Packers failure

1. SPE 80945
Ratings Standardization for Production Packers
John Fothergill, SPE, Baker Oil Tools
Copyright 2002, Society of Petroleum Engineers Inc.
This paper was prepared for presentation at the SPE Production Operations Symposium, held
in Oklahoma City, Oklahoma, 22-25 March 2003.
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presented, have not been reviewed by the Society of Petroleum Engineers and are subject to
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Abstract
Longstanding ambiguity surrounding performance ratings for
production packers continues to be a topic of concern, as
increasingly demanding completion environments drive more
critical product selection processes. Inconsistencies in
manufacturer testing methodologies and design validation
procedures have previously not supported a quality selection
process. Completion engineers, not equipped with a thorough
understanding of the nuances of packer performance
characteristics under various load conditions, have been
dependent upon the technical expertise and good faith of the
manufacturer.
This paper gives the completion engineer a working
understanding of applied packer performance ratings. The
evolution of qualifying testing procedures is discussed, as well
as the most recent advancements in the standardization
process. Ratings standardization set forth in ISO 14310,
establishing both quality control and design validation grades,
is described. Completion engineers and other decision
makers, as well as salesmen need this information for
informed product comparisons and proper matching of product
to application.
Introduction
This paper is to provide the information necessary for critical
evaluation of only one component in the completion system.
Although beyond the scope of this paper, it is important to
recognize how the entire system must also be critically
evaluated. If the value of accurate well data is not self
evident, it should become so through the discussion of how
that criteria effects the packer. The near infinite variety of oil
and gas completion scenarios makes detailed discussion of
applications impractical, but good completion planning
practices will ensure that some specific information is
consistently available in the completion planning process,
including:
• Casing/Liner and tubing data
• Dogleg severity and well bore deviation
• Initial bottomhole pressure
• Bottomhole temperature
• Wellbore preparation
• Perforating
• Completion fluids
• Specific hostile conditions / CRA requirements
• Anticipated life of the completion
• Production media and rates
• Anticipated stimulation conditions over the life of the
completion
• Multi-zone flow control requirements
• ID compatibility
• Minimum bottomhole pressure
• Landing conditions
• Packer setting requirements and limitations
• Well intervention
With the requirements and limitations of the applications
clearly defined, cost comparisons and the economic
benefit of any proposed value enhancing features in the
system can be fairly evaluated. This statement is true
only if the completion engineer can trust in the validity of
claims made by the manufacturer and there is a standard
in place supporting those claims. The implications of
product liability have historically guided manufacturers to
limit their recommendations to a product perceived
adequate for the application. Fringe applications that
stretch product limitations increasingly drive the need for
standardization in today’s environments.
Ratings in Perspective
Historically, misconceptions surrounding ratings have
persisted more from a lack of understanding, rather than
any attempt to be misleading.
Example: The manufacturer was asked to develop a
packer capable of sustaining a differential pressure of
6,000 psi. The packer was developed and tested in
the casing sizes and weights specified.
Pressure was applied below the packer to the
specified limit, and some subjective pressure value
would be applied for a safety factor. When
successful, the manufacturer offered the product rated

2. 2 SPE 80945
to 6,000 psi. Temperature might or might not have
been considered, depending on the manufacturer.
Evolution toward improving sophistication of design and
testing from that reference point has varied dramatically
among manufacturers. Improvements in testing procedures in
support of ratings can be attributed to the lessons learned in
application, as much as any initiative on the part of
manufacturers. Those faced with the most demanding
application requirements were forced to develop both quality
programs and design validation processes to meet those
requirements. The basic test of applying maximum pressure
expectations evolved into more extensive tests.
Testing began to incorporate attempts to simulate more, if not
all, of the anticipated conditions to which the tool would be
subjected in application. Issues of practicality still imposed
limitations on the manufacturer to fully test the anticipated
conditions. Time to market and development costs continued
to constrain the technical verification process for any new
product development. The need for some compromise of
technical verification and economic justification became
apparent in establishing valid and broadly applied ratings
standards. A clear understanding of the design and application
issues would first have to be in place to move forward.
How Packers Work and How Packers Fail
Before a packer’s rating can have value, it is necessary to
understand its function and how various loading conditions
and environmental factors influence its ability to perform. By
simplest definition, the packer’s function is to grip and seal. It
must remain anchored stationary within the casing, and it must
maintain pressure sealing integrity with differential pressures,
either below or above the tool.
