Encapsulated lost circulation materials based on shape-memory polymer foam

Patent metadata

Field	Value
Publication number	US-2025059837-A1
Application number	US-202318449378-A
Country	US
Kind code	A1
Filing date	Aug 14, 2023
Priority date	Aug 14, 2023
Publication date	Feb 20, 2025
Grant date	—

Abstract

An encapsulated lost circulation material includes: a particulate having a core including a compressed shape-memory polymer foam, and a disintegrating agent, the disintegrating agent including at least one of a phase change material or a gas-producing material; and a shell encapsulating the core. A method of reducing lost circulation includes: introducing into a subsurface a wellbore fluid including the encapsulated lost circulation material; heating the disintegrating agent to cause the phase change material to expand, or to cause the gas-producing material to produce a gas, or a combination thereof to break the shell; and releasing the compressed shape-memory polymer foam from the encapsulated lost circulation material; expanding the released shape-memory polymer foam; and filling a void or fracture of the subsurface with the expanded compressed shape-memory polymer foam to reduce fluid loss.

First claim

1 . An encapsulated lost circulation material comprising a particulate having
a core comprising a compressed shape-memory polymer foam, and a disintegrating agent, the disintegrating agent comprising at least one of a phase change material or a gas-producing material; and a shell encapsulating the core, wherein the phase transition material has a phase transition temperature between 112.5° F. and 1100° F. and a volumetric expansion of at least 5% during a phase transition relative to a volume of the phase change material before the phase transition wherein the volumetric expansion exerts sufficient pressure on the shell to break the shell and release the compressed shape-memory foam.

2 . The encapsulated lost circulation material of claim 1 , wherein the core comprises the phase change material, and the a the phase transition temperature is between 125° F. and 1,000° F. and the volumetric expansion is at least 10% during the phase transition relative to the volume of the phase change material before the phase transition.

3 . The encapsulated lost circulation material of claim 2 , wherein the core comprises the phase change material, and the phase change material comprises at least one of an inorganic salt, an eutectic mixture of inorganic salts, a metal hydroxide, an eutectic mixture of an inorganic salt with an organic material, a hydrate of an inorganic salt, a hydrate of metal hydroxide, or an organic material, wherein the organic material is selected from the group consisting of a parrafin, d-mannitol, hydroquinone, adipic acid, urea, acetamide, erythritol, phthalic anhydride, maleic acid, 2-chlorobenzoic acid, a sugar, a sugar alcohol, and a fatty acid

4 . The encapsulated lost circulation material of claim 1 , wherein the core comprises the gas-producing material, and the gas-producing material comprises at least one of an azo compound, an azide compound, or a metal carbonyl.

5 . The encapsulated lost circulation material of claim 1 , wherein the shell comprises at least one of alginate, cellulose, starch, chitosan, dextran sulfate, pectin, xanthan gum, a polymethacrylate, a polydimethylsiloxane, a polystyrene, a polyvinyl acetate, a polyvinylpyrrolidone, silica, alumina, titania, sodium silicate, calcium carbonate, nickel, nickel phosphorus, a nickel alloy, an iron oxide, an oxyhydroxide, or an iron salt.

6 . The encapsulated lost circulation material of claim 1 , wherein the compressed shape-memory polymer foam comprises closed cells.

7 . The encapsulated lost circulation material of claim 1 , wherein the compressed shape-memory polymer foam comprises open cells.

8 . The encapsulated lost circulation material of claim 1 , further comprising a magnetic material.

9 . The encapsulated lost circulation material of claim 8 , wherein the magnetic material is disposed in the shell of the encapsulated lost circulation material.

10 . The encapsulated lost circulation material of claim 8 , wherein the magnetic material is disposed in the core of the encapsulated lost circulation material.

11 . The encapsulated lost circulation material of claim 8 , wherein the magnetic material is coated on the disintegrating agent.

12 . A wellbore fluid comprising a carrier and the encapsulated lost circulation material of claim 1 .

13 . The wellbore fluid of claim 12 , wherein the wellbore fluid is a drilling fluid.

14 . The wellbore fluid of claim 12 , further comprising an activator.

15 . A method of reducing lost circulation, the method comprising:
introducing into a subsurface a wellbore fluid comprising an encapsulated lost circulation material having a core comprising a compressed shape-memory polymer foam and a disintegrating agent, the disintegrating agent comprising at least one of the phase change material, or a gas-producing material, and a shell encapsulating the core, wherein the phase transition material has a phase transition temperature between 112.5° F. and 1100° F. and a volumetric expansion of at least 5% during a phase transition relative to a volume of the phase change material before the phase transition; heating the disintegrating agent to cause the phase change material to expand, or to cause the gas-producing material to produce a gas, or a combination thereof to break the shell; and releasing the compressed shape-memory polymer foam from the encapsulated lost circulation material; expanding the released shape-memory polymer foam; and filling a void or fracture of the subsurface with the expanded compressed shape-memory polymer foam to reduce fluid loss.

16 . The method of claim 15 , wherein the wellbore fluid is a drilling fluid.

17 . The method of claim 15 , wherein the encapsulated lost circulation material further comprises a magnetic material.

18 . The method of claim 17 , wherein the method further comprises applying an electromagnetic radiation to the magnetic material to generate heat, and heating the disintegrating agent with the heat generated from the magnetic material.

19 . The method of claim 15 , wherein expanding the released shape-memory polymer foam comprises contacting the release shape-memory polymer with the wellbore fluid, which comprises an activator.

Assignees

• Baker Hughes Oilfield Operations Llc

Inventors

• Dolog Rostyslav
• Darugar Qusai A
• Suresh Radhika
• Mazyar Oleg

Classifications

• C09K8/518

  Foams · CPC title

• C09K8/035

  Organic additives · CPC title

• C09K8/536

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

• C09K8/516

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

• E21B21/003 Primary

  Means for stopping loss of drilling fluid (plastering the borehole wall E21B33/138) · CPC title