10. downhole cementing equipment

8/13/2019 10. Downhole Cementing Equipment

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Section 10

Downhole CementingEquipment

Table of Contents

Introduction..............................................................................................................................................10-3

Topics...................................................................................................................................................10-3

Learning Objectives ............................................................................................................................. 10-3

Unit A: Guiding and Floating Equipment................................................................................................10-3

Guide Shoes..........................................................................................................................................10-3

Super Seal II Float Shoe...................................................................................................................10-4

Super Seal II High-Port Up-Jet (HPUJ) Float Shoe ......................................................................... 10-4

Super Seal II Down-Jet Float Shoe ..................................................................................................10-5

Super Seal II Float Collar.................................................................................................................10-5

Insert Flapper Float Valve....................................................................................................................10-6

Backpressure Valves ............................................................................................................................ 10-6

Pressure Differential Fill (PDF) Float Shoes and Collars .................................................................... 10-7

Unit A Quiz .......................................................................................................................................... 10-8

Unit B: Casing Attachments ....................................................................................................................10-9

Clamps..................................................................................................................................................10-9

Centralizers...........................................................................................................................................10-9

Wall Cleaners ..................................................................................................................................... 10-10Cement Baskets ..................................................................................................................................10-11

Unit B Quiz ........................................................................................................................................ 10-12

Unit C: Primary Cementing Plugs ......................................................................................................... 10-13

Bottom Plugs......................................................................................................................................10-13

Top Plugs............................................................................................................................................10-13Latch-down Plugs...............................................................................................................................10-14

Unit C Quiz ........................................................................................................................................ 10-16

Unit D: Multiple Stage Cementing Tools ..............................................................................................10-17

Type-P External Sleeve (ES) Cementer .............................................................................................10-17

Type-H External Sleeve (ES) Cementer.............................................................................................10-18Stage Tool Plug Sets .......................................................................................................................... 10-18

Full-Opening (FO) Multiple-Stage Cementer .................................................................................... 10-19

External Sleeve Inflatable Packer Collar (ESIPC) .............................................................................10-20

Unit D Quiz ........................................................................................................................................ 10-21

Answers to Unit Quizzes....................................................................................................................10-22

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Introduction

Use for Section Notes

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Unit A: Guiding and Floating Equipment

Introduction

During the early stages of the drilling process,

the hole will be lined with steel casing to prepare

the well for production or deeper drilling. The

steel casing provides a smooth bore for the tools

necessary to drill and complete the well. The

types of downhole equipment discussed in this

section contribute to a good cement job; they

help ensure a uniform cement sheath behind the

casing.

As you learn more about downhole equipment,

keep in mind that any item that will be used

inside the casing must be made of drillable

material.

Topics

This chapter covers the following topics:

A. Guiding and Floating Equipment

B. Casing Attachments

C. Primary Cementing Plugs

D. Multiple-Stage Cementing Tools

Learning Objectives

Upon completion of this section, you should be

familiar with:

Functions of downhole equipment

Descriptions of the basic types of equipmentused downhole

Uses and applications of downholeequipment


Guiding equipment helps guide casing past

ledges and doglegs to the bottom of the hole.Floating equipment allows casing to be run in

the hole partially empty, which takes some of

the stress off of the rig structure and draw-

works. Also, backpressure valves in floatingequipment permits the release of pressure in the

casing, after the cement job, to reduce

microannulus problems. A microannulus may be

created when stressed casing (due to internal

pressure) is allowed to relax after cement has

already hardened and bonded. As the casing

contracts, the slight reduction in casing outside

diameter results in a very narrow gap betweenthe cement and casing that may allow fluid

travel and compromise the isolation of zones.

Some of the more commonly used types of

guiding and floating equipment will be dis-

cussed in this unit. These include:

Shoes

Collars

Backpressure valves

Guide Shoes

Guide shoes and down-jet guide shoes have the

following primary purposes:

They protect the casing string from theimpact associated with landing casing on

bottom

They direct casing away from ledges,reducing the chance of sidewall cave-in

They help casing pass through narrow,deviated holes and areas with hard shoulders

The standard guide shoe has a large-ID hole

through its center, allowing maximum cement

pumping rates and the passage of self-fill orifice

tubes and balls dropped in the casing string. The

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rounded nose of these guide shoes is made from

high-strength cement that can be drilled out

easily with tri-cone rock bits or PDC bits.

Down-jet guide shoes have additional side ports

in the steel case that allow fluids to discharge

through both the cement nose and the ports. Thejetting action of the fluid pumped through these

ports helps remove wellbore cuttings and filter

cake.

