Engineering Procedure 17 March 2022

SAEP-333
Cathodic Protection Monitoring
Document Responsibility: Cathodic Protection Standards Committee

Previous Revision: 28 November 2019 Next Revision: 17 March 2027

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 Document Responsibility: Cathodic Protection Standard Committee SAEP-333
Issue Date: 17 March 2022
Next Revision: 17 March 2027 Cathodic Protection Monitoring

Contents

SUMMARY OF CHANGES ............................................................................................................................. 3

1 SCOPE ...................................................................................................................................................... 4

2 CONFLICTS AND DEVIATIONS............................................................................................................. 4

3 REFERENCES .......................................................................................................................................... 4

3.1 SAUDI ARAMCO REFERENCES ...................................................................................................... 4

3.2 INDUSTRY CODES AND STANDARDS ........................................................................................... 4

4 TERMINOLOGY ................................................................................................................................. 5

4.1 ACRONYMS ................................................................................................................................................. 5

4.2 DEFINITIONS ............................................................................................................................................... 5

5. SAFETY ........................................................................................................................................................ 8

6. MONITORING PROCEDURES ........................................................................................................................ 8

6.1 RECTIFIER PERIODIC CHECK AND MONITORING PROCEDURES .................................................................... 8

6.2 RECTIFIER PERIODIC CHECK AND MONITORING PROCEDURES .................................................................. 11

6.3 SOLAR POWER CP SYSTEM PERIODIC MAINTENANCE AND MONITORING PROCEDURES ........................... 12

6.4 CATHODIC PROTECTION SYSTEM SURVEYS ............................................................................................... 13

6.5 PARALLEL & CROSSING FOREIGN PIPELINE CROSSINGS INTERFERENCE MONITORING .............................. 24

6.6 CATHODIC PROTECTION MONITORING EQUIPMENT-USE AND MAINTENANCE ......................................... 25

6.7 RECORDS AND REPORTS............................................................................................................................ 26

7. RESPONSIBILITIES ...................................................................................................................................... 27

APPENDIX A-1 - CATHODIC PROTECTION MONITORING CRITERIA .................................................................... 28

APPENDIX A-2: CATHODIC PROTECTION COUPON TEST STATIONS................................................................... 32

APPENDIX A-3: ELECTRICAL RESISTANCE SOIL CORROSION PROBES ................................................................. 37

APPENDIX A-4: ATTACHMENTS TO SAEP-333 .................................................................................................... 45

DOCUMENT HISTORY ................................................................................................................................. 46

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 Document Responsibility: Cathodic Protection Standard Committee SAEP-333
Issue Date: 17 March 2022
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Summary of Changes

Paragraph Number

Change Type Technical Change(s)

(Addition, Modification,
Previous Current Deletion, New)
Revision Revision
(28 November 2019 (10 March 2022)

3.1 3.1 Addition Added a reference standard, SAEP-350 Regular

Maintenance and Testing for Industrial Stationary
Batteries
3.2 3.2 Addition Added a reference standard, ISO-15589-1
Petroleum, petrochemical and natural gas
industries — Cathodic protection of pipeline
systems —Part 1: On-land pipelines
6.2.3 Addition Bonding & Interference test for pipeline corridor
added
6.4.3.2.2 Addition Measure structure-to-electrolyte AC potentials
(annually) at pipeline test facilities
6.4.3.2.5 6.4.3.2.6 Modification Soil corrosion probes (SCPs) corrosion rate as
per ISO standard
6.4.3.2.7 Addition AC coupons and AC AC induced voltage /
potential at test stations which are close to the
HV power lines
6.4.3.2.8 Addition Measure open circuit potential of pipe and
galvanic anode annually
6.4.3.2.9 Addition CIPS (Close Interval Potential Survey) should be
carried out on pipelines that have history of
external and are of critical nature
6.4.3.2.10 Addition Any external corrosion and/or leaks related
anomalies shall be thoroughly investigated and
CP status at these locations shall be reported to
track the external protection status of leaked or
corroded locations
6.4.3.5.6 Addition Pipeline CP System Downtime Criteria added

6.4.5 Addition Annually test the road crossing casings for

electrical isolation. Such test shall include
measuring the casing potential and carrier pipe
potentials
6.5.4 Addition All such interference monitoring shall be carried
out once at least on annual basis. Interference
monitoring should be carried out by interrupting
the foreign pipeline
6.7 Addition Records for all CP system sufficient to
demonstrate the effectiveness of the corrosion
control measures shall be maintained as long as
the facility involved remains in service shall be
maintained throughout the asset life or until such
time the asset has been de-commissioned.

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1. Scope
This procedure provides the instructions and establishes the responsibilities to
monitor cathodic protection (CP) systems for onshore and offshore facilities.
Note:
Cathodic protection is essential to protect the underground and submerged steel structure from
corrosion and it is proven to prolong its life expectancy. For this reason, it is cost effective that
the proponent corrects deficiencies as soon as possible/practical and within a maximum of 6
months from reporting”.
2. Conflicts and Deviations
Any conflicts between this document and other applicable Mandatory Saudi
Aramco Engineering Requirements (MSAERs) shall be addressed to the
EK&RD Manager.

Any deviation from the requirements herein shall follow internal company
procedure SAEP-302.

3. References
All referenced specifications, standards, codes, drawings, and similar material
are considered part of this engineering procedure to the extent specified,
applying the latest version, unless otherwise stated.

3.1. Saudi Aramco References

Saudi Aramco Engineering Procedures

SAEP-302 Waiver of a Mandatory Saudi Aramco Engineering
Requirement
SAEP-332 Cathodic Protection Commissioning
SAEP-350 Regular Maintenance and Testing for Industrial Stationary
Batteries
Saudi Aramco Materials System Specification
26-SAMSS-059 Insulating Oil
Saudi Aramco General Instructions
GI-0002.100 Work Permit System
GI-0428.001 Cathodic Protection Responsibilities
Supply Chain Management Manual
CU 22.03 Processing and Handling of Hazardous Material
3.2. Industry Codes and Standards
ISO-15589-1 Petroleum, petrochemical and natural gas industries —
Cathodic protection of pipeline systems —Part 1: On-land
pipelines

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4. Terminology

4.1. Acronyms
CP: Cathodic Protection
CSD: Consulting Services Department
CTS: Coupon Test Station
ER: Electrical Resistance
GOSP : Gas and Oil Separation Plant
HDD: Horizontal directional drilling
HVAC: High Voltage Alternating Current
ICCP: Impressed Current Cathodic Protection
MSAER: Mandatory Saudi Aramco Engineering Requirements
NEC: National Electric Code
NEMA: National Electrical Manufacturers Association (USA)
NDB: Negative Drain Bond
PMT: Project Management Team used as a truncated version of Saudi
Aramco Project Management Team (SAPMT)
SAPMT: Saudi Aramco Project Management Team (often shortened to
PMT)
SCP: Soil Corrosion Probe
VpCI: Vapor Phase Corrosion Inhibitor
WIP: Water Injection Plant

4.2. Definitions
Bond Cable: A cable installed between two metallic structures to provide
electrical continuity between the structures for cathodic protection.
Calcined Petroleum Coke Breeze: A carbonaceous backfill used as a
conductive backfill media for impressed current anodes in soil.
CPA Probe: A CP assessment probe is a multi-electrode probe designed to
enable measurement of the soil resistivity in addition to representative polarized
and depolarized potentials for the pipeline or other buried or immersed metallic
structure at the probe location.
CP Coupon: A CP coupon is a single electrode coupon that has been designed
to enable measurement of representative potentials or current densities on a
pipeline or other buried or immersed metallic structure at the coupon location.

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CP System Operating Circuit Resistance: The total effective resistance seen by

the output terminals of the cathodic protection power supply, or the total
working resistance in a galvanic anode system.
CP System Rated Circuit Resistance: The cathodic protection power supply
rated output voltage divided by the rated output current. For photovoltaic power
supplies, the rated output current for this calculation is the design current.
Cross Country Pipeline: A pipeline between; two plant areas, another cross-
country pipeline and a plant area, or between two cross-country pipelines.
Deep Anode Bed: Anode or anodes in a vertical hole (typically 25 cm diameter)
with a depth exceeding 15 m (50 ft).
Design Agency: The organization or company contracted by Saudi Aramco for
the design of a CP system. The Design Agency may be the Design Contractor,
the Lump Sum Turn Key Contractor or an in-house design organization of Saudi
Aramco.
Drain Point: The location on the cathodically protected structure where the
negative cable from the rectifier or negative junction box is fastened to the
structure.
Flowline: A pipeline connected to a well.
Galvanic Anodes: Anodes fabricated from materials such as aluminum,
magnesium or zinc that are connected to the buried structure to provide
cathodic protection current without the requirement for an external cathodic
protection power supply. Galvanic anodes are also referred to as sacrificial
anodes.
Hazardous Areas: Those areas where fire or explosion hazards may exist due
to flammable gases or vapors, flammable liquids, combustible dust, or ignitable
fibers or filings (see NEC Article 500).
Impressed Current Anodes: Anodes fabricated from materials such as High
Silicon Cast Iron (HSCI) or Mixed Metal Oxide (MMO) that are immersed or
buried and are connected to the positive terminal of a DC power supply to
provide cathodic protection current.
Resistivity Tester: A meter designed to measure ground resistivity, or can be
connected to measure resistance in a format that excludes the resistance of the
test wires.
Negative Cable: A cable that is electrically connected (directly or indirectly) to
the negative output terminal of a cathodic protection power supply. This
includes bond cables to a cathodically protected structure.
Off-Plot: Off-plot refers to any area outside of the plot limits.
On-Plot: On-plot refers to any area inside the plot limits.
Perimeter Fence: The fence which completely surrounds an area designated
by Saudi Aramco for a distinct function.

