An onshore gas producer needed additional compression capacity as reservoir pressure declined. The gas stream carried hydrogen sulphide, which ruled out a standard catalogue package and put the selection squarely into engineered territory.
Scope of supply
- Two engine-driven reciprocating compressor packages
- Materials selected for sour service in accordance with NACE MR0175 / ISO 15156
- Skid-mounted units complete with scrubbers, coolers and control panel
- Spare parts package for the first two years of operation
- Commissioning and operator familiarisation at site
The constraint
Sour service changes the entire specification chain, not just the wetted parts. Valve materials, gasket selection, vent routing and instrument selection all follow from it, and an error at quotation stage surfaces months later as a rejected inspection.
How it was handled
Selection started from the gas analysis and the operating envelope rather than from a horsepower figure. Material certificates were reviewed against the specification before release for manufacture, and third-party inspection was carried out at the manufacturer’s works prior to shipment.
Outcome
Both units were delivered within the agreed window and commissioned without material rework. The spare parts package was sized from the manufacturer’s recommended list and the plant’s own consumption history rather than from a standard template.