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CUT & THREAD FISHING PROCEDURES AND BEST PRACTICESVersion 2005Jan15

A CUT & THREAD FISHING OPERATION is the most dangerous operation involving wireline. Prior to starting a cut & thread operation ensure the following is completed:

A written HARC is completed and discussed with all involved

This “CUT & THREAD” procedure is reviewed with all involved

The operation involves several companies, including the operating company, the rig company, the fishing hand and Schlumberger. It is an integrated effort with one supervisor, the Operator Wellsite Supervisor.

Communication is critical for a safe & successful fishing job

EVERYONE INVOLVED IS EMPOWERED TO STOP THE OPERATION IF THEY FEEL IT IS UNSAFE!!

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Hang Sheave In DerrickTry to hang sheave with fishing sling so it will not interfere with the handling of drillpipe

Lower sheave must be moved away from rotary toprevent interference with rig floor operations andcable contact with top drive

Clear the rig floor while derrick man hangs the sheave.

In order to determine the proper fishing assembly to use, the derrick man should provide a best estimate of the distance available between the top of pipe and the sheave.

Use Longest Links Available108” 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 eliminatecable rubbing; If one is not available, have rig make one

Do not use the Varco Wireline Adapter commonly known as “Bicycle Wheels”

108”

TopDrive

TopDrive

>108”

Tension DeviceSwitch to TDK if using CMTD ( if available)(Prevents cable backlash)

Compare TDK and CMTD readings so that fishing operationis performed under correct tension

Do not pre-load lower sheave withair hoist tension; Sheave shouldhang freely until weight is applied

TDK

CMTD

DesirableNot

Desirable

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Cut the CablePull 1,000 to 2,000 lbs over normal tensionand secure T-Bar cable clamp to cable

If hole is straight, cut cable 5 to 7 feetabove rotary table

If hole is deviated, cut cable 10 feet aboverotary table plus 1 foot for every 1,000 feetgreater than 10,000 feet

Use proper size cable bushing in T-Bar and mark cable to ensure there is no slippage

Test T-Bar for slippage before cutting cable

T-Bar

Cable

T-Bar

Rig Up Spearhead OvershotUse tapered cones from LEH-Q on top of fishing weights

If available, use heavier-shorter fishing weights withknuckle joints and swivel, or Wire Rope Weight with CooperKnuckle-Swivel (a must on top drives!!)

Minimum restrictions for all drilling hardware (jars, drillcollars, and heavy weight) must be known to determine size of overshot guide to use

Always use the largest guide that will fitthrough drilling hardware

Never use “after-market” non-SLB rope sockets.

Swivel used to prevent cable torque from backing off spear assembly.

OrOr

Cooper Knuckle -Swivel

KnuckleJoints

Overshot Guide

Rig Up SpearNever use spears which contain “W’s” in their workorder numbers

Always use Hexagon Adapter when stripping over;Hexagon Adapter will stop on top of no-go if droppedaccidentally

Only use plain adapter when drill pipe ID is too small forHexagon Adapter and switch back to Hexagon Adapter as soon as drill pipe ID permits

Hexagon Adapter

Never use “after-market” non- SLB rope sockets

TaperedCone

Work Order NumberStamped Here

2

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Assemble OvershotAssemble 4-11/16” overshot, spiral type grapple, and no-go (preferred method)

If basket type grapple is used, assemble5-3/4” overshot, basket grapple, and no-go

ALWAYS VISUALLY INSPECT grapple for proper size for job and NEVER installa used grapple

4 11

/16”

5 3/

4”

Thread Cable Thru OvershotRemove hex adapter, pass well end of cable through downholeovershot and reinstall hex adapter (Remember, 2 1/4” hex adapter will not pass through the smaller ID no-go)

Make-Up Torque

Bowl to Top Sub

5 3/4” 4 11/16” 7600 3200

Bowl to Guide 5 3/4” 4 11/16” 1700 1300

NotDesirable Desirable

Install Drain SubDrain sub with blow out disk aids in grapple cleaning and prevents pullingwet drillpipe after disk is blown

Install above downhole overshot assembly

Blow Out Disk

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Thread ThroughSlowly ( <2000 FPH) pull overshot assembly to derrick manto thread through bottom hole assembly

Communication is critical at this point to prevent pulling assembly into the sheave!! Use radios!! Clear rig floor!!

Make sure all minimum restrictions are known in pipe

Flag line at winch after bottom of assembly reaches the the top of pipe. This flag may need to be adjusted in Step 5 when full stands of pipe are used.