Figure 10.2 - Super Seal Float Shoe

Super Seal II High-Port Up-Jet(HPUJ) Float Shoe

The High-Port Up-Jet (HPUJ) float shoe jets the

formation face to remove detrimental mud cake

and cuttings, increasing the chances of a

successful cement-to-formation bond. The high

circulation rates and cement flow rates that are

possible with the Super Seal II float valveallow turbulent flow at the shoe without

damaging the float valve.

Figure 10.1 - Guide Shoe

Super Seal II Float Shoe

The Super Seal II standard float shoe attaches

to the lower end of the casing string. This floatshoe includes the Super Seal II backpressure

valve assembly, which helps prevent cement in

the cased hole from re-entering the casing ID.

The plastic valve and stem materials are

surrounded by drillable concrete, making the

equipment easy to drill out with PDC or tri-cone

rock bits. The high-strength, durable rounded

nose safely guides the casing to the bottom of

the hole. This equipment is available in all

tubing and casing sizes with API 8-rd and

buttress threads. The standard casing grade is K-

55 material. Customers can request any casing

grade and premium thread by special order.

The HPUJ shoe includes six fluid-discharge

ports strategically placed to jet the circulation

fluid or cement upward, enhancing fluid

turbulence far above the floating equipment.

These up-jet ports, along with four (or fewer)

down-jet ports, distribute the fluid in the annular

space above and below the float shoe, helping

prevent channeling near the shoe.

Approximately 40% of the fluid pumped

through the equipment is discharged at a high

velocity through the bottom of the float shoe,

removing material in its path and helping

maneuver the casing past ledges and tight

sections of the wellbore.

If the casing string is reciprocated during

cementing, cement jetted through the exit ports

remove mud cake from the formation face. Field

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reports indicate that the HPUJ float shoe can

substantially reduce the number of casing strings

requiring secondary squeeze cementing

operations. All casing sizes of the Super Seal

II HPUJ float shoe use the same autofill strap

used for the Super Seal II float valve. When

engaged, this strap allows the casing to fillautomatically with wellbore fluid while it is

being run in the hole, saving time and reducingthe ram effect of running casing.

Figure 10.4 Super Seal II Down-JetFloat Shoe

Super Seal II Float Collar

The Super Seal II float collar includes the

Super Seal II backpressure valve, which

prevents cement pumped into the casing/

wellbore annulus from re-entering the casing ID

during cementing operations. The float collar is

normally installed one or two joints above the

float or guide shoe. All casing-size Super Seal

II float collars include an autofill strap (at no

additional cost). This strap, which is installed

between the valve and pressure seat, is

deactivated by flow rate. The autofill strapallows wellbore fluids to enter the casing with

the first joint, reducing surge pressure on the

formation and reducing casing fill time from the

surface. When the autofill strap is pumped loose

with a high fluid rate, the float valve is re-turned

to a dependable Super Seal II backpressure

valve for floating or cementing. The autofill

strap will deactivate if the flow through the

valve reaches a predetermined rate (4 bbl/min

for the 2 in. valve and 6 bbl/min for the 4

in. valve).

Figure 10.3 Super Seal II High-Port Up-Jet (HPUJ) Float Shoe

Super Seal II Down-Jet FloatShoe

The Super Seal II down-jet float shoe includes

the Super Seal II float valve, which prevents

cement backflow from re-entering the casing ID.

In addition to the center hole through the float

valve, four to six fluid ports are drilled in the

outer case below the float valve. These ports

direct some of the fluid downward during

circulation. Pressurized fluid jets out of the side

ports and the guide nose, helping removecuttings and filter cake, creating turbulence

around the shoe, and improve cement

distribution and casing-to-formation bonding.

Additionally, the external jets on the outer case

provide an alternative cement flowpath if the

bottom center port becomes plugged with well

debris.

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Figure 10.5 Super Seal Float Collar

Insert Flapper Float Valve

The insert flapper float valve is a backpressure

check-valve assembly installed between the pin

and box ends of API 8-rd or buttress thread

casing joints. The insert flapper float valve is

used for casing flotation and cementing

operations in wells with moderate temperature

and depth. It can be used for differentialpressures up to the collapse pressure of the

lightest weight of J-55 casing in the casing size

in which it is run. The insert flapper float valve

can be installed in long or short API 8-rd or

buttress casing coupling. Because of limited

space between the casing box and pin, insert

flapper float valves are not available for

premium-thread casing. One or more insert

valves can be run in a casing string or in

conjunction with a standard float shoe or guideshoe.

Because they are made from aluminum, insertflapper valve assemblies can be drilled out easily

with a medium-tooth, tri-cone rock bit. PDC bits

should not be used to drill out insert flapper

valves.

The insert float valve has a large flow area and

can be easily converted to autofill equipment if

an orifice self-fill unit is installed. The self-fill

unit includes a weighted plastic valve and plastic

orifice tube. The orifice tube holds the flapper

open until a weighted plastic setting ball is

dropped into the casing. Once the ball reaches

the valve seat, pressure is applied to shear out

the plastic orifice tube, which allows the valve to

close. This equipment operates efficiently inmud systems containing high concentrations of

lost-circulation material.

