The first industrial extraction of natural gas took place in 1825, in the state of New York, USA. Since then, trillions of cubic meters of gas have been used around the world; a significant percentage of the economically recoverable global reserves.
The key term here is ‘economically recoverable’ – in the past, smaller reserves of gas were simply not viable. The technology required to process, store and transport gas as Liquefied Natural Gas (LNG) was simply too expensive to deploy at or around every small reserve of gas.
Progress in electrification technology, however, has had a substantial impact on what’s possible. By using electric drive motors to run the compression and cooling systems for liquefaction, significant amounts of space can be saved.
Modern e-houses, the electrical hearts of enormous Floating Production & Storage Offloading facilities (FPSOs), have reached a level of scale and efficiency that they can easily provide power for the thousands of people and heavy industrial processes that are required for gas processing and liquefaction at sea. The onboard electrical systems are also so resilient that they may only require maintenance every 4-5 years. Historically, mechanically driven processes produced more heat, had greater emissions, were less reliable and were physically larger – making the viability of Floating Liquefied Natural Gas (FLNG) production more challenging.
Electrification has therefore driven a dramatic impact on the economics of LNG extraction. First, the industrial processes required for gas liquefaction can fit aboard a seaborne vessel – admittedly a very large one, the size of four soccer fields or more, but one that is nonetheless a quarter the size of a land-based gas liquefaction plant.
Second, these vessels can be moved – completely shifting the economics of LNG production. Even relatively small deposits can be tapped as local processing makes them viable, and the vessel can then move on to support the next nearby deposit. And indeed, larger deposits that extend horizontally through tens of kilometers can have the vessel redeployed and relocated to ensure untapped resources are left to a minimum; whilst minimizing the need for expensive pipelines.
Third, processing LNG on site delivers environmental benefits as it can be shipped directly to markets around the world where needed by an LNG tanker – cutting time to market by 30-40%, and reducing the energy burden needed to ship gas to a processing plant or into storage first. Conditions at sea for processing LNG are excellent as well, with large amounts of cold water available to support processing of gas and cooling – producing less polluting waste gases. To continue improving system efficiency, the industry will see more high-speed, transformer-less applications where the generator and motor are connected and operated at the same voltage level with no transmission in between.
Shell has pioneered FLNG at the Prelude gas field off the coast of Australia, and Petronas expects to deploy a FLNG vessel in 2015 at the Kanowit gas field. In addition to powering the vessels, electrical systems and drives play a huge role in securing their resilience and stability – large turbines help keep the vessel steady even in torrential weather conditions, allowing for the safe docking of LNG tankers and the safety of everyone aboard the FPSO.
We expect a fast continued emergence of these vessels – as many as one or two new vessels taking to sea a year over the next few years. As energy demands continue to grow at a rapid pace, gas will play a greater and greater role in meeting the need for clean power as global economies try to meet the dual imperatives to increase power production and reduce emissions.
What else can we expect in the future? How can we act now to meet these dual imperatives?