DO NOT EXCEED THIS FLAG WITHOUT 1st STOPPING THE OPERATION, YOU WILL PULL INTO THE SHEAVE!!!

First Stand of Drillpipe,Collars, or Heavy Weight

Remove T-BarTighten overshot to bottom of first standof drillpipe

Stab spearhead overshot, pull cabletension, check for slippage, and remove T-bar cable clamp after completing check

Remove IDW and position spooling armto one side (If CMTD is used, do not remove)

T-Bar

Tightened Overshot Assembly

Spear Stabbed intoOvershot

Cable Tension= 1000 lbsto 2,000 lbs + Normal

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When Slips Are SetAfter the slips are set, floorhand 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

Use correct C-plate for pipe size

C-PlateLocation

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3 1/2 IF4 1/2 IF

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Trip In SlowlyMaintain Proper Cable Tension(1,000 to 2,000 lbs plus normal)

Pay particular attention to top drive / block; If weights are in danger of hanging up top drive, slack off slightly. but do so carefully. Pull back to 1-2K lbs over once the weights are clear.

Drillpipe

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Flag Line AgainFlag line again at drum and bottom sheave when spear isstabbed in spearhead overshot

ONCE FLAGS ARE SET, DO NOT EXCEED WITHOUT 1ST SHUTTING DOWN OPERATIONS AND DISCUSSING WITH ALL !! YOU WILL PULL INTO THE SHEAVE!!

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Flag LineAfter 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 drillpipe by the derrick man. Derrick man will thread overshotassembly through drillpipe.

ONCE FLAGS ARE SET, DO NOT EXCEED WITHOUT 1ST SHUTTING DOWN OPERATIONS AND DISCUSSING WITH ALL !!

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Pull overshot to derrick man who will thread through another stand of drillpipe (watch flag at at drum)

Re-thread Overshot

Stab OvershotAttach drain sub to second stand of drillpipe

Position pipe over spearhead overshot and slackoff until “the other flag ” on the drum is reached

Keep hands in safe position

C-Plate

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Drillpipe

Make overshot connection, pull enough tension toremove C-plate, and adjust tension again tonormal plus 1,000 lbs to 2,000 lbs.

Too low of tension will result in cable being damaged or completely cut by the overshot assembly as it moves downward. NOW YOU HAVE A CABLE FISHING JOB ON YOUR HANDS!!!!

Make Overshot Connection

C-Plate

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Hands

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Make-Up DrillpipeDrillpipe is made-up and tightenedSlips are pulled and the descent begins

Do not rotate pipe in hole

Observe tension, if it increases stop & discuss

Slips

Tripping in HoleRepeat procedure for each standof drillpipe until circulation depthis reached

If excessive open hole is present,circulation every 10 stands (especiallyif lost circulation material is used)should be considered to keep grappleclean

Remember to watch your speed!!!! Going in the hole slowly is the only wayIf crew changes, STOP… review HARC & Fishing procedure before proceeding

Trip in Slowly

1

Set Slips andDisconnect Overshot

2

3

Rethread OvershotThrough Drillpipe

4

C-Plate

Stab Overshot Make OvershotConnection

5

Then Make-UpDrill Pipe

Remove C-Plate

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Engage FishMaintain normal tension plus 1,000 to 2,000 lbs and approachfish slowly;Observe tension and set at least 2,000 additional pounds on fish; Pull at least 2 joints of drillpipe (60’) and observe tensionA minimum tension loss of 2,000 lbs should be observed to confirm latch (a tension resulting in 0 after pulling pipe wouldbe 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!!!

Install Circulating SubInstall sub one stand above fish

Never put circulating sub in hole

Spearhead Overshot

Circulating Sub

Spearhead Sub

C-Plate

Kelly or Top Drive

CirculatingBasket

Circulating Sub

Circulate One Stand Above FishCuttings and debris should be removed from downhole 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

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Blow Drain Sub DiskApply mud pump pressure to blow disk insub

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 pumped out of the overshot

Blown Disk

Drain Sub

Reconfirm EngagementRepeat engagement process at least twice to ensuretool is still in downhole overshot

Again, observe tension and set at least 2,000 additional pounds on fish; Pull at least 2 joints of drillpipe (60’) and observe tensionA minimum tension loss of 2,000 lbs should be observed to confirm latch (a tension resulting in 0 after pulling pipe wouldbe a definite indication of engagement)

Break Weak PointInstall 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 recordtension at which break occurs

Make sure rig floor is clear and inspect lower sheave chain before proceeding

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Install TIW ValveInstall TIW valve before spoolingcable onto drum

This could aid in controlling well iftrouble occurs

Logging Cable

TIW Valve

Spool CableObserve square knot as itgoes over upper and lowersheaves

Afterwards, reinstall IDWto measure cable

Do not pull the weakpoint assembly over the sheave!!

