Process for in situ upgrading of a heavy hydrocarbon using asphaltene precipitant additives

Patent metadata

Field	Value
Publication number	US-9670760-B2
Application number	US-201314066993-A
Country	US
Kind code	B2
Filing date	Oct 30, 2013
Priority date	Oct 30, 2013
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

A process for in-situ upgrading of a heavy hydrocarbon includes positioning a well in a reservoir containing a heavy hydrocarbon having an initial API gravity no greater than about 20, an n-heptane asphaltene content at least about 1 wt. %, and a viscosity at 35° C. greater than about 350 centistokes; injecting hydrocarbon solvent(s) and asphaltene precipitant additive(s) into the well at a ratio by volume of the solvent to the heavy hydrocarbon of about 0.1:1 to about 20:1 under reservoir conditions so as to provide an upgraded hydrocarbon in the reservoir having an improved API gravity, a reduced asphaltene content, and a lower viscosity; and producing the upgraded hydrocarbon from the well. The process of the present invention can be also carried out at higher temperatures such as by injecting steam with the one or more hydrocarbon solvents and the one or more asphaltene precipitant additives into the well.

First claim

What is claimed is:

1. A process for in situ upgrading of a heavy hydrocarbon comprising the steps of:
(a) positioning a well in a reservoir containing a heavy hydrocarbon having an initial API gravity of less than or equal to about 20, an n-heptane asphaltene content as measured by the ASTM D-6560 of at least about 1 wt. %, and a viscosity at 35° C. greater than about 350 centistokes (cSt);
(b) injecting one or more hydrocarbon solvents and one or more asphaltene precipitant additives into the well in any order at a ratio by volume of the solvent to the heavy hydrocarbon of from about 0.1:1 to about 20:1 under reservoir conditions so as to provide a blend containing an upgraded hydrocarbon and precipitated asphaltenes in the reservoir, wherein the upgraded hydrocarbon has an improved API gravity greater than the initial API gravity, a reduced asphaltene content as compared with the heavy hydrocarbon, and a lower viscosity as compared with the heavy hydrocarbon and wherein the blend contains precipitated asphaltenes in a higher amount than in a similar blend not containing the one or more asphaltene precipitant additives; and
(c) producing the upgraded hydrocarbon from the well without the precipitated asphaltenes such that the precipitated asphaltenes remain in the reservoir.

2. The process of claim 1 wherein the one or more hydrocarbon solvents are injected at a ratio by volume of the solvent to the heavy hydrocarbon of about 0.1:1 to about 1.5:1.

3. The process of claim 1 wherein the one or more hydrocarbon solvents are injected at a ratio by volume of the solvent to the heavy hydrocarbon of about 0.1:1 to less than 1:1.

4. The process of claim 1 wherein the one or more hydrocarbon solvents are injected at a ratio by volume of the solvent to the heavy hydrocarbon of about 0.1:1 to about 0.9:1.

5. The process according to claim 1 , wherein the heavy hydrocarbon having an initial API gravity of less than or equal to about 20 comprises a heavy crude oil or an extra heavy crude oil.

6. The process according to claim 1 , wherein the one or more hydrocarbon solvents include a C1-C8 hydrocarbon solvent.

7. The process according to claim 1 , wherein the one or more hydrocarbon solvents are selected from the group consisting of propane, butane and mixtures thereof in liquid or gas form.

8. The process according to claim 1 , wherein the one or more hydrocarbon solvents comprise C1-C10 fractions.

9. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are injected into the heavy hydrocarbon at a ratio by weight of the one or more asphaltene precipitant additives to the one or more hydrocarbon solvents of from about 10 ppm:1 to about 10000 ppm:1.

10. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are injected into the heavy hydrocarbon at a ratio by weight of the one or more asphaltene precipitant additives to the one or more hydrocarbon solvents of from about 50:1 to about 1000 ppm:1.

11. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are peroxide containing asphaltene precipitant additives.

