure of a job
• Not corrected by wireline measurement
• Two people should keep figures independent and compare periodically
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
6/87
Fishing Tools
•
•
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
Every well will dictate the tool, there is no one tool to cure all
Run fishing assembly at moderate speed
• Could cause lost circulation
• Might hit a tight place and become stuck
• When POOH don’t create a swabbing action
When washing over or washing down
• Be sure if you are getting enough cuttings out to offset the
amount you are washing. If you are not, then it is possible to
build a bridge above the tools and become stuck
7/87
Methods of Recovering Stuck Pipe
1.
Back off
Unscrew the pipe at a selected threaded joint above the stuck point using an explosive
run on wireline inside or outside the pipe.
“Back-Off” can be “electric” or “mechanic” depending on the procedure and tools used
•
•
•
•
Schlumberger Private
•
“Back-off” is performed if the fishing plan asks for screwing a tool or fishing
assembly into the thread of pipe or BHA component left stuck in the hole
Drill pipe, drill collars and other drilling tools generally have large coarse threads
that are more suitable for disconnection
“Back-off” on tubing is difficult because threads are generally fine and longer
A “string shot” (explosive cord wrapped around a steel bar) is used to loosen the
threads and sometimes it is sufficient to knock the pipe free
Additional “back-off” of sections of tubing strings left stuck inside casing can be
done with the assistance of special tools (Reversing Tool) connected to the tubing,
after the first mechanic disconnection (“blind back off”)
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
8/87
Methods of Fishing Stuck Pipe
•
Reversing Tool for Backing Off Tubulars
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
9/87
Methods of Recovering Stuck Pipe
2.
Chemical Cutters
•
•
•
•
Schlumberger Private
Use a radial jet of chemical solution (halogen fluoride)
propelled by an explosive that react with the steel and
cuts the tubular from inside. It is run with wire line and
positioned inside the pipe body.
More economical than the back off because it is faster!
Safe for rig personnel since no torque of the pipe is
necessary.
No flare or burn or swelling of the cut pipe, so it does not
need to be dressed before catching it on the outside with
an overshot or inside with a spear.
Requires 100 ft of clean fluid above tool when fish cut is
made for a better performance.
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
10/87
Chemical cutter effect
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
11/87
Methods of Recovering Stuck Pipe
Jet Cutter
•
End of pipe will be flared where the cut
is made which will need to be removed
Good when the well is to be abandoned
or when the cost does not allow for use
of the chemical cutter.
May cause damage to casing or an
adjacent string if the pipe is touching it
when the cut is made.
•
•
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
3.
12/87
Methods of Recovering Stuck Pipe
Effects of jet cutter
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
13/87
Methods of Recovering Stuck Pipe
4.
Mechanical Cutter
•
•
•
•
Schlumberger Private
Cut the pipe internally or externally using a tool equipped with a set
of knives and run on a small diameter / concentric work string
Not used very often since it is more economical to use wireline tools
than to run a string
Should only be used if other options are definitely not available
Most commonly used in work over operations
It can be run and operated with coiled tubing
Depending on the condition of the top of the cut pipe then a fishing
tool is selected.
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
14/87
Methods of Recovering Stuck Pipe
4. Mechanical Cutter - Internal and External Cutter
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
15/87
Methods of Recovering Stuck Pipe
4. Mechanical Cutter - Internal and External Cutter
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Anchor by slowly rotating to the right whilst
lowering the string.
• The Wiper blocks resist rotation.
• This in turn will move the slips into the engage
position, gently go down with draw-works line
while rotating at 10-20RPM and watching the
torque.
• Free rotation with little or no reverse torque
indicates that the cut is complete.
16/87
Methods of Recovering Stuck Pipe
5. External Catch Tools: Overshot
OVERSHOT 150 series
•
•
•
•
•
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
Probably used more than any other
fishing tool
The lower guide directs the fish into
the overshot
The internal grapple expands to allow
the fish to pass into it
When upward pull is exerted, the
grapple is contracted by the tapers of
the bowl and holds fish secure
A packer seals off outside of the fish
allowing circulation through it as long
as the internal diameter of the fish is
not blocked.
The tool can be released from the fish
by slacking off the string, followed by
right hand rotation
18/87
Methods of Recovering Stuck Pipe
5. External Catch Tools: Overshot
OVERSHOT 70 series
Schlumberger Private
• This short catch overshot releases in the same way as the
150 series overshot by firstly sharply bumping downward and
then turning with right hand rotation.
