SP-2161 Material Selection and Corrosion Control For Surface Facilities - V1
SP-2161 Material Selection and Corrosion Control For Surface Facilities - V1
SP-2161 Material Selection and Corrosion Control For Surface Facilities - V1
Document ID SP-2161
Security Restricted
Owner UEC
Version 1
Keywords: This document is the property of Petroleum Development Oman, LLC. Neither the whole
nor any part of this document may be disclosed to others or reproduced, stored in a retrieval system,
or transmitted in any form by any means (electronic, mechanical, reprographic recording or
otherwise) without prior written consent of the owner.
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II REVISION HISTORY
Description
Issue Authors Approved
Date (see Revision Record for
No (name) (name)
details)
1. Pedro Rincon, UEOC1
2. Steve Jones, UEOC11
September Original issue under PDO Nasser Behlani,
0 3. Janardhan Saithala,
- 2014 SP-2161 UEOC-CFDH
UEOC 17
4. Cheng Ai Khoo, UEOC1A
This SP is revised to be an
amendments and
supplements to 1. Cheng Ai Khoo, UEC1A
39.01.10.12-Gen which 2. Pedro Rincon, UEC2
November - Nasser Behlani,
1 incorporates content 3. Talal Nabhani, UEC1
2017 UEC-CFDH
previously in DEP 4. Mohamed Ghafri, UEC11
30.10.12.15-Gen and SP-
2041 which are now
withdrawn.
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Table of Contents
I. DOCUMENT AUTHORISATION ......................................................................................... 2
II. DOCUMENT HISTORY ....................................................................................................... 3
PART I. INTRODUCTION ................................................................................................................. 6
1.1 SCOPE .................................................................................................................................... 6
1.3 DEFINITIONS............................................................................................................................ 6
1.3.3 Abbreviation .......................................................................................................................... 6
1.9 SPECIFICATION OWNERS RESPONSIBILITY AND REVISION TO THE DOCUMENT ............................... 7
1.10 REFERENCED STANDARDS ....................................................................................................... 7
PART II. GENERAL REQUIREMENTS.............................................................................................. 9
2 GENERAL.............................................................................................................................. 9
3 REQUIREMENT FOR SPECIFIC MATERIAL GROUPS ..................................................... 10
3.1 GENERAL............................................................................................................................... 10
3.2 STAINLESS STEEL (PREN > 13 AND FE > 50%) .......................................................................... 10
3.2.2 High Chloride Exposures ..................................................................................................... 10
3.2.4 Austenitic and Duplex Stainless Steel (< 6% Mo) ............................................................... 11
3.3 NICKEL ALLOY (PREN > 6 AND FE < 50%) ................................................................................. 11
3.4 GLASS REINFORCED PLASTIC (GRP) ........................................................................................ 11
4 SPECIAL MATERIALS REQUIREMENTS .......................................................................... 11
4.2 W ELDING (INCLUDING CLAD AND OVERLAY WELDED EQUIPMENT)............................................... 11
4.6 PROTECTION AGAINST GALVANIC CORROSION .......................................................................... 11
PART III. GENERAL REQUIREMENTS............................................................................................ 12
2 PRODUCTION SYSTEMS .................................................................................................. 12
2.2 DOWNHOLE TUBING AND LINERS.............................................................................................. 12
2.3 CASING ................................................................................................................................. 12
2.4 TREES AND DOWNHOLE EQUIPMENT ........................................................................................ 12
2.5 VESSELS AND PIPING .............................................................................................................. 12
2.6 PIPING, FITTINGS, VALVES AND OTHER COMPONENTS ............................................................... 15
2.9 GLYCOL DEHYDRATION SYSTEM .............................................................................................. 15
2.10 FLARE AND RELIEF SYSTEM .................................................................................................... 15
2.11 ROTATING EQUIPMENT ........................................................................................................... 15
2.12 BOLTS ................................................................................................................................... 16