Initial setting forces apply loads, wedging the slips into the
casing wall through movement of the cones. These same
forces supply energy for the packing element system,
generating rubber pressure sufficient to produce the sealing
effect. Conditions after setting can act to enhance the initial
sealing and anchoring effect, but when increased sufficiently,
will ultimately produce failure. The area(s) of failure can be
predicted by the combination of the applied loads.
Variations in design will influence load carrying
characteristics, but all have failure modes associated with
extremes of the same conditions. The basic load matrix (Table
1) provides the basis for evaluating the simultaneous effects of
both differential pressures and applied axial loads.
Temperatures and other environmental conditions, as well as
the packer’s component materials, will influence the packer’s
ability to carry combined loads.
Table 1 – Rating Envelope Quadrants
Tension Applied with
Pressure Above the
Packer
Tension Applied with
Pressure Below the
Packer
Compression Applied with
Pressure Above the
Packer
Compression Applied with
Pressure Below the
Packer
Anchor Threads
Bearing Shoulder
Body Lock Ring
Upper Slip
Upper Cone
Packing Element
Lower Cone
Lower Slip
Body
Guide-to–body
connection
Lower guide
1
6
7
3
4
5
2
Fig. 1 Basic Permanent Production Packer Configuration
The seven most common areas of failure on a permanent
production packer are enumerated, including body
collapse (3), packing element system failure (4), pin
collapse at the body/lower guide connection (5), b
guide connection failure (2), anchor attachment failure (1),
body lock ring failure (7), and bearing failure (6)
ody-to-
.

3. SPE 80945 3
Packer Performance Envelopes
Development of the performance envelope represents a major
step forward in bringing practical meaning to packer ratings.
With an understanding of the interaction of combined loading
conditions, it is possible to produce a representation of a
predictable safe operating zone (performance envelope) for a
packer. The performance envelope concept has made it
possible to evaluate the packer’s design, calculating the
envelope parameters, based on dimensional and material
specifications. Worst case conditions of the application can
then be overlaid to the envelope.
TensionCompression
Above Below
Differential Pressure
Force
4
3
7
6
5
4
3
21
It is important to realize this envelope does not define points
of failure. Rather, it only illustrates limits that can be
calculated to provide predictably reliable performance. Where
conditions of actual application define a condition outside the
envelope, risks are introduced. The level of risk might or
might not be deemed acceptable, following careful evaluation.
When using performance envelopes as a comparative tool
between competing manufacturers, it also important to
recognize the influence of variations in acceptable safety
factors, and how they might be calculated.
For instance, manufacturer A sets standards defining any
calculated bearing damage to components as beyond
acceptable. Manufacturer B considers that same calculation’s
degree of bearing failure not significant enough to interfere
with the performance of the system. Taking this latitude
wherever possible affords Manufacturer B the opportunity to
enhance the perception of performance, despite having no real
performance advantage. For this reason, performance
envelope representations are most appropriately used as tool in
evaluating each manufacturer’s tool to a given application.
Incorporating the performance envelope in the completion
planning process provides the opportunity to make necessary
modifications in the completion design, material changes,
and/or procedural changes to ensure reliable performance. If
the performance envelope is to be used in a manufacturer-to-
manufacturer comparison for performance value to price,
close scrutiny as to calculated values is necessary for a fair
comparison.
Using the Performance Envelope
Familiarization with the four quadrants of loading conditions
and the associated failure modes provides understanding of the
failure implications. With this knowledge, the completion
engineer can reasonably evaluate the implied risks when all
best efforts still point to some conditions beyond the envelope
boundaries.
Each of the failure modes are examined here. Distinction is
made concerning what conditions constitute potential damage
to the tool, and what conditions can result in catastrophic
failure. This discussion is limited to permanent production
packers, but the same considerations apply to retrievable
production packers or service packers. Although the
differences in configuration of retrievables will apply loads to
components different from those in the permanent packers,
loading implications can be similar.
Body Collapse
This failure mode is defined by collapse of the packer body
onto the outside diameter (OD) of the seal assembly. This
condition results from excessive stress generated in the body.
The excessive stress can be produced by differential pressures
from above or below the packer, packer to tubing forces, or
the combined effects of these forces. These forces act on both
the cross-sectional area of the body and that of the packing
element system. Any compressive or tensile forces applied to
the body are permanently trapped between the slips.