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Photovoltaic Module: A number of solar cells wired and sealed into an

environmentally protected assembly.
Pipeline: The term “pipeline” is used generically in this standard and can be
used to refer to any type of pipeline.
Plant Area: A plant area is the area within the plot limits of a process or
hydrocarbon storage facility. Scraper trap and launcher areas are not Plant
areas.
Plot Limit: The plot limit is the boundary around a plant, process or
hydrocarbon storage facility. The plot limit may be physical such as a fence, a
wall, the edge of a road or pipe rack, chains and posts or a boundary indicated
on an approved plot plan.
Positive Cable: A cable that is electrically connected (directly or indirectly) to
the positive output terminal of an ICCP power supply, including impressed
current anode cables.
Process Pipeline: A pipeline typically associated with a plant process and
typically above ground within a plant facility.
Production Pipeline: A pipeline transporting oil, gas or water to or from a well.
These include flow-lines, test-lines, water injection lines, and trunk-lines.
Reference Electrode: An industry standardized electrode used as a common
reference potential for cathodic protection measurements. A copper/copper
sulfate (Cu/CuSO4) reference electrode is typically used for soil applications. A
silver/silver chloride (Ag/AgCl/0.6M Cl) reference electrode is typically used for
aqueous applications.
Soil Transition Point: The on-grade location where a pipeline enters or exits the
soil, i.e., above grade to below grade transition, or below grade to above grade
transition.
Subject Matter Expert (SME): For the purposes of this document, the SME
shall be the assigned Consulting Services Department cathodic protection
specialist.
Surface Anode Bed: Anode or anodes connected to a common CP power
supply, installed either vertically or horizontally at a depth of less than 15 m (50
ft).
Test-line: A pipeline that is used for testing an individual well or group of wells.
Thermite Weld: An exothermic process to make electrical connections between
two pieces of copper or between copper and steel.
Transmission Pipeline: A cross country pipeline transporting product between
GOSPs, WIPs or other process facilities.
Trunk-line: A pipeline designed to distribute or gather product from two or more
wells, typically connecting flow-lines or injection lines to the associated GOSP
or WIP.

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Utility-line: A pipeline designed to deliver an end use service product (typically

water, gas or air).

5. Safety
Cathodic protection personnel are responsible for obtaining appropriate work
permits (in accordance with GI-0002.100) and associated gas test results from
the operations foreman before starting any job. Inspect excavations and
confined spaces and ensure they are in a safe condition prior to entering. This
includes testing for gas, as discussed above.
Appropriate personal protective equipment (PPE), such as safety glasses,
safety shoes with electrically insulated soles, etc., shall be worn. Fall restraining
devices shall be used when working on top of structures such as storage tanks.
Appropriate safety precautions must be followed when making electrical
measurements, and include:
a) Personnel must be knowledgeable and qualified in electrical safety
precautions prior to installing, adjusting, repairing or removing impressed
current cathodic protection equipment.
b) Use caution when long test leads (100 meters or longer) are extended
near overhead high voltage AC power lines, since hazardous voltages
can be induced into the test leads. Use rubber mats, rubber gloves, or
both, when making measurements near high voltage AC power lines.
c) Use caution when stringing test leads across streets, roads and other
locations subject to vehicular traffic.
d) Use caution when making tests at electrical isolation devices.
Appropriate voltage detection instruments or voltmeters with insulated
test leads should be used to determine if hazardous voltages exist before
proceeding with tests.
e) Use properly insulated test lead clips and terminals to avoid contact with
unexpected hazardous voltages. Test clips should be attached one at a
time each time a connection is made. A single hand should be used to
make the connection, in a well-balanced body position, while the other
hand should be free from resting on any surface.
f) Testing should be avoided when there are thunderstorms or rain in the
area. Remote lightning strikes can create hazardous voltage surges that
travel along the pipe under test.

6. Monitoring Procedures

6.1. Rectifier Periodic Check and Monitoring Procedures

6.1.1. Rectifier Monthly Checks

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Check and report rectifiers monthly to determine if they are operating.

This can be done by Operations or Maintenance personnel who visit the
site on a regular basis for purposes other than those relating to cathodic
protection. If the checks are done by non-cathodic protection personnel,
they shall be having an electrician qualification, capable to read/measure
rectifier output (voltage and current) and report any noticed/suspected
abnormality in rectifier operation to the cathodic protection personnel
who operate the system.
Note:
Rectifiers fitted with remote monitoring systems do not need to have the monthly
checks performed through field personnel visits. The monthly rectifier checks
requirement also does not apply to Northern Area Producing Offshore platforms.

6.1.2. Rectifier Quarterly Checks

Cathodic protection personnel shall visit rectifier sites on a quarterly
basis to read and record rectifier output volts and amps. Verify these
readings with a portable meter and calibrate rectifier meters accordingly.
When these data are collected by Remote Monitoring System which are
down-loaded and saved in Proponents system then there is no need to
visit the field to specifically to collect this data.

6.1.3. Rectifier Bi-annually (Six-Monthly) Checks

Check and record oil level, color and oil temperature on oil-immersed
units (as per 26-SAMSS-059).
For rectifiers protecting multiple pipelines (pipeline corridors) read and
record individual current to each pipeline connected to the rectifier
directly, through NDB or through pipe-to-pipe bond within NDB vicinity. It
does not apply for those with underground NDB.

6.1.4. Rectifier Annual Checks

6.1.4.1. Visual Inspection

Annually, visually inspect the cabinet, terminals, and components for
mechanical damage, continued serviceability, access, and safety.

6.1.4.2. Transformer Oil Checks

For oil-immersed units, sample and check the transformer oil as follows:
a) Open the rectifier drain spout to collect approximately one (1) liter
of the oil in a clean and clear glass container.
If sediment, sludge, or water drains with the oil during sampling,
continue draining until the contaminant has been flushed out, and
then collect approximately 1 liter of oil.

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If the sediment has not been flushed out after 4 liters of oil have
drained, completely drain and re-fill the rectifier with new oil. Top
up with new oil, if required, to make-up for oil drained for testing.
b) Where applicable, replace the oil if it is dark or cloudy and difficult
to see through, or if the oil appears to be full of suspended
particles. It is much easier to visually judge the quality of used oil
if compared to a sample of new oil.
If required by the operating department, transformer oil may be lab-
tested for dielectric characteristics and contamination if oil
quality is questionable.
c) Dispose used oil following procedures outlined in Supply Chain
Management Manual, Topic CU 22.03.

6.1.4.3. Remote Monitoring

For rectifiers equipped with remote monitoring units (RMUs), verify the
accuracy of the data being transmitted by the RMU, and the alarm
functions. This could be done either by connecting a laptop computer to
the RMU in the rectifier, or by comparing the data monitored at the
rectifier with that being transmitted to the host computer.
For the data collected by RMU, certify these readings with a calibrated
portable meter and confirm that the RMU data and actual data are
aligned. In case of difference between these two beyond reasonable
error, then appropriate calibration for the RMU will be required.

6.1.4.4. Rectifier voltage and current

Annually verify the rectifier voltage and current readings with a portable
meter and calibrate rectifier meters accordingly.

6.1.4.5. Rectifier Negative Junction Box

If there is a multiple negative current return junction box connected to
the rectifier, determine the current in each cable.
For those with underground NDB, conduct “On/Off” potential survey for
all pipelines at the nearest test posts to the rectifier.

