prEN 1918-5

Gas infrastructure - Underground gas storage - Part 5: Functional recommendations for surface facilities prEN 1918-5

Scope

This document covers the functional recommendations for the design, construction, testing, commissioning, operation, maintenance and abandonment of the surface facilities for underground gas storage (UGS), between the wellhead and the connection to the gas grid.
It specifies practices which are safe and environmentally acceptable.
For necessary subsurface facilities for underground storage, the relevant part of EN 1918-1 to EN 1918-4 applies. In this context, "gas" refers to flammable gas:
— which is in a gaseous state at a temperature of 15 °C and under a pressure of 0,1 MPa. The stored product is also named fluid.
— which meets specific quality requirements in order to maintain underground storage integrity, performance, environmental compatibility and fulfils contractual requirements.
This comprises:
— gas not in liquid phase under subsurface conditions;
— methane-rich gases;
— natural gas;
— biomethane;
— synthetic methane;
— hydrogen of various purities;
— any mixtures of the gases above;
— hydrocarbon gas in liquid phase under subsurface conditions such as:
— ethylene;
— liquified petroleum gas (LPG).
NOTE 1 Correspondingly the EN 1918 series can be considered where applicable for underground storage of any other fluid e.g. helium, carbon dioxide, compressed air, rDME (renewable dimethyl ether) and hydrogen transport fluids (such as ammonia and LOHC).
This document is not intended to be applied retrospectively to existing facilities.
NOTE 2 Correspondingly this document can be considered for major conversions in case of significant change of gas composition.