Monovalent brines for use as wellbore fluids

Patent metadata

Field	Value
Publication number	US-2022396726-A1
Application number	US-202017776408-A
Country	US
Kind code	A1
Filing date	Nov 9, 2020
Priority date	Nov 13, 2019
Publication date	Dec 15, 2022
Grant date	—

Abstract

The invention relates to a wellbore fluid, which is a monovalent brine comprising one or more alkali bromide salt(s) and one or more TCT-reducing additive(s) selected from the group consisting of alkali nitrates. A method of treating a subterranean formation, comprising placing the wellbore fluids of the invention in a wellbore in the subterranean formation is also provided.

First claim

1 . A wellbore fluid, which is a monovalent brine comprising one or more alkali bromide salt(s) and one or more TCT-reducing additive(s) selected from the group consisting of alkali nitrates.

2 . A wellbore fluid according to claim 1 , wherein the monovalent brine comprises water and a binary salt mixture consisting of sodium bromide and alkali nitrate, said monovalent brine being of density in the range from 1.47 to 1.55 g/ml.

3 . A wellbore fluid according to claim 2 , wherein the monovalent brine is sodium bromide/sodium nitrate brine.

4 . A wellbore fluid according to claim 3 , which is sodium bromide/sodium nitrate brine of density from 1.49 gr/ml to 1.52 gr/ml and TCT below −5.0° C.

5 . A wellbore fluid according to claim 4 , comprising from 35 to 38% by weight sodium bromide and from 13 to 18% by weight sodium nitrate in aqueous solution.

6 . A wellbore fluid according to claim 2 , wherein the monovalent brine is sodium bromide/potassium nitrate brine.

7 . A wellbore fluid according to claim 6 , which is sodium bromide/potassium nitrate brine of density from 1.48 gr/ml to 1.51 gr/ml and TCT below −5.0° C.

8 . A wellbore fluid according to claim 7 , comprising from 35 to 42% by weight sodium bromide and from 7 to 10% by weight potassium nitrate in aqueous solution.

9 . A wellbore fluid according to claim 1 , which is a monovalent brine comprising water and a ternary salt mixture consisting of a first alkali bromide, a second alkali bromide and alkali nitrate.

10 . A wellbore fluid according to claim 9 , wherein the first alkali bromide is sodium bromide, the second alkali bromide is either lithium bromide, potassium bromide or cesium bromide and the alkali nitrate is sodium nitrate.

11 . A wellbore fluid according to claim 10 , wherein the monovalent brine is sodium bromide/lithium bromide/sodium nitrate brine of density higher than 1.47 gr/ml.

12 . A wellbore fluid according to claim 11 , with density from 1.47 gr/ml to 1.49 gr/ml and TCT below −5.0° C.

13 . A wellbore fluid according to claim 12 , comprising from 30 to 35% by weight sodium bromide; from 5 to 10% by weight lithium bromide; and from 6 to 10% by weight sodium nitrate in aqueous solution.

14 . A wellbore fluid according to claim 10 , wherein the monovalent brine is sodium bromide/potassium bromide/sodium nitrate brine of density higher than 1.51 gr/ml.

15 . A wellbore fluid according to claim 14 , with density from 1.51 gr/ml to 1.54 gr/ml and TCT below −5.0° C.

16 . A wellbore fluid according to claim 15 , comprising from 30 to 37% by weight sodium bromide; from 5 to 10% by weight potassium bromide; and from 6 to 10% by weight sodium nitrate in aqueous solution.

17 . A wellbore fluid according to claim 10 , wherein the monovalent brine is sodium bromide/cesium bromide/sodium nitrate brine of density higher than 1.53 gr/ml.

18 . A wellbore fluid according to claim 17 , with density from 1.53 gr/ml to 1.57 gr/ml and TCT below −5.0° C.

19 . A wellbore fluid according to claim 18 , comprising from 33 to 37% by weight sodium bromide; from 5 to 10% by weight cesium bromide; and from 5 to 10% by weight sodium nitrate in aqueous solution.

20 . A wellbore fluid according to claim 1 , having nearly neutral pH.

21 . A method of preparing wellbore fluid with improved stability against crystallization, comprising formulating one or more alkali bromide(s) and at least one alkali nitrate in water to give a monovalent brine, where the nitrate is present in an amount sufficient to achieve TCT-lowering effect of not less than 5° C. compared to the corresponding nitrate-free brine of equal density.

22 . A method according to claim 21 , wherein the alkali bromide comprises sodium bromide and the alkali nitrate is sodium nitrate.

23 . A method according to claim 21 , wherein the alkali bromide comprises sodium bromide and the alkali nitrate is potassium nitrate.

24 . A method of treating a subterranean formation, comprising placing the wellbore fluids of claim 1 in a wellbore in the subterranean formation.

25 . (canceled)

26 . (canceled)

27 . (canceled)

Assignees

• Bromine Compounds Ltd

Inventors

• Shandalov Elizabeta
• Masarwa Mohamad
• Cohen David

Classifications

• C09K8/845

  containing inorganic compounds · CPC title

• C09K8/528 Primary

  inorganic depositions, e.g. sulfates or carbonates · CPC title

• C09K8/05 Primary

  containing inorganic compounds only, e.g. mixtures of clay and salt · CPC title