3 PIPELINES .......................................................................................................................... 16
3.2 PROCESS PIPELINES............................................................................................................... 16
3.5 W ATER INJECTION PIPELINES .................................................................................................. 16
3.8 MULTIPORT SELECTOR VALVES (MSV) ...................................................................................... 16
4 UTILITIES ............................................................................................................................ 17
4.1 W ATER SYSTEMS ................................................................................................................... 17
4.1.5 Firewater System ................................................................................................................. 17
4.1.6 Water Injection System ........................................................................................................ 17
4.2 INHIBITORS AND OTHER CHEMICALS ......................................................................................... 17
4.3 MISCELLANEOUS UTILITY SYSTEMS.......................................................................................... 17
5 STEAM INJECTION SYSTEMS .......................................................................................... 17
5.1 GENERAL............................................................................................................................... 17
5.2 PRODUCTION EQUIPMENT ....................................................................................................... 18
PART IV. AMENDMENTS/SUPPLEMENTS TO ISO 15156 ............................................................. 19
ISO 15156 PART 2: CRACKING RESISTANT CARBON AND LOW ALLOY STEELS, AND THE USE OF CAST IRONS
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ANNEX B QUALIFICATION OF CARBON AND LOW ALLOY STEELS FOR H2S SERVICE BY LABORATORY TESTING
5.1 TEST PROCEDURES TO EVALUATE THE RESISTANCE OF CARBON AND LOW ALLOY STEELS TO SSC
............................................................................................................................................................. 21
ISO 15156 PART 3: CRACKING RESISTANT CRAS (CORROSION RESISTANT ALLOYS) AND OTHER ALLOYS
CARBON AND LOW ALLOY STEELS, AND THE USE OF CAST IRONS
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PART I INTRODUCTION
This specification is written as amendments and supplements to DEP 39.01.10.12-Gen
Specification (February 2017). For ease of reference, the clause numbering mentioned in DEP
39.01.10.12-Gen has been used throughout this part of the specification. Clauses in DEP
39.01.10.12-Gen which are not addressed in this specification shall remain valid as written.
This specification shall be used during project life cycle to ensure technically proven and
economically acceptable materials selection for Petroleum Development Oman LLC (PDO)
projects.
This document is intended for use by PDO, its Contactors/Subcontractors and Design
Consultants and vendors for all PDO equipment and facilities.
1.1 SCOPE
Add the following additional list item after the last paragraph:
1.3 DEFINITIONS
1.3.3 Abbreviations
Term Definition
ALARP As Low As Reasonably Practicable
API American Petroleum Institute
ASTM American Society Testing Materials
AYS Actual Yield Stress
BA Breathing Apparatus
CFDH Corporate Function Discipline Head
CLR Crack Length Ratio
CP Code of Practice
CSCC Chloride Stress Corrosion Cracking
CTR Crack Thickness Ratio
DEP Design Engineering practice
ERW Electric Resistance Welded
FBE Fusion Bonded Epoxy
GRE Glass Reinforced Epoxy
GU Guideline
HDPE High Density Polyethylene
HSE Health Safety Environments
HV Vickers Hardness
ISO International Organization Standardization
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Term Definition
MCI Materials, Corrosion and Inspection
MDMT Minimum Design Metal Temperature
MESC SPE Materials and Equipment Standards and Codes Specification
MOT Maximum Operating Temperature
MSV Multi Selective Valves
ND Nominal Diameter
PDO Petroleum Development Oman
PR Procedure
SP Specification
TA2 Technical Authority 2
1. PDO CFDH Materials and Corrosion is responsible for authorizing all amendments to this
specification.
2. This specification will be reviewed and updated as and when required. The review authority will
be CFDH of Materials, Corrosion and Inspection.
PDO standards take precedence over DEPs and other International, Regional, National and
Industry standards
15. DEP 30.48.00.31-Gen: Protective Coatings for Onshore and Offshore Facilities.
16. DEP 31.38.01.15-Gen: Piping Classes – Exploration and Production Appendix A: Detailed
Changes per Piping Class.
17. DEP 31.48.40.31-Gen: Thermal Spray Coating of Aluminium
18. DEP 31.38.01.84-Gen: Piping Classes – Service and Materials Selection Index.
19. DEP 31.40.10.19-Gen: Glass Fibre Reinforced Plastic Pipeline and Piping Systems.
20. DEP 31.40.20.37-Gen: Line Pipe for Critical Service (Amendments/Supplements to ISO
th
3183: 2012 and API SPEC 5L 45 edition).
21. DEP 31.40.20.30-Gen: Pipeline Fittings (amendments/supplements to ISO 15590-2) and
low temperature process piping fittings.
