52 |
Oilfield Technology
August
2015
The project covered the supply of four containerised ‘plug
and play’ modules. These include an instrument air module,
weighing 42 t and containing ZT55 oil‑free screw compressors
and desiccant dryers combined with pre‑and after‑filtration
units. Three further process air modules were also supplied, each
weighing 34 t, containing ZT250 oil‑free screw compressors, air
handling units and desiccant dryers with pre‑and‑after filtration.
All four modules have been specially designed to operate in
extreme ambient temperatures of ‑40 ‑ +45˚C.
Meetingtheneedsofaglobal industry
Atlas Copco’s Systems Hemel Hempstead custom engineering
workshop recently underwent a major expansion following a
£680 000 (€870 000) upgrade. The workshop has seen its total
floor area expanded from its original 850 m
2
to 1950 m
2
. An
external 12 x 15 m covered test area has also been built, adding a
valuable additional space for testing large engineered packages
in any weather. Packages can be moved around in the workshop
more easily thanks to the provision of two new 5 t cranes,
trackways and controls, which complement three existing cranes.
Other new additions include two modern spray paint booths
to replace the original single unit and a new grit blast facility,
meaning that virtually any customer paint specification can be
met. These additions increase working capacity and throughput,
shortening lead times to the customer.
The site in Hertfordshire, UK, is one of five strategically‑located
custom engineering facilities that form Atlas Copco’s Systems
business unit, which is focused on developing bespoke packaged
solutions from the company’s standard range. The other facilities
are in Antwerp (Belgium), Houston (USA), Pune (India), Wuxi (China),
and Sao Paolo (Brazil), which helps ensure that inspection and
testing procedures take place close to the customer location.
Bespokesystems
Bespoke systems – which can comprise compressors,
air treatment, dryers, filters, air receivers and control systems –
are typically mounted on a skid or built into a container so that
they can be transported in their entirety to locations around the
world within the energy, industrial power and petrochemical
markets.
The successful delivery of such solutions is reliant on far
more than advanced facilities, because end‑to‑end expertise is
perhaps the most important factor for clients entrusting entire
projects to a single team. That is why the experienced team of
over 40 engineers at Systems Hemel Hempstead can cover all
aspects of the process – from design and project management to
assembly, testing, quality control and documentation. Additional
to this UK engineering skill set, the expertise of other Atlas Copco
companies is made available via a web‑based application, iC3,
which allows separate teams to remotely access data and
drawings, as well as providing equipment details locally,
which are pivotal to the provision of after‑sales support. With
3600 field service engineers in 180 countries, the company is able
to ensure the reliable service that is so important to the smooth
running of oil and gas operations.
Testing is an essential phase of any new deployment. But in
the case of packaged solutions, testing can be carried out – and
even witnessed by the end user – before shipping, which can
dramatically reduce onsite commissioning time.
The fundamental heartbeat of these solutions are typically
oil‑free compressors, which are now generally acknowledged
as the most suitable option for offshore environments on the
grounds of purity, efficiency, lower maintenance requirements,
sustainability, longevity, reliability and regulatory compliance,
when compared with their oil‑injected counterparts. That is not
to say oil‑injected compressors have no place in this industry
– these are supplied according to demand – but oil‑free
dominates the market and the reasons are hard to resist.
Essential components for success
Perhaps above all else, reliability, safety and reduced risk of
failure – and its potentially catastrophic consequences – are
the key concerns for oil and gas operators. Air compressors
that are oil‑injected will always be faced with the challenge of
extracting that oil and while there are numerous approaches
to resolve that, oil‑free technology bypasses the problem
completely. While oil‑injected compressors rely on filtration
– and regular maintenance or replacement of filter elements
– there is always an element of risk that is simply absent from
oil‑free solutions.
But after safety and reliability, overall costs are an
increasingly important consideration in such a competitive
industry. And while the oil‑free compressors are often accused of
having a higher upfront cost than their oil‑injected counterparts,
the final calculation, including not just initial investment but
maintenance and operation costs, tends to favour oil‑free. This
is especially true of variable speed drive (VSD) air compressors,
which intrinsically adjust their power consumption according to
the need at any particular moment.
Another regular component of packaged solutions for
the offshore industry tends to be a nitrogen generator, with
efficiency once again being a big influence. Using pressure
swing absorption technology, combined with air compressors
and dryers, enables the economical generation of gases on site,
which can reduce both costs and emissions.
As an example, Atlas Copco’s NGM membrane nitrogen
generators are ideally suited to the oil and gas industry. The
membrane allows nitrogen to pass and other gases, such as
oxygen, water vapour and CO
2
, to permeate. The NGM series
delivers flows from 5 to 500 Nm
3
/h and purities from 95% to 99%.
The benefits of integrating these pieces of technology into
a cohesive whole to meet unique customer specifications are
easy to see in a world where ‘one size fits all’ no longer suits
everyone.
Figure 3.
Example of a customengineered compressedair package.
