Infrared Thermography
Surveys for the Oil, Gas & Petrochemical Industries
The Power Industries
APT Infrared Thermography plays a hugely important role within
the oil, petrochemical, chemical, and power generation industries.
With the current global energy crisis, and the huge demand
for energy on the increase, these energy-based industries
must continue to meet higher volume demands while endeavoring
to reducing operational costs and preventing failures. Such
failures can lead to losses in production which in turn can
cause massive monetary costs as well as ongoing effects that
can be felt as far down as the consumer. This webpage will
discuss the areas where APT Infrared Thermography is used
within the petrochemical and energy sectors such as furnaces,
generator cores, and offshore oil and gas platforms.
Introduction to APT Infrared Thermography in the
Petrochemical Industry
The petrochemical industry is a fascinating, varied and challenging
industry in which to carry out the many different types of
nondestructive testing and predictive maintenance inspections.
Within any refinery complex there numerous plants that carry
out a specific function and process; and within each plant
there is a multitude of equipment from steam powered, to hydraulic,
electrical & mechanical. There is positive/negative pressurised
equipment and a varied amount of exotic metals and alloys.
The terminology used to simplify this is “the Balance
of Plant”. Experienced inspectors know, the words “balance
of plant” simply mean you must be prepared to meet the
confusing and unexpected.
When we think of petrochemical plants and operations we usually
think of an oil refinery; however, the process of oil refining
is undertaken in multiple stages. There are separate chemical
plants within a petrochemical refinery, and usually, where
there is a region of petrochemical and hydrocarbon activity,
there are also other forms of process or chemical plants such
as methanol, ammonia, etc. Due to the complexities of this
I will undertake a brief explanation of each area:
Oil & Gas Offshore Platforms
Before any oil can be refined or any gas can be used to run
power generation turbines, it must be retrieved from deep
below the ground. In the offshore environment this usually
means drilling wells and maintaining and managing them via
an offshore platform. Once the wells have been drilled and
the flow of gas and oil is harnessed and controlled, the offshore
process is relatively simple in concept. A platform’s
main function is to retrieve the gas and oil from the wells,
whilst controlling the flow, separating the solids, liquids
and gases, and thereafter distributing the needed products
whether it be oil or gas via usually via the undersea pipelines
to the mainland.
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Undertaking APT Infrared Thermography on an offshore platform
can be on standard equipment such as electrical switchgear
and pumps. However materials coming up from the wells can
cause detrimental erosion problems to the pipelines, valves,
and vessels. One of the most common ways of monitoring sand
etc is via ultrasonic sensors mounted at strategic locations
on flow lines. Unfortunately, like all technologies, these
ultrasonic sensors do have their limitations. An effective
means of monitoring sand being carried up from the wells is
by conducting a thermographic survey of the separator vessels.
The main function of an offshore separator is to quickly separate
sand, water, oil, and gas. We know that out of these four
materials, sand sinks in water while oil floats, and gas is
light and cold and will remain on top. Also, each of these
materials has a very different thermal capacitance and conductivity
making it possible to use APT Infrared Thermography to locate
and highlight the relative levels of solids and fluids.
Using thermal images we can distinctively differentiate between
the layers of sand, water, oil, and gas. We can even see the
sand’s flow pattern through the outlet nozzles, which
can help to determine which valves will be more affected by
the erosive power of sand.
Our APT Infrared Thermography engineers undertaking thermographic
surveys for separator sediment levels have a firm understanding
of fluid dynamics, thermodynamics, and erosion mechanisms,
along with a good understanding of heat transfer, emittance,
and reflectance. With this knowledge our APT Infrared Thermography
engineers are qualified to make accurate diagnoses which in
turn leads to proper, cost-effective means of minimizing the
problems or, hopefully, eliminating the problems. It may be
something as simple as packing gravel/stone in the well to
reduce the flow of sand, thus alleviating the overall mass
travel of sand and as a result reducing the wear on valves
etc.
Pumping from Sea to Land
Once the platforms are operational and are producing, there
are usually two main products that are sent to two different
places. The crude oil is generally piped via undersea pipelines
to large holding tanks for further refining. A common application
of APT Infrared Thermography at this stage is monitoring holding
tank levels.
