Simulations

Compression Machinery Simulations – The Problem

If compression design expertise is not present within the core project team, project success can be constrained by the following issues:

• During the option select process, the team simply re-uses design concepts and values from other projects.
• There is a disconnect in knowledge between the project team and the machinery OEM.

Copying is not Suitable

One cannot simply take compressor designs from other projects and apply them to new ones. This is because both the process conditions and the required compressor design are application-specific – i.e.:

• Every oil and gas installation is unique, with its own blend of compositions, pressures, temperatures and flows. It is for this reason that each compression facility design is application-specific.
• The performance, even the name plate performance, which can be achieved by a centrifugal compressor is design specific. Even if the best-in-class performance is attained, its magnitude will be a function of numerous influences, such as:
  • Process conditions.
  • Concept select and arrangement.
  • Future operating requirements.

Given the above variables and factors, when it comes to compressor design it is clearly inappropriate to simply ‘copy what was done on a previous project’ – an approach not unheard of in the industry.

A Disconnected Approach is Problematic

When the core project team which is tasked with designing a compression facility does not include specialist compressor design expertise, project capability can commonly be limited by the following facts:

• The team defining the compression requirements know a lot about what happens outside of the compressor flanges, but less about what happens inside the machine.
• The OEM knows a lot about his machinery, but less about the application-specific characteristics of the plant and production systems outside of the compression skid.

In an attempt to overcome this disconnect, the project team often have little choice but to rely on vendor contact every time they require an appraisal of compressor performances achievable with the current design approach. Invariably, projects will progress through design iterations as the solution is honed down to the selected option, however, approaching the vendor for technical appraisal and new performance curves for every design iteration becomes burdensome and overly time consuming.

Inevitably some expediencies will be adopted, which may involve assumptions regarding achievable compressor performances. This is problematic when one considers that each application and each compressor design is unique, meaning that assumptions may lead to the inclusion of erroneous performance in project simulations. The implications of these assumptions on project quality and timescales can be significant.

Compression Machinery Simulations – The Solution

Clearly, if application-specific designs are to be included in the option select and development process, an alternative way of working is required. So how is Mirade’s approach different?

Mirade performs specialist compressor design work in-house, which affords a joined-up approach.

Specialist In-House Compressor Design

Mirade understands and has specific knowledge of the aerodynamic performance of centrifugal compressors. By applying this in conjunction with specialist simulations, Mirade is able to derive application-specific performances for each compressor section, including performance curves. Importantly, this design work is performed in-house, negating the need for there to be a consultation with an OEM every time a design iteration or option evaluation is required.

By engaging Mirade, the operator / owner is able to approach the compressor OEM with a far more developed specification – affording a more meaningful and accurate appraisal of vendor offerings.

A Joined-Up Approach

Mirade understands both the performances attainable for a given compressor selection and the operating needs and characteristics of the process facilities, pipeline networks and well systems. Therefore, the decision made by Mirade as to which compressor selection is optimum honours the joined-up approach to compression system design.