MetalSkin - Weatherford International

ouble
one
Current
production
7 in.
Target
zone
Application Answers
Accessing Deeper
Reserves
MetalSkin ®
MetalSkin Monobore Open-Hole Clad
MetalSkin Cased- and Open-Hole
Liner and Monobore Open-Hole Clad Systems
Challenge
Enhanced exploration techniques are identifying
deeper horizons, many of which underlie existing
field developments. As wells deplete and fields
mature, operators consider using existing wells to
develop these new reserves to prolong the life of
the wells, the field, and the facilities. The challenge
is to perform these operations, either by deepening
or by plugging back and sidetracking the existing
wells, in such a way as to maintain sufficient
hole size to facilitate subsequent completion,
stimulation, and production operations. Standard
methods of lining the deepened well—to complete
and produce the newly opened zones—result in
a greatly reduced ID. This reduced ID can inhibit
production capacity and impede well access.
13-3/8 in.
9 5/8-in.
9 5/8-in.
13-3/8 in.
5 in. 7 in.
Current
production
7 5/8- × 9 5/8-in.
Target
zone
Answer
Cased- and Open-Hole Liner and
Monobore Open-Hole Clad Systems
MetalSkin Cased-Hole Liner
MetalSkin Open-Hole Liner
Weatherford’s MetalSkin open-hole and cased-hole
liner systems are designed to deal with welldeepening
drilling challenges, while the monobore
open-hole clad system can be used to seal off
old production and problem zones. Metal Skin
solid-expandable systems facilitate the redrilling
of mature wells, thereby enhancing their long-term
production capabilities. These systems can be
used to line the redrilled section with no loss in
hole size. The MetalSkin system can be expanded
in place to isolate problem zones or provide well
integrity over the full length of the redrilled section,
as required for subsequent production and/or
remediation operations.
MetalSkin systems economically
deepen mature production wells
to access new reserves.
Trouble
zone
© 2009 Weatherford. All rights reserved.

Current
production
Trouble
zone
Target
zone
Base Case
Existing Condition in Mature Well
13-3/8 in.
9-5/8 in.
The current producing zone in a cased and perforated well
has been depleted. The well will be reentered to access
reserves from a deeper target zone. Above this new zone,
a trouble zone is expected, which will require isolation
before drilling into the new target zone.
2
Current
production
Trouble
zone
Target
zone
MetalSkin ®
Cased- and Open-Hole Liner and
Monobore Open-Hole Clad Systems
Conventional Deepening
13-3/8 in.
9-5/8 in.
7 in.
5 in.
A cement squeeze isolates the depleted production zone.
The existing 9 5/8-in. shoe is drilled out in the 8 1/2-in. hole
through the trouble zone. This zone is isolated with a 7-in.
cemented liner, tied back above the current production zone.
The deeper target zone is then drilled in a 6 1/8-in. hole and
cased with a 5- or 5 1/2-in. liner, depending on burst and
collapse requirements.
© 2009 Weatherford. All rights reserved.

Current
production
Trouble
zone
Target
zone
Expandable Approach – Option 1
13-3/8 in.
13-3/8 in.
9-5/8 in. 9-5/8 in.
7 in.
5 in.
7 5/8- × 9 5/8-in.
cased-hole liner
8-1/2 in. monobore
open-hole clad
Current
production
Trouble
zone
Target
zone
13-3/8 in.
5 in. 7 in.
5 in.
If a cement squeeze job is not sufficient to effectively isolate
the depleted (current) zone, then a 7 5/8- × 9 5/8-in. casedhole
liner can be installed over the existing perforations.
Subsequently, instead of running a conventional cemented liner
to isolate the trouble zone, an 8 1/2-in. monobore open-hole
clad is set. This liner temporarily isolates the trouble zone with
no loss of hole size, enabling the target zone to be drilled in the
8 1/2-in. hole. Because the hole size has been saved, it is now
possible to run conventional 7-in. flush-joint casing across the
trouble zone and the new producing interval, and tie this casing
back above the old cement-squeezed interval. When compared
with a conventional approach, this application of an expandable
liner gives a higher productivity index because of the increased
hole size.
3
MetalSkin ®
Cased- and Open-Hole Liner and
Monobore Open-Hole Clad Systems
Expandable Approach – Option 2
Conventional Expandable Conventional Expandable
13-3/8 in.
9-5/8 in. 9-5/8 in.
7 in.
8-1/2 in. monobore
open-hole clad
7 5/8- × 9 5/8-in. MetalSkin
open-hole liner
The production potential of the well can be even further
increased by replacing the 7-in. conventional liner across the
new target zone with a 7 5/8- × 9 5/8-in. open-hole liner. This
liner can again be tied back above the old producing interval,
as well as permanently casing the trouble zone. This approach
then equates to a further increase in the ID through the new
reservoir section from just over 4 in. in the conventional
approach to 7 in. with this open-hole liner approach.
© 2009 Weatherford. All rights reserved.