Fig. 2. Areas outside the envelope are beyond the
calculated safe operating zone. The numbers represent a
failure mode, called out in Fig. 1, resulting from axial
loading and differential pressure.
Consequences: Although body collapse can have serious
implications, it does not imply a catastrophic failure. This
situation might result in enough friction force on the OD of the
seal assembly to prevent free movement of a floating seal
assembly, or the ability to remove an anchor seal assembly,
but it will not cause the packer to leak or move. This effect is
represented in region 3 of the rating envelope.
Packing Element System Failure
This system is comprised of the packing element and
supporting back-up rings. Failure of the system can occur
with the packing element extruding through the back-up
system, or by degradation of the packing element due to
temperature or chemical effect, or failure of the back-up
system.
Extrusion of packing element through small gaps in the back-
up system or anomalies in the casing ID can result when the
temperature rating of the packing element material is
exceeded, particularly in combination with differential
pressures and packer-to-tubing forces that exceed the tool’s
rating.
Degradation of the packing element resulting from excessive
temperature or chemical effect is an application design issue
that must be considered in the completion system plan. It is

4. 4 SPE 80945
not expressed as part of the pressure and axial load limits
represented in the rating envelope.
Failure of the packing element back-up system is the bending
or shearing of the back-up rings. The back-up system is
designed to expand to the casing ID, filling the extrusion gap
between the packer’s OD and casing ID. Excessive pressure
can produce this failure, so it follows for a given size packer,
support for the back-up system is reduced, relative to
increased casing ID.
Consequences: Failure of the packing element system is
catastrophic. Once the sealing integrity is compromised, well
pressure can no longer be controlled, failing the completion
system. This limitation is illustrated in region 4 of the rating
envelope.
Pin Collapse at the Body/Guide Connection
This failure mode is possible in applications with a plug set in
a nipple below the packer, or where a seal bore extension is
fitted to the bottom of the packer. Similar to body collapse,
exposure of thread connection to pressure can cause deflection
of the pin connection of the packer. This has the same
implications as body collapse, resulting in sticking the sealing
assembly.
Consequences: As with body collapse, stuck seals can cause
high tubing stresses, but is considered non-catastrophic.
Unlike body collapse, deflection of the pin connection to point
of interference with seal assembly is not a locked in force, and
equalization of the pressure will normally allow the pin
connection to return to its original dimension. Region 5 of the
rating envelope illustrates this limitation.
Body-To-Guide Connection Failure
Failure of the body-to-guide connection is defined as one of
two variations. It can occur as a failure of the material at the
thread relief when tensile forces exceed the body material’s
yield strength. A failure of the thread itself can occur when
tensile loads exceed the bearing strength of the threads. This
connection is affected by both differential pressure from
below the packer and packer-to-tubing tensile forces. This
condition will normally occur as a result of the additive forces
of both differential pressure and tensile load, and is typically
at issue during stimulation procedures.
TensionCompression
Above Below
Differential Pressure
Force
Stimulation
Production
Fig. 3. The point within the envelope referencing the
production condition is safely within the performance
range of the packer. However, the combination of forces
associated with ballooning and contraction of the tubing
during stimulation, indicate tensile forces at the packer,
possibly causing failure.
The importance of considering the impact of anticipated
stimulation procedures is illustrated in Figure 3. Plotting of
both producing and stimulating conditions would imply other
options should be considered. Although it is acceptable for
the producing condition, it would likely be necessary to
consider changing to a higher yield strength material in the
packer, or allowing the seal assembly to float in order to
manage the stresses of stimulation.
Consequences: Failure of the body-to-guide connection is a
catastrophic failure. The connection’s failure would free the
body to move up through the packer. The guide, with its
attachments, would fall downhole. The rating limit of the
connection is represented in region 2 in the rating envelope.
Anchor Attachment Failure
This failure can occur only when the tubing is anchored to the
packer, which is normally accomplished with a left hand
square thread or jay lug / jay slot type anchor. Both
configurations are similar in load considerations of material
strength versus contact area. Failure can occur in the thread
relief if tensile loads exceed the body’s material yield strength.
Failure of the thread itself can occur when the thread’s shear
or bearing strength is exceeded. The same would apply to the
jay lug / jay slot. Swelling of the body can also be seen as a
failure, or as a contributing factor in the failure of the thread or
jay lug. This would occur when the elastic burst limit of the
wall is exceeded.
