Integrated storage/offloading facility for an LNG production plant
An LNG production plant positioned at a production location adjacent to a body of water is described. The LNG production plant includes a plurality of spaced-apart facilities including a first facility and a second facility, each facility provided with plant equipment related to a pre-determined function associated with the production of LNG, where the first facility is an onshore facility and the second facility is an integrated storage/offloading facility arranged on a gravity-based structure having a base that rests on the seabed at a selected location within the body of water.
1. An LNG production plant positioned at a production location adjacent to a body of water, the LNG production plant comprising:
a plurality of spaced-apart facilities including a first facility and a second facility, each facility provided with plant equipment related to a pre-determined function associated with the production of LNG, wherein the first facility is an onshore facility and the second facility is an integrated storage/offloading facility arranged on a gravity-based structure having a base that rests on the seabed at a selected location within the body of water; and
a cryogenic pipeline from the onshore facility to the integrated storage/offloading facility;
wherein:
the first facility is a liquefaction facility for receiving a stream of pre-treated gas from a gas processing facility and liquefying the pre-treated gas to produce a product stream of LNG;
the integrated storage/offloading facility includes: a first cryogenic storage tank operatively associated with the liquefaction facility for receiving and storing the product stream of LNG from the liquefaction facility via the cryogenic pipeline, a boil-off gas re-liquefaction facility, and an LNG transfer facility for transferring LNG from the first cryogenic storage tank to a second cryogenic storage tank onboard an LNG Carrier on an as-needs basis;
a subsea pipeline is provided from the integrated storage/offloading facility to the onshore gas processing plant;
boil-off gas is generated during the transfer of the LNG through the cryogenic pipeline to the first cryogenic storage tank of the integrated storage/offloading facility; and
the boil-off gas is: compressed and transferred through the subsea pipeline to the onshore facility, or recycled back to the integrated storage/offloading facility, or liquefied at the re-liquefaction facility at the offshore location.
2. The LNG production plant of claim 1 , wherein the first cryogenic storage tank of the integrated storage/offloading facility stores the LNG at a higher pressure compared with the second cryogenic storage tank of the LNG carrier.
3. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility is a breakwater for the LNG Carrier.
4. The LNG production plant of claim 1 , wherein the cryogenic pipeline is a cryogenic subsea pipeline or a cryogenic pipeline on a trestle and connects to the gravity-based structure at a subsea location.
5. The LNG production plant of claim 1 , wherein the first facility is a gas processing facility for receiving raw hydrocarbons from a producing well and treating the raw hydrocarbons to remove contaminants therefrom to produce a stream of treated gas as a source of feed to the liquefaction facility for receiving the stream of treated gas from a gas processing module and liquefying the natural gas to produce LNG, and wherein the LNG transfer facility is located on the gravity-based structure with the integrated storage/offloading facility.
6. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility is transportable from a construction location to an assembly location by towing or on floating barges.
7. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility is transportable from an assembly location to the production location by towing or on floating barges.
8. The LNG production plant of claim 1 , wherein commissioning of the integrated storage/offloading facility is done at an onshore construction location or an onshore assembly location prior to transportation of integrated storage/offloading facility to the production location.
9. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility includes a ballast storage compartment, and the integrated storage/offloading facility is settled into the selected location by way of addition of a ballasting material to the ballast storage compartment.
10. The LNG production plant of claim 9 , wherein the ballast storage compartment is arranged around the periphery of the integrated storage/offloading facility or arranged toward the base of the integrated storage/offloading facility for ballasting.
11. The LNG production plant of claim 9 , wherein the ballast storage compartment is at least partially filled with one or both of a solid ballasting material or a liquid ballasting material.
12. The LNG production plant of claim 11 , wherein the solid ballasting material is iron ore or sand.
13. The LNG production plant of claim 11 , wherein the liquid ballasting material is one or more of: water, condensate, monoethylene glycol (MEG), methanol, diesel, demineralised water, diesel, or, LPG.
14. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility includes a boil-off gas reliquefaction facility.
15. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility has at least one lateral side which has a length of a sufficient size to allow an LNG Carrier to be moored along alongside the gravity-based structure without overhang of the LNG Carrier beyond an end of the gravity-based structure.
16. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility has a lee side, whereby, in use, the LNG Carrier approaches the integrated storage/offloading facility from the lee side of integrated storage/offloading facility.
17. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility has a longitudinal axis aligned substantially parallel to the direction of a predominant current for bi-directional berthing of an LNG Carrier.
18. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility comprises a plurality of similarly-sized sub-facilities, which are integrated at a construction location, the production location, or at an independent assembly location.
19. The LNG production plant of claim 18 , wherein the sub-facilities are constructed at a plurality of construction locations and towed to a common assembly location for integration.
20. The LNG production plant of claim 18 , wherein the sub-facilities are assembled to form the integrated storage/offloading facility at the assembly location and testing or commissioning of the sub-facilities is conducted a construction or assembly location before transportation of the integrated storage/offloading facility to the production location.
21. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility is movable from a first production location to a second production location.
22. The LNG production plant of claim 1 , wherein a portion of boil off gas is a source of fuel for a first power generation system which forms part of the integrated storage/offloading facility or a second power generation facility onboard the LNG Carrier.
23. The LNG production plant of claim 1 , wherein a first portion of the LNG produced by the liquefaction facility is transferred directly into a second cryogenic storage tank onboard an LNG Carrier and a second portion of the LNG produced by the liquefaction facility is stored in the first cryogenic storage tank of the integrated storage/offloading facility.
24. The LNG production plant of claim 1 , wherein the integrated storage/offloading facility has a multilateral footprint in plan view.
25. The LNG production plant of claim 24 , wherein the footprint is triangular, rectangular, square, pentagonal or hexagonal such that, in use, a first LNG Carrier berths at a first lateral side of the integrated storage/offloading facility while a second LNG Carrier berths at a second lateral side of the integrated storage/offloading facility.
26. The LNG production plant of any claim 1 , further comprising a breakwater facility positioned adjacent to the integrated storage/offloading facility at the selected location.
27. The LNG production plant of claim 1 , wherein a first breakwater facility is located towards a first end of the integrated storage/offloading facility and a second breakwater facility is located towards a second end of the integrated storage/offloading facility.