• The Short catch overshot (series 70) allows you to catch the
outside diameter of a tubular fish which has a SHORT
FISHNECK, for example a DP tool joint
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
19/87
Methods of Recovering Stuck Pipe
5. External Catch Tools: Die Collar
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Is used for fishing the outside of tubular at the last
attempt to latch onto a fish, when everything fails.
• When the Die collar is engaged onto the fish it is
very difficult to release because of the tool design
• Used when the outer diameter of the fish is not
known.
• When the die collar engages it cuts thread on the
outside diameter of the fish and does not
disconnect easily. It is recommended to run a
safety joint in order to disconnect drill string.
20/87
Methods of Recovering Stuck Pipe
6. Internal Catch Tools: Spear
Schlumberger Private
• Are used for catching the internal
diameter of a tubular fish.
• There are a several types of spear, two
standard are illustrated here:
• Shoulder type mandrel
• Flush type mandrel
• Should run with bumper sub
• Set with left-hand rotation
• Release with right-hand rotation
• The bite must first be broken by sharp
downwards movement of the string the
rotate to the right
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
21/87
Methods of Recovering Stuck Pipe
6. Internal Catch Tools: Taper Tap
Is used for engaging the internal diameter of the fish.
Is only used as a last resort.
Made of hardened steel like the die collar.
Run with safety joint to be able to disconnect the
fishing string
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
•
•
•
22/87
Other Fishing Procedures
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
7. Wire line recovering
Line is Parted
1. Rope Spears and Grabs
• The best tool for fishing parted wire line is
the rope spear.
• Use a stop plate sub, this tool will prevent
the wireline fish from getting wrapped
around you fishing assembly higher up
• Catch wireline near the top and have tension
the string regularly. Wireline is normally
more compacted near bottom
• Can be used up inside a washover assembly
23/87
Other Fishing Procedures
7. Wire line recovering
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
Line is Intact
1. Cable Guide Method (cut and strip)
• Choose for deep open hole situations or where radioactive
instrument is stuck
• Safest method
• Very high success ratio
• Cutting cable and stripping over is time consuming
24/87
Other Fishing Procedures
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
8. Loose Junk Recovery
• Tools or equipment accidentally
left in hole
• Broken off in the hole or
accidentally dropped
• Use Impression blocks – if it is
unknown what the fish is or
how it is positioned in the hole.
This will aid in visualization of
how the problem may be solved
to recover the fish.
26/87
Other Fishing Procedures
8. Loose Junk Recovery
1.
•
•
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
Magnets
Permanent Magnets
• Have circulating ports around their outer edge so that any fill
covering the junk maybe washed away
Electromagnets
• Run on a conductor line
• Can make quicker trips and have increased lifting power, they
cannot reach the fish if it is covered with debris.
Magnets will only pick up ferrous metal and cannot recover
brass, aluminum, carbide and stainless steel.
27/87
Other Fishing Procedures
8. Loose Junk Recovery
1.
Magnets (cont…)
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
28/87
Other Fishing Procedures
8. Loose Junk Recovery
2.
Junk Basket Core Type
•
Will circulate out fill and cut core in the formation
• Catchers break core off and retrieve it along with any junk
in the bottom of the hole
If the catchers snags on the junk and remains stationary the
finger will break off leaving additional junk in the hole
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
29/87
Other Fishing Procedures
8. Loose Junk Recovery
Reverse Circulation Basket
•
•
Used for recovering junk at the bottom of the hole
At the bottom of the body inside is a finger basket.
• Allows debris to pass one way
• Normal circulation can be used,
• When you are ready to fish a ball is dropped
and a sleeve is moved for change the flow.
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
3.
30/87
Other Fishing Procedures
8. Loose Junk Recovery
4.
Junk Sub or Boot Basket
•
•
•
•
Good for picking up relatively small junk such as
steel cuttings, carbide inserts bit teeth and ball
bearings
Run directly above a bit or junk mill
Can be run in tandem 2 or 3 above each if
necessary
Will only work with circulation running down the
string and up through the annulus
Junk basket collects loose junk in the basket due
to reduced annular velocity at the junk basket
opening.
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
•
31/87
Other Fishing Procedures
8. Loose Junk Recovery
5. Junk Mill
• Used for milling on junk for shortening tubular
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
32/87
Fish Milling Operations - Taper Mill & Pilot Mill
• Used for opening up a restriction in steel and also as a guide mill.
• Pilot mill used for milling thick wall tubular guided centrally by the
small pilot.
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
33/87
Skirted Mills
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Is used in milling over fish.
• Ideal in OH as the skirt acts as a very good
guide.
• Used in cased hole, the skirt protects the
inner wall of the casing.
