Operaciones con Winche en Pozos Petroleros

Schlumberger Private

WLWL-- JDA JDA PrePre--School Program School Program

WINCH OPERATIONS

2 WLH-JDA-PRE-SCHOOL

June 06


ObjectivesObjectivesAt the end of this presentation, you will be able to:At the end of this presentation, you will be able to:

Define: IDW; its function; how motion is measured; its calibration policy; Wheel Correction and how it is calculated.

Define: CMTD, its function, define strain gauge and how tension is measured, calibration policy.

Define function of modular and spider weak-points; Describe the application of each.

Define: Logging Tension (Tn), Cable SWL, MAX SAFE PULL (MSP), MAX SAFE OVERPULL (MSOP).

State the formula for weak-point selection based on Upper weak-point rating and SWL of Cable.

Understand how weak-point selection is affected as the well gets deeper/shallower.

(OH-JFE): State the ratings of Yellow, Orange, Tan Weak-points; Describe rating reduction with temperature.

(MAXPRO-JFE): Describe how the upper and lower rating of a spider weak-point is calculated.

Define the primary intentions of the WL Depth Control Policy.


June 06


ObjectivesObjectivesAt the end of this presentation, you will be able to:At the end of this presentation, you will be able to:

State the Accuracy and Repeatability of the WL depth measurement

Describe : Tool Zero at surface, RULS, RULB, Log down vs. Log-up correction, re-zero at surface, correlation log.

State the formula for manually calculating stretch.

Describe the difference between: First Log in well; Subsequent Log ; Subsequent trip.

State the maximum permitted speeds for running a winch in/out of a hole; also in terms of proportion of tension.

Describe how the following alarms are set as a proportion of tension : High/Low tension Alarm/Shutdown.

Describe how the following alarms are set relative to position in well : Top of well /Bottom of well Alarm/Shutdown.

(under supervision) set all the alarms on a WFDD in the Shop Computer/or on a job.

Describe the function of the SAFE WINCH PLACARD as the primary SOP that must be adhered to during Operations.

Remember! this icon gives you the reference (see LAST SLIDE). Also , you can click the number during the slide show to go directly to the reference.

1


June 06


IDW

DEPTH CONTROL PROCEDURES : 1DEPTH CONTROL PROCEDURES : 1-- TechnologyTechnology-- IDWIDW2,5,6(Chapter 14)

In Wireline we provide our clients with the most accurate depth in the oil industry. We achieve this by a combination of policy and procedures as well as technology. The Integrated Depth Dual-Wheel Spooler (IDW) is the device we use to measure depth accurately and precisely. The IDW outputs depth (and subsequently speed) and direction.

The cable moves in between the wheels

Wheel Circumference = 30 inch Encoder disk slots = 300Resolution = 30 / 300 = 0.1 inch

The depth is measured by an encoder module attached to each wheel. When a wheel moves the encoder outputs an electrical pulse every 0.1

inches (the period of the pulse). We can count the the number of pulses and the time

to get depth and speed. 2,5

1

The encoder uses an LED (Light Emitting Diode) to send light through 300 equally spaced slots positioned on a disk (disk moves with the wheel). The light sensor (photo-diode) outputs a pulse each time light comes through a slot. 2,5

2

Wheel Correction (WC) and Calibrations

In reality, the wheel will not move exactly 0.1 in for each pulse due to errors introduced by the cable or by wear in the wheels. For Example: if the cable moves 10,000 pulses (83.33 ft) and the IDW records 10,004then the wheel correction is –4.

