Oil-in-water stable, emulsified spacer fluids

Patent metadata

Field	Value
Publication number	US-10633571-B2
Application number	US-201816112526-A
Country	US
Kind code	B2
Filing date	Aug 24, 2018
Priority date	Sep 19, 2013
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

Some embodiments described herein provide a method comprising method comprising providing an oil-in-water emulsified spacer fluid comprising a binary surfactant mixture, solvent non-aqueous base fluid, and an aqueous base fluid, wherein the binary surfactant mixture comprises a surfactant and an amphiphilic co-surfactant, wherein the surfactant is present in an amount in the range of from about 0.5% to about 30% by weight of the oil-in-water emulsified spacer fluid and wherein the amphiphilic co-surfactant is present in an amount in the range of from about 0.5% to about 30% by weight of the oil-in-water emulsified spacer fluid, and introducing the oil-in-water emulsified spacer fluid into a subterranean formation comprising a residual non-aqueous fluid therein, wherein the binary surfactant mixture in the oil-in-water emulsified spacer fluid emulsifies at least a portion of the residual non-aqueous fluid.

First claim

What is claimed is:

1. An oil-in-water emulsified spacer fluid comprising:
a binary surfactant mixture, solvent non-aqueous base fluid, and an aqueous base fluid,
wherein the binary surfactant mixture comprises a surfactant and an amphiphilic co-surfactant in a ratio of surfactant to amphiphilic co-surfactant in the range of about 1:2 to 2:1,
wherein the surfactant is a betaine and is present in an amount in the range of from about 0.5% to about 5% by weight of the oil-in-water emulsified spacer fluid and wherein the amphiphilic co-surfactant is present in an amount in the range of from about 0.5% to about 5% by weight of the oil-in-water emulsified spacer fluid, and
wherein the amphiphilic co-surfactant is selected from the group consisting of an alcohol; an alkyl alcohol; an aliphatic alcohol; an alicyclic alcohol; an unsaturated aliphatic alcohol; an unsaturated alicyclic alcohol; a polyhydric alcohol; an aromatic alcohol; an ethoxylated alcohol; a propxylated alcohol; a glycol; a glycol ether; a polyglycol amine; a phenol; an ethoxylated phenol; a propxylated phenol; and any combination thereof;
wherein the non-aqueous fluid is a paraffin and the non-aqueous fluid is present in an amount in the range of about 1% to about 10% by weight of the oil-in-water emulsified spacer fluid,
wherein the oil-in-water emulsified in a subterranean formation comprising a residual non-aqueous fluid therein,
wherein the binary surfactant mixture in the oil-in-water emulsified spacer fluid emulsifies at least a portion of the residual non-aqueous fluid; and
wherein the combination of betaine and amphiphilic co-surfactant in a ratio of surfactant to amphiphilic co-surfactant in the range of about 1:2 to 2:1 together with paraffin in the amount of about 1% to 10% by weight of the oil-in-water emulsified spacer fluid is able to produce an emulsion having low surfactant content which remains stable against settling for a period of time greater than 48 hours.

2. The oil-in-water emulsified spacer fluid of claim 1 , wherein the binary surfactant mixture is capable of increasing the water wettability of a subterranean formation.

3. The oil-in-water emulsified spacer fluid of claim 1 , wherein emulsified spacer fluid is an oil-in-water microemulsion comprising dispersed phase droplets having an average diameter in the range of from about 1 nm to about 100 nm.

4. The oil-in-water emulsified spacer fluid of claim 1 , wherein the emulsified spacer fluid is an oil-in-water miniemulsion comprising dispersed phase droplets having an average diameter in the range of from about 50 nm to about 1 μm.

5. The oil-in-water emulsified spacer fluid of claim 1 , wherein the emulsified spacer fluid is an oil-in-water macroemulsion comprising dispersed phase droplets having an average diameter in the range of from about 1 μm to about 100 μm.