6.1.5. Periodic Rectifier Check Data

Record all data taken during the annual check on a data sheet similar to
and containing all the information shown on the example in Appendix J.
Note:
1) Except in areas of vandalism, Proponents may elect to conduct the first annual
periodic check 12 months after commissioning, and then every 24 months, if the system

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is operating normally. Revert to the 12 / 24 month cycle if system malfunctioned,

repaired, and / or re-commissioned.
2) Remote monitoring system data may be printed out in the report format of the system
software, or as required by the proponent.
6.2. Rectifier Periodic Check and Monitoring Procedures

6.2.1. Anode Bed Annual Checks

Evaluate the performance of each anode bed annually. Measure current
output levels of impressed current anodes and/or galvanic anodes.
For the impressed current anode beds, the total current output level
should match the coinciding quarterly rectifier reading with a tolerance of
±10%. In case of anode bed designed current capacity is less than the
TR rated current capacity then the TR shall be operated within the anode
bed designed current capacity.

6.2.2. Junction Boxes Annual Check

Annually, individually check all anode junction box connections and
fittings for cleanliness and tightness. Any required maintenance shall be
conducted as follows:
a) Take apart and clean all connections and bolted fittings, using wire
brush or emery paper.
b) Apply Burndy oxide inhibiting compound (or equivalent) to all cables
and connections, then reinstall all cables and connections.
c) Seal or reseal all conduit openings with a sealing compound.
d) Inspect, and if required, repair or replace the door seals.
e) Check grounding cable connection to junction box (if applicable),
and tighten connection if required.
f) Repair and rectify the damaged/worn out parts of
cables/connections, etc.

6.2.3. Bond Box Annual Check

Check Pipe-to-soil survey potential survey at all bond boxes
Check current and current direction for pipeline connection at the bond
boxes
When multiple rectifiers are protecting different pipelines in the corridor,
check for bonding of the nearby pipelines protected by different CP
system by carrying out interference test. Interference test shall be carried
out by cycling one rectifier on and off at a time and measuring the
potentials all nearby pipelines. Test shall be repeated for all rectifiers.
Any test location that indicate a more negative potential shift in response

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to turning off a rectifier is indicating current discharge and shall be

mitigated immediately within a maximum time of one month.

6.2.4. Periodic Anode Bed Check Data

Record all data taken during the annual check on a data sheet similar to,
and containing all the information shown on, the example in Appendix J.
Note:
1) Except in areas of vandalism, Proponents may elect to conduct the first annual
periodic check 12 months after commissioning, and then every 24 months, if the system
is operating normally. Revert to the 12 / 24 month cycle if system malfunctioned,
repaired, and / or re-commissioned.
6.3. Solar Power CP System Periodic Maintenance and Monitoring Procedures

6.3.1. Solar Systems Monthly Checks

Check and report solar power CP system monthly to determine if they are
operating. This can be done by Operations or Maintenance personnel who
visit the site on a regular basis for purposes other than those relating to
cathodic protection. If the checks are done by non-cathodic protection
personnel, they shall be having an electrician qualification, capable to
read/measure solar unit’s output (voltage and current) and report any
noticed/suspected report any abnormality in unit’s operation to the cathodic
protection personnel who operate the system.
Note:
Solar systems fitted with remote monitoring systems do not need to have the monthly
checks performed through field personnel visits.
6.3.2. Solar Systems Quarterly Checks
Cathodic protection personnel shall visit Solar Powered CP sites on a
quarterly basis to read and record systems output volts and amps.
Verify these readings with a portable meter and calibrate local meters
accordingly.
For systems protecting multiple pipelines (pipeline corridors) read and
record individual current to each pipeline connected to the system
directly, through NDB or through pipe-to-pipe bond within NDB vicinity. It
does not apply for those with underground NDB.
Quarterly, thoroughly clean and check the solar system(s), as follows:
a) Clean the panel glass to be free of dust, sand, and salt
accumulations.
b) For maintenance of the batteries please refer to SAEP-350.
c) Check and adjust solar array performance and regulator operation
as per the manufacturer's instructions.

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d) Record all data taken during the quarterly check on a data sheet
similar to, and containing all the information shown on, the
examples in Appendices C, D, and E.
Note:
The frequency for the battery checkup shall be increased, if required, to ensure
that the electrolyte in the battery cells can be maintained at the levels
recommended by the manufacturer.
6.3.3. Solar Systems Annual Checks
Annually, in addition to the quarterly checks listed in 6.3.2 above, carry
out the following tests:
a) Disconnect the batteries from the load and solar panels, and
check the individual battery voltage. If the individual battery voltage is
lower than 25% of the average rated output of the batteries, replace the
individual battery. For maintenance of batteries please refer to SAEP-
350
b) If further evaluation is required, use a data logger to verify battery
performance over a 4-day period.

6.4. Cathodic Protection System Surveys

6.4.1. General

6.4.1.1. Perform structure-to-electrolyte potential measurements at the

locations where the structure-to-electrolyte potentials were measured
during the CP commissioning survey, or subsequent monitoring surveys.
The locations of the potential measurements can be changed or the
quantity increased to ensure that the structure-to-electrolyte levels in the
critical areas are adequately monitored.

6.4.1.2. Cathodic protection structure-to-electrolyte potentials are

measured by connecting the instrument positive terminal to the structure
and the negative (Common) terminal to the reference electrode which is
in contact with the electrolyte. With this connection the instrument
indicates a negative polarity sign which means the structure is opposite
to the polarity with respect to the reference electrode. Therefore, the
structure potential is negative and for Figure 1 below written as: -850
mV/ ref. This connection arrangement as well as the polarity of the
potential readings shall be properly recorded.

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Figure 1: Potential Measurement for Offshore and Onshore Structures

Note:
Reference Electrodes shall be verified/calibrated and/or certified to ensure the
reliability of the readings.
6.4.1.3. Use a portable copper/copper sulfate reference electrode for
onshore structures, and a portable silver/silver chloride reference
electrode for offshore structures and water storage tanks.

6.4.1.4. Where stationary reference electrodes have been installed,

measure and record the structure-to-electrolyte potentials using these
stationary electrodes and verify with portable reference electrode, if
applicable.

6.4.1.5. Place the portable reference electrode as close as possible to

the structure. In dry soil, pour sufficient amount of water on the soil
around the electrode to minimize the contact resistance and to obtain
valid readings. Added water should not contaminate the soil with
chlorides.

6.4.1.6. A good metallic contact (low resistance) between the voltmeter

and the structure is required. If connecting above-grade to a coated
structure, make a small cut through the coating layer to ensure a good
metallic contact.

6.4.1.7. Measure structure-to-electrolyte potentials with a multiple /

selectable input impedance voltmeter. At each onshore test location,
take the measurement at two values of input impedance to validate the
measured value. If the measured value changes by more than +/-5 mV,
the measured value is unreliable and water should be poured on the
ground before re-measurement.

6.4.1.8. When taking potential measurements on offshore structures or

tank internals, add an additional weight to the reference electrode to

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overcome buoyancy and drift from the structure. If using metallic

weights, keep 3 inches, at least, distance from the tip of the reference
electrode.

6.4.1.9. When taking structure-to-electrolyte potential measurements, on

both onshore and offshore structures, place the reference cell as close
as possible from the structure and as far from the anode or anode bed as
possible.
Note:
The proponent should correct CP system deficiencies at the earliest possible time (i.e.,
but shall not exceed 6 months from reporting).
6.4.2. Offshore

6.4.2.1. Fixed Structures:

6.4.2.1.1. Conduct a comprehensive structure-to-water potential

survey annually. This survey shall include readings at the water
surface, every 10 meters thereafter, and one at the sea bed, with
a minimum of two readings on each jacket leg and pipeline riser.
Check all bonding cables prior to reading structure-to-electrolyte
potentials.

6.4.2.1.2. Measure the voltage difference between accessible

well casings, conductors, etc., to check for complete continuity
(fixed cell test). The difference in voltage between all casings, on
the same well platform (including the conductor pipe) should be
less than 10 mV for continuity.

6.4.2.1.3. The structure-to-electrolyte potentials shall be -900 mV

/ Ag-AgCl or more negative (Table 4 Appendix A-1).
Note:
a) For structures protected by impressed current systems, measure and record
the output of each anode or anode string.
b) For underwater surveys conducted by divers, other work such as removal of
excessive marine growth, debris removal, and taking photographs, videotaping, etc.,
should be added to the diver's tasks, if required by the proponent.
6.4.2.2. Well Casings:
Take current (amperes) readings on each well casing on offshore well
platforms with impressed current systems by divers using a clamp on
Sea Clip. Clip is to be installed around the conductor under water on the
seabed or at any location above the water where accurate reading of the
return current can be obtained. CP personnel will monitor and record the
readings at the surface.

6.4.2.3. Submarine Pipelines:

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6.4.2.3.1. Annually measure structure-to-water potentials at each end of

each submarine pipeline. Record the potential survey data on a data
sheet similar to Appendix H of SAEP-332, or other appropriate data
forms. The structure-to-electrolyte potential shall be -900 mV/ Ag-AgCl
or more negative (Table 4 Appendix A-1).