22. DEP 39.01.10.11-Gen: Selection Of Materials for Life Cycle Performance (Upstream
Facilities) Materials Selection Process
23. DEP 39.01.10.12-Gen: Selection of Materials for Upstream Equipment (Including
Amendments and Supplements to ISO 15156: 2016)
24. DEP 39.01.10.32-Gen: Specification for Nickel Base Alloy 718 (UNS N07718) for Oil and
Gas Drilling and Production Equipment (Amendments/Supplements
to API Standard 6A718).
25. ISO 13709: Centrifugal pumps for petroleum, petrochemical and natural gas
industries.
26. ISO 15156-1: Petroleum and natural gas industries-Materials for use in H2S-
containing environments in oil and gas production-Part 1: General
principles for selection of cracking-resistant materials
27. ISO 15156-2: Petroleum and natural gas industries-Materials for use in H2S-
containing environments in oil and gas production-Part 2: Cracking-
resistant carbon and low alloy steels, and the use of cast irons
28. ISO 15156-3: Petroleum and natural gas industries-Materials for use in H2S-
containing environments in oil and gas production-Part 3: Cracking-
29. ISO 17025: General requirements for the competence of testing and calibration
laboratories.
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2 GENERAL
b) For all carbon steel and low alloy steels, if the hydrogen sulphide concentration (H2S)
present in the equipment over the life cycle will exceed either 3 mbar (0.05 psi) partial
pressure H2S in the gas phase or 10 ppmmass in aqueous phase, then sour service
requirements of this specification and DEP 39.01.10.12-Gen shall be applied.
9. For gas production environments (produced gas with or without produced water) and
downstream of separator, salt accumulation scenarios shall be evaluated as part of
materials selection process. Presence of formation water shall be included in the
evaluation. Assumptions of lower chloride levels can only be determined with a proper salt
materials balance studies approved by the Process Technical Authority and supported by
operation and maintenance philosophy.
10. In liquid full systems, the partial pressure of CO2 and /or H2S to be used in corrosion
calculations shall be the design pressure of the CO2 and H2S in the gas phase at the last
gas liquid separation point, unless gas fugacity is made available.
11. Intrusive corrosion monitoring systems (i.e. access fittings) SHALL [PS] not be installed or
used in gas pipeline or multiphase/liquid lines pipelines classified as sour or critically sour
(as per SP-1190 classification). These pipelines shall be designed to have a combination
of non intrusive corrosion on-line monitoring technologies, as well as selection of effective
integrity operating windows mentoring.
Fluid type / Threats Requirement
1. New projects – coupons / probes prohibited.
a) Dry gas: Focus on water dew point on-line monitoring &
process control. If corrosion monitoring required install at
least one approved non intrusive technique.
b) Wet gas: Focus on on-line corrosion inhibitor availability
and install at least one approved non intrusive technique.
Gas (Sweet: Dry and wet)
2. Existing projects – coupons / probes not permitted without
variance approval.
a) Dry gas: Retrieval only permitted at low pressure (<7 bar).
Install at least one approved non intrusive technique if
water dew point on-line monitoring is not available.
b) Wet gas: Retrieval only permitted at low pressure (<7 bar).
Install at least one approved non intrusive technique.
New projects / Existing: coupons / probes permitted but
alternative non intrusive techniques shall be considered.
Sweet liquid / multiphase
Reduce operating pressure for retrieval to < 70 bar.
Coupons / probes prohibited.
All sour and critically sour
Alternative non intrusive techniques are mandatory.
pipelines
(Retrievals for existing coupons / probes to be undertaken at
low pressure (< 7 bar) with BA set available for escape.
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3.1 GENERAL
2. Technical requirements for Corrosion Resistant Alloys (CRA), refer to CRA materials
purchasing specification.
4. Delete list item and Table 1, and replace with the following:
6. Delete list item and Table 1, and replace with the following Table 1 in this specification:
The threshold maximum operating temperature (MOT) given in Table.1 of this specification
shall be used as default values where below the thresholds maximum operating
temperature, no mitigation against external CSCC is required and above the thresholds
maximum operating temperature, shall require mitigation against CSCC with Thermal
Sprayed Aluminium (TSA) in accordance with DEP 30.48.40.31-Gen.
Table.1: Maximum operating temperature limits for stainless steel materials in salt laden,
desert environment and oxygen contaminated exposures.
Stainless Steel Type Threshold Maximum Operating Temperatures
o o
SS 316L 60 C in desert & 50 C for costal
o o
22 Cr Duplex 120 C in desert & 100 C for costal
o o
25 Cr Super Duplex 120 C in desert & 100 C for costal
o
6 Mo 120 C
Notes:
1. Maximum operating temperature, as defined in DEP 01.00.01.30.Gen, shall be used to
determine the external coating requirement.