The insert float valve is more economical than

standard floating equipment but should not be

used under any of the following circumstances:

in wells over 7000 ft

where pressures exceed the collapsepressure of the lightest weight range of

casing being used (for example, 17 in., 20

lb/ft J55) when bottomhole temperature is more than

200F .

Figure 10.6 Insert Flapper Float ValveSelf-Fill Unit and Insert Flapper Float Valve

Backpressure Valves

Backpressure valves were briefly discussed

under float collars. They are one way valves that

keep the flow of fluid from re-entering the

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Automatic fill equipment is used tocasing. Two common types of valves are the

flapper and poppet valves (Fig. 10.6). reduce rig time

The flapper valve uses a spring-loaded flapper

that has a rubber coating around a beveled edge,

which seals on a tapered seat. The spring is a

low force type (it requires only a small amountof pressure to open the valve).

reduce fluid surge effects of running casing

prevent the sticking of casing

Flapper type equipment can be converted toautomatic fill by installing a fill tube through the

middle of the tool. This holds the flapper off its

seat.

When pumping stops, the spring pushes the

valve back against the seat, preventing fluid

from entering the casing.The diameter of the fill tube can be chosen to

somewhat control the flow rate of fluid into the

casing. To stop the flow rate and convert from

automatic fill to float valve, a ball must be

landed on a seat in the fill tube, pressure applied,

and sheared out of the valve.

The poppet valve uses a rubber-coated, spring-

loaded valve, which seals on a plastic seat. The

poppet is pushed downward by fluid pressure

allowing the fluids to be pumped through the

valve. Once the pumping has stopped, a shut off

is created when the poppet is pushed up against

the seat by a spring.To convert the poppet valve to automatic fill,

specially designed stand-off lugs are insertedbetween the spring loaded valve and the seat.

This allows fluid flow to occur through the valve

from either direction. To cause the valve to act

as a backpressure valve, a specified pump rate

must be achieved that will open the valve

sufficiently to free the stand-off lugs. The lugs

then flow downward from the poppet, allowing

the valve to seat when pumping is stopped.

Flapper ValveFlapper Valve Poppet ValvePoppet Valve

Pressure Differential Fill (PDF)

Float Shoes and Collars

The pressure differential fill (PDF) float shoe

and collar include a float valve. This valve

allows casing to be filled while it is run in the

hole, and it allows fluid circulation at any time

without deactivating the fill unit. PDF float

shoes and collars can be run in the same casing

string. They allow fluid to enter the bottom of

the casing while maintaining a constant

differential pressure between the inside and

outside of the casing at the floats. This pressure

maintains a constant fluid height inside the

casing.

Figure 10.7 Back Pressure Valves

To decrease differential pressure in deep holes

and minimize the possibility of collapsing the

casing, it is necessary to allow some fluid to

enter the casing as it is lowered in the hole.Flapper and poppet valve systems can be

modified to allow the casing to be filled

automatically, but you will have no control over

how much fluid will enter; the amount of fluid in

the annulus directly affects the amount of fluid

which enters the casing.

PDF floating equipment is supplied in the

differential-fill mode, and it is ready to be run in

the hole. After all casing has been run, a

weighted plastic ball is dropped in the casing

from the surface and pumped through the tool.

This procedure deactivates the differential-fill

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Unit B: Casing Attachments

option. After the ball passes the float collar

and/or shoe, the PDF flapper closes against its

seat, preventing cement from re-entering the

casing ID.

The PDF floating equipment is supplied in either

a float collar or a float shoe in common casingsizes. All equipment run with these tools must

have an ID large enough to allow passage of the

weighted ball that releases the backpressure

valve. Tool sizes from 4 1/2to 6 5/8in. require a

1 3/8in. diameter ball, while tools 7 in. and

larger require a 2 3/8in. diameter ball.

PDF floating equipment should not be used in

wells deviated more than 30 from vertical, and

it should not be drilled out with PDC bits. PDF

equipment cannot be used with Super Seal II

floating equipment.

Figure 10.8 Pressure Differential Fill(PDF) Float Shoe and Collar.

Unit A Quiz

Fill in the blanks with one or more words to check your progress.

1. The purpose of guiding equipment is to help casing travel downhole without causing

____________________________________________.

2. The purpose of floating equipment is to help prevent ____________________ problems.

3. A (an)______________________ is run on the first joint of casing.

4. Side ports in a guide shoe help to remove __________________________ and

____________________ .

5. The main difference between a guide shoe and a float shoe is that a float shoe contains a

_____________________. Fluid can only flow ______________ the casing.

6. A (an)___________________________________ can sometimes be used instead

of standard float equipment in a well less than 7000 ft and at bottomhole

temperatures less than 200F.