Consequences: Failure of the anchor connection is
catastrophic. The seal assembly is freed from the packer seal
bore, resulting in loss of the completion system’s pressure
integrity. Limits of the anchoring device are represented in
region 1 of the rating envelope.

5. SPE 80945 5
Body Lock Ring System Failure
Failure of the body lock ring system can result with stresses
exceeding the material’s shear or bearing strength. This
applies to ring itself or its supporting components.
Consequences: With failure of the body lock ring system, the
body is allowed to float as pressure reversals are experienced.
Although the slips have locked in packing element force,
movement of the body will cause wear on the ID of the
packing element. This can eventually cause a leak, but in the
absence of pressure reversals, there are no serious
consequences associated with the body lock ring failure.
Limits of the body lock ring system are represented in region 7
of the rating envelope.
Bearing Failure
This failure mode is associated with both anchor and locator
type seal assemblies. Bearing failure can occur when
compressive packer-to-tubing force exceeds the bearing
strength of the material at the contact point between the
anchor or locator and the packer. Another criterion of failure
is the stress generated by the radial component of the contact
force.
Consequences: There is potential, with extremely high
compressive loads, to swage the seal assembly into the body
when the seal assembly’s top shoulder angle is shallow.
Minor bearing failure that only causes slight deformation of
the mating surfaces will not compromise the completion
system. The bearing load limitation is represented in region 6
of the rating envelope.
Factors Influencing the Rating Envelope
In addition to the design characteristics and configuration of a
packer, there are other variables that can significantly move
the performance boundaries. Aside from the availability of
cross-sectional area in the packer’s construction, two other
areas warrant discussion, due to their influence on
performance. The influence of both material selection and the
packer size, relative to the casing ID, have been referenced in
the evaluation of failure modes.
The effect of material selection is illustrated in Figure 4. It is
important to understand the dynamics of material selection to
achieve the optimum completion design. History has shown
the waste of thousands of dollars spent in material selection
criteria that was unwarranted for the application. Likewise,
lack of attention to characteristics of the materials and how
conditions will affect them can contribute to catastrophic
failure or shortened life of the completion. Ideally, the
flexibility, reliability and economy of the completion system
are all optimized in planning the completion design.
TensionCompression
Above Below
Differential Pressure
Force
110,000 psi
MYS
80,000 psi
MYS
Fig. 4. The change in material selection from 80,000 psi
MYS to 110,000 psi MYS can provide a proportional
increase in performance.
Sizing of the packer relative to casing ID will enhance or
restrict performance, as referred to in the discussion of
limitations of the packing element and back-up systems.
Figure 5 illustrates the effect of changing casing ID for a given
size packer. Flexibility in packer size selection is not only
limited by the manufacturer’s product offering, but is also
affected by the casing string design. Casing string design can
be particularly problematic where heavy weight casing is set
above the packer setting depth in lighter weight casing, while
also requiring high differential pressure control.
TensionCompression
Above Below
Differential Pressure
Force
38 ppf
23 ppf
Fig. 5. The example shows the performance envelope
change in pressure rating limits for 7-in. casing,
comparing the inside area for 23 ppf casing with the
extended area available with 38 ppf casing.
While considering alternative manufacturers for the
completion system design, there will often appear to be more

6. 6 SPE 80945
flexibility in casing weight range coverage with one
manufacturer’s product versus another’s. These differences
can be attributed to how a manufacture approaches the design
requirement. One manufacturer might design for target
pressure ratings, while the other emphasizes the broadest
possible coverage of casing weights. It is important in
evaluating options to recognize the effect of packer OD to
casing ID, most importantly where high pressure, high
temperature, or both are anticipated.
Importance of Understanding the Rating Envelope
The performance envelope concept is an excellent tool in
bringing understanding and predictability to how a tool should
perform and how it might fail in application. With that said,
there remain serious questions that need to answered before
committing what can today be millions of dollars into high
risk completions. The decision maker for any completion
should be able to make that decision with full confidence that
what is represented in a rating envelope can be validated by
the manufacture.
Only in recent years has a concerted effort been made in the
industry to give the decision maker better tools to evaluate the
claims made by manufacturers. Historically, a completion
engineer would not only need to know what questions to ask,
but also how to ask them, to ensure the product was accurately
represented.
The broad use of 10,000 psi rated retrievable packers,
available from several manufacturers, can serve to illustrate
how the validity of claims can be distorted.
