Process for the removal of deposits from an oil or gas well, and/or from the surface structures, and/or from the equipment connected therewith, and/or from hydrocarbon bearing formations

Patent metadata

Field	Value
Publication number	US-9845424-B2
Application number	US-201113642938-A
Country	US
Kind code	B2
Filing date	Apr 14, 2011
Priority date	Apr 23, 2010
Publication date	Dec 19, 2017
Grant date	Dec 19, 2017

Abstract

Process for the removal of deposits from an oil or gas well, and/or from surface structures, and/or from the equipment connected therewith, and/or from hydrocarbon-bearing formations, comprising:—injecting at least one oil-in-water nanoemulsion into said oil or gas well, and/or surface structures, and/or equipment connected therewith, and/or hydrocarbon bearing formations; leaving said nanoemulsion in said oil or gas well, and/or surface structures, and/or equipment connected therewith, and/or hydrocarbon bearing formations, for a predetermined time.

First claim

The invention claimed is:

1. A process for removing deposits, the process comprising:
injecting at least one oil-in-water nanoemulsion into at least one space selected from the group consisting of an oil well, a gas well, a surface structure, and a hydrocarbon bearing formation; and
leaving the at least one nanoemulsion in the space for from 1 hour to 10 days,
wherein said oil-in-water nanoemulsion has a dispersed phase consisting essentially of an oil and a dispersing phase consisting essentially of water and at least one surfactant, and
wherein said oil-in-water nanoemulsion is prepared according to a process comprising diluting a homogeneous water/oil mixture (1) in a dispersing phase consisting of water to which at least one surfactant (2) has been added,
wherein:
the homogeneous water/oil mixture (1) comprises water, in an amount ranging from 65% by weight to 99.9% by weight with respect to a total weight of the mixture (1), and at least two surfactants (1) having a different hydrophilic-lipophilic balance from one another, in amounts such that the mixture (1) is homogenous;
an interface tension of the homogeneous water/oil mixture (1) is lower than or equal to 1 mN/m;
the surfactants (1) and (2) are selected from the group consisting of a non-ionic surfactant, an anionic surfactant and a polymeric surfactant; and
amounts of said dispersing phase and of said surfactant (2) are such that the oil-in-water nanoemulsion has a hydrophilic-lipophilic balance higher than that of the homogeneous water/oil mixture (1).

2. The process of claim 1 , wherein said process is suitable for removing organic deposits.

3. The process of claim 1 , wherein said oil-in-water nanoemulsion has a dispersed phase consisting of an oil and a dispersing phase consisting of water and at least one surfactant.

4. The process of claim 3 , the dispersed phase is distributed in the dispersing phase in the form of droplets having a diameter ranging from 10 nm to 500 nm.

5. The process of claim 4 , wherein the dispersed phase is distributed in the dispersing phase in the form of droplets having a diameter ranging from 15 nm to 200 mn.

6. The process of claim 1 , wherein said oil-in-water nanoemulsion has a hydrophilic-lipophilic balance value higher than or equal to 9.

7. The process of claim 6 , wherein said oil-in-water nanoemulsion has a hydrophilic-lipophilic balance value ranging from 10 to 16.

8. The process of claim 1 , wherein, in said oil-in-water nanoemulsion, the dispersed phase is distributed in the dispersing phase in the form of droplets having a specific area (area/volume) ranging from 6000 m 2 /l to 300000 m 2 /l.

9. The process of claim 8 , wherein, in said oil-in-water nanoemulsion, the dispersed phase is distributed in the dispersing phase in the form of droplets having a specific area (area/volume) ranging from 15000 m 2 /l to 200000 m 2 /l.

10. The process of claim 1 , wherein surfactants are present in said oil-in-water nanoemulsion in an amount ranaing from 0.1% by weight to 20% by weight with respect to a total weight of said oil-in-water nanoemulsion.

11. The process of claim 10 , wherein surfactants are present in said oil-in-water nanoemulsion in an amount ranging from 0.25% by weight to 12% by weight with respect to the total weight of said oil-in-water nanoemulsion.

12. The process of claim 1 , wherein said oil is present in said oil-in-water nanoemulsion in an amount ranging from 2% by weight to 20% by weight with respect to a total weight of said oil-in-water nanoemulsion.

13. The process of claim 12 , wherein said oil is present in said oil-in-water nanoemulsion in an amount ranging from 3% by weight to 15% by weight with respect to a total weight of said oil-in-water nanoemulsion.

14. The process of claim 3 , wherein a surfactant selected from the group consisting of a non-ionic surfactant, an ester of a fatty acid of sorbitan, a polymeric surfactant, and mixtures thereof is present in said dispersing phase.

15. The process of claim 3 , wherein said oil is selected from the group consisting of an aromatic hydrocarbon, a linear hydrocarbon, a branched hydrocarbon, a cyclic hydrocarbon, and mixtures thereof.

16. The process of claim 3 , wherein said water is selected from the group consisting of a demineralized water, salt water, and a mixture thereof.

17. The process of claim 1 , wherein said oil-in-water nanoemulsion has a pH ranging from 7 to 13.

18. The process of f claim 17 , wherein said oil-in-water nanoemulsion has a pH ranging from 8 to 12.

19. The process of claim 1 , wherein said oil-in-water nanoemulsion is injected into the space at a temperature ranging from 5° C. to 90° C.

20. The process of claim 19 , wherein said oil-in-water nanoemulsion is injected into the space at a temperature ranging from 15° C. to 80° C.

21. The process of claim 19 , wherein said oil-in-water nanoemulsion is left in the space for a time ranging from 8 hours to 2 days.

Assignees

• Del Gaudio Lucilla
• Leo Giuseppe
• Belloni Alessandra
• Albonico Paola
• Eni Spa

Inventors

• Del Gaudio Lucilla
• Leo Giuseppe
• Belloni Alessandra
• Albonico Paola

Classifications

• C09K8/524 Primary

  organic depositions, e.g. paraffins or asphaltenes · CPC title