Subsea on-site chemical injection management system

Patent metadata

Field	Value
Publication number	US-9309750-B2
Application number	US-201414316534-A
Country	US
Kind code	B2
Filing date	Jun 26, 2014
Priority date	Jun 26, 2014
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A system includes a subsea on-site chemical injection management system configured to inject a chemical mixture into a well, wherein the subsea on-site chemical injection management system includes a subsea on-site head tank configured to store a plurality of discrete chemicals, a subsea on-site mixing unit configured to mix one or more of the plurality of discrete chemicals to create one or more chemical mixtures, and a subsea on-site distribution unit configured to distribute the one or more chemical mixtures to the well.

First claim

The invention claimed is:

1. A system, comprising:
a subsea on-site chemical injection management system configured to inject a chemical mixture into a well, wherein the subsea on-site chemical injection management system comprises:
a subsea on-site head tank configured to store a plurality of discrete chemicals, wherein the subsea on-site head tank comprises an elevated reservoir and a plurality of discrete chemical outlets at a base of the subsea on-site head tank;
a subsea on-site mixing unit configured to mix one or more of the plurality of discrete chemicals to create one or more chemical mixtures; and
a subsea on-site distribution unit configured to distribute the one or more chemical mixtures to the well.

2. The system of claim 1 , wherein the subsea on-site chemical injection management system comprises a local pump coupled to a wellhead of the well, wherein the local pump is configured to elevate a pressure of the one or more chemical mixtures prior to injection into the well.

3. The system of claim 1 , wherein the elevated reservoir comprises a plurality of internal storage tanks, wherein each of the plurality of internal storage tanks is configured to store a respective one of the plurality of discrete chemicals.

4. The system of claim 1 , wherein the subsea on-site head tank is configured to mount on a sea floor.

5. The system of claim 1 , wherein the subsea on-site chemical injection management system comprises a plurality of fluid conduits extending from the base of the head tank to the subsea on-site mixing unit, wherein each of the plurality of fluid conduits is configured to flow a respective one of the plurality of discrete chemicals.

6. The system of claim 1 , wherein the subsea on-site chemical injection management system comprises at least one fluid conduit extending from the subsea on-site mixing unit to the subsea on-site distribution unit, wherein each of the at least one fluid conduit is configured to flow a respective one of the one or more chemical mixtures.

7. The system of claim 1 , wherein the subsea on-site mixing unit comprises a controller configured to regulate one or more components of the subsea on-site mixing unit, wherein the controller comprises a memory configured to store at least one formula of the one or more chemical mixtures.

8. The system of claim 7 , wherein the controller is configured to communicate with a top side processing unit at a surface above the subsea on-site chemical injection management system.

9. The system of claim 1 , comprising an autonomous underwater vehicle configured to transfer additional amounts of the plurality of discrete chemicals from a top side processing unit to the subsea on-site head tank.

10. A method, comprising:
flowing a plurality of discrete chemicals from an elevated reservoir of a subsea on-site head tank through a plurality of discrete chemical outlets formed in a base of the subsea on-site head tank to a subsea on-site mixing unit;
mixing one or more of the plurality of discrete chemicals within the subsea on-site mixing unit to create one or more chemical mixtures;
flowing the one or more chemical mixtures from the subsea on-site mixing unit to a subsea on-site distribution unit; and
distributing the one or more chemical mixtures to a subsea well.

11. The method of claim 10 , comprising storing each the plurality of discrete chemicals in individual internal storage tanks disposed in the elevated reservoir of the subsea on-site head tank.

12. The method of claim 11 , wherein flowing the plurality of discrete chemicals from the subsea on-site head tank to the subsea on-site mixing unit comprises using hydrostatic pressure of the plurality of discrete chemicals in the individual internal storage tanks to flow the plurality of discrete chemicals from the subsea on-site head tank to the subsea on-site mixing unit.

13. The method of claim 11 , comprising refilling the individual internal storage tanks of the subsea on-site head tank with the plurality of discrete chemicals using an autonomous underwater vehicle.

14. The method of claim 10 , wherein mixing one or more of the plurality of discrete chemicals within the subsea on-site mixing unit to create one or more chemical mixtures comprising mixing one or more of the plurality of discrete chemicals according to a formula stored in a memory of the subsea on-site mixing unit.

15. The method of claim 10 , comprising elevating a pressure of the one or more chemical mixtures with a local pump of the subsea well prior to injection into the subsea well.

16. The method of claim 10 , wherein distributing the one or more chemical mixtures to the subsea well comprises regulating distribution of the one or more chemical mixtures with a controller of the subsea on-site distribution unit, wherein the controller is configured to communicate with a top side processing unit at a surface above the subsea on-site distribution unit.

17. A system, comprising:
a subsea on-site chemical injection management system configured to inject a chemical mixture into a well, wherein the subsea on-site chemical injection management system comprises:
a subsea on-site head tank comprising an elevated reservoir configured to store a plurality of discrete chemicals, a column supporting the elevated reservoir, and a plurality of discrete chemical outlets at a base of the column, wherein each of the plurality of discrete chemical outlets is configured to output a flow of a respective one of the plurality of discrete chemicals;
a subsea on-site mixing unit configured to mix one or more of the plurality of discrete chemicals to create one or more chemical mixtures; and
a local pump coupled to a wellhead of the well, wherein the local pump is configured to elevate a pressure of the one or more chemical mixtures prior to injection into the well.

18. The system of claim 17 , wherein the subsea on-site chemical injection management system comprises at least one subsea mount configured to mount the subsea on-site head tank, the subsea on-site mixing unit, or a combination thereof, to a sea floor.

19. The system of claim 17 , wherein the subsea on-site chemical injection management system comprises a subsea on-site distribution unit upstream of the local pump, wherein the subsea on-site distribution unit is configured to meter and distribute the one or more chemical mixtures to the local pump.

20. The system of claim 17 , wherein the subsea on-site head tank comprises:
a plurality of internal storage tanks disposed within the elevated reservoir, wherein each of the plurality of internal storage tanks is configured to store a respective one of the plurality of discrete chemicals; and
a plurality of inlets, wherein each of the plurality of inlets is in fluid communication with a respective one of the plurality of internal storage tanks, and each of the plurality of inlets is configured to receive a flow of a respective one of the plurality of discrete chemicals from an autonomous underwater vehicle.

Assignees

• Cameron Int Corp

Inventors

• Coonrod Donald Scott

Classifications

• E21B37/06

  using chemical means for preventing or limiting {, e.g. eliminating,} the deposition of paraffins or like substances · CPC title

• E21B33/068

  having provision for introducing objects or fluids into, or removing objects from, wells (cementing-heads E21B33/05) · CPC title

• E21B33/076

  specially adapted for underwater installations · CPC title

• E21B43/01 Primary

  specially adapted for obtaining from underwater installations · CPC title

• E21B41/02 Primary

  in situ inhibition of corrosion in boreholes or wells · CPC title