Method for storing and transporting crude oil

• US 20020062860A1
• Filed: 09/20/2001
• Published: 05/30/2002
• Est. Priority Date: 10/17/2000
• Status: Active Grant

• Current Assignee: Baker Hughes Holdings LLC (Baker Hughes Company)
• Original Assignee: Baker Hughes Incorporated (Baker Hughes Company)
• Inventors: Stark, Joseph L., Means, C. Mitch
• Granted Patent: US 6,893,874 B2
• Time in Patent Office: Days
• US Class Current: 137/88
• CPC Class Codes: E21B 37/06 using chemical means for preventing or limiting , e.g. eliminating, the deposition of paraffins or like substances
• CPC Class Codes: Y10T 137/2499 Mixture condition maintaining or sensing
• CPC Class Codes: Y10T 436/12 Condition responsive control
• CPC Class Codes: Y10T 436/21 Hydrocarbon

Abstract

Disclosed is a method for transporting blended crude oils comprising the steps of; (a) admixing a first crude oil with a second, different crude oil to form a crude oil admixture; (b) determining a first value representing the content of unprecipitated asphaltenes in the admixture; (c) holding the admixture for a period of time at standard conditions; (d) determining a second value representing the content of unprecipitated asphaltenes in the admixture; and (e) either: (i) transporting the admixture if the second value is the same as or within a predetermined range of the first value; or (ii) taking remedial action to prevent asphaltene precipitation prior to transporting if the second value is outside a predetermined range from the first value. Also disclosed is a method for estimating the storage stability of stored crude oils and crude oil admixtures.

Claims

1. In one aspect, the present invention is a method for transporting blended crude oils comprising the steps of;

(a) admixing a first crude oil with a second, different crude oil to form a crude oil admixture;

(b) determining a first value representing the content of unprecipitated asphaltenes in the admixture;

(c) holding the admixture for a period of time at standard conditions;

(d) determining a second value representing the content of unprecipitated asphaltenes in the admixture; and

(e) either;

(i) transporting the admixture if the second value is the same as or within a predetermined range of the first value;

or

(ii) taking remedial action to prevent asphaltene precipitation prior to transporting the admixture if the second value is outside a predetermined range from the first value.

2. The method of claim 1 wherein the admixture is transported through a pipeline, pipes or in tanks.

3. The method of claim 1 wherein the determining of a first or second value representing the content of unprecipitated asphaltenes in the admixture is done using a sensor.

4.he. The method of claim 3 wherein the sensor is a fiber optic attenuated total reflectance probe.

8. The method of claim 1 wherein the remedial actions include the addition of an additive, which prevents or mitigates the precipitation of asphaltenes, to the admixture.

12. The method of claim 1 wherein steps (a), (b), (c) and (d) are performed using a model crude oil blend.

5. The method of claim 4 wherein a processor makes real time relative concentration determinations of asphaltenes in the admixture.

6. The method of claim 5 wherein the fiber optic attenuated total reflectance probe has an exposed surface in contact with the admixture.

7. The method of claim 6 wherein the processor determines absorbance from the sensor data as a function of wavelength.

9. The method of claim 6 wherein the data from a fiber optic attenuated total reflectance probe is UV absorbance data.

10. The method of claim 9 wherein the UV absorbance data is absorbance in the range of from about 220 nm to about 800 nm.

11. The method of claim 10 wherein the UV absorbance data is absorbance in the range of from about 220 nm to about 400 nm.

13. The method of claim 12 wherein step (e) further comprises making a large scale blend based upon the model crude oil blend prior to executing steps (e)(i) and

15. The method of claim 14 further comprising taking remedial actions if the crude oil or crude oil admixture is going to be held for longer than the estimated storage stability .

16. The method of claim 15 wherein the determining of a first or second value representing the content of unprecipitated asphaltenes in the crude oil or crude oil admixture is done using a sensor.

17. The method of claim 16 wherein the sensor is a fiber optic attenuated total reflectance probe.

18. The method of claim 17 wherein a processor makes real time relative concentration determinations of asphaltenes in the crude oil or crude oil admixture.

19. The method of claim 18 wherein the fiber optic attenuated total reflectance probe has an exposed surface in contact with the admixture.

20. The method of claim 19 wherein the data from an a fiber optic attenuated total reflectance probe is UV absorbance data.

21. The method of claim 20 wherein the UV absorbance data is absorbance in the range of from about 220 nm to about 800 nm.

22. The method of claim 21 wherein the UV absorbance data is absorbance in the range of from about 220 nm to about 400 nm.

23. The method of claim 22 wherein steps (a), (b), (c) and (d) are performed using a model crude oil blend.

14. A method for determining the storage stability of crude oil or crude oil admixtures comprising the steps of:

(a) determining a first value representing the content of unprecipitated asphaltenes in the crude oil or crude oil admixture;

(b) holding the crude oil or crude oil admixture for a period of time at standard conditions;

(c) determining a second value representing the content of unprecipitated asphaltenes in the crude oil or crude oil admixture;

(d) estimating the storage stability of the crude oil or crude oil admixture, the estimation being based upon the difference, if any between the first value and second value.