Clear rig floor when near surface

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Square Knot

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Tie Square KnotCut off rope sockets on both well end and unit end of cable

Tie square knot in cable, pull tight ,and tape ends

Square knots reduce cable breaking strength by 50%!!

Consult In-Touch on High Tension jobs!!

Don't pull tension on a square knot above 25% of the cable break strength. In that case use two T-bar method to get the knot to the drum plus at least three wraps before pulling.

To Logging Unit To Well

OPTIONALOPTIONAL

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Removing FishRemove guide and bump tool vertically against rig floor to free grapple control

Spin tool and grapple out of overshotby 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 inovershot to minimize damage

Grapple Control

Guide Shoe

Grapple

Tripping Out of HoleDo not rotate pipe while tripping out of hole;Rotation may cause fish to disengage and fallout of downhole overshot

DO NOT ROTATE DRILLPIPE!!!Drillpipe

At SurfaceInstall make-up plate at first availabletool collar and remove overshot assembly

Remove remaining toolstring with air hoist, cover hole, and finish breaking and cleaning tools in rat hole

Make sure air hoist is rated for toolstring

Make-up Plate

Downhole OvershotWith Fished Tool

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Reverse Cut and Thread

USE THIS TECHNIQUE IF:a) The weakpoint can not be safely broken due to deviation and doglegsb) If you want the cable to remain attached to the toolstring until it reaches the

casing or surface (normally when fishing with RA sources)c) If you suspect the rubber boot on the top of bridle is wedged inside the

grapple (when fishing with logging bridles) impeccable

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Method1: Single T-Bar and Reef Knot method

Provides an alternative to breaking the weak point after the tool string has been engaged in the grapple.

- Safest and most reliable fishing technique - Only one cable clamp is needed- Cable tension can be continuously monitored. If the fish is pulled out of the grapple, you can see the tension increase and act promptly.- The disadvantage is that the procedure is relatively slow and requires a lot of co-ordinatingwith the derrick man.

Method2: Dual T-Bar method- Not a recommended procedure- No longer have control over the down hole tension of the cable. - Need too feed a lot of slack into the pipe. - Should the fish fall out of the grapple and become stuck, excessive tension may either strip the cable out of the cable clamp or break the weak point. - To use this method you must be 100% sure that the tool is properly engaged in the grapple.

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13 Single T-Bar and Reef Knot method

Cut Spear and OvershotBreak the last stand and put a T-Bar on the cable and slack until spear,overshot, and weights are out

Cut off the spear,overshot and weights on both end of cable

Cut

Remove cable from Drill PipeRe-attach one weight bar and pull the cable out of the drill pipe with help from derickman.Lower the cable once it is out of the drill pipe

NOTE: - Need at least 1 weight bar as counter weight so that cable will not slip from the top sheave- Better to pull the cable by hand instead of using winch for better control (reduce chances of weight bar knocking the top sheave)

Tie Square KnotRemove the weight bar from the uphole end of the cable.

Tie square knot in cable, pull tight, and tape ends.

NOTE:Make sure the tails of the knot is long enough and and properly taped to avoid the knot from coming loose.

Remove

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14 Reversing outPull up with the winch until the knot is tightNOTE:Clear the rig floor when picking up the cable. In case the knot unravels, the cable will come out through the upper sheave and fall on the rig floor

Remove the T-Bar and slack down until the knot is inside the drill pipe

Driller will pull up the drillpipe and break the next connection.

Remove cable from Drill PipeHave the driller pull up the drill pipe

Pull the wireline cable up 90ft/30m (or depending on the length of the drillpipe connection)

Slack off the cable until the knot is out of the pipe

Cut both ends of the cable

Make sure knot is tight

Cut

Continue Reversing outRe-attach one weight bar and pull the cable out of the drill pipe with help from derickman.

Lower the cable once it is out of the drill pipe

Remove the weight bar. Tie a square knot and keep doing this until the bottom of the fish is in the casing shoe or the tool is at surface

You can proceed with breaking the weakpoint by following the previous instructions.

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Preparing the T-BarConnect slings to the T-Bar handle and attach the sling to the rig air tugger

Have the Driller pick up the drill pipe, and pick up the slack on the air tugger as well along with the drill pipe

Dual T-Bar method

Cut Spear and OvershotBreak the last stand and put a T-Bar on the cable and slack until spear,overshot, and weights are out

Cut off the cable on the downhole end.

