WELL CONSTRUCTION

Centralizer Sub
Delivering optimal centralization and
standoff in wells with tight restrictions
 “Cementing is 80% placement, and placement is 80% centralization.
If you can’t centralize the pipe and place cement in more than 99% of the
annular areas—you can’t expect to achieve reliable long-term isolation.”
– Mike Cowan, Senior Research Fellow, The University of Texas at Austin

Weatherford centralizer subs

keep you centered, even in
tight-tolerance wells.

Wellbores today reach farther than ever, Solving challenges in

which means casing IDs must stay as large ultratight applications
as possible. To achieve proper cementing in • Running centralizers through
these conditions, centralizers have to pass restrictions less than 0.5 in.
through close-tolerance casing restrictions as
• Centralizing casing in underreamed
narrow as 0.125 in. and still centralize strings in
holes of 4 in. or more
underreamed open holes of 4 in. or more.
• Passing through a casing window
Weatherford centralizer subs can go places that and then centralizing casing for
conventional centralizers simply can’t. These re-entry and sidetracking
tools enable you to pass through ultratight
• Running casing or liner to bottom in
restrictions and centralize casing in the larger
both vertical and highly deviated wells
wellbore. The rugged design and construction
leave the centralizer uncompromised to • Rotating casing or liner to reach bottom
properly center the casing. As a result, you and to improve the cementing job
achieve optimal standoff for improved cement • Meeting casing requirements for the
placement and, ultimately, reliable isolation. sub portion of the tool in these areas:

We patented the original centralizer sub – burst

design in 1995. Since then, we have run our – collapse
subs and evolved our portfolio to satisfy
– tension
industry demands. Our ongoing commitment
to continual improvement assures you that – drift
our subs meet or exceed performance
requirements.

2 © 2015 Weatherford. All rights reserved.

Our centralizer subs are engineered
for a lifetime of integrity.
Centralizers affect more than your ability to reach total depth.
They also have a critical impact on cementing integrity.
When you select Weatherford centralizer subs, you get the
benefit of 20 years of production and field experience.

Advanced designs for any installation

We manufacture each centralizer sub from a single piece
of steel or corrosion-resistant alloy, which matches the
burst, collapse, and tensile ratings of most casing sizes. For
specialized performance, we also offer custom designs. By
applying finite element analysis and proprietary calculations,
we can machine materials to the exact dimensions and
mechanical properties you need. In addition, we can
determine the right bow style, size, and number.

Thorough testing for superior performance

To ensure field performance, we simulate actual field
applications and use internal testing protocols that exceed API
requirements. During testing, we flex the bows multiple times,
conduct a 100-percent weld inspection, pass the centralizer
sub through ultratight restrictions, and measure the starting,
running, and restoring forces. This process provides you
accurate performance data and quality assurance.

Expert advice on the right program

Whatever your centralization challenge, our experienced sales
and applications teams can analyze your well and recommend
the optimal solution. For every application, we run proven
CentraPro Plus® software to select the proper centralizer and
determine effective placement. This enables you to reach
bottom and achieve the necessary standoff for a quality
cement job. Our clients have successfully run thousands of
casing strings using our subs with this approach.

Built-in benefits

• Most experience in the industry

• Rapid response team for expediting orders with short lead times
• Extensive selection of raw materials for unique metallurgy
• Customer-defined quality plans with third-party inspection
• Manufacturing capability in multiple global locations:
– Houma, LA
– Ortana, Italy
– Abu Dhabi, UAE

© 2015 Weatherford. All rights reserved. 3

An extensive portfolio for diverse applications
Our broad centralizer sub portfolio includes three main product families: centralizer subs, rotating
centralizer subs, and centralizer sub guide shoes. We have solutions for nearly every existing
centralizer-sub application, and we can custom build technologies for new challenges.

541 Centralizer Sub

The original centralizer sub features our smallest rigid OD. This
enables it to go places that some rotating subs cannot. The
sub has a low running force in restrictions and previous casing,
and it has a high restoring force in the open hole.

541R Rotating Centralizer Sub

The 541R rotating centralizer sub freely rotates inside the
centralizer, which enables the casing or liner string to rotate.
Like the original centralizer sub, it has a low running force and
a high restoring force. The running and restoring force have
been optimized to suit any application.

Centralizer Sub Guide Shoe

Designed and built for specific needs, centralizer sub guide
shoes are available for either rotating or standard centralizer
sub designs. These guide shoes come with nose, nose material,
and jet configurations as needed.

542 Centralizer Sub

The 542 centralizer sub features solid blades and is
typically used with deviated strings to reduce drag.
The sub enables casing to get to bottom, especially
in deviated and extended-reach-drilling wells.

540 Centralizer Sub

The 540 centralizer sub is run in deepwater wells
when a solid centralizer must pass through ultratight
clearances. This sub allows positive standoff around
the shoe, which reduces the risk of differential sticking
and guides casing over ledges.

