Polymer delivery in well treatment applications

Patent metadata

Field	Value
Publication number	US-9574128-B2
Application number	US-16680408-A
Country	US
Kind code	B2
Filing date	Jul 2, 2008
Priority date	Jul 17, 2007
Publication date	Feb 21, 2017
Grant date	Feb 21, 2017

Abstract

This invention relates to compositions and methods for treating subterranean formations, in particular, oilfield stimulation compositions and methods using water-in-water polymer emulsions to uniformly dissolve a rheologically active polymer, such as a thickener or friction reducer, in the treatment fluid. The emulsions have a low viscosity and are easily pumped for mixing into a treatment fluid, where upon dilution with an aqueous medium, the polymer is easily hydrated without forming fish-eyes. The partitioning agent in the water-in-water emulsion does not generally affect the rheology of the treatment fluid. The invention also relates to further processing of the emulsion by wet grinding, high shear mixing and/or heating to enhance the hydration rate in the preparation of the well treatment fluid.

First claim

We claim:

1. A method of preparing a polymer concentrate for use in a fluid for treating a subterranean formation penetrated by a well bore, comprising:
a. in a first step, admixing a rheological polymer, a partitioning agent and a first aqueous medium comprising water to form a heterogeneous mixture comprising:
a partitioning agent-rich phase comprising water and at least a portion of the partitioning agent, wherein the partitioning agent-rich phase is continuous and
a dispersed polymer rich phase finely dispersed in the partitioning agent-rich phase, wherein the dispersed polymer-rich phase comprises water and at least a portion of the rheological polymer;

b. mechanically, thermally, or mechanically and thermally processing the heterogeneous mixture to increase a rate of hydration of the polymer upon dilution in a second aqueous medium,
wherein the heterogeneous mixture is a liquid-liquid mixture.

2. The method of claim 1 wherein the processing step comprises heating the heterogeneous mixture to a temperature above 60° C.

3. The method of claim 1 wherein the processing step comprises wet grinding the heterogeneous mixture.

4. The method of claim 1 wherein the processing step comprises high shear mixing of the heterogeneous mixture.

5. The method of claim 1 wherein the processing step comprises ultrasonification of the heterogeneous mixture.

6. The method of claim 1 , wherein the heterogeneous mixture comprises from 5 to 20 percent of the rheological polymer, by weight of the water in the mixture, and a weight ratio of the partitioning agent to the thickening polymer is from 1:4 to 4:1.

7. A method for supplying a hydrated polymer solution, comprising:
a. supplying rheological polymer solids, a partitioning agent and a first aqueous stream comprising water to a mixing zone to form a water-in-water emulsion comprising:
a partitioning agent-rich phase comprising water and at least a portion of the partitioning agent, wherein the partitioning agent-rich phase is continuous, and
a rheological polymers solids-rich phase finely dispersed in the partitioning agent-rich phase, wherein the rheological polymers solids-rich phase comprises water and at least a portion of the rheological polymer solids;

wherein the water-in-water emulsion is a liquid-liquid mixture;
b. optionally mechanically, thermally or mechanically and thermally processing the water-in-water emulsion stream to improve hydratability of the rheological polymer;
c. supplying the water-in-water emulsion stream with a second aqueous stream to a dilution zone to form a rheologically modified aqueous stream.

8. The method of claim 7 wherein the processing step comprises heating the water-in-water emulsion to a temperature above 60° C.

9. The method of claim 7 wherein the processing step comprises wet grinding the water-in-water emulsion.

10. The method of claim 7 wherein the processing step comprises high shear mixing of the water-in-water emulsion.

11. The method of claim 7 wherein the processing step comprises ultrasonification of the water-in-water emulsion.

Assignees

• Chen Yiyan
• Lin Lijun
• Sullivan Philip F
• Schlumberger Technology Corp

Inventors

• Chen Yiyan
• Lin Lijun
• Sullivan Philip F

Classifications

• C09K8/90

  of natural origin, e.g. polysaccharides, cellulose · CPC title

• C09K8/68 Primary

  containing organic compounds · CPC title

• C09K8/70

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

• C09K8/685 Primary

  containing cross-linking agents · CPC title

• C09K8/887

  containing cross-linking agents · CPC title