2. Costal area is defined as within 10 km from the shore.
3. For any stainless steel equipment / piping with maximum operating temperature less than or
equal to the threshold temperature above, Thermal Sprayed Aluminium (TSA) and organic
coating are not required unless specified in the materials selection report.
4. For any stainless steel / piping that is not classified as Safety Critical Element (SCE) in
accordance with PR-1992 with maximum operating temperature exceeding the above
threshold limits and the failure risk is tolerable and ALARP, apply organic coating as per SP-
1246 only if required for HSE reasons / color coding or as specified in the materials selection
report.
5. For any stainless steel equipment / piping classified as SCE in accordance with PR-1992
except lube oil and instrument air,having a maximum operating temperature that exceeds the
above threshold limits, TSA in accordance with DEP 30.48.10.31-Gen shall be applied.
Waiving the TSA requirements shall be by producing a documented risk assessment and
demonstration of ALARP authorised by Technical Safety Engineer, TA2.
7. Delete list item
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11. If application of TSA is not feasible for small bore (DN 50) and below, use of organic
coating, re-coated or replaced is acceptable if a life cycle cost benefit can be
demonstrated.
4. Direct contact of zinc, zinc containing coating or contamination by zinc with safety critical
stainless steel equipment SHALL [PS] be prevented.
For details regarding the choice of fibre and resin, refer to SP-2092. Information not
covered in SP-2092, refer to DEP 30.10.02.13-Gen.
For use of GRP pipeline and piping, refer to SP-2092 and SP-2156. For information not
covered in those SPs, refer to DEP 31.40.10.19-Gen.
1. Carbon steel material connected to Corrosion Resistant Alloy (CRA), insulation gasket is
required at the flanges interface, except free water (operated above controlled water dew
point) system..
2. Carbon steel with internal coating connected to CRA material, the carbon steel flange face
shall also be coated and insulation gasket is required.
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2.3 CASING
Delete all reference to Table.4 in DEP 39.01.10.12-Gen and replace with Table.4 in this
specification.
3. Add the following additional list item after the last sentence:
For carbon steel with epoxy or glass flake internal coated pressure vessel connected to
CRA piping, nozzle flange face shall have weld overlay with CRA material. Nozzles shall
be designed to enable the internal part to be coated with the same material as the vessel.
If coating is not feasible due to size constraints, the nozzle material shall be of CRA
material.
Requirements for internal coating of vessels and piping shall be as provided in SP-1246.
Vessel linings (e.g., glass flake epoxy systems) shall not be selected for erosive conditions.
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Notes:
(1) For the risk of external chloride stress cracking stainless steel components, refer to,Part II, list
item 3.2.2 of this specification.
(2) These limits are for pH ≥ 3.8.
(3) The upper limitation is dependent on the resin system employed; refer to DEP 30.10.02.13-Gen
for recommended upper temperature limits of thermosetting resins.
(4) For some corrosion resistant alloys, e.g, AISI 316L, more detailed sour service SCC limits can
be found in Section IV of this specification. Refer also to SP-2163 and DEP 31.38.01.84-Gen.
(5) Any value of NaCl means < 250 g/l; not proven for saturated conditions.
(6) Refer to SP-1246 for external protective coating.
(7) SDSS currently under evaluation for expanding the limit of H2S.
Piping classes shall be selected for required material, corrosion allowance and service
conditions as specified in SP-2163 and DEP 31.38.01.15-Gen
3. All the applicable MESC SPEs shall be followed for piping, fittings, valves and other
components.
2. Add the following additional list item after the last sentence:
In Table A1.2, add S-8 (SS 316 / 316L) material class as per ISO 13709, Table H.1 if
specified by Materials Selection report.
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2.12 BOLTS
3 PIPELINES
3. All water injection lines shall be HDPE lined carbon steel or thermoplastic lined pipes (e.g;
FCP).
1. Multiport selector valve materials selection shall conform to Table 3.8.1 below.
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4. UTILITIES
4.1.1 General
Table 16 Add the following:-
Reference for non metallic materials, refer to SP-2092 and SP-2156. Information not
available in these SPs, refer to DEP 31.40.10.19-Gen
Note:
(1) SS 316L is only allowed up to 250 ppm of TDS.
