Reservoir management by controlling acid gas build-up in reservoir by partial CO2 removal processes
Methods are provided for reducing the quantity of acid gas reinjected into a reservoir by partial CO 2 removal processes. The methods include acid gas removal, acid gas enrichment, generation of a CO 2 rich stream and an H 2 S rich stream, and reinjection of the H 2 S rich stream into the reservoir. The acid gas enrichment can be performed by a solvent-based acid gas enrichment unit, a membrane-based acid gas enrichment unit, or a combination of a solvent-based acid gas enrichment unit a and membrane-based acid gas enrichment unit. The system includes an acid gas removal unit, one or more acid gas enrichment units, and an acid gas reinjection compressor. The acid gas enrichment unit can be a solvent-based acid gas enrichment unit, a membrane-based acid gas enrichment unit, or a solvent-based acid gas enrichment unit and a membrane-based acid gas enrichment unit.
1. A method of capturing sulfur compounds from an acid gas waste stream in an isolated field, the method comprising:
introducing a gas stream to an acid gas removal unit, the gas stream comprising natural gas, carbon dioxide and hydrogen sulfide;
separating the gas stream in the acid gas removal unit to produce an acid gas stream and a sweet gas stream, wherein the acid gas removal unit is operable to produce the sweet gas stream of quality for further processing or sale, wherein the sweet gas stream comprises natural gas and the acid gas stream comprises hydrogen sulfide and carbon dioxide;
introducing the acid gas stream to an acid gas enrichment unit;
separating the acid gas stream in the acid gas enrichment unit to produce an enriched acid gas stream and a waste gas stream, the waste gas stream comprising carbon dioxide and the enriched acid gas stream comprising hydrogen sulfide, and wherein the acid gas enrichment unit utilizes a removal process operable to selectively separate carbon dioxide and hydrogen sulfide in the acid gas stream;
introducing the enriched acid gas stream to an enriched acid gas reinjection compressor;
compressing the enriched acid gas stream in the enriched acid gas reinjection compressor to an operating pressure to generate an enriched acid gas reinjection stream, the operating pressure exceeding pressure of a reservoir; and
injecting the enriched acid gas reinjection stream into the reservoir.
2. The method of claim 1 , wherein the method of capturing sulfur compounds from an acid gas waste stream is performed in an absence of a sulfur removal unit.
3. The method of claim 1 , wherein the method of capturing sulfur from an acid gas waste stream is performed in an absence of a thermal oxidizer.
4. The method of claim 1 , wherein the waste gas stream comprises less than 150 ppm hydrogen sulfide.
5. The method of claim 1 , further comprising the step of discharging the waste gas stream to atmosphere.
6. The method of claim 1 , further comprising the step of introducing the waste gas stream to an enhanced oil recovery system.
7. The method of claim 1 , wherein the acid gas removal unit is selected from the group consisting of an absorption process using a solvent, an absorption process using an absorbent, an adsorption process, a membrane unit, and combinations of the same.
8. The method of claim 1 , further comprising the steps of:
combusting the waste gas stream in a combustion device to produce a combusted waste gas stream; and
discharging the combusted waste gas stream to atmosphere;
wherein the combustion device is selected from the group consisting of a waste gas heater, a flare, a thermal oxidizer, and combinations of the same.
9. The method of claim 1 , wherein the enriched acid gas stream comprises at least 2 weight percent hydrogen sulfide.
10. The method of claim 1 , wherein the enriched acid gas stream comprises at least weight percent hydrogen sulfide.
11. The method of claim 1 , wherein the enriched acid gas stream comprises at least weight percent hydrogen sulfide.
12. The method of claim 1 , wherein the enriched acid gas stream comprises at least weight percent hydrogen sulfide.
13. The method of claim 1 , wherein the acid gas enrichment unit comprises a solvent acid gas enrichment (sAGE) unit operable to absorb hydrogen sulfide from the acid gas stream into a solvent.
14. The method of claim 1 , wherein the acid gas enrichment unit comprises a membrane acid gas enrichment (mAGE) compressor and a mAGE unit, and further comprising the steps of:
compressing the acid gas stream with the mAGE compressor to produce a compressed acid gas stream; and
introducing the compressed acid gas stream to the mAGE unit.
15. The method of claim 1 , wherein the acid gas enrichment unit comprises a hybrid membrane acid gas (mAGE) compressor, a hybrid mAGE unit, and a hybrid solvent acid gas enrichment (sAGE) unit, and further comprising the steps of:
introducing an enriched acid gas recycle to the acid gas stream to generate a combined acid gas stream;
compressing the combined acid gas stream with the hybrid mAGE compressor to produce a compressed combined acid gas stream;
introducing the compressed combined acid gas stream to the hybrid mAGE unit;
separating the compressed combined acid gas stream in the hybrid mAGE unit such that the hybrid mAGE unit produces a feed CO2 stream and the enriched acid gas stream;
introducing the feed CO2 stream to the hybrid sAGE unit, the hybrid sAGE unit operable to absorb hydrogen sulfide from the acid gas stream into a solvent; and
producing the enriched acid gas recycle and the waste gas stream from the hybrid sAGE unit by absorption and regeneration of the solvent.
