Methods for temporary fracture isolation

Patent metadata

Field	Value
Publication number	US-2019024490-A1
Application number	US-201816040879-A
Country	US
Kind code	A1
Filing date	Jul 20, 2018
Priority date	Jul 21, 2017
Publication date	Jan 24, 2019
Grant date	—

Abstract

Methods for temporary fracture isolation are provided. An existing fracture is treated with a chemical diverter. The chemical diverter is exposed to conditions causing it to expand, plugging the fracture. A new fracture can be created through the application of pressure and fluid, without disrupting the plugged fracture. The chemical diverter can then be removed through biodegradation or the application of a solvent to reopen the first fracture.

First claim

We claim at least the following:

1 . A method for temporary fracture isolation comprising:
providing a chemical diverter to a first fracture, wherein the chemical diverter is a shape memory polymer; causing, in a predetermined manner, the shape memory polymer to increase in dimension at a particular location in the first fracture; plugging the first fracture with the shape memory polymer; and applying pressure and fluid via a pump to the fracture to create at least one new fracture.

2 . The method of claim 1 , wherein the shape memory polymer has an activated state and a programmed state, wherein in the activated state of the shape memory polymer has an activated state diameter, wherein in the programmed state of the shape memory polymer has a programmed state diameter, wherein the activated state diameter is about 5 to about 20% greater than the programmed state diameter, wherein the shape memory polymer in the programmed state will convert to the shape memory polymer in the activated state when an activation temperature of about 60° C. to about 180° C. is applied to the shape memory polymer in the programmed state, wherein the shape memory polymer is in the programmed state.

3 . The method of claim 2 , further comprising:
exposing the shape memory polymer in the programmed state to the activation temperature in the fracture; and converting the shape memory polymer in the programmed state to the shape memory polymer in the activated state upon exposure to the activation temperature inside the fracture, wherein the diameter of the shape memory polymer in the activated state has a diameter that is greater than the diameter of the shape memory polymer in the programmed state, wherein the activated particles plug the fracture.

4 . The method of claim 1 , wherein chemical dissolution, biodegradation, or both of the shape memory polymer occurs to reopen the first fracture.

5 . The method of claim 1 , wherein the chemical diverter comprises a thermosetting shape memory polymer, an ionomer, an ionic polymer, or a combination thereof.

6 . The method of claim 1 , wherein the chemical diverter has a core surrounded by a thermosetting shape memory polymer, and wherein the core is selected from a group consisting of: sand, bauxite, and ceramic.

7 . The method of claim 5 , wherein the thermosetting shape memory polymer is in the form of particles, and wherein the shape of the particles is selected from spheres, discs, fibers, or combinations thereof.

8 . The method of claim 2 , wherein the activation temperature is from about 70° C. to about 90° C.

9 . The method of claim 2 , wherein the activated state diameter is about 3 to about 50% greater than the programmed state diameter.

10 . The method of claim 4 , wherein the chemical dissolution of the shape memory polymer occurs by the addition of a solvent comprising hydrofluoric acid, hydrochloric acid, ionic liquids, ethylene glycol, diethylene glycol, cyclohexanol, N-Methyl-2-pyrrolidone, bacteria, or a combination thereof.

11 . A method for temporary fracture isolation comprising:
providing a shape memory polymer to a first fracture, wherein the shape memory polymer comprises a plurality of particle sizes; causing, in a predetermined manner, the shape memory polymer to increase in dimension at a particular location in the first fracture; plugging the first fracture with the shape memory polymer; applying pressure and fluid via a pump to the fracture to create at least one new fracture; and introducing a solvent to dissolve the shape memory polymer to reopen the first fracture.

12 . The method of claim 11 , wherein sizes of the plurality of particle sizes are selected based on the size of the first fracture.

13 . The method of claim 11 , wherein the shape memory polymer has an activated state and a programmed state, wherein in the activated state of the shape memory polymer has an activated state diameter, wherein in the programmed state of the shape memory polymer has a programmed state diameter, wherein the activated state diameter is about 5 to about 20% greater than the programmed state diameter, wherein the shape memory polymer in the programmed state will convert to the shape memory polymer in the activated state when an activation temperature of about 60° C. to about 180° C. is applied to the shape memory polymer in the programmed state, wherein the shape memory polymer is in the programmed state.

14 . The method of claim 13 , further comprising:
exposing the shape memory polymer in the programmed state to the activation temperature in the first fracture; and converting the shape memory polymer in the programmed state to the shape memory polymer in the activated state upon exposure to the activation temperature inside the first fracture, wherein the diameter of the shape memory polymer in the activated state has a diameter that is greater than the diameter of the shape memory polymer in the programmed state, wherein the activated particles plug the first fracture.

15 . The method of claim 11 , wherein the chemical diverter comprises a thermoplastic shape memory polymer, an ionomer, an ionic polymer, or a combination thereof.

16 . The method of claim 11 , wherein the chemical diverter has a core surrounded by a thermoplastic shape memory polymer, and wherein the core is selected from a group consisting of: sand, bauxite, and ceramic.

17 . The method of claim 15 , wherein the thermoplastic shape memory polymer is in the form of particles, and wherein the shape of the particles is selected from spheres, discs, fibers, or combinations thereof.

18 . The method of claim 13 , wherein the activation temperature is from about 70° C. to about 90° C.

19 . The method of claim 13 , wherein the activated state diameter is about 3 to about 50% greater than the programmed state diameter.

20 . The method of claim 15 , wherein the solvent is selected from hydrofluoric acid, hydrochloric acid, ionic liquids, ethylene glycol, diethylene glycol, cyclohexanol, N-Methyl-2-pyrrolidone, bacteria, or a combination thereof.

Assignees

• Univ Louisiana State

Inventors

• Dahi Taleghani Arash
• Li Guoqiang

Classifications

• E21B33/138

  Plastering the borehole wall; Injecting into the formation · CPC title

• E21B43/26 Primary

  by forming crevices or fractures · CPC title

• C09K8/516

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

• C09K8/508

  macromolecular compounds {(C09K8/512 takes precedence)} · CPC title

• C09K8/426

  for plugging · CPC title