7. The figure to the right is a (an) ___________________ type valve.

8. Some fluid should enter the casing in deep holes to decrease the differential

pressure to minimize the possibility of _______________________.

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CentralizersCasing attachments are devices installed on theoutside of the casing string to help successfully

complete a primary cementing job.

Bow-Spring CentralizersIncluded in this unit are

Clamps Bow-spring centralizers help center the casing inthe wellbore during cementing operations,

allowing the cement to be evenly distributed

around the casing string. The degree to which

the casing is centered (standoff) depends on the

performance of the centralizer and the spacing

between the centralizers installed on the casing

OD. Bow-spring centralizers, both welded andnonwelded, provide the following advantages:

Centralizers

Wall Cleaners

Cement Baskets

Clamps

All casing attachments must be installed or

fastened to the casing by some method. If they

are not installed over a casing collar, then a

clamp must be used to secure or limit the travel

of the various casing attachments. There are a

number of different types of clamps (Fig. 10.9).

One type is simply a friction clamp that uses a

set screw to keep the clamp from sliding.

They help center the casing in the wellbore,allowing even distribution of cement around

the casing.

They help reduce casing drag on thewellbore during casing running operations.

They help prevent differential sticking of thecasing.

Another type uses spiral pins that are driven

between the clamp and the casing to supply the

holding force. Others have dogs (or teeth) on the

inside, which actually bite into the casing.

Where corrosion problems exist, any clamp that

could scar the surface of the casing is unusable.

Clamps should drawnot pushthe casing

equipment into the hole.

They increase fluid turbulence at the tool,

helping remove filter cake from thewellbore.

They can be run through hole restrictions inthe wellbore or through smaller casing

strings that are cemented in the well, thereby

centering the casing below the restriction.

Welded Bow-Spring Centralizer

Welded bow-spring centralizers are available in

two styles: slip-on and hinged. Slip-on

centralizers are manufactured with solid endrings, requiring the centralizer to be slipped on

the casing OD during installation. Hinged

centralizers are manufactured in segments,

allowing the centralizer to be installed easily

around the casing OD. Hinge pins hold the

segments together during installation. All

welded bow-spring centralizers are

manufactured to API Specification 10D.Figure 10.9 - Clamps

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Centralizers with turbofins attached to each bow

spring are designed to create localized turbulent

fluid flow at the centralizer. The turbofins divert

the fluid flow, more evenly distributing cement

around the casing.

The dual-contact (double bow) welded

centralizer is designed for small-clearance

casing-to-hole size applications. The centralizer

will perform as a standard bow centralizer in

holes up to 1/2in. smaller than the centralizers

nominal OD. When run in holes less than 1/2 in.

smaller than the OD, the center of the centralizercontacts the casing OD, performing as a rigid

centralizer. Because of its high restoring forcewith very little spring deflection, the dual-

contact centralizer is excellent for deviated and

horizontal wellbores. The dual-contact

centralizer should only be installed between a

collar and stop ring never over a casing collar.

All welded and nonwelded bow-springcentralizers are available in most common

hole/casing sizes.

Figure 10.11 Nonwelded Bow-SpringCentralizer

Figure 10.10 Welded Bow-SpringCentralizer Wall Cleaners

Since drilling fluid and cement should not be

mixed together, good cement bonds between

casing and cement and between cement and

formation depend upon removal of the filter

cake from across formations.

Nonwelded Bow-Spring Centralizer

Nonwelded bow-spring centralizers are available

in the hinged style only. The bow springs of this

centralizer are attached to the end rings without

welding. The centralizer bow end is connected

to the end rings with a locking tab that bears the

load force on the centralizer. The centralizers aresupplied in hinged segments joined by hinge

pins in each segment. All nonwelded centralizers

meet or exceed the requirements of API

specification 10D, which dictates the minimum

restoring and maximum starting forces for

centralizers for various casing/hole size

combinations.

Wall cleaners or scratchers (sometimes called

mud stirrers) are installed on the outside of thecasing to mechanically remove mud filter cake

from the wall of the hole with spring steel spikes

or cables.

Mechanical cleaners on the casing agitate the

mud and make it easier to displace. The motion

of the scratchers breaks the gel strength of the

mud in the annulus and helps thin the fluid so

that it can be displaced out of the hole. Mud

removal is also helped by pumping the cement

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slurry at a rate high enough to create turbulent

flow.

Two common types of scratchers are rotation

and reciprocation. The rotation-type scratcher

(Fig. 10.12) cleans the formation when the

casing is rotated at about 15 to 20 rev/min. Acontinuous length of scratchers is needed across

the zones to be cleaned.

