On natural gas and gas storage
Natural gas is the number three source of energy for the global economy after oil and coal. It is one of the cleanest, most readily available and efficient fossil fuels. Natural gas has a broad range of applications, with the production sector being the largest user. It is also utilised to generate heat and, electricity; it serves households and the transport sector and feeds the production of agricultural fertilisers. Under conditions prevailing on the earth surface, natural gas is present in a gaseous state and, therefore, is transported using pipeline systems.
Creation and production of natural gas
Natural gas had been created in the earth's crust from organic material buried deep under layers of sedimentary rock under conditions of high pressures and temperatures over millions of years. It is typically found associated with other fossil fuels, such as oil or coal beds. In the early days of oil production, associated natural gas was regarded as undesirable, one that complicated production. The genuine value of the gas came to the fore when the economic and industrial conditions made it possible to build a transport infrastructure all the way from source to final customer. Currently, natural gas is typically produced by processing associated gas during oil production or by withdrawing it from gas fields.
Transport and marketing
Being of very low density, natural gas represents a challenge in terms of transport or storage. Capital-intensive pipeline systems need to be built to transport gas to the place of consumption, frequently thousands of kilometres away. This is why there are regional natural gas markets with their own rules of operations, markets dependent on the physical reach of the pipeline infrastructure. This model, however, is exposed to the increasingly competitive transport of LNG carried by huge tankers across the seas to wherever demand may be. This LNG supply market is becoming global as it appears better poised to respond to regional fluctuations of natural gas demand.
Gas storage
Stable natural gas supply continues to rely primarily on underground storage, which offers an indispensible service by helping balance seasonal volatility of demand and safeguarding against interruptions of supply similar to what the European gas industry experienced in January 2009. There are three types of underground gas storage facilities:
- depleted natural gas fields
- aquifer reservoirs
- salt cavern reservoirs
The underground formations of the Láb 4 UNGSF are depleted natural gas fields converted to serve as storage reservoirs. During the injection season, when the demand for natural gas is low, gas is injected into the underground formations, and during the withdrawal period it is extracted from the same formations. In terms of capacity, the Láb 4 UNGSF can meet nearly 10% of Slovakia's annual consumption of natural gas and can therefore be described as a strategic element of the national economy.
More information about natural gas and the elements of the gas market chain can be found here.