Oil & Gas Innovation Summer 2020 Digital | Page 49

the device seems to be operating normally,
it is easy to understand why taking a
unit off line to have this confirmed may
seem like a low priority. In some cases, it
may even seem unnecessary and nothing
more than an added expense. The issue
here, of course, is that these devices are
in place to measure actual conditions,
not merely to confirm what is expected.
If an instrument’s calibration is no longer
within tolerance limits, what looks like
a confirmation of expected results could
really be a misrepresentation of conditions
that are outside of acceptable limits. This
can result in costly negative consequences.
As is the case with preventive maintenance,
the best way to ensure the accuracy of
the calibration is to adhere to a regular
calibration and verification schedule.
VympelCare is designed to address both
of these aspects of equipment operation:
preventive maintenance and calibration /
verification – tasks that should be carried
out on a regularly scheduled basis even
when there does not appear to be an
immediate need. In the best case, these
two activities would be done at the same
time, minimizing the downtime of the
instrument involved and ensuring the
device, when calibrated, is in optimal
condition. This approach ensures the least
interruption in service. In fact, this is a pretty
good description of VympelCare: a program that
provides regular maintenance as well as the best
calibration / verification of Vympel instruments.
More specifically, VympelCare is a regularly
scheduled service provided by Vympel GmbH
and OGE, designed to make it easy for the
owners and operators of Vympel instruments
to follow through on carrying out regular
preventive maintenance and calibration.
Three times a year, Vympel sets aside a week
to provide VympelCare at its facilities in
Düsseldorf, Germany. Customers that intend to
take advantage of this service simply register in
advance that they wish to reserve one of the slots
available for an upcoming VympelCare session.
The instruments are then sent to Vympel
on the appointed date. Active promotion of
VympelCare is intended to remind the owners
of Vympel instruments of the importance of
regular preventive maintenance and calibration,
while offering an easy and economical way to
carry out these tasks. By optimizing the logistics
involved, a device is usually sent back to its
owner in a week to ten days, ready to go back
into service.
The devices covered by VympelCare are
Vympel’s state-of-the art chilled-mirror
hygrometers of the CONG Prima, FAS,
and Hygrovision series. These instruments
incorporate cutting-edge technology to measure
the water dew point (WDP) and hydrocarbon
condensation temperature (HCT) in natural gas.
These analyzers can all measure both the water
dew point and the hydrocarbon condensation
temperature. This type of instrument is an
important quality control device that is used for
a number of applications at many points along
the natural gas delivery chain, from production
Hygrovision mini and mini SL semi-automated manual chilled-mirror dew point analyzer.
to processing and transportation.
Measurement of the water dew point is a way
of directly measuring the moisture content
in natural gas as well as establishing the
temperature at which water will condense out
of the gaseous phase to form liquid droplets
in the gas stream. Moisture content is an
important indicator of gas quality. Gas that is
too wet can result in the formation of clathrate
hydrates in the pipeline, which can obstruct
the gas flow and may lead to catastrophic
accidents. An accurate measurement of the
water dew point is critical to ensuring the
quality of the gas and protecting the pipeline
and other equipment.
Similarly, measurement of the hydrocarbon
condensation temperature provides
information about the temperature at which
hydrocarbons will begin to precipitate out
of the gaseous phase, forming hydrocarbon
liquids. The presence of these condensates
in the gas flow can cause significant damage
to equipment such as gas fired turbines. In
addition, accurate measurement of the gas
flow requires that it remain in a single phase
(gaseous). As is the case with liquid water,
hydrocarbon liquids in a natural gas pipeline
can cause a number of problems, so knowing
the temperature above which the gas must be
maintained is essential information.
Apart from the operational imperatives, these
two measurements are also important for
contractual and regulatory reasons. Failure
to conform to specified water dew point
and hydrocarbon condensation temperature
values can result in fines, fees, or other
financial penalties.
VympelCare is intended to help keep these
critical analyzers online and operating
with as little interruption as possible, while
ensuring that they provide not only accurate
information, but also the “best” information.
Upon arrival at Vympel GmbH in Germany,
maintenance service is provided by Vympel
technicians, helping to ensure that once they
are returned to their owners, the analyzers
will operate well without interruption.
VympelCare service includes comprehensive
inspection of the analyzer, cleaning of the
measurement chamber, updating the software
if a new version has been released, making any
minor adjustments to optimize performance,
and preparing the analyzer for calibration.
Then these units are sent to the Open Grid
Europe (OGE) lab in Essen, Germany for
calibration / verification. Calibration at OGE
ensures that the analyzers will provide the best
information.
To explain what is meant by the term “best
information” it is necessary to understand that
when it comes to chilled-mirror analyzers, all
calibrations are not created equally. The Open
Grid Europe (OGE) lab in Essen developed
a method for the harmonized calibration
of automatic hydrocarbon condensation
temperature analyzers with different levels of
sensitivity, for the GERG Project 1.64. This
method establishes 5mg/m3 of hydrocarbon
condensate as the threshold for reporting
the condensation temperature. In other
words, the temperature at which 5mg/m3 of
hydrocarbon liquids have condensed onto the
chilled mirror’s surface is considered to be
the hydrocarbon condensation temperature.
Measurements taken by an analyzer calibrated
to this standard will be much less
influenced by changes in gas composition,
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