Cable-TypeCable-Type Wire-TypeWire-Type

Wire TypeWire Type

Cable TypeCable Type

Figure 10.12 - Scratchers

The reciprocation-type scratcher has either long

steel spikes (Fig. 10.12) or a cable (Fig. 10.12).

These devices scratch or clean the formation as

the casing is picked up 10 to 15 ft off the bottom

of the hole. Be carefulsome reciprocation typescratchers can be installed upside down and

would be useless when they reach the producing

formation.

It is good practice not to have scratchers

working across a lost circulation zone, since the

filter cake and lost circulation material should

not be removed. However, it is possible to run

the reciprocation type (no cable type) scratcher

in a lost circulation zone with minimal

disturbance of the filter cake.

Movement of the casing, in addition to the use

of mechanical cleaners, greatly increases the

ability of the cement slurry to more completely

displace the mud and prevent mud channels

through the cement. This movement can be

either rotation or reciprocation during the

circulating and displacing operations.

Cement Baskets

Cement baskets are also installed on the outsideof casing. They help support some of the

hydrostatic pressure that the cement slurryproduces until it sets and protect the producing

formation against cement contamination. A

cement basket has a canvas or metal liner

supported by steel staves (Fig. 10.13).

This canvas liner filters out the cement solids,

which may form a bridge between thecasingand hole. The maximum amount of pressure that

any cement basket should ever be expected to

hold is approximately 50 psi. A cement basketshould be able to travel the full length of the

pipe joint.

Figure 10.13 Cement Basket

Cement baskets are used

above weak zones that may break downunder the hydrostatic pressure of the cement

slurry for cementing casing through a shoe joint to

provide extra support for the column of

cement.

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Unit C: Primary Cementing Plugs

Unit B Quiz


1. If a casing attachment is not installed over a casing collar, then a (an) _____________ is used to

fasten the equipment to the casing.

2. If youre working on a well that will likely have corrosion problems, youll want to avoid the use of

any clamp that could ____________ the casing, like a clamp which has ________________.

3. A uniform cement sheath around the casing largely determines the effectiveness of the

__________________ between the wellbore and casing.

4. The casing attachments used to center the casing in the hole are called

_______________________________________.

5. Scratchers are used to mechanically remove ________________ from formations.

6. Rotation type scratchers clean the formation when the casing is___________.

7. Reciprocation type scratchers clean the formation when the casing is

______________________________.

8. In addition to using mechanical scratchers, mud displacement is also helped by the

___________________ of cement, and the _______________________ of the casing during a

cement job.

9. Cement baskets support some of the _________________________, which the slurry produces until

it sets. They have a ____________________ liner, which filters out cement solids that can form a

___________________between the casing and the wellbore.

10.Cement baskets are usually used above a ________________________.

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Plugs used in primary cementing minimize

cement contamination in the casing by wiping

the casing clean and serving as a barrier between

wellbore fluid and cement. Included in this unit

areCasing

Top Cementing Plug

CementSlurry

Boundary

Layer of Mud

Mud

Accumulation of

mud-contaminatedcement from wipedaway boundarylayer

Bottom plugs

Top plugs

Latchdown plugs

Bottom Plugs

The function of the bottom plug is to enter the

casing ahead of the cement slurry. It wipes mud

and solids from the casing wall and keeps those

solids ahead of the plug. Bottom plugs are

almost always used in primary cementing,except when lost circulation materials are being

run with the cement.

Figure 10.15 Top plug run without abottom plug.

Top Plugs

Bottom Plugs

When the bottom plug reaches the float collar or

float shoe, the differential pressure between the

inside of the casing and annulus ruptures the

diaphragm on top of the plug to allow the slurry

to flow out of the shoe and up the annulus. The

plug body is strong enough to withstand the

forces of impact and the differential pressure to

rupture.

Top Plugs

A top plug is pumped down by displacement

fluid after all the slurry has been pumped (Fig.

10.15). It prevents the displacement fluid from

channeling through the more viscous cement

slurry. Top plugs have no diaphragm and fluid

can not be pumped through them. When it

reaches the top of the bottom plug, pressure will

build up and indicate that the job is complete. Figure 10.16 Cross-section of cementingplugs.

Although the top and bottom plugs perform

somewhat the same function (separating two

fluids), they are quite different structurally (Fig.

10.16).

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Top plugs have rubber wipers to wipe the casing

and can withstand considerably more pressure.

To help with easy identification, top plugs are

black and bottom plugs are red. Top and bottom

plugs have a solid core of plastic.

Latch-down Plugs

Latch-down plugs are usually used with tubing,

casing and interstring cementing; however, they

may also be used with conventional casing float

equipment. The latch-down plug functions as a

top plug, and its snap ring locks into a groove inthe baffle when it is pumped down after the job

(Fig. 10.17). The latch-down feature helps

ensure that the cement and top plug will not

move back up the casing.