34/87
Other Fishing Procedures
7. Washing Over the Fish - Shoes
• Wash over or Burn Shoe.
Schlumberger Private
• Used for washing and lightly
milling over fish that is stuck in
open hole or in the cased hole.
• Wave pattern type,Castle type,
etc. Depending of the leading
edge shape.
• The leading edge is made up of
crushed tungsten.
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
36/87
Other Fishing Tools - Coarse Thread Safety Joint
• Is used in Drilling, fishing and washover
strings whenever and wherever a
releasing safety connection is needed
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
37/87
Other Fishing Tools – Fishing Jars
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• The fishing jar is used in the fishing as a means if
jarring a tight fish free.
• The fishing jar is a single acting jar allowing you
only to jar upwards out of the hole
• This tool is approximately half the length of a
drilling jar
• Drilling jars are double acting and can be used
to jar up and jar down.
38/87
Other Fishing Tools – Bumper Sub
• For freeing mechanical stuck by jarring downwards.
• Installed in the drilling string or fishing string just
below the jar.
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
39/87
Other Fishing Tools – Impact String
W ork string
Ham m er weight
Schlumberger Private
Accelerator
drill collars
Hydraulic Fishing Jar
Bum per Sub
Fishing tool
Fish
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
40/87
Fishing Procedures - Weight Indicator Readings
Overpull Limit
Overpull
Schlumberger Private
Normal Pick-up Weight
Free Rotating Weight
Normal Set Down Weight
Set Down
Set Down Limit
Empty Block Weight
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
41/87
Fishing Procedures – Over Pull Limit
•
•
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
Determined by tensile strength of the drill pipe
Overpull limit calculation
1. Make a drawing and write the next data:
• Class
• Grade
• Length
• Diameter
• MW
• Weight
• Tensile resistance
2. Calculate the Buoyancy factor = 1 – (MW/Steel Density)
3. Calculate the Buoyancy weights for DC and HW
4. Calculate the Buoyancy weight for DP
42/87
Fishing Procedures – Over Pull Limit
5. Sum the weights from steps 4 and 5
W total = (WHW+WDC)+WDP1
6. Subtract the W total to the DP Tensile Strength
Schlumberger Private
Overpull Limit = DP1 Tensile Strength – W total
7. If there are more than one DP grade, then calculate the Buoyancy
Weight for DP2 and addition it to W Total calculated in step 5
8. Calculate the Overpull limit subtracting DP2 Tensile Strength.
9. The Overpull limit will be the minimum calculated
(Note: Sometimes, the limiting factor is the rig capacity).
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
43/87
Fishing Procedures – Over Pull Limit
Data:
DP2
HW
DC
Amount
Acum
Lenght Length
Description
[ft]
[ft]
Pin
Box
Weight [lb
/ ft]
1
8 1/2 ''
1
Barrena
0.82
0.82
4 1/2 Reg
90.00
2
8 3/8"
1
Estab
4.92
5.74
4 1/2 Reg Box
4 IF
90.00
3
6 1/2 ''
1
DC Corto
7.38
13.12
4 IF
4 IF
90.00
4
8 3/8"
1
Estab
4.92
18.04
4 IF
4 IF
90.00
5
6 1/2 ''
1
DC
29.53
47.57
4 IF
4 IF
90.00
6
8 3/8"
1
Estab
4.92
52.49
4 IF
4 IF
90.00
7
6 1/2 ''
5
DC
147.64
200.13
4 IF
4 IF
90.00
8
4 1/2 ''
3
HWDP
88.58
288.71
4 IF
4 IF
41.00
9
6 1/4 ''
1
Jar
32.81
321.52
4 IF
4 IF
41.00
10
4 1/2 ''
15
HWDP
442.91
764.44
4 IF
4 IF
41.00
11
4 1/2 ''
489
DP 4 1/2"
4,644
5,409
4 IF
4 IF
27.37
Schlumberger Private
DP1
Outside
Diameter
Item
[in]
Mud Weight: 13.74 ppg
DP grade E-75, Premium
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
44/87
Fishing Tool Shop
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
46/87
Fishing Tools
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
47/87
Fishing Tools
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
48/87
Logging Tools Fishing
Schlumberger Private
With the “Cut and Thread” Procedure
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
49/87
Step 1 – Hang Sheave in Derrick
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Try to hang sheave with fishing sling so
it will not interfere with the handling of
drillpipe
• Lower sheave must be moved away
from rotary to prevent interference with
rig floor operations and cable contact
with top drive
• Stay away from under sheave while
derrick man hangs it
50/87
Use Longest Links Available
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• 108” ones are standard; try to use 140” ones or
longer
• Inspect every 5,000’ and before going into
open hole for cable wear, damage of fishing
