Foam or viscosified composition containing a chelating agent

Patent metadata

Field	Value
Publication number	US-9725643-B2
Application number	US-201314395740-A
Country	US
Kind code	B2
Filing date	Apr 24, 2013
Priority date	Apr 27, 2012
Publication date	Aug 8, 2017
Grant date	Aug 8, 2017

Abstract

The present invention relates to a foam containing water, between 5 and 30 wt % on total weight of the foam of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), a foaming agent, and at least 25 vol % on total volume of the foam of a gas, and having a pH of between 2 and 5, to a viscosified composition containing water, between 5 and 30 wt % on total volume of the composition of a chelating agent selected from the group of glutamic aid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), and at least 0.01 wt % on total weight of the composition of a viscosifying agent, and having a pH of between 2 and 5, and to a process for treating a subterranean formation comprising introducing the above foam or viscosified composition into the formation.

First claim

The invention claimed is:

1. Foam containing water, between 5 and 30 wt % on total weight of the foam of a chelating agent selected from the group of glutamic acid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), N-hydroxyethyl ethylenediamine-N,N′,N′-triacetic acid or a salt thereof (HEDTA), a foaming agent, and at least 25 vol % on total volume of the foam of a gas and having a pH of between 2 and 5 wherein the amount of foaming agent is between 10 ppm and 200,000 ppm on total foam weight.

2. Foam of claim 1 , wherein the gas is N 2 , CO 2 , air or natural gas.

3. Foam of claim 1 , having a temperature of between 77 and 400° F.

4. Viscosified composition containing water, between 5 and 30 wt % on total weight of the composition of a chelating agent selected from the group of glutamic acid N,N-diacetic acid or a salt thereof (GLDA), aspartic acid N,N-diacetic acid or a salt thereof (ASDA), methylglycine N,N-diacetic acid or a salt thereof (MGDA), and at least 0.01 wt % on total weight of the composition of a viscosifying agent, and having a pH of between 2 and 5.

5. Viscosified composition of claim 4 , wherein the viscosifying agent is selected from the group of consisting of cellulosic derivatives, guar or guar derivatives, xanthan, carrageenan, starch polymers, gums, polyacrylamides, polyacrylates, betaine-based surfactants, viscoelastic surfactants, natural clays and synthetic clays.

6. Viscosified composition of claim 4 , wherein the amount of viscosifying agent is more than 0.01 and up to 2 wt % on total composition weight.

7. Viscosified composition of claim 4 , having a temperature of between 77 and 400° F.

8. Viscosified composition of claim 4 , wherein the viscosifying composition in addition contains a further additive from the group of foam extenders, crosslinking agents, anti-sludge agents, surfactants, corrosion inhibitors, mutual solvents, corrosion inhibitor intensifiers, foaming agents, viscosifiers, wetting agents, diverting agents, oxygen scavengers, carrier fluids, fluid loss additives, friction reducers, stabilizers, rheology modifiers, gelling agents, scale inhibitors, breakers, salts, brines, pH control additives, bactericides/biocides, particulates, crosslinkers, salt substitutes, relative permeability modifiers, sulfide scavengers, fibres, nanoparticles, and consolidating agents.

9. Viscosified composition of claim 8 , wherein the amount of corrosion inhibitor is more than 0 and up to 2 vol % on total volume.

10. Foam or of claim 1 , wherein the foam in addition contains a further additive from the group of foam extenders, crosslinking agents, anti-sludge agents, surfactants, corrosion inhibitors, mutual solvents, corrosion inhibitor intensifiers, foaming agents, viscosifiers, wetting agents, diverting agents, oxygen scavengers, carrier fluids, fluid loss additives, friction reducers, stabilizers, rheology modifiers, gelling agents, scale inhibitors, breakers, salts, brines, pH control additives, bactericides/biocides, particulates, crosslinkers, salt substitutes, relative permeability modifiers, sulfide scavengers, fibres, nanoparticles, and consolidating agents.

11. Foam of claim 10 , wherein the amount of corrosion inhibitor is more than 0 and up to 2 vol % on total volume.

Assignees

• Akzo Nobel Chemicals Int Bv
• Akzo Nobel Chemicals Int Bv

Inventors

• De Wolf Cornelia Adriana
• Nasr-El-Din Hisham
• Bang Edwin Rudolf Antony
• Wang Guanqun
• Baltussen Josef Johannes Maria
• Theeuwen Conrardus Hubertus Joseph
• O Boen Ho
• Van Eijk Marcel Cornelis Paulus

Classifications

• C09K8/536 Primary

  characterised by their form or by the form of their components, e.g. encapsulated material · CPC title

• C09K8/725 Primary

  Compositions containing polymers · CPC title

• C09K8/94

  Foams · CPC title

• C09K8/76

  for preventing or reducing fluid loss · CPC title

• C09K8/703

  Foams · CPC title