6.4.2.3.2. For new structures perform complete pipe-to-water potential

surveys (under water) every eight (8) years. For existing structures,
especially old structures and that show cathodic protection potentials not
meeting the Saudi Aramco requirements, accelerated anode
consumption, external coating damage and metals loss as indicated by
other surveys/assessment (ILI survey, ROV Survey, and diver survey),
frequency of survey shall be increased to ensure continued protection of
the structures. Exact intervals for such surveys will vary depending on
structure condition and this is to be decided by the Proponent. A general
recommendation is to consider five-year interval with further increase to
this frequency based on structure condition as indicated by various
assessments.

6.4.2.3.3. Diver team surveys (under water) shall include inspection of all
bracelet anodes, and structure-to-water potential readings shall be taken
midway between bracelet anodes or at 150 m intervals where no anodes
exist. A database shall be built for all previous surveys and anode
replacements. Bracelet anode inspection shall include visual survey to
identify the galvanic anode consumption percentage. All galvanic anodes
consumed to 80% and more must be replaced immediately. Galvanic
anode consumption affects the protection status of the structure and
hence it is important to maintain a data base of the galvanic anodes
consumption. Such data base shall include previous anode consumption
as identified by the underwater survey and subsequent consumption as
well. For example, from the past survey if the anode consumption has
been recorded as 80% but replaced subsequently, then surveying this
replaced anode in the next survey is not considered necessary unless
potentials near the anode indicate poor protection levels. Whereas in the
previous survey if the galvanic anode consumption was recorded as 50%
and more, it is more important to survey these anodes and all the anodes
not surveyed previously or not replaced previously and record further
consumption. This way it is possible to more effectively concentrate on
areas of poor protection and/or accelerated galvanic anode consumption
locations and build a data base which help in making decision on anode
replacement.

6.4.2.3.4. Any external corrosion and/or leaks related anomalies shall be

thoroughly investigated and CP status at these locations shall be
reported to track the external protection status of leaked or corroded
locations. When ILI survey indicates external wall thickness loss or
corrosion indications, CP potential measurements at these areas will

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help evaluate the status and recommend mitigation and hence some
correlation between the wall thickness anomaly and CP system
potentials should be produced for a comprehensive evaluation. Potential
of the pipeline must be surveyed at locations of anodes and farthest from
the anodes as well. Any areas of under protection (not meeting the
requirements of SAES-X-300) must be marked as area of concern and
should be evaluated with performance of nearby anode, such as anode
integrity, consumption pattern, etc., to carry out suitable remedial
measure including anode replacement.

6.4.3. Onshore

6.4.3.1. General:
Perform a comprehensive cathodic protection potential survey within 12
months of commissioning and annually thereafter. Prior to the survey,
check all power sources and bonds for proper operation. The survey
shall include an evaluation of CP systems and measurements of the
level of protection on all structures which receive cathodic protection.
After the survey, complete all repair or upgrade requirements and
conduct spot checks or pipeline section resurvey in affected areas.
6.4.3.2. Buried Pipelines:

6.4.3.2.1. Measure structure-to-electrolyte potentials with all CP systems

energized, at all KM test stations, at pipeline transition points, road
crossings, valves, appurtenances and other locations where there are
test points, bond stations or above/below ground transitions. These
measurements shall be made with the portable copper/copper sulfate
reference electrode placed directly above the pipeline. Instruments that
will facilitate measuring the instant "OFF" potential measurements maybe
installed where needed.

6.4.3.2.2. When there are high voltage AC power lines that are within 50
meters of the pipeline and paralleling the pipeline for more than 500
meters, measure the structure-to-electrolyte AC potentials (annually) at
the test stations, bond stations and any other above ground
appurtenance within 500 meters of the power line.

6.4.3.2.3. Measure the pipe-to-soil potential with the stationary reference

electrode if available.

6.4.3.2.4. Record the structure-to-electrolyte potential on a data sheet

similar to Appendix G of SAEP-332, or other suitable form. The
measured structure-to-electrolyte potentials shall comply with the criteria
listed in Table 1 Appendix A-1.
Additional survey methods such as close interval surveys (CIS), direct
current voltage gradient (DCVG) and current mapping (CPCM) maybe

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conducted. CP assessment probe maybe installed to further investigate

the protection level.

6.4.3.2.5. CP Coupon Test stations are used to monitor CP levels and

efficiency for buried coated pipelines in various soils. See Appendix A-2
for CP coupons installation and monitoring details. The following
additional measurements shall be conducted quarterly for the first year of
installation and at least once annually after 12 months at the CP
coupons:
• Instant “Off”/polarized potential of the CP coupon, and shall be
made using a portable copper/copper sulfate reference electrode
placed inside the Coupon Test Station reference tube: Protection
criterion shall be a CP Coupon “Off” potential of -850 mV/ Cu-
CuSO4
• Depolarized potential – protection criterion shall be 100 mV
negative polarization vs. Instant “Off”/polarized potential.
• CP Coupon Current – calculating of CP current density
• Polarization curve assessment
• Potential vs current (data collection by data logger)

6.4.3.2.6. Soil corrosion probes (SCPs) measurements may be used as

an alternative to the potential criterion to assess the effectiveness of
cathodic protection, by measuring the corrosion rate of the SCP. The
measured corrosion rate of the SCP shall be less than 0.01 mm per year
(as per ISO-15589-1) for the pipeline to be considered as having
effective cathodic protection. Measurements shall be conducted quarterly
for the first year of installation and at least once annually after 12 months
at the soil corrosion probes locations. See Appendix A-3 for details
regarding suitability of using these probes and the installation and
monitoring details. It is preferable to dig up the probe after the first 12
months of service, to visually confirm that the corrosion rates measured
from the probes are actually those being experienced on the probe and
the pipeline.

6.4.3.2.7. AC coupons should be installed for testing purposes near high

voltage power lines. Measure the AC induced voltage / potential at test
stations which are close to the HV power lines where the pipeline is
entering and leaving the common corridors and near to electrical
isolation points.

6.4.3.2.8. 3-pin galvanic anode test station monitoring requires checking

the pipe-to-soil potential, and current output of the galvanic anode:

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Measure open circuit potential of pipe and anode by disconnecting the

connection between pipe and anode and by connecting the voltmeter
positive to the terminal of pipe and anode one by one respectively,
however, the voltmeter negative shall be connected to a reference
electrode both times. This measurement shall be taken at least once on
annual basis.
After connecting the circuit again, measure the potential by connecting
the voltmeter positive to the terminal labeled “P/S”, and the voltmeter
negative to a reference electrode.
Measure the galvanic anode current by measuring the voltage drop
across the 0.01 ohm shunt, using a millivoltmeter. Connect the meter
positive to the “P” terminal and the negative lead to the “A” terminal on
the test station. The measured voltage will have positive polarity if the
anode is providing protective current to the pipe. For the 0.01 ohm
shunt, 1 mV = 100 mA of current flow.

6.4.3.2.9. CIPS (Close Interval Potential Survey) should be carried out

on pipelines that have history of external and are of critical nature. CIPS
survey will help evaluate the CP status at critical locations and are
carried out at close intervals of 1 to 3 meters. Length of pipeline section
for CIPS survey should be decided by the proponent based on historical
protection status and external corrosion status.

6.4.3.2.10. Any external corrosion and/or leaks related anomalies shall

be thoroughly investigated and CP status at these locations shall be
reported to track the external protection status of leaked or corroded
locations. When ILI survey indicates external wall thickness loss or
corrosion indications, CP potential measurements at these areas will
help evaluate the status and recommend mitigation and hence some
correlation between the wall thickness anomaly and CP system
potentials should be produced for a comprehensive evaluation. Any
areas of under protection must be marked as area of concern and should
be evaluated with performance of the CP system rectifier operating
parameters, anode beds, etc., and suitable remedial measure including
CP system upgrade and anode bed replacement etc., shall be carried
out immediately if required. If, carrying out repair and remedial measures
are expected to take longer time such as more than 6 months, in such
cases temporary protection with the help of galvanic anodes and/or
temporary power supply shall be implemented in the interim period.

6.4.3.3. Buried Plant Piping:

Measure the structure-to-electrolyte potentials when all plant CP
systems are energized. The measurements shall be taken on the

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straight run pipelines and on sections buried in the areas within the plant
boundary. These include the structures and piping sections buried
under SSD fences, in areas where buried piping anchors are present, at
pipeline transition points, at all soil access test holes, and in areas
where equipment or other buried structures are congested. Record all
data taken during the survey on a data sheet similar to and containing
all the information shown on the example in Appendix F. The measured
structure-to-electrolyte potentials shall comply with the criteria and
spacing listed in Table 1 Appendix A-1.