The Latch-down Casing Plug and Baffle may be

used above most conventional floating

equipment to help control fluid and pressure

from below. The Latch-down plug may also be

used when there is no floating equipment run on

the casing string. Prevention of fluid entry into

the casing string also permits immediate release

of surface pressure when the cement column has

been pumped in place. Additionally, the latch-

down feature helps assure that the cement or top

plug will not back up the casing which might

necessitate drilling out if completions are madeclose to the float collar.

The baffle is installed either on top of the float

or in the desired casing collar above and held in

place by the pin end of the casing. A rubber

gasket seals against the upper joint and the

coupling threads. The latch-down plug acts as

the top cement plug and follows the cement

slurry down the casing to reduce the possibility

of contamination or channeling with the drilling

mud or fluid used to displace the cement. When

the plug reaches the baffle, normally 500 to

1,000 psi above circulating pressure forces thelatching nose of the plug into the baffle and

locks it in place.

The maximum pressure that the baffle will

withstand is dependent upon the proper make-up

of the casing joints and the weight range of the

casing. A differential of 3,000 psi should not be

exceeded in any light weight casing. Higher

differential pressures are allowable in heavier

weight casing with a maximum of 5,000 psi inthe heaviest weights.

Figure 10.17 Latchdown plug and baffle.

The latch-down baffle may be installed either on

top of the float shoe or float collar, or in any

casing collar above a float collar. It is held in

place by the thread end of the casing. A rubber

seal on the plug provides a fluid seal from both

directions.

Instead of a float collar, a latch-down plug may

be used in conjunction with a guide shoe to save

rig time.

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Summary of Downhole EquipmentType of Equipment Major Function(s) Location

Guide Shoe To guide casing into wellTo help protect casing ends

First joint of casing

Float Shoe Same as guide shoeTo prevent fluid or cementflowback

First joint of casing

Baffle Collar To provide a landing seat forplugs

1-3 joints above shoe (dependingon depth of well)

Float Collar Same as baffle collarTo prevent fluid or cementflowback

1-3 joints above shoe

Insert Float Valve Same as float collar In casing collar

Back Pressure Valve To prevent fluid or cementflowback

In floating equipment

Automatic Fill Valve To automatically allow fluid intothe casing to eliminate rigdowntime cause by stopping tofill the casingTo reduce ram effect

In float shoes and collars

Differential Fill Valve To allow fluid to enter casing todecrease differential hydrostaticpressure

In float shoes and collars

Clamp To fasten attachments As required

Centralizer To center casing in hole 1 per joint from 200 ft. aboveformation to 200 ft below it, 1 per

3 joints in open holeWall Cleaner To remove mud filter cake from

wall of holeFrom 100 ft above producingformation through it

Cement Basket To help protect formations fromhydrostatic pressure of cementuntil it sets

Above weak formations

Bottom Plug To Act as a mechanical spacerbetween mud and cement slurry

Between well fluids and cement

Top Plug To act as a mechanical spacerbetween cement slurry anddisplacement fluid

Between well fluids and cement

Latch-down Plug Same as top plug Between well fluids and cement

Multiple Stage Cementing Tools To cement in two (or more)stages

Depends on hole conditions

Formation Packer Equipment To pack off formationsTo isolate zones

Depends on hole conditions

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Unit D: Multiple Stage Cementing Tools

Unit C Quiz


1. Primary cementing plugs minimize _____________________ by _____________ the casing clean.

2. These plugs serve as a (an) _____________ between fluids and cement.

3. A bottom plug enters the casing _______________ the cement slurry. The _________________

pressure between the inside of the casing and the annulus causes the plug(s) ________________ to

rupture.

4. Bottom plugs are almost always used in primary cementing, except when

______________________________________ is (are) being run.

5. A top plug enters the casing ______________________ the cement slurry. When it seats on/at the_______________________, pressure will increase. This indicates that cement placement is

____________________.

6. _____________________ are black and have a deep cup on top; ______________________are red

and shallow.

7. A (an)_______________________ plug functions in the same way as a top plug, but it has a

(an)______________________, which locks into a groove in its baffle.

8. To save rig time, you might use a latchdown plug in conjunction with a guide shoe instead of a (an)_______________________.

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During multiple-stage cementing, cement slurry

is placed at predetermined points around the

casing string in several cementing stages.

Multiple-stage cementing can be used for the

following applications:

heavy-duty seals and backup rings that

prevent seal damage during operations

compatibility with three-stage cementingapplications

cementing wells with low formation

pressures that will not withstand the

hydrostatic pressure of a full column ofcement

Type-P External Sleeve (ES)Cementer

Type-P external sleeve (ES) cementers can be

used in most vertical wells, regardless of depth,

pressure, or temperature. The Type-P cementer

should not be used in wells deviated more than30 from vertical when using a free-fall opening

plug. Otherwise, the free-fall opening plug will

not fall by its own weight through well casing.

