Hydrogen cavern pad gas management

• US 9,656,807 B2
• Filed: 08/26/2014
• Issued: 05/23/2017
• Est. Priority Date: 05/08/2014
• Status: Active Grant

• Current Assignee: Air Liquide Large Industries U S LP (L'Air Liquide SA)
• Original Assignee: Air Liquide Large Industries U S LP (L'Air Liquide SA)
• Inventors: Strybos, Ronald, Dony, Azadeh
• Primary Examiner(s): Pinnock, Tara M.
• Application Number:
  US14/468,531
• Publication Number:
  US 20150321848A1
• Time in Patent Office: 1,001 Days
• Field of Search: 405 52, 405 53, 405 59, 222394, 21017001
• CPC Class Codes: B65G 5/00 Storing fluids in natural or artificial cavities or chambers in the earth
• CPC Class Codes: F17C 1/007 Underground or underwater storage
• CPC Class Codes: F17C 2221/012 Hydrogen
• CPC Class Codes: F17C 2221/013 Carbone dioxide
• CPC Class Codes: F17C 2221/014 Nitrogen
• CPC Class Codes: F17C 2221/016 Noble gases (Ar, Kr, Xe)
• CPC Class Codes: F17C 2221/017 Helium
• CPC Class Codes: F17C 2221/031 Air
• CPC Class Codes: F17C 2223/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2223/035 High pressure (>10 bar)
• CPC Class Codes: F17C 2225/0123 gaseous, e.g. CNG, GNC
• CPC Class Codes: F17C 2225/035 High pressure, i.e. between 10 and 80 bars
• CPC Class Codes: F17C 2225/036 Very high pressure, i.e. above 80 bars
• CPC Class Codes: F17C 2250/043 Pressure
• CPC Class Codes: F17C 2250/0491 Parameters measured at or inside the vessel
• CPC Class Codes: F17C 2250/0626 Pressure
• CPC Class Codes: F17C 2270/0152 Salt caverns
• CPC Class Codes: F17C 2270/0155 by using natural cavities
• CPC Class Codes: F17C 7/00 Methods or apparatus for discharging liquefied, solidified, or compressed gases from pressure vessels, not covered by another subclass
• CPC Class Codes: Y02E 60/32 Hydrogen storage

Abstract

A method of pad gas management in an underground storage volume including storing a first compressible fluid, determining a transient minimum operating pressure (P_trans), measuring the pressure (P_act), removing at least a portion of the first compressible fluid, concurrently, introducing an incompressible fluid, thereby producing a transient pressure condition controlled by the flow rate of the incompressible fluid, such that P_trans<P_act. The method may also include a length of casing, permanently cemented into the surrounding rock formations, with a final cemented casing shoe defining the practical endpoint at an approximate depth (D_casing), determining a transient pressure gradient (G_trans) for the underground storage volume, wherein P_trans<D_casing×G_trans. The maximum removal of the first compressible fluid is controlled such that P_min<P_act, and wherein the transient pressure condition has a duration (D) of less than 7 days, more preferably less than 5 days.

Claims

1. A method of pad gas management in a salt cavern, comprising:

storing a volume of hydrogen in a salt cavern, wherein during normal operating conditions the cavern integrity is preserved by maintaining a minimum allowable pressure (P_Min) within the salt cavern by means of retaining a minimum volume of hydrogen (V_Min);

removing at least a portion of said hydrogen from said salt cavern, thereby temporarily reducing the volume of hydrogen in the salt cavern to below the minimum volume thereby producing a transient minimum operating pressure (P_trans) for said salt cavern; and

concurrently, introducing brine into said salt cavern, thereby producing a temporary operating condition wherein P_trans<

P_min,

wherein said temporary operating condition has a duration of less than 7 days.

2. The method of claim 1, further comprising:

a length of casing, permanently cemented into surrounding rock formations, with a final cemented casing shoe defining the practical endpoint at a depth (D_casing); and

determining a transient pressure gradient (G_trans) for said salt cavern, wherein P_trans<

D_casing×

G_trans.

3. The method of claim 2, wherein 0.2 psi/ft of depth<

G_trans<

0.3 psi/ft of depth.

4. The method of claim 1, wherein said a does not exceed a predetermined maximum flow rate (F_max).

5. A method of pad gas management in a salt cavern, comprising:

storing a volume of hydrogen in a salt cavern, wherein during normal operating conditions the cavern integrity is preserved by maintaining a minimum allowable pressure (P_Min) within the salt cavern by means of retaining a minimum volume of hydrogen (V_Min);

removing at least a portion of said hydrogen from said salt cavern, thereby temporarily reducing the volume of hydrogen in the salt cavern to below the minimum volume thereby producing a transient minimum operating pressure (P_trans) for said salt cavern, thereby producing a temporary operating condition wherein P_trans<

P_min,

wherein said temporary operating condition has a duration of less than 7 days.

6. The method of claim 5, further comprising:

a length of casing, permanently cemented into surrounding rock formations, with a final cemented casing shoe defining the practical endpoint at a depth (D_casing); and

determining a transient pressure gradient (G_trans) for said salt cavern, wherein P_trans<

D_casing×

G_trans.

7. The method of claim 6, wherein 0.2 psi/ft of depth<

G_trans<

0.3 psi/ft of depth.