6.4.3.4. Above Ground Storage Tanks:

6.4.3.4.1. Tank Bottoms:

Measure the structure-to-electrolyte potentials at the same locations
where they were measured during the commissioning survey (as much
as practical).
a) Take a minimum of four (4) potential measurements at equal intervals
around each tank bottom. The spacing of the readings shall not be
greater than 20 meters.
b) Measure and record the potential difference between any stationary
reference electrodes (usually buried under the tank) and the tank.
Measure and record the current output of the anodes (galvanic or
impressed current). Record all data taken during the survey on a
data sheet similar to and containing all the information shown on the
example in Appendix G. The potentials shall meet the criteria listed
in Table 3 Appendix A-1.
c) If soil access holes (outside the ring wall) are available, measure the
tank-to-soil potentials at these test access holes. If there are no test
access holes, take the tank potential measurements at locations
within two meters of the tank shell and at least one meter from any
buried bare copper grounding cables. Monitoring tubes maybe
installed underneath existing tanks if needed (HDD, micro tunneling,
etc.).
d) Where anodes are installed around the tank periphery, measure the
potentials at locations midway between the anodes to minimize
anode gradient effects.
e) Where tank bottom access tubes are installed through the tank
concrete ring wall, measure the tank-to-soil potentials through these
access tubes using a portable copper/copper sulfate reference
electrode.

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f) Where slotted monitoring tubes are installed under the tank bottom,
pull a portable reference electrode trough the tube and take readings
at 1-meter intervals over the length of the tube under the tank. A wet
cotton sponge may be wrapped around the tip of the electrode to
improve electrical contact of the electrode with the soil surrounding
the slotted tube. Do not add water in the slotted pipe or access holes
thru the ring-wall.
g) Where the 100 mV depolarization criterion is to be utilized, then
follow procedures given below:
• Record the “instant off” potential within one second of interrupting
the rectifier. If more than one rectifier is connected to the
structure being monitored, all the rectifiers should be
synchronized to be turned off at the same time.
• Allow the structure to depolarize for a period of 24 hours.
• Record the potential after 24 hours.
• The system is considered protected if the difference between the
“instant off” potential and the depolarized potential is more than
100 mV.
• If the 100 mV depolarization is not achieved within 24 hours, the
structure can be allowed to depolarize up to a maximum of 7
days.
• If the 100 mV depolarization is still not achieved after 7 days of
depolarization, corrective action shall be implemented to increase
Cathodic Protection.
h) Tanks having second bottoms (two bottoms), rather than replacement
bottoms, may have stationary reference electrodes installed between
the two bottoms. Measure the structure-to-electrolyte potentials of the
bottoms with reference to these electrodes. Measure and record the
current output of any anodes installed between the two bottoms.
Double bottom tanks with no stationary reference electrodes cannot
be monitored via. structure-to-electrolyte measurements.
i) Tanks having secondary containment may have stationary reference
electrodes installed between the bottom and the containment lining.
Measure the structure-to-electrolyte potentials of the bottom with
reference to these electrodes. Measure and record the current output
of any anodes installed between the bottom and the containment
liner.

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6.4.3.4.2. Water Storage Tank Internals:

Annually perform a comprehensive tank-to-water potential survey.
Measure and record tank-to-water potentials at the upper water
level, midway between the upper level and the bottom and at the
bottom of the tank. Measure and record the current output of each
anode or anode string. Record all data on a data sheet similar to
Appendix H, or other suitable form. The potentials shall meet the
criteria listed in Table.3 Appendix A-1.

6.4.3.5. Well Casings:

6.4.3.5.1. Annually conduct a comprehensive well casing and associated

flowline survey. Conduct the survey with all rectifiers turned on. Use the
following procedure for conducting this survey:
a) For all new well casings, determine if the casing is:
1. bare, or
2. FBE coated for the top two/three joints, or
3. FBE coated beyond the top two/three joints. Indicate
whether the landing base is filled with sweet sand or not.
This should be noted, and the current required determined
accordingly.

b) If galvanic anodes are present, measure the current output of

the galvanic anodes using a clip-on ammeter. Record the
measurement, including the direction of the current flow. This
current may be too small (or zero) to measure in some cases.
c) Measure the well casing current and the flowline current and
direction using a clip-on ammeter. Adjust the rectifier(s) as
required, to achieve the minimum casing current drain, as
specified in Table.2 Appendix A-1.
d) Measure the flowline potential at the transition point. If the
potential is greater than -2.5 volts, reduce the rectifier output(s)
appropriately.

6.4.3.5.2. Conduct the structure-to-electrolyte potential measurements

for the flowlines at a minimum of three locations, which shall include at
the well head, the mid-point of the flowline and the termination point. A
flowline can terminate at the GOSP or at a trunk line. Measure potentials
with all CP systems turned ON. Take additional readings at the road
crossings for the above-ground flowlines.

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6.4.3.5.3. Plant water supply well casings shall be made electrically

continuous with impressed current system in the plant. If isolated, install
a bond box.

6.4.3.5.4. Record all data taken during the survey on a data sheet similar
to and containing all the information shown on the example in Appendix
I. The current drains for well casings and the flowline potentials shall
meet the criteria listed in Table 1 and Table 2 Appendix A-1.

6.4.3.5.5. Well Casing CP System Downtime Criteria:

The following table details the maximum downtime criteria for single
well casing cathodic protection systems:
Minimum “ON”
Maximum Cumulative
Duration Between Two
Field Downtime “Off Days” Per
Consecutive
Duration 12-Month Period
Downtimes
Abqaiq and
<14 days 60 2 x No. of “Off” days
Uthmaniyah*
2 x No. of “Off” days but
Others <30 days 60
not less than 30 days
* All efforts should be exerted to minimize the downtime period in Uthmaniyah to less
than 14 days.

6.4.3.5.6. Pipeline CP System Downtime Criteria:

Area Maximum Continuous Cumulative “Off Days” Minimum “ON” Duration

Downtime Duration Per 12-Month Period Between Two Consecutive
Downtimes
Very corrosive <14 days 60 2 x No. of “Off” days
areas (sabkha,
wadi)
Others <30 days 60 2 x No. of “Off” days but not less
than 30 days

Note:
Deviations from these specified durations requires the processing of an Engineering
Standards Waiver Request. Alternatively, temporary power supplies or temporary
portable power generators can be utilized during the downtime, if cost optimum.
6.4.3.5.7. In areas of frequent vandalism, underground junction boxes
and anchored CP cables maybe installed.

6.4.4. Sheet Pilings, Trestles and Piers

Measure structure-to-electrolyte potentials on the soil sides of sheet
piling, and on-shore trestle and pier pilings using a copper/copper sulfate
reference electrode. Measure the potential measurements on the water
sides of the sheet piling, and off-shore trestle and pier pilings, using a
silver/silver chloride reference electrode. The measured structure-to-

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electrolyte potentials shall comply with the criteria as listed in Appendix

A-1.

6.4.5. Isolating Devices

6.4.5.1. Isolating devices, e.g., isolating spools, joints and flanges, are
sometimes used in cathodic protection systems to isolate buried
protected structures from above grade unprotected structures. Test the
integrity of all isolating devices with an RF isolation checker (tester)
instrument or fixed RE (reference electrode) methods. Do not use an
ohm-meter to check for continuity. Inspect and test these isolation
devices at least annually to ensure their effectiveness.

6.4.5.2. When faulty insulation in a flange is suspected, where applicable

measure insulation efficiency between each bolt and the flange.
Insulation check is performed using RF (Radio Frequency) checker or
fixed RE (reference electrode) methods. If one or more faulty bolt
insulators are found, mark these for repair. If all bolts show that they are
isolated, then the flange gasket is faulty. Replace the faulty flange gasket
when practical or wait for the T&I.

6.4.6. Road Crossing Casing Tests

Annually test the road crossing casings for electrical isolation. Such test shall
include measuring the casing potential and carrier pipe potentials. A potential
difference between the pipe and casing that is greater than 100mV is indicative
of an isolated casing. Less than this amount does not necessarily mean that the
casing is shorted, however the results are not considered definitive and other
such as using RF isolation tester and other methods will be required.
6.4.7. Hydrocarbon Vessels and Tanks Internals

6.4.7.1. Monitor hydrocarbon vessel internals using the installed galvanic

anode monitoring system (AMS), or permanent reference electrodes, as
applicable. With AMS, calculate the anode remaining life.

6.4.7.2. Crude or product tank CP system effectiveness is determined by

visual inspection when the tank is opened for T&I or other maintenance.
Galvanic anode consumption rates should be calculated from the
remaining dimensions of the anodes.

6.4.8. Underground Storage Tanks

Measure structure-to-soil potentials at 1-meter intervals over the length
of the underground storage tank, reservoir or oil-sumps. These
potentials should be taken over the centerline of the tank and also at a 1-
meter distance along the sides of the structure.

6.5. Parallel & Crossing Foreign Pipeline Crossings Interference Monitoring

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6.5.1. Measure structure-to-electrolyte readings at locations where a known

foreign pipeline crosses or comes within 75 meters of a Saudi Aramco
pipeline. Place the reference cell directly over the crossing or over the
foreign pipeline at the closest point to the Saudi Aramco line.