We must calibrate the IDW every 6 months or 50 well-sitetrips or after 500,000 ft to measure the Wheel Correction. 2,5

3 What if I don’t have any calibrations? 2,5

We can estimate a value for the wheel correction based on the formula:

WC = CRC + WWC + WDC

Where:

CRC = Cable Rolling CoefficientDue to squeezing of the cable by the wheels (Average= +8)

WWC = Wheel Wear CoefficientGroove created on the wheel by moving cable (negative value)

WDC = Wheel Diameter CoefficientSet by the factory to –8 to offset the effect of the CRC

4

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June 06


DEPTH CONTROL PROCEDURES : 2DEPTH CONTROL PROCEDURES : 2--Policy and PracticePolicy and Practice2

We have discussed the technology side of the Wireline depth measurement policy. The other component in delivering the most accurate possible depth is the policy and procedures applied by the practitioners (i.e. you). Here we see an overview of the Wireline depth control policy and its practice that you will soon be implementing in the field. 2

The Primary aim of the Depth Control Policy is to

provide an Accurate,Accurate,Repeatable and TraceableProcedure that is Uniform

Worldwide.

AccuracyAccuracy : aimed at : +/- 5 ft/10,000 ft = 0.05 %

Repeatability : aimed at : +/- 2 ft/10,000 ft = 0.02 %

This means that for a 10,000 ft This means that for a 10,000 ft well, our well, our accuracy range is 9995 ft accuracy range is 9995 ft ––10,005 ft10,005 ft and we will and we will repeat that repeat that measurement within +/measurement within +/-- 2ft, every 2ft, every time .time .Lets see the wellLets see the well--site procedure site procedure

for thefor the FIRST RUN IN HOLEFIRST RUN IN HOLE

TOOL ZERO

After Rig-up and setting up the Depth System,

ZERO the Depth on the Drill Floor

1

RIG-UP LENGTH AT SURFACE (RULS)

After running in hole measure the distance

between the IDW and Rig Floor (mark the cable).

Repeat this near the bottom of the well (RULB)

2

RIG-UP LENGTH CORRECTION (RULC)

RULC= RULS-RULB

(should be less than 1ft).

Add RULC to the depth system

This corrects for Rig-up slack at surface.

3

CORRELATION

Perform a Down-log and an Up-log over a small interval where there is a clear marker. Correct the UP-LOG to the same depth as the DOWN-LOG

4

Tool Re-Zero at Surface (ZRCS)

Re-Zero the tool when it comes back to surface should be within +/- 2ft per 10,000 ft. If more than 2 ft report this and repeat all the same

procedures for the next run.

5

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June 06


DEPTH CONTROL PROCEDURES : 2DEPTH CONTROL PROCEDURES : 2--Policy and PracticePolicy and Practice2

Usually a Wireline operation will require more than one run in the well (Subsequent Log)and often we will go back to that well at another date to do some more work (Subsequent trip). Our policy covers the procedure for the subsequent run and the subsequent trip to the well to ensure a consistent depth. 2

Manual calculation of Stretch

We can calculate a the approximate stretch due to tension using a formula:

Stretch = 1/2 x L x E x (Tup - Tdown)

Where:

L = Length of the cable or Depth

E = Elastic stretch coefficient

= 9.63 x 10 –7 for Heptacable

T= Tension in lbs

NOTE: this is just a check (we correct for stretch

using the Log down vs. Log Up method that has

been described)

Subsequent LOG means that we have Subsequent LOG means that we have not changed our rignot changed our rig--up in any way up in any way

(i.e. we pull out of the well and (i.e. we pull out of the well and connect another tool and run back connect another tool and run back

in.in.

Lets see the wellLets see the well--site procedure site procedure for thefor the Subsequent LOGSubsequent LOG

11-- Tool ZeroTool Zero

(as before)(as before)

22-- Log upLog up

(this log must over(this log must over--lap with a lap with a section from the first Run)section from the first Run)

33-- Correlate Correlate

TieTie--in this log with the first log. in this log with the first log. The 2 logs should agree over the The 2 logs should agree over the

entire interval.entire interval.

Subsequent TRIP means that we rigSubsequent TRIP means that we rig--down completely and come back to down completely and come back to the wellthe well--site on another occasion.site on another occasion.