equipment, and tightness of fishing equipment
• If available, install roller assembly on top
drive to eliminate cable rubbing; If one is not
available, have rig make one
• Do not use the Varco Wireline Adapter
commonly known as “Bicycle Wheels”
51/87
Flexible Wire Rope Sinker Bar Assembly
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Use instead of rigid fishing
weights when possible on top
drive rigs
• The flexible weight passes
smoothly around the top drive
as the block is lowered
52/87
Tension Device
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Switch to TDK if using CMTD
(Prevents cable backlash)
• Compare TDK and CMTD
readings
so
that
fishing
operation is performed under
correct tension
• Do not pre-load lower sheave
with air hoist tension; Sheave
should hang freely until weight
is applied
53/87
Step 2 – Cut the Cable
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Pull 1,000 to 2,000 lbs over normal
tension and secure T-Bar cable clamp
to cable
• If hole is straight, cut cable 5 to 7 feet
above rotary table
• If hole is deviated, cut cable 10 feet
above rotary table plus 1 foot for every
1,000 feet greater than 10,000 feet
• Use proper size cable bushing in TBar and mark cable to ensure there is
no slippage
54/87
Rig Up Spearhead Overshot
• Use tapered cones from LEH-Q on top of
fishing weights
Schlumberger Private
• If available, use heavier-shorter fishing
weights with knuckle joints and swivel or
Wire Rope Weight with Swivel
• Minimum restrictions for all drilling
hardware (jars, drill collars, and heavy
weight) must be known to determine size of
overshot guide to use
• Always use the largest guide that will fit
through drilling hardware
• Never use “after-market” rope sockets
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
55/87
Rig Up Spear
235 ft-lbs and retightened every 5000
ft during drill pipe RIH.
A 160 lb person standing on a 1.5 ft long pipe wrench
while tightening will produce 240 ft-lbs of torque.
Jumping on the wrench will increase the torque.
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
56/87
Schlumberger Private
• Never use spears which contain “W’s” in
their work order numbers
• Always use Hexagon Adapter when
stripping over;
• Hexagon Adapter will stop on top of no-go if
dropped accidentally
• Only use plain adapter when drill pipe ID is
too small for Hexagon Adapter and switch
back to Hexagon Adapter as soon as drill
pipe ID permits
All connections should be tightened to
• Never use “after-market” rope sockets
Step 3 – Assemble Overshot
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Assemble 4-11/16” overshot, spiral type
grapple, and no-go (preferred method)
• If basket type grapple is used, assemble 5-3/4”
overshot, basket grapple, and no-go
• If fishing for AMS, use extensions to engage
below bottle-neck section and choose
appropriate guide shoe
• ALWAYS VISUALLY INSPECT grapple for proper
size for job and NEVER install a used grapple
57/87
Thread Cable Through Overshot
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Remove hex adapter, pass well end of cable through down hole
overshot and reinstall hex adapter
• Remember, 2 1/4” hex adapter will not pass through the smaller ID
no-go
58/87
Install Drain Sub
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Drain sub with blow out disk
aids in grapple cleaning and
prevents pulling wet drill pipe
after disk is blown
• Install above down hole
overshot assembly
• Commonly used in the US
59/87
Step 4 – Thread Through
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Slowly pull overshot
assembly to derrick man to
thread through bottom hole
assembly
• Make sure minimum
restrictions are known
60/87
Remove T-Bar
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Tighten overshot to bottom of
first stand of drill pipe
• Stab spearhead overshot, pull
cable tension, and remove Tbar cable clamp
• Remove IDW and position
spooling arm to one side
61/87
When Slips Are Set
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• After the slips are set, a floor hand
should position elevators away from
spearhead assembly until elevators are
clear of assembly. If not done, elevators
could catch hex adapter and cause
cable to break
• Afterwards, install C-plate, slack off
cable, and release overshot with
special tongs
62/87
Step 5 – Flag Line
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• After tripping in with drill collars,
jars, and heavy weights, flag line at
drum and bottom sheave with rags,
tape, paint, etc...
