Emulsion preventer for completion brines

Patent metadata

Field	Value
Publication number	US-10537829-B2
Application number	US-201615296505-A
Country	US
Kind code	B2
Filing date	Oct 18, 2016
Priority date	Oct 20, 2015
Publication date	Jan 21, 2020
Grant date	Jan 21, 2020

Abstract

Emulsion-preventing compositions may contain one or more sorbitan esters; and one or more non-ionic surfactants; where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5. Methods may include contacting an emulsion with a treatment fluid, the treatment fluid containing one or more sorbitan esters and one or more non-ionic surfactants, where the ratio of the one or more sorbitan esters to the one or more non-ionic surfactants is in the range of 1:1 to 1:5; and separating the emulsion into an aqueous phase and an oleaginous phase.

First claim

What is claimed is:

1. A method comprising:
emplacing a wellbore fluid into a wellbore, the wellbore fluid comprising:
a base fluid;
one or more sorbitan esters; and
one or more nonionic surfactants;
wherein the volumetric ratio of the one or more sorbitan esters to the one or more nonionic surfactants is in the range of 1:1 to 1:5,

wherein the wellbore fluid meets at least two of the following three criteria:
(1) Biodegradation
a) >60% in 28 days as measured by OECD 306 or any other OSPAR-accepted marine protocols,
b) or in the absence of valid results for such tests:
i. >60% in 28 days as measured by OECD 301B, 301C, 301D, 301F, 310, Freshwater BODIS or
ii. >70% in 28 days as measured by OECD 301A, 301E;

(2) Bioaccumulation
a) a bioconcentration factor of less than 100;
b) log P ow ≤3 and molecular weight>700, or
c) if the conclusion of a weight of evidence expert judgment under Appendix 3 of OSPAR Agreement 2008-5 is positive; and

(3) Aquatic Toxicity
a) LC 50 >10 mg/l or EC 50 >10 mg/l.

2. The method of claim 1 , further comprising:
contacting the wellbore fluid with an emulsion in the wellbore; and
demulsifying the emulsion into an aqueous phase and an oleaginous phase.

3. The method of claim 1 , wherein the one or more sorbitan esters are selected from one or more of a group consisting of alkoxylated sorbitan esters, polysorbates, and sorbitans esterified with mono-, di-, tri-, or tetra-esters of C8-C22 alkyl or alkenyl fatty acids.

4. The method of claim 1 , wherein the one or more nonionic surfactants are alkyl glycosides of the general formula:

where X is a number from 1 to 4; and Y ranges from 4 to 25.

5. The method of claim 1 , wherein the wellbore fluid further comprises a mutual solvent.

6. A method comprising:
contacting an emulsion with a treatment fluid, the treatment fluid comprising:
one or more sorbitan esters, and
one or more nonionic surfactants,
wherein the volumetric ratio of the one or more sorbitan esters to the one or more nonionic surfactants is in the range of 1:1 to 1:5; and

separating the emulsion into an aqueous phase and an oleaginous phase,
wherein the treatment fluid meets at least two of the following three criteria:
(1) Biodegradation
a) >60% in 28 days as measured by OECD 306 or any other OSPAR-accepted marine protocols,
b) or in the absence of valid results for such tests:
i. >60% in 28 days as measured by OECD 301B, 301C, 301D, 301F, 310, Freshwater BODIS or
ii. >70% in 28 days as measured by OECD 301A, 301E;

(2) Bioaccumulation
a) a bioconcentration factor of less than 100;
b) log P ow ≤3 and molecular weight >700, or
c) if the conclusion of a weight of evidence expert judgment under Appendix 3 of OSPAR Agreement 2008-5 is positive; and

(3) Aquatic Toxicity
a) LC 50 >10 mg/l or EC 50 >10 mg/l.

7. The method of claim 6 , further comprising:
isolating the separated aqueous phase; and
injecting the separated aqueous phase into a wellbore.

8. The method of claim 6 , wherein the one or more sorbitan esters are selected from one or more of a group consisting of alkoxylated sorbitan esters, polysorbates, and sorbitans esterified with mono-, di-, tri-, or tetra-esters of C8-C22 alkyl or alkenyl fatty acids.

9. The method of claim 6 , wherein the one or more nonionic surfactants are alkyl glycosides of the general formula:

where X is a number from 1 to 4; and Y ranges from 4 to 25.

10. The method of claim 6 , wherein the treatment fluid further comprises a mutual solvent.

11. The method of claim 6 , wherein the treatment fluid comprises a mutual solvent at a concentration within the range of 0.1 vol % to about 50 vol %.

12. A method, comprising:
emplacing a wellbore fluid into a wellbore, the wellbore fluid comprising:
a base fluid;
a surfactant package comprising:
one or more sorbitan esters present in the surfactant package in an amount ranging from about 5 to about 50 vol % of the surfactant package; and
one or more nonionic surfactants present in the surfactant package in an amount ranging from about 50 to about 95 vol % of the surfactant package, the one or more nonionic surfactants comprising at least an alkyl glycoside of the general formula:

where X is a number from 1 to 4; and Y ranges from 4 to 25.

13. The method of claim 12 , wherein the wellbore fluid meets at least two of the following three criteria:
(1) Biodegradation
a) >60% in 28 days as measured by OECD 306 or any other OSPAR-accepted marine protocols,
b) or in the absence of valid results for such tests:
i. >60% in 28 days as measured by OECD 301B, 301C, 301D, 301F, 310, Freshwater BODIS or
ii. >70% in 28 days as measured by OECD 301A, 301E;

(2) Bioaccumulation
a) a bioconcentration factor of less than 100;
b) log P ow ≤3 and molecular weight >700, or
c) if the conclusion of a weight of evidence expert judgment under Appendix 3 of OSPAR Agreement 2008-5 is positive; and

(3) Aquatic Toxicity
a) LC 50 >10 mg/l or EC 50 >10 mg/l.

14. The method of claim 12 , further comprising:
contacting the wellbore fluid with an emulsion in the wellbore; and
demulsifying the emulsion into an aqueous phase and an oleaginous phase.

Assignees

• Mi Llc

Inventors

• Sui Changping
• Chinwangso Pawilai
• Zhang Hui
• Young Steven

Classifications

• C02F2101/325

  Emulsions · CPC title

• C02F2103/10

  from quarries or from mining activities · CPC title

• B01D17/047 Primary

  with separation aids · CPC title

• C02F1/686

  Devices for dosing liquid additives · CPC title

• C09K8/584

  characterised by the use of specific surfactants · CPC title