Release the spear from the overshot using the special thong

Cut

Remove cable from Drill PipePull the cable out of the drill pipe with help from derickman.

Lower the cable once it is out of the drill pipe

Secure the uphole end of the cable since it will not be used for now

NOTE: - Better to pull the cable by hand instead of using winch for better control (reduce chances of weight bar knocking the top sheave)

Air Tugger

Slings

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Pulling Out PipeLower down the top T-Bar using the air tugger

Rat back the drill pipe into the derrick

Cut the cable close to the lower T-Bar

Continue doing this until the bottom of the fish is in the casing shoe or the tool is at surface

You can proceed with breaking the weakpoint by following the previous instructions.

Installing 2nd T-Bar

Have the Driller break the connection, and then pick up the drill pipe just enough to install the 2nd T-Bar

Make sure the air tugger is holding the top T-Bar firmly

NOTE:Be careful not to pick up too much. If not you can break the weakpoint

Removing Cable from Top T-BarClear the rig floor of all unnecessary personnel

Have the derickman slowly loosen up the top T-bar. The cable should slide down from inside the drill pipe

If the cable not coming out, the operator needs to pull the cable out by using a long hook. Make sure he is at a safe distance before pulling out the cable.

Cut

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When Things Go Wrong

Spearhead Cable Shortens During Descent 

If cable cutting length calculations are incorrect at the beginning of the job, the spearhead will move closer to the rig floor as the downhole overshot approaches the fish. This can be a real problem with highly deviated and dog-legged wells. During the descent, cable is pulled off the wall reducing its original length. Normal tension also increases to keep the spearhead assembly at the same distance above the rig floor. This is similar to holding a rope and applying a force in the center to cause a deflection. As the deflection increases, the rope’s length decreases (Fig. 1). When this reaches an unacceptable level where the C-plate can’t be applied, the operation will come to a halt (Fig. 2). One option to solve this problem is to install an extension below the spearhead to increase the distance from the rig floor.  

Figure 1

New Length

Original Length

  Figure 2 Option two involves cutting the cable below the spearhead and adding extra cable by building two new rope sockets and using a double ended torpedo (Fig. 3). After this extra length is added, the spearhead is reinstalled and tested.

Spearhead

Spearhead(Inside Pipe)C-Plate

Slips

Unable to Use C-PlateBecause Spearhead is

Below Top of Pipe Connection

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When Things Go Wrong Continued…..

Figure 3

There is a slight possibility that too much cable may be added using these options. When this happens, slacking off on the cable becomes a reality whenever the C-plate is removed or installed and can cause cable damage if not performed correctly (Fig. 4). Slacking when the pipe is motionless is fine and should not cause any problems as long as it is removed and the correct tension regained before the pipe is moved.

Figure 4 

Double Ended Torpedo

Spearhead Assembly

Rope Socket Housing

Rope Socket Housing

Extension

Spearhead Assembly

Option #2 Option #1

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When Things Go Wrong Continued…..

Cable Breaks While Breaking Weak Point 

•Since the fish is already in the grapple, the cable can located by tripping out pipe. Once the other end is recovered, the T-bar can be reinstalled and the cable pulled again as before.  •Proper tension must be maintained throughout the entire fishing operation. Slack cable can cause broken armors and weak spots in the cable. With slack in the hole, the cable can double back around the guide and get cut. At the very least, this could produce a weak spot and unfavorable results when attempting to break the weak point.

Dropped Spearhead Assembly 

•If the spearhead with rope socket and cable is accidentally dropped into the pipe, run the cable overshot with the largest applicable guide down the pipe and attempt to engage the spear. It should only be a few hundred feet below the rotary.

•If this fails, have the drill pipe pulled and retrieve the spearhead. The no-go in the downhole overshot should catch the hex adapter.

Can’t Confirm Engagement 

There are four major reasons why tool engagement can not be confirmed. They are:•Inoperative or malfunctioning tension device Confirm Tension Device is working correctly

•Debris in the downhole overshot An overshot full of debris can prevent the grapple from engaging the fish. The only way to clear it is by circulating. If circulation does not solve the problem, one of the other conditions may exist.

•Slack in the cable Slack in the cable during a fishing job can produce a large coiled “wad” inside the downhole overshot preventing engagement (Fig. 4). This is why maintaining the proper tension throughout the operation is so important.

•Wrong size grapple If the wrong size grapple is used, there is still a slight chance that the tool can be retrieved. Grapples operate in a range and can expand a little more than indicated to accept a slightly larger fish.