Networks (experimental)

Network CAPEX

How a pipeline network is priced — per-segment sizing, spacing boosters, and junction boosters where flows merge.

Once a network exists as a set of segments (each with a flow and a junction flag), its investment cost is estimated by the same physical model as single-pipeline CAPEX, extended for multiple pipes.

Experimental feature. Networks mode is under active development. Some technical aspects are still being validated with domain researchers. If you find results that don’t make sense, please open a GitHub issue or email co2gis.support@gmail.com.

Key difference from single-pipeline CAPEX

	Single pipeline	Network
Diameter	one diameter from the global mass flow	one diameter per pipe, from that pipe’s own flow
Segments	the route split by the pressure budget	each pipe split by the pressure budget
Boosters	spacing boosters only	spacing boosters plus junction boosters

A trunk carries more flow than a spur, so it gets a larger diameter — the pricing reflects this automatically.

Three cost components

1. Pipe cost

Each pipe (network segment) is sized independently:

Convert the segment’s flow (Mt/yr) to mass flow (kg/s).
Derive the pipe inner diameter from the Darcy–Weisbach equation inverted for mass flow.
Walk the segment cell by cell, accumulating the COMET cost formula (Fc · Fs · [Flu(1 − 0.1N) + 0.1N · Fci]) weighted by cell length, then multiply by the pipe unit cost and diameter.

2. Spacing boosters

A pipe that exceeds the booster spacing (~150 km at reference parameters) is split into pressure-budget segments. A compressor is placed at each segment boundary to recover the pressure drop. Booster cost is proportional to mechanical power (itself proportional to mass flow and pressure).

3. Junction boosters

An extra compressor is added where flows merge (a junction segment — junction = 1 in the output layer). This reflects the additional re-pressurisation needed where two pipeline streams combine. The booster is sized for the merged (downstream) flow.

Total

$I_{\text{total}} = \sum I_p \;+\; \sum I_b^{\text{spacing}} \;+\; \sum I_b^{\text{junction}}$

The Price Estimation tab in Network mode logs a per-pipe breakdown: role (spur or trunk — inferred from flow), diameter, length, pipe cost, and where a junction booster was added.