A modern liquefied natural gas (LNG) project is a major undertaking that often exceeds $20 billion in capital investment. This is more than the economies (measured in gross domestic product) of half of the world’s countries.
These projects are very complicated mechanical systems whose parts must work in harmony from the bottom of the gas well, through pipelines and processing plants, to the ship that stores the gas as LNG at -161C.
So how do you start one of these machines? It starts with the planning. Each project plan has a program to start and test the machinery – the commissioning plan.
This details how to test each component for integrity and operational readiness, and then how to test that component with the other parts of the project.
Usually it requires the services of commissioning crews who specialise in this activity. Their skills are quite different to the construction crews who build the equipment.
Testing integrity ensures the component’s construction is sound. For example, a pipeline may be pressure-tested above its expected operating pressure to verify its construction is sound, and safe to work with. This is usually done with water as the pressure can be more easily controlled. Finding enough water, and then recycling it, can be a challenge in remote areas.
Operational testing ensures the component operates as planned, and responds to the control systems and safety requirements.
This is like a test flight for an airplane. You can test its integrity on the ground, but a test flight is needed before it can be approved to carry passengers.
A gas project’s operational testing often requires flaring excess gas at the well-sites, compressor stations, pipelines and LNG plants. This must be done as not all of the plant has been tested to take the gas, and it is safer to burn off the excess during this phase.
Once the plant has been proven, the gas is saved for commercial sale and the amount of flared gas decreases markedly.
Modern control systems are at the heart of gas projects. Electrical controls use computers, data links and sensors to monitor all aspects of the plant.
Thousands of gas wells can be monitored via microwave links to one control room for any operational adjustments. This decreases the distance field operators need to travel to check wells and plant, and ensures quick action, such as shutting down the operation, can be taken if something unusual occurs.
These systems are all tested extensively during the commissioning phase – again just as aircraft systems are checked.
Testing a gas project to its operational limits, flaring gas and new types of project activity are all part of commissioning or proving of a project. Once proven, the normal operational phase can begin – and the $20 billion machine starts its productive life.