Type-P ES cementers are available in 4 1/2to 20

in. casing sizes. The standard case material

grade is L-80 steel. Other casing grades can be

provided at the customers request.

cementing to isolate only certain sections

of the wellbore

placing different blends of cement in thewellbore

cementing deep, hot holes where limitedcement pump times restrict full-bore

cementing of the casing string in a single

stage

Halliburton manufactures two types of external

sleeve (ES) stage cementers: the Type-P ES

cementer, which is a plug-operated stage

cementer, and the Type-H ES cementer, which is

a hydraulically opened stage cementer. Both the

Type-P and the Type-H cementers have thefollowing features:

short, single-piece mandrel design without

threaded or welded segments

field-adjustable opening and closing

pressures

clear surface indications of opening and

closing

smooth bore after drillout with no exposed

sleeves to interfere with the operation of

workover tools on subsequent trips in and

out of the casing strings

drillability with either PDC or roller-cone

rock bits

compatibility with second-stage bottom

plug sets Figure 10.18 - Halliburton Type-P ExternalSleeve (ES) Cementer

external closing sleeve that is locked

closed by the top cementing plug

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During cementing operations, the first-stage

cement is mixed and pumped into the casing in a

conventional manner. The first-stage shutoff

plug, which is launched in the casing after the

first-stage cement, lands on the shutoff baffle

installed on the float collar. This shutoff plug

provides a positive shutoff, which helps preventcement over displacement around the shoe joint.

After the first-stage cementing operation iscompleted, a free-fall opening plug is dropped

down the casing ID to land and seal in the

cementer. Pressure applied to the casing opens

the cementer, allowing wellbore fluid to be

pumped into the casing/wellbore annulus. Fluidcirculation to the surface is normally maintained

until the first-stage cement has set up in the

annulus. The second-stage cement is then

pumped through the open cementer ports,

followed by a second-stage closing plug. Theclosing plug seats in the cementer, and pressure

is applied to the casing to close the tool. After

both stages are cemented, the cementer seats,

and plugs are drilled out with a rock bit or a

PDC bit.

Figure 10.19 Halliburton Type-H ExternalSleeve (ES) Cementer

plug dropped through the casing ID. The Type-

H cementer can be used in highly deviated wells,

in horizontal wells, and above an openhole

completion or slotted liner. After the second-

stage cementing operation, a second-stage

closing plug pumped behind the second-stage

cement closes the cementer. Lock rings in the

external closing sleeve lock the cementer in the

closed position. After both cementing stages, the

cementer seats, and plugs are drilled out with a

roller-cone rock bit or a PDC bit.

Type-H External Sleeve (ES)Cementer

The Type-H external sleeve (ES) cementer is a

hydraulically opened stage cementer that can be

used in most wells, regardless of depth, pressure,

or temperature. Although the Type-H ES

cementer operates much like a Type-P cementer,

it can be opened with internal casing pressure in

addition to the free-fall plug after the first-stage

shutoff plug lands. This design feature saves

time by eliminating the need for dropping a free-

fall plug from the surface. A baffle adapter is

recommended in the casing string above the

float collar to seat the first-stage shutoff plug.

Type-H ES cementers are available in 4 1/2to 20

in. casing sizes. The standard material grade is

L-80 grade steel. Other grades can be provided

at the customers request.

Stage Tool Plug SetsWhen the first-stage cementing plug has seated,casing pressure can be applied to hydraulicallyopen the Type-H ES cementer. Normally, thecementer should be opened immediately after

the first-stage cement is pumped and the shutoff

plug has been bumped. If the well is deviated

less than 30 from vertical, the Type-H ES

cementer can also be opened with a free-fall

Plug sets for operating both Type-P and Type-H

cementers must be ordered separately from the

cementer. The individual components of each

plug set depend on the type of tool to be

operated.

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A standard plug set for two-stage cementing

consists of the following equipment:Full-Opening (FO) Multiple-Stage Cementer

a shutoff baffle installed on top of the float

collar (for 8-rd and buttress) The full-opening (FO) multiple-stage cementeris used to place an indefinite number of cement

stages or other fluids at selected points along theoutside of a casing string. An indefinite number

of FO cementers can be run in the casing string.

Standard material grade is L-80. Other grades

can be supplied at customers request.

a shutoff plug (for both Type-P and Type-

H cementers)

a free-fall opening plug (required for the

Type-P cementer; optional for the Type-H

cementer)

a closing plug (for both Type-P and Type-

H cementers)When one or more FO cementers are run in the

casing string, the first stage of cement can be

pumped in the conventional manner. All

subsequent cementing stages are pumped

through a workstring run inside the casing.