Hypothetical Example: A well is to be completed, anticipating
stimulation soon after completing. The completion engineer
has run tubing movement calculations to confirm loads on the
packer. It appears the packer will be exposed to a maximum
treating pressure differential of 9,800 psi. The initial bottom-
hole temperature is 340°F, being cooled to 120°F during
treatment. Tubing movement will apply 80,000# packer-to-
tubing tensile stress.
The completion engineer asks the following questions of a
packer manufacturer’s sales representative:
Q: Do you have a retrievable packer rated to 10,000 psi?
A: Yes
Q: Is it rated for the 340°F?
A: Yes, it is rated to 350°F.
Q: Will it withstand 80,000# tensile load?
A: Yes, it is rated to 90,000#
The completion engineer ordered the packer, only to see it fail
late in the stimulation job, which had been proceeding
according to plan. The completion engineer accuses the sales
representative of misrepresenting his product. The sales
representative responds that he was not given enough
information. He did not realize his customer expected the
packer to be subjected to those conditions described to occur
in combination.
Why did the packer fail? Technically, it failed because the
combined loads added boost force into the packing element,
applied to both the cross-sectional areas of the packer body
and the packing element system. The packing element
integrity was already partially compromised by the
temperature. Proper design validation testing would have
shown this packer should have been rated to 6,000 psi, when
subjected to the additional tensile load and temperature
conditions. The failure could have been avoided by reviewing
the requirements with a properly developed and validated
performance envelope for the packer.
Design Validation Testing
It is important to emphasize the performance envelope concept
is a relatively new tool. Regardless of manufacturer, many of
the packers they offer will not have a performance envelope to
document their ratings. Typically, only packers developed in
recent years will be supported by a ratings envelope.
Regardless of whether an envelope has been created, the
testing regime that qualifies a packer’s rating is of utmost
importance. Prior to the recent efforts to standardize design
validation testing, there was no standard to support claims
made by any manufacturer. Several considerations that should
have been accounted for in testing were subject to
compromise, either out of ignorance or cost and time to
market considerations. Among them are the following:
• Combined loading
• Pressure reversals
• API casing tolerances
• Temperature
o Maximum setting temperature
o Minimum setting temperature
o Cool down
• Gas or fluid environment
The previous hypothetical example of an application
scenario indicates just how the lack of a representative
design validation testing procedure can be misleading. A
valid testing regime should attempt to replicate the
conditions expected in application.
Combined Loading – The necessity of subjecting the packer
to the combined loads of pressure differentials, with applied
tensile and compressive loads has been discussed in the
ratings envelope and failure mode discussion. The inter-
dependent relationships of the packer’s components dictate
that combined loading is essential to design validation.
Pressure Reversals – While applying combined loads, the
packer should be subjected to pressure reversals. Every
packer design will be expected to withstand some cycling of
pressure differentials from below to above, and again from
below. Testing often exposes a packing element system
failure only after pressure reversal, where a single pressure
build up would not expose the failure.
API Casing Tolerances – The variations in casing ID for any
given casing weight can be viewed as building a safety
factor into the rating of a packer. Historically, packers were

7. SPE 80945 7
tested only in the nominal ID for the specified casing
weights. Upgraded testing programs, in recent years, have
demonstrated the inadequacy of that testing. It left no
margin for casing variances, due either to corrosion, wear, or
mill variations. Not only does this impact sealing integrity,
but also the reliability of proper slip setting, or slip release in
case of retrievable packers. Some packers on the market
today are also still plagued by problems associated with
stroke length issues related to casing ID variations.
The API tolerances were established as an allowable range in
weight per foot for API certified tubulars. ID tolerances are
extrapolated values according to casing weight, derived as
follows:
Calculation for Min/Max OD
OD = Nominal OD of Tubing
OD Tolerance,
For OD ≤ 4”, TOL = ± .031
For OD ≥ 4-1/2”, TOL = .010 X OD, - .005 X OD
For OD ≤ 4”
ODmin = OD - .031
ODmax = OD + .031
For OD ≥ 4-1/2”
ODmin = OD – (.005 X OD) = 0.005 X OD
ODmax = OD + (.010 X OD) = 1.010 X OD
Calculation for Min/Max ID
ID = Nominal ID of Tubing
WPE = Plain-End Weight of Tubing
WPEmax = WPE + (.065 X WPE) = 1.065 X WPE, lbs.
WPEmin = WPE – (.035 X WPE) = 0.965 X WPE, lbs.