6.5.2. Measure potentials on both structures with the nearest Saudi Aramco
rectifier cycled “On” and “Off” (use 4(sec ON):1(sec OFF). If the
measurements indicate that the Saudi Aramco C.P. system is depressing
the protection level on the foreign pipeline, when “On”, by 50 mV or more,
forward written notification to the owner of the foreign line.

6.5.3. If the protection level on the Saudi Aramco line is less than acceptable
per Table 1 Appendix A-1, then conduct a close interval survey in the
vicinity of the crossing for approximately 50 meters in each direction over
the Saudi Aramco line. If the close interval survey indicates that
interference is occurring on the Saudi Aramco line, notify the owner of the
foreign pipeline and implement additional cooperative testing with
corrective action.

6.5.4. All such interference monitoring shall be carried out once at least on
annual basis. Interference monitoring should be carried out by interrupting
the foreign pipeline (where possible).

6.6. Cathodic Protection Monitoring Equipment-use and Maintenance

6.6.1. Use voltmeters, ammeters, and reference electrodes suitable for CP

monitoring. Check meter batteries before each survey to ensure they
function properly.

6.6.2. Conduct a semi-annual check (verification) on electrical instruments,

maintenance tools, and testing devices for calibration. Calibration shall be
performed depending on the condition of the digital meter. Condition could
be assessed by checking against similar (or new) meters (voltage verifier
maybe used), when the accuracy/ error margin exceeds ±5 mV, the meter
shall be calibrated.

6.6.3. Use high input impedance meters for structure-to-electrolyte potential

measurements, especially in areas of high soil resistivity. Input impedance
should be in the 20+ mega-ohm range. Multimeters with various setting
levels of input impedance are preferred.

6.6.4. Use a clamp-on-ammeter for the direct measurements of DC currents.

Meters having current measuring capacity up to 200 amps and a variety of
clamp sizes are preferred. When changing clamp sizes for the same meter,
refer to the manufacturer's instructions for the appropriate factor for the
clamps. To measure the small value currents i.e., Mg anode current output,
the DC clamp meter with range of 200mA to 4000mA shall be used.

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6.6.5. Properly maintain copper/copper sulfate and silver/silver chloride

reference electrodes, as follows:

6.6.5.1. Clean the tips of the copper/copper sulfate electrodes, and

ensure that the electrodes contain an adequate volume of electrolyte
with an excess of copper sulfate crystals. Inspect and test the electrodes
one against another or against a standard voltage source, periodically.
The voltage difference shall not exceed a maximum differential of ±10
mV. If this maximum is exceeded, a complete clean-up is needed. In
the clean-up, remove the oxide layer on the copper rod by using fine
sand paper, and renew the copper sulfate electrolyte. Rinse the copper
rod thoroughly after sanding, before reinstalling in the electrode casing.
Fill the electrode half full, as a minimum, with a saturated water solution
of copper sulfate. Use only distilled water and chemically pure copper
sulfate. Also, add an excess of copper sulfate crystals, equal to
approximately 10% (by weight) of the saturated solution in the cell.

6.6.5.2. Inspect and test silver/silver chloride electrodes one against

another or against a standard voltage source, periodically. If the voltage
difference is larger than 10 mV, a replacement is required.

6.6.6. Check test leads of voltmeters used for structure-to-electrolyte

measurements periodically, for continuity and integrity. Repair or replace
faulty leads or connections before making measurements.
Note:
To verify the continuity of the leads, short the leads and measure their resistance. It
should be very close to zero.
6.7. Records and Reports

The responsible proponent organization shall collect and record all field data on
the appropriate forms (see typical data recording forms attached as Appendices
to this Procedure), and issue survey reports. The report for the annual CP
survey shall summarize the CP status of all protected structures and the
performance of all CP systems. It shall also include recommendations to
eliminate deficiencies. The annual cathodic protection survey report will be
reviewed by CSD at the request of the proponent organization.
Each operating proponent organization shall maintain database of all periodical
CP monitoring & maintenance records including field survey data, failure
investigation reports, remedial actions in a one location easily accessible to all
stake holders.
Records for all CP system sufficient to demonstrate the effectiveness of the
corrosion control measures shall be maintained as long as the facility involved

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remains in service shall be maintained throughout the asset life or until such
time the asset has been de-commissioned.
7. Responsibilities

7.1. Refer to GI-0428.001, “Cathodic Protection Responsibilities,” for details of the

organizational responsibilities for implementing this Engineering Procedure.

7.2. Each operating proponent of CP shall maintain at all times qualified personnel
to conduct the survey and which are as follows:
a) Data Collection Survey Team shall have at least one of these personnel
with NACE International CP level 1 certification.
b) Data Review & Interpretation shall be carried out by NACE International
CP level 2 certified personnel.
c) Operation Unit CP Team should have at least one of these personnel
with NACE International CP level 2 certification.
d) Inspection Unit CP Team should have at least one of these personnel
with NACE International CP level 2 certification.

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Appendix A-1 - Cathodic Protection Monitoring Criteria

Table 1: Cathodic Protection Monitoring Criteria- ONSHORE Structures

FACILITY – ONSHORE
PROTECTION
(All readings taken with Cu-CuSO4 reference electrode,
CRITERIA(13)
unless otherwise noted)
PIPELINES
Non-Subkha -1,100 mV
In Subkha -1,000 mV
In Subkha, FBE Coated, CP Coupon “Off” Potential -850 mV “Off”(6)
Mothballed -1,100 mV
Buried Crossovers and Bypasses -1,000 mV(1)
Non-Subkha or Subkha, using Soil Corrosion Probe
Less than 0.4 mpy(10)
(Corrosion Rate)
Non-Subkha or Subkha, using AC/DC Multimeter Less than 12V AC(11)
(AC Voltage under HVAC Power line)
VALVE SITES
Motor Operated Valves -1,000 mV(1)
Gas and Hand Operated Valves -1,000 mv(1)
PLANTS (including Pump Stations, GOSPs and Bulk
Plants)
-850 mV(1)
Hydrocarbon Lines
-850 mv(2)
Metallic Fire Water Lines
At Cathodic Protection Coupon (for all onshore structures)
Polarization/depolarization 100 mV
current density (non-sabkha) 20 mA/m2
current density (sabkha) 40 mA/m2

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Table 2: Cathodic Protection Monitoring Criteria - Well Casings

Casing Current Drain (Amps)

Well Casings (12)
Bare Casings Coated Casings
GAS WELLS
Abu Jifan, Fazran, Khurais, Mazalij, Midyan, Nuayyim, Shayba
Rectifier 15-20 1.5-5
Photovoltaic 15-20 1.5-5
Ghazal, Jufayn, Kassab, Manjurah, Sahba, Shaden, Tinat, Waqr, Sahba, (ZMLH), (AWTD), (WDYH)
Rectifier 35-40 1.5-5
Photovoltaic 35-40 1.5-5
Haradh, Hawiyah, Harmaliyah, Midrikah, Nujayman, Shedgum, Uthmaniyah, (ANDR), (DAMM),
(KRSN)
Rectifier 35-40 30-35
Photovoltaic 35-40 30-35
OIL PROD. AND WATER INJECTION WELLS
(7, 8)
Uthmaniyah
Rectifier 30-35 5-7
Photovoltaic 30-35 5-7
Abqaiq, Abu Ali, Hadriyah, AinDar, Berri, Dammam, Fadhili, Fazran, Hawiyah, Khursaniyah, Manifa,
Qatif, Safaniyah, Shedgum
Rectifier 20-25 2-4
Photovoltaic 20-25 2-4
Ginah, Haradh, Hawtah, Harmaliyah, Midyan, Nuayyim, Shaybah, (ABMK), (Umjurf), (Hazmiyah),
(Nislah), (Burmah)
Rectifier 12-15 1-3
Photovoltaic 12-15 1-3
Abu Jifan, Khurais, and Mazalij
Rectifier 2-5 0.5-5
Photovoltaic 2-5 0.5-5
WATER SUPPLY WELLS
Abu Jifan, Khurais, and Mazalij, (Fazran)
Rectifier 1-3 0.2-0.5
Photovoltaic 1-3 0.2-0.5
Other Areas(9)
Rectifier 5-7 0.5-1
Photovoltaic 5-7 0.5-1

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Table 3: Cathodic Protection Monitoring Criteria- Storage Tanks

