PENTANE-HEXANE SOLVENT IN SITU RECOVERY OF HEAVY OIL

• US 20120325470A1
• Filed: 02/24/2012
• Published: 12/27/2012
• Est. Priority Date: 02/25/2011
• Status: Active Grant

• Current Assignee: Fccl Partnership. (Cenovus Energy Incorporated)
• Original Assignee: Fccl Partnership. (Cenovus Energy Incorporated)
• Inventors: Gupta, Subodh, Gittins, Simon D., Bilozir, Mark A.
• Granted Patent: US 8,844,639 B2
• Time in Patent Office: Days
• US Class Current: 166/272.3
• CPC Class Codes: C09K 8/592 Compositions used in combination with generated heat, e.g. by steam injection
• CPC Class Codes: E21B 43/2406 Steam assisted gravity drainage [SAGD]
• CPC Class Codes: E21B 43/2408 SAGD in combination with other methods

Abstract

An integrated thermal recovery process using a solvent of a pentane or hexane or both as an additive to, or sole component of, a gravity-dominated process for recovering bitumen or heavy oil from a reservoir. A pentane-hexane specific solvent fraction is extracted at surface from a diluent stream. That pentane-hexane solvent fraction is then injected into the reservoir as part of a gravity-dominated recovery process within the reservoir, and when that solvent fraction is subsequently produced as part of the oil or bitumen blend, it is allowed to remain within the blend to enhance the subsequent blend treating and transportation steps. Meanwhile, the remainder of the diluent from which the solvent stream had been extracted is utilized at surface as a blending stream to serve as an aid in treating of produced fluids and also to serve as a means of rendering the bitumen or heavy oil stream pipelineable.

Claims

1. A method of recovering heavy oil or bitumen from a reservoir under a gravity-dominated recovery process comprising:

providing a pentane-hexane solvent;

injecting the pentane-hexane solvent into the reservoir as part of the gravity-dominated recovery process; and

producing heavy oil or bitumen and recovered liquid pentane-hexane solvent from the reservoir.

2. The method of claim 1, wherein the pentane-hexane solvent is injected with steam.

3. The method of claim 2, wherein the pentane-hexane solvent is greater than 50 percent pentane or hexane or mixtures thereof.

4. The method of claim 3, wherein the pentane-hexane solvent is greater than 80 percent pentane or hexane or mixtures thereof.

5. The method of claim 3, wherein at least 50 percent of the injected pentane or hexane or mixtures thereof is recovered in the heavy oil or bitumen and recovered liquid pentane-hexane solvent.

6. The method of claim 4, wherein at least 80 percent of the injected pentane or hexane or mixtures thereof is recovered in the heavy oil or bitumen and recovered liquid pentane-hexane solvent.

7. The method of claim 1, further comprising diluting the produced heavy oil or bitumen and the recovered liquid pentane-hexane with a diluent.

8. The method of claim 2, wherein the pentane-hexane solvent is between 2 wt % and 20 wt % of the steam.

9. The method of claim 1, wherein a diluent comprising pentane-hexane is separated into a pentane-hexane fraction to provide the pentane-hexane solvent, and an abridged diluent fraction.

10. The method of claim 9, wherein the separation is by fractionating.

11. The method of claim 10, wherein the fractionating provides a light ends fraction.

12. The method of claim 10, wherein the fractionating provides a heavy ends fraction.

13. The method of claim 11, wherein the light ends fraction and the pentane-hexane fraction are combined to provide the pentane-hexane solvent.

14. The method of claim 9, wherein the abridged diluent and the produced heavy oil or bitumen are combined to provide a blended oil.

15. The method of claim 1, further comprising collecting hydrocarbons containing substantially pentanes and hexanes from the heavy oil or bitumen to provide the pentane-hexane solvent.

16. The method of claim 15, wherein the hydrocarbons are collected from a blended oil tank, containing heavy oil or bitumen.

17. The method of claim 15, wherein the hydrocarbons are collected from an emulsion treater.

18. An integrated solvent aided thermal recovery system comprising:

an alkane separation unit adapted to receive an alkane diluent and separate the alkane diluent to provide a pentane-hexane solvent and an abridged diluent fraction;

an injection unit for providing the pentane-hexane solvent to an oil sand reservoir;

a production until for producing fluids from the oil sand reservoir, the produced fluids including heavy oil or bitumen and substantially the pentane-hexane solvent;

a treating unit adapted to receive the produced fluids and a first portion of the abridged diluent fraction to provide a diluted bitumen blend; and

a blending unit, adapted to receive the diluted bitumen blend from the treating unit, and a second portion of the abridged diluent fraction for combination to provide a blended oil for shipment.

19. The system of claim 18, wherein the injection unit is adapted to provide steam to the oil sand reservoir with the pentane-hexane solvent.

20. An integrated solvent aided thermal recovery system comprising:

an injection unit for providing a pentane-hexane solvent to an oil sand reservoir;

a production until for producing fluids from the oil sand reservoir, the produced fluids including heavy oil or bitumen and substantially the pentane-hexane solvent;

a treating unit adapted to receive the produced fluids and a first portion of a diluent to provide a diluted bitumen blend;

a blending unit, adapted to receive the diluted bitumen blend from the treating unit, and a second portion of the diluent for combination to provide a blended oil for shipment; and

a vapor recovery unit adapted to receive vapors containing pentane-hexane from the blending unit or the production unit, or both, and condensing the pentane-hexane to provide the pentane-hexane solvent.

21. The system of claim 20, wherein the injection unit is adapted to provide steam to the oil sand reservoir with the pentane-hexane solvent.