VariForm™ Centralizer Sub

The VariForm centralizer sub is the next generation of the 541R
bow-spring centralizer. This sub features a high-performance
VariForm centralizer mounted by a patent-pending method onto
the centralizer sub body.

4 © 2015 Weatherford. All rights reserved.

Application Guide
Our family of centralizer subs features high-quality, welded products for ● Best choice
various casing sizes. Nonrotating and rotating centralizer sub versions give
you options to address specific casing running and cementing challenges. ● Can be used without limiting operations

● Can be used with caution

Not recommended

Rigid VariForm Bow Spring

542 540 Sub 541 541R
Vertical Strings ● ● ● ● ●
Deviated Strings ● ● ● ● ●
Horizontal Strings ● ● ● ● ●
ERD Strings ● ● ● ● ●
Rotating Casing ● ● ● ●
Reciprocating Casing ● ● ● ● ●
Cased Hole ● ● ● ● ●
Open Hole ● ● ● ● ●
Underreamed: 0.875 in. < Restriction < 1.5 in. ● ● ● ● ●
Underreamed: Restriction ≤ 0.875 in. More Than Casing OD ● ● ● ● ●
Oversized/Washed-Out Hole ● ● ● ● ●
Uncemented Completion ● ● ● ● ●
Uncemented CRA Completion ● ● ● ● ●
Protects Tools in String ● ●

How the centralizer sub works

Our centralizer sub features a machined body

with an integral bow spring centralizer secured
to it. The springs compress near the sub
body OD when going through the ultratight
restriction. After the centralizer sub reaches the
open hole, the bow springs expand to provide Bows in Bows in
standoff in the underreamed sections. As non-compressed compressed
state state
cement slurry is pumped between the casing
and the wellbore, the sub keeps the casing
centered in the well for excellent centralization.

Bows in non-compressed state.

Bows in compressed state. Bows collapse flush to the body.

© 2015 Weatherford. All rights reserved. 5

Operational support
with a global footprint
Our local teams can assist your centralizer-sub applications anywhere in the world. When you’re on the job,
we can revise simulations on-site or remotely from our closest city, country, or global facility. Once the job
is complete, we can help you analyze performance according to cement-bond logs and hookload data.
In addition to these services, we offer 360º torque-turn technology for offline makeup of centralizers to the
casing, which saves you significant rig time and enhances safety.

Key locations Regional offices

Ultradeepwater, Black Sea

Ran casing up to The all-in-one WellMaster deepwater

system, including rotating centralizer
15X FASTER subs, provided a simple, fast, and
effective solution to eliminate potentially
using the WellMaster™ costly problems in a weak formation.
system with 541R The operator ran a liner to a TD of
16,213 ft (4,942 m) and performed a
centralizer subs flawless cement job at rates of up to
45 ft/min (13.7 m/min) with zero mud
spills and zero recordable incidents.

6 © 2015 Weatherford. All rights reserved.

There’s more to cementing
a well than just cement.
The challenging wells you cement today must provide a lifetime of integrity. Our centralizer
subs are just one part of a product portfolio and service suite that can help you construct
wells in the toughest environments and make them last. We can help you properly install
and centralize casing, place cement optimally, and achieve long-term isolation.

Identify drilling challenges Design out risk; design Select products and
and objectives in deep water, in lower well construction services that meet design
shale, HPHT, a  nd conventional costs a nd longer requirements with our reliable
applications. productive life. technology.

Casing centralization
Increase stand-off, prevent differential
sticking, and eliminate channeling
• Casing accesories
• Centralizers

Casing installation • Placement software services Wellbore isolation

Reach total depth Prevent fluid migration
safely and efficiently and reduce well
construction costs
• Float equipment
• Inflatable packers
• Surge reduction systems
• Isolation systems
• Torque-and-drag reduction
• Swellable packers

WELL
INTEGRITY

Integrity confirmation Cement placement

Measure cement bond quality Ensure effective cement
• Cement-bond-logging tools slurry displacement
• Stage cementing tools
• Wiper plugs and darts

© 2015 Weatherford.
© 2015 Weatherford.All
Allrights
rightsreserved.
reserved. 7
For more than half a century, Weatherford has provided an
extensive portfolio of products to meet your casing centralization
needs. To learn more about how our centralizer subs can
enhance the integrity of your well, contact an authorized
Weatherford representative or visit weatherford.com.

weatherford.com © 2015 Weatherford. All rights reserved. 11791.00

Weatherford products and services are subject to the Company’s standard terms and conditions, available on request or at weatherford.com. For more information contact an authorized Weatherford representative.
Unless noted otherwise, trademarks and service marks herein are the property of Weatherford and may be registered in the United States and/or other countries. Weatherford products named herein may be protected
by one or more U.S. and/or foreign patents. Specifications are subject to change without notice. Weatherford sells its products and services in accordance with the terms and conditions set forth in the applicable
contract between Weatherford and the client.