6. The oil-in-water emulsified spacer fluid of claim 1 , further comprising an additive selected from the group consisting of a salt; a weighting agent; an inert solid; a fluid loss control agent; an emulsifier; a dispersion aid; a corrosion inhibitor; an emulsion thinner; an emulsion thickener; a viscosifying agent; a gelling agent; a proppant; a lost circulation agent; a foaming agent; a gas; a pH control additive; a breaker; a biocide; a crosslinker; a stabilizer; a chelating agent; a scale inhibitor; a gas hydrate inhibitor; an oxidizer; a reducer; a friction reducer; a clay stabilizing agent; and any combination thereof.

7. The oil-in-water emulsified spacer fluid of claim 1 , wherein the co-surfactant is a tertiary-butyl alcohol.

8. An oil-in-water emulsified spacer fluid comprising:
a binary surfactant mixture, solvent non-aqueous base fluid, a weighting agent, and an aqueous base fluid,
wherein the binary surfactant mixture comprises a surfactant and an amphiphilic co-surfactant in a ratio of surfactant to amphiphilic co-surfactant in the range of about 1:2 to 2:1,
wherein the surfactant is a betaine and is present in an amount in the range of from about 0.5% to about 5% by weight of the emulsified spacer fluid and wherein the amphiphilic co-sulfactant is a tertiary-butyl alcohol present in an amount in the range of from about 0.5% to about 5% by weight of the emulsified spacer fluid,
wherein the non-aqueous fluid is a paraffin and the non-aqueous fluid is present in an amount in the range of about 1% to about 10% by weight of the oil-in-water emulsified spacer fluid,
wherein the oil-in-water emulsified in a subterranean formation comprising a residual non-aqueous fluid therein,
wherein the binary surfactant mixture in the oil-in-water emulsified spacer fluid emulsifies at least a portion of the residual non-aqueous fluid; and
wherein the combination of betaine and amphiphilic co-surfactant in a ratio of surfactant to amphiphilic co-surfactant in the range of about 1:2 to 2:1 together with paraffin in the amount of about 1% to 10% by weight of the oil-in-water emulsified spacer fluid is able to produce an emulsion having low surfactant content which remains stable against settling for a period of time greater than 48 hours.

9. The oil-in-water emulsified spacer fluid of claim 8 , wherein the binary surfactant mixture is capable of increasing the water wettability of a subterranean formation.

10. The oil-in-water emulsified spacer fluid of claim 8 , wherein emulsified spacer fluid is an oil-in-water microemulsion comprising dispersed phase droplets having an average diameter in the range of from about 1 nm to about 100 nm.

11. The oil-in-water emulsified spacer fluid of claim 8 , wherein the emulsified spacer fluid is an oil-in-water miniemulsion comprising dispersed phase droplets having an average diameter in the range of from about 50 nm to about 1 μm.

12. The oil-in-water emulsified spacer fluid of claim 6 , wherein the emulsified spacer fluid is an oil-in-water macroemulsion comprising dispersed phase droplets having an average diameter in the range of from about 1 μm to about 100 μm.

13. The oil-in-water emulsified spacer fluid of claim 8 , further comprising an additive selected from the group consisting of a salt; an inert solid; a fluid loss control agent; an emulsifier; a dispersion aid; a corrosion inhibitor; an emulsion thinner; an emulsion thickener; a viscosifying agent; a gelling agent; a proppant; a lost circulation agent; a foaming agent; a gas; a pH control additive; a breaker; a biocide; a crosslinker; a stabilizer; a chelating agent; a scale inhibitor; a gas hydrate inhibitor; an oxidizer; a reducer; a friction reducer; a clay stabilizing agent; and any combination thereof.

14. The oil-in-water emulsified spacer fluid of claim 8 , wherein the weighting agent is present in an amount of about 50% to about 55% by weight of the oil-in-water emulsifier fluid.

Assignees

• Halliburton Energy Services Inc

Inventors

• Ravi Krishna
• Lewis Sam
• Agapiou Kyriacos

Classifications

• C09K8/28

  containing organic additives · CPC title

• C09K8/26 Primary

  Oil-in-water emulsions · CPC title

• C09K8/40 Primary

  Spacer compositions, e.g. compositions used to separate well-drilling from cementing masses · CPC title

• E21B33/14

  for cementing casings into boreholes · CPC title

• E21B21/08

  Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10) · CPC title