Groningen output may be zero some days this summer: GTS

Daily production from the Netherlands' Groningen field could fall to zero during some periods this summer, with the Norg storage facility and Germany's Gaspool expected to be fully supplied with converted high-calorie gas, Dutch system operator GTS has said.

Norg is expected to be completely filled with low-calorie gas that has been created through nitrogen ballasting this summer, a GTS spokesperson told Argus at the E-World conference in Essen, Germany. Norg, which provides much of the seasonal swing in Groningen output, is currently filled directly from the Groningen field.

The plan is to not have to use Groningen to supply Germany's Gaspool market area this summer, with some "technical solutions" having been found to enable this, GTS said. Low-calorie deliveries to Gaspool at the Oude Statenzijl-Bunde border can only be made directly from Groningen's De Eeker and Zuiderpolder clusters.

The combination of these two measures will allow daily Groningen summer output to be brought down to the "minimum required" for parts of this summer. This could mean that daily output could be zero over some periods this summer, "depending on the situation".

The compressors at the field need to be operated in such a way that Groningen can be ramped up quickly to support the system "if something fails". Technicians are investigating how this is feasible.

Groningen output may still have to step up on days when northwest European low-calorie demand is higher than the nitrogen ballasting facilities can "handle".

Aggregate field output does not have to be kept consistently above zero in order to maintain minimum flow rates at clusters and transfer stations, GTS said.

The dual requirements to fill Norg and supply Gaspool have in previous summers prevented a sharper reduction in Groningen output over periods when heating demand has been minimal.

Norg to be filled with converted gas alone

GTS expects Norg stockbuild to be made with converted high-calorie gas alone this summer, which could curb Groningen summer offtake substantially relative to previous years.

It is possible that some Groningen gas may be used for the Norg stockbuild this summer, depending on the "physical situation of the system", GTS said. But there is a "low chance" of this being required.

The ability to meet Norg injection demand with converted supply alone suggests that there may be scope to cut Groningen offtake even further than suggested by GTS in its advice on Groningen production this gas year. The system operator had said that Norg would be partly filled with converted gas, which would reduce the required Groningen production by 800mn m³ over the entire gas year.

Norg will also not be completely refilled this summer, which is another of the measures suggested by GTS to enable Groningen production to be brought down to 11.8bn m³ in a gas year with heating degree days in line with the long-term average.

The company has advised the economy ministry that injections could be kept 1bn m³ below withdrawals this winter. It does not have a specific start-of-winter stock target in mind.

Gaspool supplied with converted gas

Groningen may no longer be required to supply Oude Statenzijl this summer, which could further curb field offtake relative to previous years.

Nam, which operates the Groningen field, is to make a "small adjustment" so that Oude Statenzijl can receive converted gas, GTS said. It did not say when this adjustment will be completed.

And the commissioning of a German blending facility at Oude Statenzijl to enrich low-calorie gas with high-calorie supply will further reduce Gaspool's reliance on supply delivered directly from Groningen.

GTG Nord, which will operate the blending site with EWE, said last month that the facility is expected on line in the first two weeks of June. Preparations on the GTS side are also "on schedule".

The Zuidbroek nitrogen ballasting facility is still scheduled to be commissioned by 1 April 2022 at the latest. It may be possible to bring it on line in the first quarter of 2022, but "we don't see any possibilities to get it operational before 2022", the system operator said. It added that the 1 April 2022 deadline is already a "very challenging timeframe" for such a complex infrastructure project.

By Natasha Fielding