16. The method of claim 14 , wherein the mAGE unit comprises a membrane with a selectivity for carbon dioxide over hydrogen sulfide of greater than 5.
17. The method of claim 14 , wherein the mAGE unit comprises a membrane with a selectivity for carbon dioxide over hydrogen sulfide of greater than 20.
18. The method of claim 14 , wherein the mAGE unit comprises a membrane with a selectivity for carbon dioxide over hydrogen sulfide of greater than 30.
19. The method of claim 14 , wherein the mAGE unit comprises a two-step membrane process.
20. The method of claim 14 , wherein the mAGE unit comprises a two-stage membrane process.
21. The method of claim 14 , wherein the mAGE unit comprises a two-step, two-stage membrane process.
22. The method of claim 14 , wherein the mAGE unit comprises a three-step membrane process.
23. The method of claim 14 , wherein the mAGE unit comprises a two-step, three-stage membrane process.
24. The method of claim 14 , wherein the mAGE unit comprises a membrane comprising a selective layer comprising a perfluoropolymer.
25. The method of claim 24 , wherein the perfluoropolymer is a monomer, copolymer, block copolymer, terpolymer, block terpolymer, or any molecular structure generated by a combination of monomers selected from the group of monomers consisting of: CYTOP™ polymer material; HYFLON™ polymer material; TEFLON™ polymer; TEFLON™ polymer AF2400; TEFLON™ polymer AF1400; TEFLON™ polymer AD60; TEFLON™ polymer AD80; perfluoro(2-methylene-4,5-dimethyl-1,3-dioxolane); perfluoro(2-methylene-1,3-dioxolane); perfluoro-2,2-dimethyl-1,3-dioxole (PDD); perfluoro-3-butenyl-vinyl ether (PBVE); Perfluoro(2-methylene-4-methyl-1,3-dioxolane) (PFMMD); and Perfluoro(2-methylene-1,3-dioxolane) (PFMD).
26. The method of claim 24 , wherein the perfluoropolymer is a homopolymer, a copolymer, a block copolymer, a terpolymer, a block terpolymer, or any molecular structure generated by a combination of monomers selected from the group of monomers consisting of:
and combinations of the same.
27. The method of claim 15 , wherein the hybrid mAGE unit comprises a membrane with a selectivity for carbon dioxide over hydrogen sulfide of greater than 5.
28. The method of claim 15 , wherein the hybrid mAGE unit comprises a membrane with a selectivity for carbon dioxide over hydrogen sulfide of greater than 20.
29. The method of claim 15 , wherein the hybrid mAGE unit comprises a membrane with a selectivity for carbon dioxide over hydrogen sulfide of greater than 30.
30. The method of claim 15 , wherein the hybrid mAGE unit comprises a two-step membrane process.
31. The method of claim 15 , wherein the hybrid mAGE unit comprises a two-stage membrane process.
32. The method of claim 15 , wherein the hybrid mAGE unit comprises a two-step, two-stage membrane process.
33. The method of claim 15 , wherein the hybrid mAGE unit comprises a three-stage membrane process.
34. The method of claim 15 , wherein the hybrid mAGE unit comprises a two-step, three-stage membrane process.
35. The method of claim 15 , wherein the hybrid mAGE unit comprises a membrane comprising a selective layer comprising a perfluoropolymer.
36. The method of claim 35 , wherein the perfluoropolymer is a monomer, copolymer, block copolymer, terpolymer, block terpolymer, or any molecular structure generated by a combination of monomers selected from the group of monomers consisting of: CYTOP™ polymer material; HYFLON™ polymer material; TEFLON™ polymer; TEFLON™ polymer AF2400; TEFLON™ polymer AF1400; TEFLON™ polymer AD60; TEFLON™ polymer AD80; perfluoro(2-methylene-4,5-dimethyl-1,3-dioxolane); perfluoro(2-methylene-1,3-dioxolane); perfluoro-2,2-dimethyl-1,3-dioxole (PDD); perfluoro-3-butenyl-vinyl ether (PBVE); Perfluoro(2-methylene-4-methyl-1,3-dioxolane) (PFMMD); and Perfluoro(2-methylene-1,3-dioxolane) (PFMD).
37. The method of claim 35 , wherein the perfluoropolymer is a homopolymer, a copolymer, a block copolymer, a terpolymer, a block terpolymer, or any molecular structure generated by a combination of monomers selected from the group of monomers consisting of:
and combinations of the same.