Standards Development

Scope

This European Standard covers the functional recommendations for design, construction, testing, commissioning, operation, maintenance and abandonment of underground gas storage (UGS) facilities in mined rock caverns up to and including the wellhead.

This European Standard does not cover the technology of lined rock.

NOTE 1 Even if not covered in this standard, the lined rock is an available technology. This European Standard specifies practices which are safe and environmentally acceptable.

For necessary surface facilities for underground gas storage, EN 1918­5 applies. In this context, "gas" is any hydrocarbon fuel:

-­ which is in a gaseous state at a temperature of 15 °C and under a pressure of 0,1 MPa (this includes natural gas, compressed natural gas (CNG) and liquefied petroleum gas (LPG). 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 European Standard specifies common basic principles for underground gas storage facilities. Users of this European Standard should be aware that more detailed standards and/or codes of practice exist. A non­exhaustive list of relevant standards can be found in Annex A. This European Standard is intended to be applied in association with these national standards and/or codes of practice and does not replace them.

In the event of conflicts in terms of more restrictive requirements in the national legislation/regulation with the requirements of this European Standard, the national legislation/regulation takes precedence as illustrated in CEN/TR 13737 (all parts).

NOTE 2 CEN/TR 13737 (all parts) contains:

­- clarification of relevant legislation/regulations applicable in a country;

- ­ if appropriate, more restrictive national requirements;

-­ national contact point for the latest information.

This European Standard is not intended to be applied retrospectively to existing facilities.

Purpose

EN 1918­4 was published in 2016.

A revision is needed to answer the standardization request M/526 of the European Commission on adaptation of infrastructures to climate change.

A revision will also anticipate the standardization request expected on hydrogen and address the storage of mixtures of hydrogen with natural gas up to 100%. The storage of mixtures of hydrogen with natural gas will be addressed in all parts of EN 1918. But the knowledge and feasibility are higher for salt caverns and surface facilities.

A revision will also anticipate and answer the draft regulation on methane emissions reduction. The revision will also improve the chapter on abandonment.