Emulsions containing water-soluble acid retarding agents and methods of making and using

Patent metadata

Field	Value
Publication number	US-11091689-B2
Application number	US-201615757423-A
Country	US
Kind code	B2
Filing date	Aug 30, 2016
Priority date	Sep 3, 2015
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

Described herein is a multi-phase aqueous composition containing a surfactant; a first phase comprising water, an acid, and a water-soluble acid retarding agent; and a second phase selected from the group consisting of an immiscible organic phase, a gas, and combinations thereof. Further described are methods of making and using such compositions.

First claim

What is claimed is:

1. A two-phase aqueous composition comprising: a surfactant having a structure in accordance with Formula I:

wherein R 1 is CH 3 (CH 2 ) 7 CH═CH—(CH 2 ) 11 , R 2 is hydrogen, R 3 is (CH 2 ) 3 —N—(CH 3 ) 2 —CH 2 — and Y is COO − ; a first phase comprising water, HCl, and acid retarder MgCl 2 ; and a second phase consisting of nitrogen, wherein the MgCl 2 is present in the first phase at a concentration of about 19 wt %.

2. The two-phase aqueous composition of claim 1 , wherein the surfactant is a foaming agent and the second phase comprises the nitrogen.

3. The two-phase aqueous composition of claim 2 , wherein the two-phase aqueous composition is a foam.

4. A method, comprising: a) providing a two-phase aqueous composition comprising: a surfactant having a structure an accordance with Formula I:

wherein R 1 is CH 3 —(CH 2 ) 7 —CH═CH—(CH 2 ) 11 , R 2 is hydrogen, R 3 is (CH 2 ) 3 —N—(CH 3 ) 2 —CH 2 — and Y is COO − ; a first phase comprising water, HCl, and acid retarder MgCl 2 ; a second phase consisting of nitrogen; and b) treating a subterranean formation fluidly coupled to a wellbore with an oilfield treatment fluid comprising the two-phase aqueous composition;
wherein the MgCl 2 is present in the aqueous composition at a concentration of about 19 wt %;
wherein the treating is an acidizing operation performed at treating pressures less than, higher than or equal to a formation fracturing pressure.

5. A method comprising: a) treating a subterranean formation fluidly coupled to a wellbore with an oilfield treatment fluid comprising a two-phase aqueous composition comprising: a surfactant comprising a foaming agent; a first phase comprising water, HCl, and acid retarder MgCl 2 ; a second phase consisting of nitrogen; wherein the two-phase aqueous composition is a foam, wherein the surfactant has a structure an accordance with Formula I:

wherein R 1 is CH 3 —(CH 2 ) 7 —CH═CH—(CH 2 ) 11 , R 2 is hydrogen, R 3 is (CH 2 ) 3 —N—(CH 3 ) 2 —CH 2 — and Y is COO − ;
wherein the MgCl 2 is present in the aqueous composition at a concentration of about 19 wt %;
wherein the treating is an acidizing operation performed at treating pressures less than, higher than or equal to a formation fracturing pressure.

6. The method of claim 5 , wherein the two-phase aqueous composition is formed by: i) introducing the surfactant and the first phase into the subterranean formation, and ii) separately introducing the nitrogen into the subterranean formation for contact with the surfactant and the first phase with sufficient energy to form a foam.

Assignees

• Schlumberger Technology Corp

Inventors

• Daeffler Christopher
• Panga Mohan Kanaka Raju

Classifications

• E21B43/27

  by use of eroding chemicals, e.g. acids · CPC title

• C09K8/66 Primary

  Compositions based on water or polar solvents (C09K8/64 takes precedence) · CPC title

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• C09K8/74

  combined with additives added for specific purposes · CPC title

• C09K8/602 Primary

  containing surfactants · CPC title