Attachment E - Proposed API Philosophy - My Committees

exhaustedcrumMechanics

Oct 24, 2013 (3 years and 9 months ago)

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Product Design and Qualification
(Validation) Testing


for


HPHT Systems



2010

HPHT Designer Issues


Design Methodology much more
rigorous FEA and Fracture Mech.


No clear definition of Material
Properties needed for FEA and
Fracture Mech.


Need to establish appropriate
HPHT performance validation
testing to prove FEA


Is one needed for fracture mechanics?

HPHT

Design

2

3

Proposed
PER15K

FAD , S
-
N
low /infinite

No

Yes

HPHT Designer Issues


Design Methodology much more
rigorous FEA and Fracture Mech.


FEA, Thermal,


FAD


BS 7910 DnV C203, API 579


Should be limited to pressure
containing, pressure controlling, seals,
and fasteners…

HPHT

Design

4

HPHT Designer Issues


Much work remaining with
respect to materials


Metallic properties
derating
, thermal
growth, da/dN, K
1Scc



ASME, API 6AF1


Seals, fasteners need creep or stress
relaxation (DMM) for life expectancy


Thermal FEA to justify temperature
zone use?


Non
-
metalics life expectancy tests


HPHT

Design

5

Crush
contact
of BX
Gasket

Bolt
Loading

Hoop
Stress
Energized
Force

High Contact
Compressive
Stress

P
L
-
M

= Temp (log t
r

+C)

Larson
-
Miller Regression Curve

From API TR 6J1

Thermal FEA plot illustrating an example

of insulating the body while keeping an adjacent

component (actuator) uninsulated to optimize seal use

6

Over complicating H
2
S Failure to Fast
Fracture

Assumed flaw size
detectable at factory during
manufacture

Elevated temperature probably
increases crack growth rate /
shortens design life

K
1Scc

HPHT Designer Issues


Need to establish appropriate
HPHT performance validation
testing to prove FEA


Is one needed for fracture mechanics?

HPHT

Design

7

Background / History / Needs Assessment


Recognition that current industry standards are not specific in
addressing the requirements for seals therefore it is left to the
equipment manufacturer/user to determine applicability of the
requirements/standardized tests



Procedures that are typically used (eg. API 6A PR2 Annex F)
are not satisfactory to provide product designs with proven,
long term reliability


Short term tests do not expose product weaknesses


Same test scenario regardless of type of product or environment


Separate testing for material and product


Material testing typically only covers compatibility with the environment
but lacks stressed induced failure mechanisms that directly apply to the
product design



8

Goals for Improved Testing / Qualification
Program


Develop protocols / methodology that will provide a better
indication of the of the long term performance of a product /
design


Educate the industry on the benefits of more rigorous testing
methods


Develop measurements/codes/processes/product markings to
ensure that products that are tested are in conformance to
the requirements


9

Current PR
-
2 Verification Process


API 6A Appendix F does not specifically state any requirement
for the verification of metallic seals.


FMC requires that metallic seals be verified to the same
requirements as wellhead equipment, connectors and fittings.


API 6A, Appendix F requires that wellhead equipment,
connectors and fitting be subjected to three temperature
cycles. Each temperature cycle starts at ambient temperature,
heats the equipment to the maximum rated temperature,
cools the equipment to the minimum rated temperature and
then brings the equipment back to the ambient temperature.
At the maximum and minimum rated temperature, the
equipment is pressured to the maximum rated pressure and
held for one hour, while checking for leakage.

10

API 6A, Annex F, PR
-
2

11

API 17D (FDIS)


New
Additions


New draft brings seals up to
same testing cycle as valves
and connectors


New draft has an Annex J for
fluid compatibility


New draft has Annex L for
hyperbaric (external) pressure
tests

12

13

Proposed PR
-
3 Test Philosophy


HPHT pressure containing, pressure controlling and seals have many
characteristics which need to be studied in greater detail than API
6A, Appendix F, PR2 addresses.


Material properties which can be affected during HPHT exposure
include, but are not limited to, wear, galling, fatigue, stress
relaxation, corrosion, and exposure to sand or grit.


Material properties “weaken” at elevated temperatures


Option 1
-

Possible higher test pressure at ambient temperature needs to be
addressed properly stress components, or


Option 2
-

Consider cycle testing of pressure and temperature in tandem.


Additional endurance test criteria which needs to be discussed
includes the addition of make
-
and
-
break cycles, additional
temperature/pressure cycles, and confirmation testing of seal
designs.


14

ASME Cycle Count

15

Higher Level of Qualification Testing

16