WPE = π/4 (OD2
- ID2
) in2
X 12/ft X .283lb/in3
WPE = π/4 (OD2
- ID2
) X 3.396, lbs.
WPE – 2.670 (OD2
- ID2
), lbs.
(OD2
- ID2
) = WPE/2.670 = .3745 X WPE
OD2
- ID2
– (.3745 X WPE)
o ID = SQRT [OD2
– (.3745 WPEmax)]
IDmin = SQRT[ODmin2
– (.3745 WPEmax)]
IDmin = SQRT[ODmin2
– (.3745 X 1.065 X WPE)]
o IDmin = SQRT[ODmin2
– (.3988 X WPE)]
The resulting tolerance ranges for a sampling of some of the
common casing sizes are illustrated, as well as the
comparative tolerance range of each.
OD PPF Min ID Nominal ID Max ID
4-1/2” 11.60# 3.940” 4.000” 4.069”
5-1/2” 20.00# 4.696” 4.778” 4.868”
7” 29# 6.088” 6.184” 6.293”
7-5/8” 33.7# 6.662” 6.765” 6.882”
OD PPF Tolerance Range
4-1/2” 11.60# .129”
5-1/2” 20.00# .172”
7” 29# .205”
7-5/8” 33.7# .220”
The implications of the API tolerance in casing ID’s are
significant, not only related to packer performance, but also to
development costs. Packers capable of performing to the
rating envelope in nominal ID’s will often fail when tested in
the minimum or maximum ID extremes. The problems of
meeting satisfactory test results are further complicated with
retrievable packers. Retrievable packers that must set in the
max ID tolerance must also set and retrieve at the min ID
tolerance. Achieving a reliable balance, both in packing
element systems and slip systems can drive testing costs to
hundreds of thousands of dollars over that required if only
testing in nominal ID’s. In the absence of a uniform standard
for design validation testing, the incentive for compromise is
obvious.
Temperature – The effect of temperature on the sealing system
of a packer should require qualification in developing the
rating envelope. Any temperature rating should be qualified
as related to applied differential pressures. A temperature
rating, independent of pressure, is in effect an empty claim.
Likewise, stating a temperature rating at a given differential
pressure rating without validating that rating at API casing ID
tolerances, can also be misleading. This relates to the packing
element’s failure mode associated with the size of the
extrusion gap between the packer OD and casing ID.
Qualification of the packing element system should include
verification of the seal at the stated maximum setting
temperature and a minimum setting temperature. An effective
minimum cool down temperature should also be verified
through the qualifying tests. Each combination in variations
of durometers to meet the rated temperature range should be
individually qualified at the rated differential pressures.
Gas or Fluid Environment Qualification – It not necessary that
every packer design be capable of maintaining a gas tight seal,
as some designs will only be exposed to fluid environments in
actual application. In such cases, attempting to verify a gas
tight seal would only drive up development costs, with no
offsetting benefit in application. Packers to be exposed to
setting in gas environment must be qualified accordingly.
Typically, this applies to packers developed for wireline
deployment, anticipating running in a pressurized well
environment. In either case, the validation of pressure
differentials, temperatures, and casing ID tolerances are still at
issue.
Moving Toward Standardized Ratings
As the knowledge of potential problems in packer applications
has developed, coupled with the increased risks of failure,
most manufacturers have attempted to upgrade testing
procedures. Existing products have generally been in use long
enough to have developed a loosely defined envelope of their
own, proven out through empirical run data. Cost constraints

8. 8 SPE 80945
have generally dictated that improved testing standards have
been limited to new product development programs.
However, in the absence of a uniform standard, the
improvements have not necessarily been consistent between
manufacturers.
The lack of uniform standards for quality and design
validation testing would continue to leave any decision maker
in the completion planning process with much uncertainty.
The decision maker has had no consistent measure for
comparison of competing claims made by manufacturers. In
addition, the array of variables associated with packer ratings
demonstrate how the reliability of performance can be
affected. Any compromise on even one of the qualifying
factors can lead to failure. This concern has driven many
decision makers to resort to costly third party inspections,
where the risks and costs of failure are extreme.
It is clear that a practical, yet comprehensive set of standards
has been needed. The need includes the realization that the
requalifying of every packer product offering of each
manufacturer is simply cost prohibitive. Some graduated
standard would be required to address proven products in low
risk application, while ensuring incremental standards would
meet the requirements of increasingly demanding applications.