Lets see the wellLets see the well--site procedure site procedure for thefor the Subsequent TRIPSubsequent TRIP

11-- Reference LogReference Log

Agree with the customer on the Agree with the customer on the log that is going to be used as a log that is going to be used as a

reference.reference.

22-- FollowFollow all procedures forall procedures for FIRST FIRST RUN in HOLE RUN in HOLE

33-- Check and Correlate Check and Correlate

Check your depth with the reference Check your depth with the reference log. If depth is within log. If depth is within 5 ft per 10,000 5 ft per 10,000 ftft of the reference log, then adjust of the reference log, then adjust the depth to the reference log (if the depth to the reference log (if

more than 5 ft, investigate) There more than 5 ft, investigate) There should be a 200ft overlap with the should be a 200ft overlap with the

reference log.reference log.

Z-Chart

As a secondarydepth control keep

a record of the depth at the

beginning and end of every wrap on

the drum and a note of tensions during the logging. This

sheet is called a Z-chart. It is used in

case of an IDW failure




June 06


Measuring Tension and the CMTDMeasuring Tension and the CMTD44,6(Chapter 11),6(Chapter 11)

The Cable Mounted Tension Device (CMTD) is a critical safety device in Wireline operations. It provides an accurate tension measurement allowing us to operate within the safe working loads of the cable.

CMTD Let see how it works:STRAIN GAUGE

This consists of resistors that are strain sensitive. These resistors are mounted on a

device which deforms when stress is applied (in this case an

axle). This deformation changes the length of the

resistor and hence it’s resistance.

The change in resistanceproduces an electrical signal proportional to that change in

resistance (using the Wheatstone Bridge circuit)

Therefore, the electrical signalis proportional to the tension

All we need to do is calibrate the CMTD by applying known tensions and measuring the

signal.

STRAIN AXLE and 4 RollersThe CMTD works by bending the cable slightly as it passes through the 4 rollers and a

Strain Axle. The stress caused by the bending is proportional to the tension in the cable. This stress is felt by the strain axle. The Strain axle contains a STRAIN GAUGE which is

designed to output an electrical signal proportional to that stress.

Note: the 2 outer rollers are specific to the size of cable being used. If you use a

different size cable then these rollers must be changed

TDC

The CMTD must be calibrated every monthusing the Tension Device Calibrator (TDC)



June 06


Logging tension safety and WeakLogging tension safety and Weak--pointspoints6(Chapter 12) 6(Chapter 12)

We lower our tools in the hole using the Wireline cable. The cable is connected to the tools using the logging head. The logging head contains an emergency release mechanism which allows us to detach the cable at the head (by pulling from surface) and hence retrieve all the cable back to surface. This release mechanism is called a weak-point. Most weak-points are designed to release at a specified tension. We call that the weak-point rating.

There are 3 classes of weak-point.

Modular weak-point1

Spider Weak-point2

Electrical Release Weak-point3

Consists of a solid metal

rod designed to break at a known range

of stress.

Used in HeptacableOperations

Spider weak-points are made by cutting a certain number of inner and outer armors of the logging cable at the logging head.

Used in all Mono-cable Operations

Specially designed to release only when

electrical current is sent to release the

weak-point. Called the ECRD (Electrically Controlled Release

Device).

Designed to be used in very deep wells with

heavy tool-strings (for Heptacable operations

only).



June 06


Unintentional PullUnintentional Pull--off Prevention: 1off Prevention: 1--Logging tensionsLogging tensions11

In order to operate the cable safely during Wireline operations, we must be aware of the limits on our tensions when pulling on the cable. Otherwise we may unintentionally “pull-off” the weak-point or may damage the cable. In either case there would be a serious loss to Schlumberger and our client.

Lets define some important equations and terms.1

EXPLANATION: WTM

WTM is subtracted out of the equations because when the tool is stuck then the formation (or whatever is holding the tool) isbearing the weight of the tool. Only the cable weight becomes important.

