Natural gas storage in salt caverns present trends in Europe

well head temperature / deg C
GILLHAUS, A. (2007): Natural gas storage in salt caverns – Present status, developments and future trends in Europe
35
30
25
20
15
10
5
0
withdrawal
Figure 9: Gas temperature at wellhead versus time.
This problem can be solved by conducting numerical simulations of the thermodynamic
conditions based on large amounts of empirical data on comparable operations.
5.3 Drilling and completion
The present maximum diameter of the gas production string (9-5/8“) currently limits the
withdrawal and injection rates as well as the withdrawal duration. This size is necessitated
by the maximum 9-5/8“ diameter of the subsurface safety valve (SSSV) stipulated by the
authorities in Europe.
Production strings with larger diameters of up to 18 5/8” are standard in the USA where no
SSSVs are stipulated.
Use is therefore made in Germany of monobore completions to achieve the maximum
possible cross-section using the stipulated 9-5/8“ diameter and thus achieve the highest
possible withdrawal and injection rates under these conditions. The first gas cavern
project to be realised in the Netherlands will also be the first to increase the flow cross-
section of the production and injection strings by installing a twin borehole (Fig. 10).
5.4 Modus operandi
gas hydrate formation temperature for
North Sea gas
Russian gas
standstill
0 10 20 30 40 50
time / days
Opposite to gas caverns liquid product caverns are operated under constant pressure: this
is done by displacing the brine into a surface brine shuttle pond during the injection of the
product from where the brine is reinjected into the cavern to displace the liquid during
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Q = 100 000 m³/h
75 000 m³/h
50 000 m³/h
25 000 m³/h