This initiative has now resulted in the development of a
uniform process to qualify both quality levels and design
validation testing procedures.
Development of ISO/FDIS 14310
The concerns expressed have been recognized by the
International Standards Organization (ISO). Work of the ISO
is carried out through technical committees. A technical
committee was formed to address theses issues, as pertaining
to packers and bridge plugs. The work was done under the
ISO Technical Committee ISO/TC 67, responsible for
materials, equipment and offshore structures for the petroleum
and natural gas industries, through Subcommittee SC 4, for
drilling and production equipment.
From the work of Subcommittee SC 4, the International
Standard ISO 14310 was prepared, addressing both quality
and design validation testing standards. Preparation of the
standard was a collaborative effort of purchasers and
manufacturers. The standard is intended to provide
requirements and information to both parties in the selection,
manufacture, testing and use of packers and bridge plugs. It is
not intended to address the installation and maintenance of
these products.
Graduated Levels of Standards
The International Standard has been developed in incremental
levels both in quality and design validation to meet increased
demands of performance. Quality levels are graduated in
three levels (Q1-Q3). Design validation testing has been
graduated in six levels (V1–V6), with one special design
validation grade (V0) to provide the purchaser the choice of
requirements to meet their preference or application.
The standard for quality control increases as the number
decreases, such that Q3 is the minimum quality standard
offered by the product standard. The Q2 rating provides
additional inspection and verification steps, and Q1 rating is
the highest, although additional upgrades can be specified by
the purchaser.
Quality Control Grades
Requirements for the three quality control grades are outlined
in Table 2. The following abbreviations and terms are used in
the table:
COC – Certificate of Conformance
MTR – Material Test Record
NDE – Non Destructive Examination
Type 1 components or welds – isolates pressure or subject to
tensile load
Type 2 components or welds – not subject to Type 1 criteria
Table 2 – Quality Control Grades
Q3 Q2 Q1
Material COC or MTR COC or MTR
Verify MTR for
Type 1
Components
COC or MTR
for other
components
Castings COC COC COC
Heat Treatment
COC
(subcontractor)
Job lot verify
(supplier/mftr)
COC
(subcontractor)
Job lot verify
(supplier/mftr)
Heat treat
certificate for
Type 1
components
Component
Traceability
Job lot traceable
for Type 1
components
Job lot traceable
for Type 1
components
Heat traceable
for Type 1
components
Component
dimensional
Sampling plan Sampling plan
100% for Type 1
components
Welding
Type 1 welds Visual
Surface NDE
per sampling
plan & visual
Surface NDE
100% & visual
Type 2 welds Visual Visual Visual
Hardness
Type 1
components
None Sampling plan 100%
Type 2
components
None None None
Component
NDE
Type 1
components
None
Surface NDE
per sampling
plan
Surface NDE
100%
Type 2
components
None None Visual
Shear devices
Heat Lot
verification
Heat Lot
verification
Heat Lot
verification
Assembly
verification
None
Functional test
ID drift
Functional test
ID drift
OD dimensional
Torque
documentation
Assembly
traceability
None None
Serialization for
Type 1
components
QC
documentation
Supplier/mftr
retained
Supplier/mftr
retained
Supplier/mftr
retained

9. SPE 80945 9
The ISO standard also includes detailed instructions for the
documentation for each of the criteria outlined in the table.
This documentation is to be maintained for a period of 5 years,
and it is available for audit by the purchaser.
Design Validation Testing per ISO/FDIS 14310
Design validation grade V6 is the minimum grade and
represents equipment for which the manufacturer has defined
the validation method. This is applied to many of the existing
industry products, proven by previous testing methods and
past performance in application. The complexity and severity
of the validation testing increase to the V0 grade. These
standards do not preclude manufacturers from offering, or
purchasers from accepting, alternative equipment or
engineering solutions. This can be particularly applicable for
innovative or developing technologies.
Standard validation grades:
V6: Supplier/manufacturer defined
V5: Liquid test
V4: Liquid test + axial loads
V3: Liquid test + axial loads + temperature cycling
V2: Gas test + axial loads
V1: Gas test + axial loads + temperature cycling
Special validation grade:
V0: Gas test + axial loads + temperature cycling + special
acceptance criteria (V1 + zero bubble acceptance criteria)
Bridge plugs may be run and tested without axial load;
however, all validation grades are applicable.
