Module 01 of 09

Plant Overview

Read this first

Everything in this guide comes down to one idea: a centrifugal compressor is a speed-controlled machine. The turbine sets the speed, the speed sets how much gas the wheel can move and how hard it can push, and the header pressures tell the control system whether that speed is right. When a pressure drifts off its target, the answer is almost always a speed change — up or down — and this tool shows you which way and why.

Trains

13 turbine-compressor trains

9 low-stage · 4 high-stage

Three-header ladder

Suction → Interstage → Injection

~600 · ~2,200 · ~4,000 psi

Speed band

4,900 – 5,350 rpm

Min governor → 105% overspeed limit

The Pressure Ladder

Suction Header~600 psi

Field gas in · LS suction

9 LS trains pull from here

LS · ratio ~3.67:1

Interstage Header

Critical

~2200 psi

LS discharge · HS suction · plant messenger (solved balance)

Shared by both stages — the plant messenger

HS · ratio ~1.82:1

Injection Header~4000 psi

HS discharge · wells

6 outlet lines · 32 injection wells

Low stage

~3.67 : 1

600 → 2,200 psi

Bigger share of the ratio work — nearly quadruples pressure

High stage

~1.82 : 1

2,200 → 4,000 psi

Smaller ratio, very dense gas — serious horsepower

Full System Boundaries

Gas does not appear magically at the suction header. Six field sources feed the plant, the Central Gas Facility next door strips liquids and returns dry gas, and thirty-two injection wells on three banks take the high-stage discharge away. Every slider in the Live Simulator maps to a real handle operators use on shift.

Field feeds

Inlet

·FS1 · FS2 · FS3 — Flow Stations
·GC1 · GC2 · GC3 — Gathering Centers
·Sum = field wet-gas rate (MMSCFD)
·Per-unit LS suction pinch holds ~99% turbine speed

Central Gas Facility

CGF

·Strips liquids next door; returns dry gas to CCP suction
·Wet gas in · dry gas return
·Shrink % = liquids / fuel left at CGF
·Net plant rate = field − liquids

Injection wells

32 wells

·WGI · West Gas Injection · 8 wells
·NGI · North Gas Injection · 14 wells
·AGI · Acid Gas Injection · 10 wells

Shut-ins cut capacity and raise injection / CDP backpressure

CDP

Common Delivery Point pressure — metered delivery into the injection distribution network

LS suction pinch

Per-unit LS suction throttle valves hold turbine speed at an adjustable setpoint (default 99%). When map speed would fall below SP, equal-percentage valves close — eye pressure drops, head rises, N holds while flow cuts.

Ambient

Ambient air temp derates gas-turbine power (~0.55%/°F above 59 °F ISO)

Specific gravity

Gas specific gravity (air = 1) — denser gas costs more horsepower; also shifts map mass loading

Nameplate HP

Nameplate shaft horsepower per train — HP from map flow × head, capped by ambient-derated nameplate

Header temps

Suction, interstage, and injection gas temperatures scale mass density and required horsepower.

Who Does the Heavy Lifting

Look at the ratios, not just the numbers. The higher-ratio machine (low stage) is very sensitive to its suction conditions — small suction pressure changes swing its flow and power hard. The lower-ratio machine (high stage) is comparatively more sensitive to the difference between its suction and discharge — a few hundred psi of injection pressure change is a big fraction of the total head it makes.

Thirteen trains do the work: nine turbines driving nine low-stage compressors (suction → interstage) and four turbines driving four high-stage compressors (interstage → injection). Each train is a gas turbine coupled to a centrifugal compressor — the turbine is the muscle, the compressor is the pump, and the shaft between them means they always turn together.