PetroSmart Academy | Synthetic teaching case | Version 1.0, 25 October 2026. This is a reproducible educational model, not a field development approval or an independently certified design.
Connect gas accounting, compressor power, cooling duty, water removal and energy cost without mixing standard and actual volumes. Use a deliberately ideal gas with Z = 1, molecular weight 18.83 kg/kmol and constant k = 1.3. These assumptions are not a validated model of a real natural-gas composition. Prerequisites are absolute pressure, ideal-gas relations, compressor efficiency and heat balances.
Throughput is 1,000,000 standard m³/day at 15 °C and 1.01325 bar absolute, dry-gas basis. It enters the compressor at 50 bar absolute and 30 °C; discharge pressure is 80 bar absolute. The corresponding mass flow is 9.217 kg/s and inlet actual volume flow is 0.2468 m³/s. Standard m³/day must not be inserted as the inlet actual volumetric rate.
Take isentropic efficiency 78% and mechanical efficiency 98%. Temperature ratio for the isentropic reference is (80/50)^[(k − 1)/k]. The ideal-gas heat capacity used consistently in this exercise is cp = kR/[(k − 1)MW] = 1.9134 kJ/(kg·K). Actual outlet temperature = Tin + (Tout,is − Tin)/ηis = 74.53 °C.
Power transferred to the gas is 785.26 kW; shaft power is 801.29 kW. No motor rating, surge margin or compressor stage count is established. For real design, replace constant properties with a suitable equation of state and validate the selected compressor map and driver basis.
Cool the gas to 35 °C using cooling water with a 10 K temperature rise and cp = 4.18 kJ/(kg·K). The ideal sensible cooler duty is 0.6971 MW, requiring 16.677 kg/s water. Gas-side heat removed equals water-side heat gained in the script. No condensation is predicted by the ideal-gas model; if condensation occurs in a real gas, add phase enthalpies and size separation equipment from the actual liquid load.
Independently assume inlet and target outlet water contents of 700 and 100 mg per dry standard m³ on the same basis as the gas rate. Removal load = 1,000,000 × (700 − 100)/1,000,000 = 600 kg/day. This is a water mass balance only. It neither sizes a glycol contactor nor proves a dew-point specification. A vendor/model assessment must define glycol strength, circulation, regeneration, losses and the contractual water/dew-point requirement.
No actual gas composition or hydrate equilibrium envelope is supplied. The compressor discharge temperature does not establish hydrate safety throughout the downstream system or during shutdown. Obtain composition-specific hydrate and dew-point predictions, transient pressure-temperature profiles and liquid holdup information. Protective functions and relief cases require their own hazard assessment; this case supplies no trip settings, relief settings or plug-removal instructions.
At 90% availability, shaft-energy equivalent is 6,317.3 MWh/year. At a hypothetical $100/MWh, the corresponding energy cost is $631,734/year. Motor efficiency and auxiliary loads are excluded; add them before estimating purchased electrical energy. Prices are assumptions, not current tariffs.
Reproduce the idealized case with calculations.py. Inspect every assumption in outputs.json. A field case additionally requires a verified EOS, fluid assay, pressure losses, compressor performance data, actual utility conditions, gas specifications and independent engineering review.