Shifting tools run 8 to 10 ft apart on the

workstring are used to open or close the FO

cementer.

a baffle adapter installed one or more

joints above the float collar (for the Type-

H cementer)

Unlike plug-operated or hydraulically opened

stage cementers, FO cementers provide the

following benefits:

They do not require operating plugs,

eliminating the need for drilling out after

cementing.Figure 10.20 Halliburton Type-P StageTool Plug Set FO cementers can be used to test, treat,

and evaluate a zone in the well before it is

closed.

Multiple FO cementers can be run in thesame casing string.

Operators can open and close these tools

as many times as necessary.

A packoff between the workstring and casing is

required to direct fluid out the open ports of the

FO cementer.

Figure 10.21 Halliburton Type-H StagePlug Set

FO cementers are available by special order for

any casing grade or premium thread. For pricing

information, customers must provide

information about casing OD, thread type,

weight, grade, and hole size.Use of a baffle adapter is the preferred method

when using a Type-H cementer with a first-stage

bottom plug.

Wells can also be cemented in three stages with

two cementers and a three-stage plug set. A

three-stage plug set must be ordered separately

from the cementers.

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Figure 10.22 Halliburton Full-Opening(FO) Multiple-Stage Cementer

External Sleeve InflatablePacker Collar (ESIPC)

The external sleeve inflatable packer collar

(ESIPC) is a combination of the ES (Type H or

Type P) cementer and a casing inflation packer.This tool provides controlled packer element

inflation through the stage-tool opening seat,

eliminating hydraulic valving bodies normally

used with inflatable packer elements. The rubber

inflatable packer element is constructed with

reinforcing metal slats to reduce packer element

damage during inflation. This inflatable packer

element allows packer differential pressures up

to 4,000 psi.

The ESIPC is commonly used in horizontal well

applications for cementing casing in the bend

radius or vertical portion of the wellbore abovean openhole completion or a slotted liner. The

packer element is inflated to prevent cement

from flowing downhole when it is pumped into

the annulus above the tool. The Type-H ESIPC

is available by special order for any casing grade

or premium thread. For pricing information,

customers must provide information about

casing OD, thread type, weight, grade, and hole

size.

Figure 10.23 Halliburton External SleeveInflatable Pack Collar (ESIPC) Type H

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Unit D Quiz


1. Multiple stage cementing tools are used when you want to cement behind the same casing string in

___________ stages.

2. The decision to cement in multiple stages would be made when high hydrostatic pressure might cause

the _________________ to break down.

3. If the Type-H ES cementer doesnt open with _________________ pressure, a

_____________________ can be dropped if the well is not deviated more than _______.

4. During the second stage, cement is displaced through _______________ in the multiple stage tool.

5. A multiple stage tool called a __________________________ has two sleeves which are operated_____________________. One sleeve moves to uncover the __________ and the other moves to

close the _____________________.

6. The first part of the plug set to enter the hole when the free fall method is used is the

_______________________.

7. Once the opening plug has landed, the Type-P ES cementer is opened by ___________________.

8. Unlike the ES cementers, the FO cementer operates _____________________ and can be opened and

closed _________________________________.

9. Formation packer equipment is used when you want to ________________ cement from flowing

_____________________.

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Answers to Unit Quizzes

Items from Unit A Quiz Refer toPage

1. damage to hole or casing 10-3

2. overweight 10-3

3. float shoe 10-4

4. wellbore cuttings, filter cake 10-4

5. backpressure valve, into 10-4

6. insert flapper float valve 10-6

7. flapper 10-7

8. collapse 10-7

Items from Unit B Quiz Refer toPage

1. clamp 10-10

2. scar, dogs (teeth) 10-10

3. cement 10-10

4. centralizers 10-10

5. filter cake 10-12

6. rotated 10-12

7. picked up 10-12

8. pumping rate, movement 10-11,12

9. hydrostatic pressure, canvas,bridge

10-12

10. weak zone 10-12

Items from Unit C Quiz Refer toPage

1. contamination, wiping 10-14

2. barrier 10-14

3. ahead, differential, diaphram 10-14

4. lost circulation materials 10-14

5. after, bottom plug, complete 10-14

6. Top plugs, bottom plugs 10-15

7. latch-down, snap ring 10-15

8. float collar 10-15

Items from Unit D Quiz Refer toPage

1. several 10-17

2. formation 10-17

3. hydraulic, free fall plug, 30 10-17,18

4. ports 10-18

5. Type-H ES Cementer,hydraulically, ports, ports

10-18

6. shut off baffle 10-197. pressure 10-18

8. mechanically, as many times asnecessary

10-19

9. prevent, downward 10-20

10. downhole cementing equipment

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