12. The process according to claim 11 , wherein the one or more peroxide asphaltene precipitant additives are selected from the group consisting of lauroyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide, m-toluoyl peroxide, peroxyacetic acid, 2,5-oxanoyl peroxide, succinic peroxide, diisopropylbenzene hydroperoxide, paramethane hydroperoxide, pinane hydroperoxide, cumene hydroperoxide, p-menthane hydroperoxide, tert-butyl peroxyacetate, tert-butyl peroxypivalate, tert-butyl peroxyneodecanoate, tert-butyl peroxyoctanoate, methyl ethyl ketone peroxide, acetone peroxide, acetylacetone peroxide, cyclohexanone peroxide, methylcyclohexanone peroxide, m-chloroperoxybenzoic acid, di-t-butyl peroxide, t-butylcumyl peroxide, t-butyl hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 1,1-bis(t-butyl-peroxy)cyclohexane, 2,2-bis(tert-butylperoxy)-butane, 2,5-dimethyl-2,5-dibenzoylperoxy-hexane, 1,3-bis(t-butyl-peroxyisopropyl)-benzene, 3,3,5-trimethylcyclohexanone peroxide, 1,1-bis(t-butyl-peroxy)-3,3,5-trimethylcyclohexane, dicumyl peroxide, and dimethylstyryl peroxydicarbonate.

13. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are polymeric methacrylate containing asphaltene precipitant additives.

14. The process according to claim 13 , wherein the one or more polymeric methacrylate asphaltene precipitant additives are selected from the group consisting of 4-vinyl pyridine methacrylate, 4-vinyl phenol methacrylate, polymaleic anhydride and mixtures thereof.

15. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are nanoparticles of metal oxides, wherein the metal is selected from the group consisting of a Group 8 metal, Group 9 metal, Group 10 metal, copper and zinc.

16. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are nanoparticles of iron oxide, nickel oxide, ruthenium oxide, platinum oxide and palladium oxide.

17. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are sulphonic acid containing asphaltene precipitant additives.

18. The process according to claim 1 , wherein the initial reservoir conditions include a temperature of between about 40° C. and about 140° C.

19. The process according to claim 1 , wherein the reservoir conditions include a pressure of between about 250 psia to about 2500 psia.

20. The process according to claim 1 , wherein the one or more hydrocarbon solvents are first injected into the heavy hydrocarbon and then the one or more asphaltene precipitant additives are injected into the mixture of hydrocarbon solvent and heavy hydrocarbon.

21. The process according to claim 1 , wherein the one or more asphaltene precipitant additives are first injected into the heavy hydrocarbon and then the one or more hydrocarbon solvents are injected into the mixture of the one or more asphaltene precipitant additives and heavy hydrocarbon.

22. The process according to claim 1 , wherein the one or more hydrocarbon solvents and one or more asphaltene precipitant additives are injected simultaneously into the heavy hydrocarbon.

23. The process according to claim 1 , wherein steam is injected along with the one or more hydrocarbon solvents and the one or more asphaltene precipitant additives in any order.

24. The process according to claim 1 , wherein the one or more asphaltene precipitant additives comprise an additive selected from the group consisting of peroxides, polymeric methacrylates, nanoparticles of metal oxides, sulphonic acids and combinations thereof.

25. The process according to claim 1 , wherein the blend contains precipitated asphaltenes in an amount at least 1.5 wt. % higher than in a similar blend not containing the one or more asphaltene precipitant additives.

26. The process according to claim 1 , wherein the blend contains precipitated asphaltenes in an amount at least 5 wt. % higher than in a similar blend not containing the one or more asphaltene precipitant additives.

Assignees

• Chevron Usa Inc

Inventors

• Ovalles Cesar
• Rogel Estrella

Classifications

• E21B43/16 Primary

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• C09K2208/10

  Nanoparticle-containing well treatment fluids · CPC title

• C09K8/594

  Compositions used in combination with injected gas {, e.g. CO2 orcarbonated gas}(C09K8/592 takes precedence) · CPC title

• E21B43/28

  Dissolving minerals other than hydrocarbons, e.g. by an alkaline or acid leaching agent (E21B43/241 takes precedence) · CPC title

• C10G2300/4037

  In-situ processes · CPC title