• When spearhead overshot is
positioned over drill pipe by the
derrick man
• Derrick man will thread overshot
assembly through drill pipe
63/87
Flag Line Again
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Flag line again at drum and
at the bottom sheave when
spear is stabbed in
spearhead overshot
64/87
Trip In Slowly
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Maintain Proper Cable Tension
(1,000 to 2,000 lbs plus normal)
• Pay particular attention to top
drive; If weights are in danger
of hitting top drive, slack off but
do so carefully
65/87
Step 6 – Rethread Overshot
• Pull overshot to derrick man who will
thread through another stand of drill pipe
(watch flag at at drum)
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
66/87
Stab Overshot
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Attach drain sub to second stand of
drill pipe
• Position pipe over spearhead overshot
and slack off until “the other flag ” on
the drum is reached
• Keep hands in safe position
67/87
Make Overshot Connection
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Make overshot connection, pull
enough tension to remove C-plate,
and adjust tension again to normal
plus 1,000 lbs to 2,000 lbs
• Re-tighten connections to 235 ft-lbs
every 5000 ft.
68/87
Step 7 – Make Up Drill pipe
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Drill pipe is made-up and
tightened
• Slips are pulled and the
descent begins
• Do not rotate pipe in hole
• Observe tension
69/87
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
70/87
Step 8 – Install Circulating Sub
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
71/87
Circulate One Stand Above Fish
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Cuttings and debris should be removed
from down hole overshot assembly by
circulation of mud at a one stand
maximum
• Only circulate long enough to ensure
grapple is clean
• Never circulate too long or too fast;
cable damage will occur
72/87
Engage Fish
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Maintain normal tension plus 1,000 to 2,000 lbs and approach fish
slowly;
• Observe tension and set at least 2,000 additional pounds on fish;
• Pull at least 2 joints of drill pipe (60’) and observe tension
• A minimum tension loss of 2,000 lbs should be observed to confirm
latch (a tension resulting in 0 after pulling pipe would be a definite
indication of engagement)
• Repeat this engagement procedure at least twice
• If tension does not decrease, the fish in not engaged
• DO NOT ROTATE PIPE AFTER ENGAGING FISH!!!
73/87
Step 9- Blow Drain Sub Disk
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Apply mud pump pressure to blow disk in sub
• Pump slug; especially for oil base mud
• (Do not trip out with oil base wet string; it’s
unsafe)
• Afterwards, repeat engagement process
before breaking weak point to make sure tool
was not blown out the overshot
74/87
Reconfirm Engagement
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Repeat engagement process at least twice to
ensure tool is still in down hole overshot
• Again, observe tension and set at least 2,000
additional pounds on fish;
• Pull at least 2 joints of drill pipe (60’) and observe
tension
• A minimum tension loss of 2,000 lbs should be
observed to confirm latch (a tension resulting in 0
after pulling pipe would be a definite indication of
engagement)
75/87
Break the Weak Point
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Install T-Bar and calculate cable
stretch required to break weak point
• (Depth) X (Stretch Coefficient)
• Move cable up and down within stretch
limit with block to work tension to
weak point
• Use block to break weak point and
record tension at which break occurs
• Make sure rig floor is clear and inspect
lower sheave chain
76/87
Step 10 – Install TIW Valve
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Install TIW valve before spooling cable
onto drum
• This could aid in controlling well if
trouble occurs
77/87
Tie Square Knot
• Cut off rope sockets on both well end and unit end of cable
• Tie square knot in cable, pull tight , and tape ends
Schlumberger Private
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
78/87
Spool Cable
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Observe square knot as it goes over
upper and lower sheaves
• Afterwards, reinstall IDW to measure
cable Schlumberger
79/87
Step 11 – Tripping Out of Hole
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Do not rotate pipe while tripping out of hole;
• Rotation may cause fish to disengage and fall
out of down hole overshot
• DO NOT ROTATE DRILLPIPE!!!
80/87
At Surface
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Install make-up plate at first
available tool collar and remove
overshot assembly
• Remove remaining tool string
with air hoist, cover hole, and
finish breaking and cleaning
tools in rat hole
• Make sure air hoist is rated for
tool string
81/87
Removing Fish
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
Schlumberger Private
• Remove guide and bump tool
vertically against rig floor to free
grapple control
• Spin tool and grapple out of
overshot by turning in a clockwise
motion
• (Tool should come free without
applying excessive force)
• If another method is used to release
tool, remove electronics from
housing in overshot to minimize
damage
82/87
Fishing with Top Drive
• Assembly made on 15 ft of
cable piece
Schlumberger Private
• Sinker Bars
• Spearhead with cone type
rope socket
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
83/87
Fishing With Top Drive
• Top Latch Assembly
Schlumberger Private
• Sinker Bar Assembly
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
84/87
Further Information
• FishingwithSlickline.pdf
Schlumberger Private
• ReverseCutandThread.pdf
• LoggingWhileFishingBestPractices.pdf
Quartz School. Module 11: Drilling Problems & Solutions / Section 3: Fishing Operations
85/87