Ageing assets can present a particular problem with respect to compression. Machinery may be operating far from its original design intent or may be based upon legacy technology.
However, there are numerous assets which are still operating even though they have passed their originally expected lifespan. If they are to continue making a contribution and to host new satellite and third-party production, maximising productivity and operability from their ageing compression systems is vital. Mirade’s knowledge and experience can greatly assist operators and asset owners in this endeavour.
Mirade can assist owners / operators of ageing assets through the following services.
As reserves are depleted and process operating pressures are reduced, the demand on the compression system can increase substantially; this can move operations close to one of numerous limiting conditions. Once one of these is reached the compression system can become a bottleneck. Through debottlenecking and pressure reduction studies, Mirade can assist operators in the extension of asset life.
Mirade can review the existing compression train designs to identify opportunities to change the volume flow and pressure regime of the compression system so that it is better suited to revised operating conditions. These take cognizance of the dimensions and ratings of existing on-skid items and where appropriate, associated plant.
Mirade are often able to identify a range of improvement options across different degrees of complexity. The flow uplifts are quantified via simulations and reviewed against production and cost criteria in addition to consideration of the extent of disruption and downtime during implementation.
The integration of third-party and satellite field production streams into existing facilities is becoming an increasingly common way to improve the profitability, viability and longevity of ageing assets. Invariably these new streams will have different compositions and arrival pressures, so accommodating them within existing compression systems alongside native production can be a challenge.
Conditions such as molecular weight differences and / or inclusion of new streams at centrifugal compression interstage can lead to changes in stage matching and shifts in the performance capability of the overall train. Mirade are able to calculate revised performance curves and apply these in the analysis of the effects of the new production streams – ensuring that capacity calculations are representative of actual capability.
Mirade can assist operators in the review of the feasibility and viability of operation with new production streams, allowing them to calculate what capacity can be offered to third-parties across various scenarios. Additionally, any knock-on effects on native production are also included in the reviews. In the event that operational difficulties or capacity shortfalls are identified by simulations, Mirade can identify improvement opportunities which may exist via rewheeling, revamps or control changes.
When a compression train has to operate far from its design intent, its operability and performance can be compromised. Flow, compositional, pressure and temperature changes all have the potential to shift compressor operation into an unfavourable regime where it may exhibit poor performance or be unduly difficult to control or start-up.
By applying their knowledge of centrifugal compression design to the operating review of ageing machines, Mirade can identify instances where underperformance or poor availability is not caused by machine condition, but by shifts in its performance capability resulting from prevailing process conditions which are far from its design intent.
Having highlighted such issues, Mirade can then demonstrate and quantify the improvements in performance and operability that would be gained through modifications to the compression train.