TANKS
Internals -900 mV(3)
Bottom Underside (as applicable)(4)
Stationary Zinc Reference Electrodes Installed Under +200 mV
Tank Bottom
Stationary Cu-CuSO4 Reference Electrodes Installed -900 mV
Under Tank Bottom
Portable Cu-CuSO4 Reference Electrodes in Soil Access -1000 mV
Holes Outside Ring Wall
Portable Cu-CuSO4 Reference Electrodes through Ring -900 mV
Wall Access Tubes
Portable Cu-CuSO4 Reference Electrode in Monitoring -900 mV
Tube Under Tank Bottom
Depolarization criterion: Minimum depolarization after 100 mV
24 hours or max. 7 days

TRESTLES AND SHEET PILING (Soil Side) -850 mV

UNDERGROUND TANKS
Underground tanks, sumps and reservoirs -850 mV

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Table 4: Cathodic Protection Monitoring Criteria- OFFSHORE structures

FACILITY – OFFSHORE Protection

(All readings taken with Ag-AgCl reference electrode) Criteria
Fixed Platforms -900 mV

Pipelines -900 mV

Trestles and Sheet Piling (Water Side) -900 mV

Notes:
1) Measured at intervals not to exceed 30 meters over all piping. (Excluding transit pipeline sections in
launcher/receiver traps and inside plant fenced area away from plant processing facilities).
2) Measured at all above-ground appurtenances.
3) Measured against an Ag-AgCl reference electrode.
4) CP systems for tanks with oil sand pad or asphalt foundations shall be operated based on the design output
of the rectifier. Dedicated CP systems for such tank foundations shall not be upgraded.
5) Applies only to tanks which do not have ring wall access tubes or under-bottom stationary electrodes.
6) Applies only to FBE coated pipelines in subkha soils. “Off” potentials are measured using a CP Coupon
Test Station.
7) In the Uthmaniyah field, operate 25 and 35 amp rectifiers (pre-1990) at maximum allowable output, provided
that the minimum current drain is 20 amperes.
8) Rectifier output should be reduced if nearby pipeline potentials exceed 3.0 volts, provided that the minimum
current drain is 20 amperes.
9) The 5 amp criterion is for water wells with dedicated CP systems, and which are less than 2,000 ft deep.
For wells deeper than 2,000 ft, operating current will be the same as specified above for the oil producing
and water injection wells for the various fields.
10) Corrosion rate criterion, in mils per year, is for the metal loss experienced by the soil corrosion probe.
11) Measured at all locations under High Voltage AC Powerlines, in AC volts.
12) For Well casings which are not covered under SAES-X-700, design and monitoring criteria of all such new areas shall be
based upon the respective design criteria considered in the Approved Design document.
13) Potential measurements related to criteria are intended to be made with respect to reference electrodes at 25 °C. Common
practice does not require a temperature correction within 10 °C of this temperature. For temperature correction factor
more than 10°C, it is recommended to consider a correction of 1mV per °C rise in temperature.

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Appendix A-2: Cathodic Protection Coupon Test Stations

A. Background
A CP coupon is used to simulate coating defects (holidays) on the structure
being evaluated. The CP coupon test station (CTS) is installed near the
pipeline and then connected to it through the wiring in the CTS head. This
allows the CP coupon to be connected to the CP system on the pipeline, thus
simulating a holiday in the coating. The CP coupon can then be disconnected
from the circuit during periodic testing, and an instant-off potential measured.
The CP coupon can then continue to be monitored and the depolarization
measured.
These measurements approximate the polarized or “off potential” and the
depolarized potential of the structure in the vicinity of the CP coupon and allow
the operator to calculate the IR drop. A second “free-corroding” native coupon
is also installed in the CTS coupon to measure the native potential of the
coupon.
Readings at CTSs shall not be interpret as justifying “non-compliance to the
potential criterion” at:
• Low cathodic protection potential levels due to poor coating
quality (disbonded)
• Ineffective or malfunctioning CP systems (CP interference)
• Other abnormal conditions resulting in poor protection.
In these cases, the cause of the poor protection should be identified, and
suitable remedial measures taken to resolve the problem.

B. Conditions for Using CP Coupon Test Stations (CTSs) as CP Monitoring Tools

CP coupons been approved in Saudi Aramco for use in low resistivity (subkha
type) soils, on cross-country FBE coated pipelines, with “excellent” coating, and
no history of corrosion in the area where the CTS is being installed. An -850
mV “off” potential or 20 (40) mA/m2 CP current density measurement of the CP
coupon is considered to indicate adequate protection. (See Section 6.4.3.2 and
Appendix A-1 above).
C. Monitoring Procedures
CTS potentials are measured using a CU/CuSO4 reference electrode and a
high impedance voltmeter. Measure the CP Coupon and Native Coupon “off”
potentials by interrupting the current flow to the CP coupon using the On/Off
switch in the test station head. The potential reading must be taken with
1 second of interrupting the current to the coupon (use 4:1 On to Off ratio for
interrupting). If using a digital voltmeter, the second reading that flashes on the
screen after the current is switched off is usually accepted as a valid “off
potential reading. A specialized recording voltmeter or data logger can also be
used to measure the off-potential 200 to 300 milliseconds after the coupon
current has been interrupted.
D. Monitoring Schedules

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For mandatory requirements please refer to the Section 6.4.3.2.4.

E. Installation Guidelines
See Installation Instructions below for details. A permanent reference cell can
be installed inside the test station tube for monitoring. Alternatively potentials
are measured using a portable reference cell with an extension to lower it down
inside the test station tube.
CP coupon should not be connected to the CP circuit for at least 4 weeks after
installation, to allow the coupon to freely corrode and essentially be comparable
to the condition of the pipe in this same soil environment.
F. CP Coupon Test Station Installation Instructions
Pre-Installation Checks
Refer to the list below for the materials required for the CTS installation for each
site. Ensure that all materials for the particular site are on-hand, prior to starting
the excavation work.
Check CP CTS to see if the two coupons at the bottom of the tube are fixed
firmly (not loose), and extend out of the bottom of the tube for the full length of
the metal coupon.
Installation Steps
• CTS is to be installed to the side of the pipeline, at pipe mid-line
depth, about 25 cm (10 inches) from the pipeline
• Excavate to top of pipe. This will locate pipe center, as well as to
allow for thermite welding of wire connection for the CTS (if
required).
• Excavate 25 cm to the side of the pipe up to the mid line of the
pipe. Try to leave undisturbed soil between the CTS and the pipe.
• Drill hole in the side of the CTS tube, just below the approximate
grade level. Insert the test lead wire (from the pipe, or existing KM
CP test Station) through this hole, and bring it to the top of the
CTS tube.
• Install CTS next to the pipe, as specified above, and backfill.
• Add “native” soil to the CTS tube (approximately 0.25 meter)
• Leave enough slack in the test head wires so that the head can
easily be removed and moved aside.
• Complete backfilling of the excavated area around the CTS and
the pipeline.

Typical Installation Sketch

The CP Coupon test station consists of a 3 inch diameter PVC tube, a test
head (Figure 2), and two 9 cm2 cylindrical carbon steel coupons. One of these
coupons is connected to the pipeline CP circuit (and is therefore called the “CP
Coupon”), through an “on/off” switch. The other remains unconnected and is
used to monitor the native potential of the coupon in the soil (“Native Coupon”).
The “connection for reference electrode” is used only if a permanent reference
electrode is installed inside the test station tube.

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Figure 2 – CP Coupon Test Station Head

Figure 3 – CP Coupon Test Station Installation

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CTS Monitoring Procedure and Records

The potential measurements for the CTS are done as follows:
1) Data is recorded with the portable electrode at grade level as well as
inside the test station tube. This is done to see if there is any significant
interference effect on the readings taken at grade level outside the test station
tube. The reading taken inside the tube is considered to be one which is more
accurate, as it is not influenced by any stray currents in the area.
2) The portable reference electrode must be lowered down into the test
station tube, and should make contact with the soil in the tube at the bottom.
This can be done by temporarily removing the test head from the tube, and
lowering the reference cell attached to an extension rod.
3) The “off” potential measurements are made by using the on/off switch in
the test head.
4) The potential reading must be taken with 1 second of interrupting the
current to the coupon (use 4:1 On to Off ratio for interrupting). If using a digital
voltmeter, the second reading that flashes on the screen after the current is
switched off is usually accepted as a valid “off potential reading. A specialized
recording voltmeter or data logger can also be used to measure the off-potential
200 to 300 milliseconds after the coupon current has been interrupted.
5) All “off” potential readings (for the pipeline, CP coupon, and the native
coupon) are taken using the on/off switch in the test station head.