To calculate the maximum safe surface tension to pull on the tool-string without breaking the weak-point, we use the

following equations2:

Maximum Safe pull: MSP = TN – WTM + (75% x LWPR),

or

MSP = MSOP + TN

Maximum Safe Over-pull: MSOP = 75% × LWPR – WTM

2EXPLANATION: MSP

The MSP is calculated for the case that the tool gets stuck and we need to know how much we can safely pull to try and free the tool without breaking the weak-point.

Where:TN = Normal logging tension coming up

WTM = Tool-string weight in mud

LWPR = Lower weak-point rating, (UWPR Upper weak-point rating)

TN is also = WTM + CW (CW= Cable weight in Mud)

3

EXPLANATION: MSOP

MSOP is a useful constant that lets us know how much we can safely pull above the logging tension at any time.

EXPLANATION: LWPR, UWPR :

All mechanical Weak-points have an upper and lower rating.

This is the range of tension within which the weak-point will break.

{NOTE: this does not apply to the ECRD}

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June 06


Unintentional PullUnintentional Pull--off Prevention:off Prevention:22--WEAKPOINT SELECTIONWEAKPOINT SELECTION11

Before every job, we must select a weak-point to use. For all mechanical weak-points (i.e.Modular and Spider) we must calculate the correct rating required to achieve our objectives.

We have 2 objectives when selecting a weak-point :

1.We must be able to break the Weak-point at the deepest point in the well without exceeding the cable Safe Working Load (SWL)

2.We want the maximum possible MSP (i.e. the largest possible weak-point rating so we can pull more to try to get free)

1

If we get stuck and decide to break the Weak-point in order to retrieve the cable then how much to we need to pull? :

Well, we take the logging tension,TN and deduct the tool weight, WTM then pull the Upper rating of the Weak-point, UWPR .

We can write this as: (TN) –WTM + UWPR

(From previous slide) TN can be re-written in your equation as WTM + CW

So: (WTM + CW) –WTM + UWPR

WTM is cancels leaving: CW + UWPR

This must be less than the safe working load of the cable (SWL):

HENCE: CW + UWPR < SWL (A)

2

….So in order to achieve our objectives we must choose the largest possible weak- point that meets criteria A

3

EXPLANATION: WTM

WTM is subtracted out of the equation because when the tool is stuck in the formation then the formation is bearing the weight of the tool. Only the cable weight becomes important. This is important to understand.

EXPLANATION: CW

We must calculate the cable weight for the maximum possible depth in the well (worst case scenario).

{ Heptacable weighs around 333 lbs (in air) per 1000 ft }

{ Mono-cable weighs around 107 lbs (in air) per 1000 ft }

….Also it follows that a deep well will have a bigger cable weight (CW) and therefore a smaller UWPR.

Hence: Deeper well = smaller weak-point

4



June 06


Unintentional PullUnintentional Pull--off Prevention:off Prevention:33--WEAKPOINT RATINGS and POLICYWEAKPOINT RATINGS and POLICY11

Lets look at examples of weak-points and their ratings as well as some practical ideas of how weak-points are affected by well conditions and what policy is applied to the use of weak-points. This applies mainly to the 2 types of mechanical weak-points.

Modular weak-points1

These weak-points are designated a colour. Yellow,

Orange and Tan are very common (and its useful to

remember these 3 ratings!).

Part No. Color Lower Rating

Upper Rating

H441403 Gray 3000 3400H441404 Red 3500 4200H441405 Black 3900 4500H441406 Yellow 4800 5400H352141 Orange 5400 6000H352149 Tan 6000 6700H441408 Blue 6700 7300

The strength of these weak-points is affected by

temperature. It is defined as a % reduction of their strength.

This temperature reduction must be applied to Upper and

lower rating when doing calculations.