Holding Tanks
The natural gas is pumped through miles of pipelines to its
main destination which is usually a power generation plant.
Some plants use fuel oil instead of natural gas to generate
power by steam generation via boilers, however for now we
will leave the focus storage tanks and focus on the much faster
moving natural gas.
Power Generation Plants
Pressure, heat, and natural gas are used to spin gas turbines,
which in turn spin the generators; this generates electrical
power through electromagnetism. Within the turbine section,
heat leaks can be found at the gas seal areas of a turbine.
This inspection can be carried out online.
Gas Turbines and Heat Leakage
The generator section contains a stator and rotor. Both can
be inspected with APT Infrared Thermography, however the generator
needs to be offline and disassembled. This type of survey
is frequently done when the stator needs to be repacked. Stator
cores are made of iron bars which contain many small thin
plates called laminations. Both the stator and rotor can be
inspected with APT Infrared Thermography by wrapping several
coils with insulated cables along the axis of the stator.
Then, a pre-calculated amount of current is applied through
the coils in order to generate a suitable flux.
Generator stator core - coils wrapped around and
ready for fluxing
This inspection is to locate potential shorts within the many
laminations that make up the entire core. Shorts in laminations
can cause large temperature rises which will ultimately lead
to a stator or rotor burn out. Below is a thermal image showing
shorted laminations in a Multi Megawatt generator stator core.
Generator stator core problems - Lamination shorts
Repairs can be as simple a process as separating the lamination
plates with a knife/tool or by using a pencil grinder to grind
out the short. Once power is generated, it is then sent to
the power station’s transformers and then to the main
substation for power
distribution to various other chemical and petrochemical plants.
Incoming and Receiving Stations
Once the power reaches the petrochemical plants, it is stepped
down via transformers and then distributed to various switchgear,
and distribution panels. It is this area where APT Infrared
Thermography would perform their thermographic survey.
A Smoothly Flowing Plant
Much of the power distribution within petrochemical plants
goes towards driving motors, pumps and compressors. This rotating
equipment is vital to a plant’s operation and can be
thought of as a plant’s heart whose job it is to pump,
compress, pressurize, and cool down the various fluids that
maintain the plant’s production. APT Infrared Thermography
inspection of rotating equipment is very common.
It can be a hot process?
The natural gas retrieved from offshore platforms is used
in many production processes within petrochemical and chemical
plants, also, we must not forget about the crude oil in our
storage tanks that needs that also needs to be refined.
The pumps, previously mentioned, also provide refined fuel
oil to fire up boilers in order to generate steam. The steam
is then used for multiple purposes such as power generation
and to drive plant turbines, which in turn drive pumps and
compressors. Either natural gas or refined fuel oil is used
to fire and heat up process heaters. In order to maintain
efficiency and safety, boilers and heaters are inspected with
APT Infrared Thermography to monitor insulation and refractory
conditions and also to monitor tube temperatures.
Insulation Damage to Water Tune
Another use for natural gas within a chemical plant is to
produce hydrogen through a process called reforming. Natural
gas is sent into many catalyst-filled tubes within a reformer
furnace and is mixed with the steam generated by the boilers.
The reformer furnace is heated via many burners that usually
use natural gas as their fuel. This heat creates a catalytic
reaction that produces hydrogen from the natural gas and steam.
Infrared Thermography is undertaken on reformer furnaces in
a similar way to boiler and heater inspections.
FCCU Regenerator Unit
The FCCU is an important part of the oil refinery. The FCCU
breaks down long chains of hydrocarbons into shorter ones
in a chemical process called cracking. This allows refineries
to make products such as gasoline and other high octane fuels.
The FCCU uses a very hot catalyst to crack the hydrocarbons
into shorter chains. The mixture then travels from the FCCU
to another distillation column so that the cracked hydrocarbons
can be extracted. A continuous FCCU has a primary reactor,
a distillation column for separating out the cracked hydrocarbons,
and a regeneration unit for cleaning the catalyst and preparing
it for reuse.
Problems in the FCCU Regenerator Unit
Previously, we learned that boilers generate steam and that
this steam is used throughout petrochemical and chemical plants.
Most of the time the steam needed must be dry and superheated.