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Record the CP potentials as follows:

Portable Ref. Cell at Grade Level Date Date Date Date

Pipeline Potential - Coupon CP “On”
Pipeline Potential - Coupon CP “Off”
Coupon Potential – Coupon CP “On”
Coupon Potential – Coupon CP “Off”
Native Coupon Potential - Coupon CP “On”
Native Coupon Potential - Coupon CP “Off”
Portable Ref. Cell inside Test Station Tube
Pipeline Potential - Coupon CP “On”
Pipeline Potential - Coupon CP “Off”
Coupon Potential – Coupon CP “On”
Coupon Potential – Coupon CP “Off”
Native Coupon Potential - Coupon CP “On”
Native Coupon Potential - Coupon CP “Off”

Material Requirements
No. Description Qty Comments
1 CP Coupon Test Station Tube 1
2 1 Connect separate wire from
CP Coupon Test Station Head
pipeline to this CTS
3 #10 AWG, STR Wire for Pipe
Quantity as required
Connection
4 Thermite Weld Equipment Quantity as required
5 2” PVC Pipe, 3 meter long (Soil 1 For portable reference cell
Access Tube), if required measurement

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Appendix A-3: Electrical Resistance Soil Corrosion Probes

A. Background
The use of electrical resistance (ER) soil corrosion probes (SCPs) to determine
actual corrosion rates can assist in determining the effectiveness of cathodic
protection (CP) in high resistivity soils. This technique is especially useful in
cases of:
• Poor reference cell soil contact resulting in erroneous CP potential
measurements, or
• When “Off” potential measurements cannot be practically taken on complex,
interconnected pipeline systems.
CP potential measurement errors can occur in:
• Very dry, high resistivity desert soils or in sand dune areas, and
• On pipelines with berms which have been sprayed with oil for soil
consolidation.
In such situations, the measured potentials may not meet the minimum
operating criterion requirement, even if the CP system output is raised, or
supplemental galvanic anode “hot spot” protection is provided at such locations.
SCPs are not a substitute for:
• Low cathodic protection potential levels due to poor coating quality.
• Ineffective or malfunctioning CP systems.
• Other abnormal conditions resulting in poor protection.
In these cases, the cause of the poor protection should be identified and
suitable remedial measures taken to resolve the problem.
B. Conditions for Using ER Soil Corrosion Probes (SCPs) as CP Monitoring Tools
The following should be used as a guide for selecting locations where SCPs
can be used to measure the effectiveness of cathodic protection:
• Pipeline with potentials lower than the minimum acceptable criterion for the
soil conditions, where remediation measures such as installing additional CP
system capacity are not practical or cost effective.
• Pipe coating must be FBE, in good/excellent condition (no blistering bare
patches or other obvious coating damage). This can be verified by bell hole
inspection.
• Pipe coating for short buried sections/road crossings which have been
reconditioned using high performance ACPS-113 coatings may also be
monitored using SCPs.
• The existing piping must have no documented history of corrosion, or
inspection records showing any leaks, ruptures or corrosion damage in the
vicinity of the location where the SCP is proposed to be installed.
• Instrument scraper records, where available, should also be used to
determine that there is no history of corrosion for the selected installation
location.

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• The soil must be homogenous over the length of pipe section that the probe
data will used for determination of CP effectiveness. Install one SCP test
station for at least every 1 kilometer of pipe section with uniform soil
conditions.
• The SCP monitoring frequency shall be as per section 6.4.3.2.5.
• A visual examination of the probe should be conducted 12 months after
installation, by excavating up the SCP, to verify the measured corrosion
rates by visual examination of the probe and pipe surface.
C. Monitoring Procedures
Use a “CK-4 Corrosometer” instrument or equivalent to measure the metal loss
on the corrosion probe. The Corrosometer data has to be converted to metal
loss (mils), and then plotted as an Excel X-Y graph, to determine the corrosion
rate in mils per year (mpy) from the slope of the trendline of the plotted data.
For potential measurements, measure the Probe and Native Coupon “off”
potentials by interrupting the current flow to the probe using the On/Off switch in
the test station head.
D. Monitoring Schedules
The SCP monitoring frequency shall be as per section 6.4.3.2.5.
E. Installation Guidelines
See Installation Instructions below for details. A “Soil Access Tube”
(see Figure 6 below for details) may be required in high resistivity soils, if
probe/coupon potentials are also desired to be measured.
The probe should not be connected to the CP circuit for at least 4 weeks after
installation, to allow the probe to freely corrode and essentially be comparable
to the condition of the pipe in the same soil environment.
F. Soil Corrosion Probe Test Station Installation Instructions
Pre-Installation Checks
Refer to the check list below for materials required for the Soil Corrosion Probe
(SCP) installation for each site. Ensure that all materials for the particular site
are on-hand, prior to starting the excavation work.
Installation Steps
1) SCP should be installed to the side of the pipeline, at pipe mid-line depth,
(3 o'clock, or 9 o'clock) about 25 cm (10 inches) from the pipeline
2) Excavate to top of pipe. This will locate pipe center, as well as to allow for
thermite welding of wire connection for the SCP (if required).
3) If there is no adjacent existing CP test station, thermite weld a #10 WAG
test lead wire to the pipe and bring it to grade level.
4) Excavate 25 cm to the side of the pipe up to the mid line of the pipe.
5) Drill hole in the side of the SCP tube, just below the approximate grade
level. Insert the test lead wire (from the pipe, or existing KM CP test

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Station) through this hole, and bring it to the top of the SCP tube.
Leave enough slack in the test lead wire so that the head can easily be
removed and moved aside.
6) Install SCP next to the pipe, and backfill.
7) Complete backfilling of the excavated area around the SCP and the
pipeline.
Typical Installation
The general installation layout of the SCP test station is shown in Figure 4
below.

Figure 4 – SCP Test Station Installation Detail

SCP Test Head Connections
The wiring arrangement for the Soil Corrosion Probe (SCP) test head is
shown in Figure 5 below. The “Probe” in the SCP is connected to the pipeline
CP circuit through an on/off switch, and is thus cathodically protected. All test
head and internal probe and coupon connections in the SCP are pre-wired by
the manufacturer, except the “probe” terminal to the on/switch terminal
connection, which has to be done at the time of test station installation in the
field.

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Figure 5 – Detail of SCP Test Station Head

Use of Soil Access Tubes
In some cases (very dry soils) an additional soil access tube may also be
installed for use in measuring potentials using a portable reference electrode,
as shown in Figure 6 below:

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Figure 6 – SCP Installation with Soil Access Tube

Material Requirements
No. Description Qty Comments
Connect separate wire
1 Soil Corrosion Probe Test Station 1
from pipeline to this SCP
2 #10 AWG, STR Wire for Pipe Connection Quantity as required
3 Thermite Weld Equipment Quantity as required
2” dia, PVC pipe (soil access tube), if
4 For reference cell access
required

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Corrosometer Monitoring Procedure

1. Turn meter “OFF”. Connect the Corrosometer connector to the plug in
the test station.

2. Turn on the meter by pressing “ON”.

3. Confirm that the “Span” (F4) is set to 25 for the label you want to record
data for (Step 6 below).
4. From the displayed menu choices, select “Read” (Press F1).

5. “Select Probe Type” will be displayed, Select “T/S” (Press F2).

6. “Select Label” will be displayed.

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Choose:
“A” for Location 1,
“B” for Location 2,
“C” for Location 3, etc.
(each test station location will have it's own label assigned to it.)
7. The meter will start reading. Wait until the flashing in the display stops
and the reading are displayed. (This usually takes about 2 minutes,
45 seconds).
SCP Monitoring Records
Record the Corrosometer data in the following Table format:
CK-4 Corrosometer Data

Date Date Date Date

Check
Measure
mpy*

* This reading is displayed using “DISP, F2” from the initial menu, if the consecutive probe readings
are more than 14 days apart.

The recorded data can be displayed by selecting “DISP, F2” from the initial
menu and pressing the correct label no.
Record the CP potentials as follows:

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Portable Ref. Cell at Grade Level Date Date Date Date

Pipeline Potential - Probe CP “On”
Pipeline Potential - Probe CP “Off”
Probe Potential – Probe CP “On”
Probe Potential – Probe CP “Off”
Coupon Potential - Probe CP “On”
Coupon Potential - Probe CP “Off”

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Appendix A-4: Attachments to SAEP-333

Please refer to SAEP-333A to view the Appendices C – K.

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Document History
17 March 2022 Major revision to incorporate standard comments from standards
website and standard committee meeting discussion.

28 November 2019 Editorial revision to change the revision cycle from 3 years to 5 years,
add the Conflicts and Deviations Section, add SAEP-302 to the
reference list.

2 May 2019 Editorial revision: Corrected title of 26-SAMSS-059, updated the

document’s contact

30 January 2017 Major revision to changed procedure for structure-to-soil potential

readings.
• Developed a drawing for structure-to-soil potential readings.
• Revised the protection criteria for well casing to coincide with SAES-
X-700.
• Revised recommended survey frequency for under water structures.
• Revised calibration requirements.
• Revised solar rectifiers’ checks.
• Revised monitoring requirement for submarine pipelines.
• Added definitions and abbreviations.

13 December 2011 Revised the “Next Planned Update.” Reaffirmed the content of the
document, and reissued with minor revision.

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