The use of GRP shall refer to SP-2156 and SP-2092 for hazardous zone restrictions for the
application of above ground firewater piping system.
9. For non metallic materials, refer to DEP 30.10.02.13-Gen for requirements of materials
compatibility with chemicals.
3. To use carbon steel option, the instrument air shall be fully dried.
5.1 GENERAL
Delete reference to Table 25. PDO MCI TA2 shall be consulted for materials selection for
steam injection projects.
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b) For produced water, refer Part III, Section 4.1 of this SP.
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7. Qualification and selection of carbon and low alloy steels with resistance to SSC,
SOHIC and SZC
7.2 Option 2 – Selection of steels for specific sour-service applications or for ranges of
sour service
7.2.1.1 General
Add the following additional list items after the last paragraph:
3. HFW / ERW line pipe grade above X-60, shall not be permitted for use in sour service
applications. Sour rated material shall always be used for HFW / ERW line pipe X-60
grade and below, includes sweet service.
8. Evaluation of carbon and low alloy steels for their resistance to HIC/SWC
3. HIC testing requirements shall be determined as per HIC testing chart requirement as
shown in Figure.8.4 in this specification. HIC test execution shall be in accordance with
DEP 30.10.02.16-Gen and the following additional requirements:-
a) For critical sour applications, all HIC tests shall include a control sample. The control
sample after testing shall exhibit minimum Average Crack Length Ratio (CLR) of
20%. If the control sample fails to meet this requirement the test shall be deemed as
invalid and shall be repeated.
b) Testing shall be carried out at PDO approved laboratories. Laboratories that have
ISO 17025 certification can be used subject to prior approval from PDO material and
corrosion engineer.
ii. The maximum individual crack length parallel to rolling direction on any section
shall not exceed 5 mm.
iii. After HIC testing, if any section of the sample reveals vertical cracks
(perpendicular to the rolling direction) greater than 0.5 mm, the shall be deemed
to have failed. .
o
4. For equipment that operates continuously above 65 C, HIC testing is not required. Short
o
temperatures transitions to below 65 C, such as during shut down and start up, are
considered to be too short to cause significant HIC, hence HIC testing is not required.
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HIC Testing
Requirement
Note: 2, 3, 4 & 5
Piping
Equipment Pipeline Valves & (MESC items)
Note: 5 & 8 Flanges
Note: 9
HDPE HDPE
Lined Lined HDPE HDPE
Lined Lined
Legend:
Claded Claded
Claded Claded Materials shall be sour rated (Note:2)
and HIC testing is required
Fittings
Note: 6 Fittings Fittings Materials shall be sour rated, however
Note :5 &7 Note: 5 & 7 HIC testing is not required
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Notes:
1. The tank mill plates shall comply with ISO 15156 sour requirements (pressure tank shall be treated as
pressure vessels).
2. All requirements specified in PDO, Shell DEPS & MESC specifications for materials in sour service
shall be met.
3. HIC testing can be waived by risk assessment which demonstrate ALARP.
4. Retesting is not allowed.
5. a) For manufacturer items (eg. pipeline etc) HIC testing to be carried out on final products after a
simulation of the final heat treatment if any.
b) For fabricated items such as vessels, heat exchanger and any fabricated fittings/items: HIC test shall
be carried out on the mill plates.
6. Inspection requirements of HIC shall be included in RBA.
7. Applicable only if pp H2S is ≥ 5mbar calculated based on MOP.
8. HIC testing frequency shall be as per DEP 31.40.20.37-Gen and DEP 31.40.21.30-Gen.
9. All piping and piping items procured on all MESC requirements.
Annex B Qualification of carbon and low-alloy steels for H2S service by laboratory testing
B.3. Test procedures to evaluate the resistance of carbon and low alloy steels to SSC
Table B.1 Delete reference to applied stress ≥ 80 % AYS. Qualification testing shall be
conducted at ≥ 90 % AYS.
ISO 15156 Part 3: Cracking resistant CRAs (corrosion-resistant alloys) and other alloys
A.6.2 Environmental and materials limits for the uses of martensitic stainless steel
A.7.2 Environmental and materials limits for the uses of duplex stainless stainless steel
Table A.24 Delete this table and refer to Table 4 of this specification.
A.9.2 Environmental and materials limits for the uses of precipitations-hardened nickel-based
alloys
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