Packers or bridge plugs verified to grade V5 through V1 shall
not be rated for casing or tubing sizes and weights that can
have a maximum ID larger than the ID used in the validation
test. Tolerances on casing/tubing ID are governed in
accordance with ISO 11960.
In addition to the general specifications for design validation
testing outlined here, the ISO standard specifies detailed
criteria and instructions concerning how the validation testing
is to be conducted for each grade. It also addresses the
management of minor and substantive design changes.
Other Efforts In Standards and Improved Reliability
It is important to emphasize that most packers on the market
today have not been subjected to the ISO standard. Some
manufacturers are attempting to validate some previously
produced products in accordance to the ISO standard, or at
least revisit their quality standards and design validation
procedures. Increasing application demands and product
liability issues have forced manufacturers to review their
existing products for more stringent standards.
The API has also recognized the need for uniform product
standards. The API specification 11D1 has been developed in
close concert with the ISO 14310 standard. Effective January
1, 2003, manufacturers have been provided the opportunity to
qualify products per the API 11D1 specification. Those
products meeting the API criteria can now carry an API
monogram, in effect being API certified.
Enhanced design validation testing is also conducted by some
manufacturers, which goes beyond the ISO standard. This
testing not only validates the rating envelope, but attempts to
simulate the anticipated worst case application scenario for the
tool. This might include additional pressure reversal cycling,
fluid exposures, flow loop testing, or other criteria for
customer special requests.
Summary
The expectation for reliable performance for packers must be
supported by thorough planning of the completion, including
all anticipated conditions beyond the initial completion. The
responsibility for the proper selection of equipment is shared
by both purchaser and manufacturer. This requires an
understanding how the equipment should be expected to
perform, and what conditions will contribute to failure.
Historically, the industry was limited in its ability to assess
and verify a product’s suitability for a given application. The
ratings envelope concept has provided an excellent tool for
comparing packer performance capabilities with its
application. The introduction of the ISO standard (ISO/FDIS
14310) and the API 11D1 specification will enhance the
benefit of rating envelopes by ensuring uniform measures. To
the extent these new standards proliferate through the industry,
either through manufacturer initiative or purchaser demand,
performance reliability should improve.
Acknowledgements
The author wishes to thank the management of Baker Oil
Tools for their encouragement and support in developing this
paper.
References
1. ISO, “Petroleum and Natural Gas Industries –
Downhole Equipment – Packer and Bridge Plugs”,
ISO Standard 14310, Latest Edition
2. Hoppman, Mark; Walker, Tim: Petroleum
Engineering International, Harts Publications, Inc.
“Predict Permanent Packer Performance”
3. McCasland, Mark; Luce, Tom: “A Systematic
Approach to Development and Deployment of
Downhole Completion Equipment for High Profile
HP/HT Projects” SPE 77822 Presented at the SPE
Asia Pacific Oil and Gas Conference and Exhibition
in Melbourne, Australia, 8 – 10 October 2002.
4. Dyson, William Q.; Coludrovich, Earl; Creech,
Rachael; Weldy, John C.; Fruge, Michael; Guidry,
Marton: “Best Completion Practices” SPE/AIDC
52810 Presented at the SPE/AIDC Drilling
Conference in Amsterdam, Holland, 9 – 11 March
1999.
5. Turner, Will: “Methods to Assess the Reliability of
Downhole Completions: The Need for Industry
Standards” OTC 12168 Presented at the Offshore
Technology Conference in Houston, TX, 1 – 4 May
2000.

10. 10 SPE 80945
6. Watson, Graeme; Hibberd, Roger; Turner, Will;
Hidding, Gert Jan: “Cost Reduction in Downhole
Completion Equipment Supply: A Case History” SPE
53914 Presented at the SPE Latin American and
Carribean Petroleum Engineering Conference in
Caracas, Venezuala, 21 – 23 April 1999.
7. Williford, James; Rice, Pat; Ray, Thomas: “Selection
of Metallugy and Elastomers Used in Completion
Products to Achieve Predicted Product Integrity for
the HP/HT Oil and Gas Fields of Indonesia” SPE
54291 Presented at the SPE Asia Pacific Oil and Gas
Conference and Exhibition in Jakara, Indonesia, 20 –
22 April 1999.
8. API “Petroleum and Natural Gas Industries –
Downhole Equipment – Packer and Bridge Plugs”,
API Specification 11D1, First Edition, July 2002