It is approximately 4 % reduction for every 100 degF

increase.

We MUST change a WEAK-POINT if it has been…1- ..pulled more than 75% of its lower break strength

2- ..exposed to temperatures higher than its rated temperature or to freezing conditions in a head without grease

3-..made marginally longer than a normal weak-point or is bent.

4-..more than 3 months since it was first used in a well.

Spider Weak-point2

The upper and lower ratings of these weak-points have to be calculated from a given nominal rating.

This table shows the SpiderWeak-point ratings for a 2-23 mono-cable.

To calculate the upper and lower rating, we must +/- 15%respectively from the strength.

e.g. an 8-3 = 1785 lbs (nominal)

Upper rating = 1785 + 15 %

Lower rating = 1785 – 15 %



June 06


Unintentional PullUnintentional Pull--off Prevention:off Prevention:44--Speed Limits and Setting alarms during loggingSpeed Limits and Setting alarms during logging11,3,3

Speed Limits1

High/ Low Tension Alarm

These are set according to

the cable speed

recommendations. Or any special well conditions

The speed limits are given as a percentage of the STATIC TENSION(tension when the tool is not moving)

However,

The Speed must never exceed 15,000 ft/hr for Open Hole an 25,000 ft/hr for cased hole operations

Alarms- these are for both tension and depth limits2

Alarms are set to warn us of critical tensions and depths. There are alarm 2 types:

1: Warning Alarm- when this is activated a loud beeping noise is heard.

2: Shut-Down Alarm- When this is activated the Winch Shuts-down.

High/ Low Tension SHUT-

DOWN

In open hole not more than 500 lbs above or

below normal logging tension. 100-200 lbs for

cased holeoperations

Top/ Bottom of Well Alarm

Top of well alarm must be set before the cable head enters the casing

for open hole operations. Before any

tubing shoes or restrictions for cased

hole operations. Bottom well alarm set to stop too much slack cable

being run in hole.

Top/ Bottom of Well SHUT-DOWN

Winch must shut down before it can get to an obstacle that may break the

weak-point. In Open hole the head must

not arrive at the Upper sheave wheel.

For cased hole operations it depends

on the rig-up



June 06


Winch Safe Operating ProcedureWinch Safe Operating Procedure33

This Placard defines the SAFE OPERATING PROCEDURES (SOP) for all winch operations. Adhering to the SOP is Mandatory.



June 06


PRACTICAL TIMEPRACTICAL TIME{UNDER SUPERVISION OF AN ENGINEER or CREW CHIEF} :

Set the Alarms on a WFDD in the SHOP

Do a FIT (and if you have time a TRIM) of a IDW and CMTD

☺ TIP: Practical tasks to be done with an ENGINEER or CREW-CHIEF : The best time to do any

type of practical is during the Post-Job checks (Just after coming back from the rig) or Pre-Job checks

(the time before going to the rig- if time allows) . At these times, Engineers will power-up the tools and

check to see that they are working. Also, at these times, the operators and technicians will be

servicing and doing maintenance on the tools. All practical tasks required during pre-school can

be learned during the Pre-Job / Post Job Checks, so go out there an get involved !!


June 06


REFERENCESREFERENCES1. Pull Off Prevention


2. Depth control Online Traininghttp://intouchsupport.com/intouch/MethodInvokerpage.cfm?caseid=3264496

3. Winch Control Standard Online Traininghttp://intouchsupport.com/intouch/methodinvokerpage.cfm?caseid=4137706

4. CMTD Online Traininghttp://intouchsupport.com/intouch/methodinvokerpage.cfm?caseid=3630834

5. IDW Online Traininghttp://intouchsupport.com/intouch/methodinvokerpage.cfm?caseid=3601934







June 06


REFERENCESREFERENCES6. Wireline Operators Manual Vol. 1 (Chapters 11, 12, 14 as referenced in the slide)



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