Current
production
Trouble
zone
Target
zone
7 in.
5 in.
Sidetrack – Option 3
Conventional Sidetrack Expandable Sidetrack
13-3/8 in.
9 5/8-in.
9 5/8-in.
13-3/8 in.
4
7 in.
MetalSkin ®
Current
production
Trouble
zone
7 5/8- × 9 5/8-in.
Cased- and Open-Hole Liner and
Monobore Open-Hole Clad Systems
Target
zone
If the well must be sidetracked to a new reservoir location, rather than simply deepened, the loss
of hole size associated with conventional casing programs can impede completion objectives.
A conventional approach for a sidetrack in an 8 1/2-in. open hole out of the existing 9 5/8-in.
casing results in a 7-in. cemented casing across the trouble zone and a 5-in. liner in the new
reservoir section. Isolating the trouble zone with a 7 5/8- × 9 5/8-in. open-hole expandable liner
enables 7-in. flush-joint casing to set in the existing 9 5/8-in. casing and set at the target total
depth (TD).
© 2009 Weatherford. All rights reserved.

Constraints
There are two standard options to work over
existing wells when accessing deeper reserves:
• The well can be reentered as is and drilled out to
reach the deeper horizon.
• The mature well can be plugged back and then
sidetracked to access the deeper reserves.
In either case, some limitations inevitably occur
using conventional methods, which can lead to
a reduction in hole size when entering the new
formation of interest. Whether deepened or
sidetracked, drilling must take place through the
original producing formation, which is probably
depleted; therefore, lost-circulation conditions that
will require remediation can be expected. These
conditions can be treated conventionally by:
• Squeeze cementing of the previous producing
zone before deepening the well. This approach
runs the risk of breakdown during drilling
operations and may require costly and timeconsuming
squeeze operations.
• A conventional liner or scab liner can be used,
resulting in a significant loss of hole size.
• If lost circulation occurs in the “old” zone of a
sidetracked well, setting a liner may be required,
thus causing a loss of hole size.
Another option is that the redrilled well be
completed in open hole; however, the production
control and isolation problems associated with
open hole are inevitable. Scab liners can ultimately
be used to isolate any problem zones, but again,
the resultant loss of hole size can be critical to
production operations.
5
MetalSkin ®
Cased- and Open-Hole Liner and
Monobore Open-Hole Clad Systems
Features, Advantages and Benefits
• MetalSkin solid-expandable cased-hole or openhole
liner systems, together with monobore openhole
clad systems, as appropriate, can be used
to address the shortcomings of conventional
solutions. These systems can provide a proven
and effective method of casing the worked-over
or redrilled well with minimal or no loss of hole
size, thereby greatly improving production, while
at the same time addressing future well access
concerns.
• The threaded expandable tubular joints of the
cased-hole liner system can be connected to
create a lengthy liner. Alternatively, a single
length of open-hole clad can be used, or several
short sections of open-hole clad can be run
to straddle trouble spots in the open hole, as
needed.
• The elastomeric seal elements, strategically
placed along the length of the liner, provide
additional effective zonal isolation in either
cased-hole or open-hole applications.
• The loss of ID can be minimized by using either
the cased-hole liner or the open-hole liner
system. If a suitable seat can be found below the
casing shoe, then the monobore open-hole clad
system can be used to retain the same ID. In
either case, the MetalSkin system can maximize
production or injection capacity.
• No matter which MetalSkin system is used, the
resultant ID is greater than that obtainable with
conventional equipment. This larger ID enables
better access to the well and to the use of
conventional tools in subsequent completion or
remedial operations.
• The MetalSkin cased-hole system provides
superior efficiency and economy and, unlike
other expandable and conventional systems,
requires no drillout.
• The well can still be deepened, if required, by
drilling through the MetalSkin cased-hole liner
after it has been set.
© 2009 Weatherford. All rights reserved.

Weatherford International Ltd.
515 Post Oak Blvd., Suite 600
Houston, Texas 77027 USA
Tel: 713-693-4000
weatherford.com
MetalSkin ®
Cased- and Open-Hole Liner and
Monobore Open-Hole Clad Systems
Learn more about the MetalSkin cased- and open-hole liner systems, as well as
the MetalSkin monobore open-hole clad system—all part of the MetalSkin family of
new-generation, solid-expandable technologies—and how they can deal with the
challenges of reworking an existing mature well by whatever means to access a
deeper zone of interest.
Contact the world’s most experienced expandable experts, with the most advanced
line of products, through your local Weatherford representative, or visit us at
weatherford.com/metalskin.
The Solid Choice TM
from the expandable experts
Weatherford products and services are subject to the Company’s standard terms and conditions, available
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Unless noted otherwise, trademarks and service marks herein are the property of Weatherford. 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.
© 2009 Weatherford. All rights reserved. 4751.00