The problem with steam is that as soon as it leaves the boiler
it starts to cool down and condensate. This condensate can
cause many problems in piping and equipment and must be expelled
from the steam lines. Steam traps are used for this job. A
steam trap’s job is to keep the dry steam in the pipes
and get rid of the harmful condensate. Although there are
many designs of steam traps, most achieve their purpose by
opening purging out the condensate at regular intervals.
As Steam energy is money, it is in a plant’s best interest
to make sure their traps have not failed in the open position
which will just waste the precious and expensive steam. APT
Infrared Thermography in conjunction with ultrasound testing
is frequently used to determine the working condition of steam
traps.
Steam Traps
In order for steam, gas, oil, and other fluids (hot or cold)
to be properly distributed throughout a chemical and petrochemical
plant, each must be sent though many lengths of piping and
be controlled or redirected through valves. APT Infrared Thermography
can also be used to verify if valves are either in the open
or closed position (passing or not). This is a relatively
simple inspection, however, the inspector should be aware
that although you can tell if the valve is passing fluid or
not, you usually cannot tell how far the valve is open.
Open or passing valve
Process piping can also become obstructed or form internal
blockages and restrictions which are usually based on the
type of fluid it carries and the temperature it maintains.
APT Infrared Thermography is very useful in identifying internal
line blockages and restrictions. A few of the causes are:
• Internal buildup may cause fluid/flow restrictions
• Internal buildup may cause pipe blockages
Insulation related problems
Chemical and petrochemical plants are not all about hot vessels
and piping. Some plants have cryogenic processes such as CO2,
ammonia, and liquefied natural gas, so there will be cold
pipes, pumps, vessels, and tanks. APT Infrared Thermography
is used to inspect these types of cold equipment for insulation-related
problems, which can lead to greater problems and also energy
and efficiency losses.
Icing of Pump Lines.
Below is a thermal image of a distillation cold box.APT Infrared
Thermography can be used to identify insulation problems within
cold vessels and piping within chemical plants.
Insulation problems
Thermographic surveys can highlight insufficient insulation.
Cold liquefied natural gas inside the tank and warm air outside
the tank caused condensation to form throughout the tank’s
external shell and domed roof. This condensation problem along
with the sea breeze hitting the tank carries over microorganisms
from the sea and air. The damp and warm conditions allow these
microorganisms to thrive on the concrete shell and steel dome
of the tank, resulting in mold and algae growth. In turn Mold
and algae love to corrode steel, which leads to external corrosion
and pitting of the steel dome of the holding tank. There is
no quick or economical fix in this instance except for frequent
cleaning and painting of the affected areas to prevent or
slow down the corrosion.
Conclusion
It is now common knowledge that APT Infrared Thermography
plays a large part of fault diagonsics within the within all
aspects of the chemical and petrochemical industry. Not only
to monitor live equipment conditions but also to help identify
design, repair, and construction oversights. Although these
are some of the more common applications for APT Infrared
Thermography within these plants, there are many more uses
and applications. Many of the thermographic applications carried
out within chemical and petrochemical plants are very challenging
and require a solid understanding of plant equipment, processes,
and heat transfer physics in order to properly identify and
diagnose problems and conditions.
We carry out many surveys each year and guarantee to offer
a professional, reliable, and helpful and offer competitive
pricing. We offer a last minute service at no extra cost,
and we also undertake weekend Infrared Infrared Thermography
surveys on both on Saturday and Sunday in order to meet your
out of hour’s survey requirements. We offer a nationwide
service offering a single supplier for all of your regional
offices and projects.
Most of our clients, who use us for the first time, continue
to use our services because of our proactive approach, this
has led to nationwide agreements with many the top UK Companies,
which allows them to benefit from even more competitive rates
as well as unrivalled service.
We also offer other specialist testing and reporting, such
as:
• Air leakage Testing to Dwellings and Commercial Buildings
• Fire Enclosure Testing
• Sound Testing
• Energy Performance certificates, EPC, SAP & SBEM
APT Thermography - Further Information
If you have any questions or queries please don’t hesitate
to contact us:
By Mobile - 07967 233836 (available 7am to
10pm)
By E-mail - info@aptthermography.net
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