Method of treating a subterranean formation with a mortar slurry designed to form a permeable mortar

Patent metadata

Field	Value
Publication number	US-2016341022-A1
Application number	US-201615156833-A
Country	US
Kind code	A1
Filing date	May 17, 2016
Priority date	May 19, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

A method of treating a subterranean formation may include preparing a mortar slurry, injecting the mortar slurry into the subterranean formation at a pressure sufficient to create a fracture in the subterranean formation, allowing the mortar slurry to set, forming a mortar in the fracture, and providing a pulse of pressure sufficient to reopen the fracture and thereby provide cracks in the set mortar. The mortar slurry may be designed to form a pervious mortar, to crack under fracture closure pressure, or both.

First claim

We claim:

1 . A method of treating a subterranean formation, comprising:
preparing a mortar slurry designed to set to form a mortar with a compressive strength below a fracture closure pressure of the subterranean formation, the mortar slurry comprising a cementitious material and water; injecting the mortar slurry into the subterranean formation at a pressure sufficient to create a fracture in the subterranean formation; while maintaining a pressure higher than the fracture closure pressure, allowing the mortar slurry to set, forming the mortar in the fracture; reducing the pressure below the fracture closure pressure; allowing the mortar in the fracture to crack, forming a cracked mortar; and exposing the set mortar to a pulse of pressure sufficient to reopen the fracture and provide additional cracks and permeability in the set cracked mortar.

2 . The method of claim 1 , wherein the pulse of pressure is provided by a compressable gas.

3 . The method of claim 1 wherein the pulse of pressure is provided by pumping a liquid into the wellbore.

4 . The method of claim 1 wherein the mortar slurry is further designed to have a viscosity of less 5,000 cP.

5 . The method of claim 1 , wherein the mortar slurry is further designed to set to form the mortar with a setting time in excess of 60 minutes after pump shut in, and wherein allowing the mortar slurry to set comprises waiting at least 60 minutes after injecting stops.

6 . The method of claim 1 , wherein the mortar slurry is further designed to set to form a pervious mortar with a compressive strength above an effective confinement stress of the formation.

7 . The method of claim 1 , wherein the mortar slurry is further designed to set to form a pervious mortar with a conductivity above 4,000 mD-ft.

8 . The method of claim 1 , wherein, prior to allowing the mortar in the fracture to crack, the mortar comprises a pervious mortar having a first conductivity, and wherein the cracked mortar has a second conductivity greater than the first conductivity.

9 . The method of claim 8 , wherein the second conductivity is above 2,000 mD-ft.

10 . The method of claim 8 , wherein the second conductivity is at least 2,000 mD-ft greater than the first conductivity.

11 . The method of claim 1 , wherein the mortar slurry is further designed to set and form the mortar with a salinity tolerance above 1% brine.

12 . The method of claim 1 , wherein a design ratio between the water and the cementitious material is between 0.2 and 0.8.

13 . A method of treating a subterranean formation, comprising:
preparing a mortar slurry designed to set to form a pervious mortar with conductivity above 10 mD-ft, the mortar slurry comprising a cementitious material, aggregate, and water; injecting the mortar slurry into the subterranean formation at a pressure sufficient to create a fracture in the subterranean formation; allowing the mortar slurry to set, forming the pervious mortar in the fracture; and after the mortar has set, providing a pulse of pressure sufficient to reopen the fracture and thereby provide cracks in the mortar.

14 . The method of claim 13 , wherein the mortar slurry is further designed to have a viscosity of less 5,000 cP.

15 . The method of claim 13 , wherein the mortar slurry is further designed to set to form the pervious mortar with a setting time in excess of 60 minutes after pump shut in, and wherein allowing the mortar slurry to set comprises waiting at least 60 minutes after injecting stops.

16 . The method of claim 13 , wherein the mortar slurry is further designed to set to form the pervious mortar with a compressive strength above an effective confinement stress of the formation.

17 . The method of claim 16 , wherein the mortar slurry is designed to set to form the pervious mortar with a compressive strength above 20 Mpa.

18 . The method of claim 13 , wherein the mortar slurry is further designed to set and form the pervious mortar with a salinity tolerance above 1% brine.

19 . The method of claim 13 , wherein a design ratio between the water and the cementitious material is between 0.2 and 0.8.

20 . The method of claim 13 , wherein the mortar slurry design further comprises sand.

21 . The method of claim 20 , wherein a design ratio between the sand and the cementitious material is between 1 and 8.

22 . The method of claim 13 , wherein the mortar slurry design further comprises retarder.

Assignees

• Shell Oil Co

Inventors

• Fonseca Ocampos Ernesto Rafael
• Hackbarth Claudia Jane
• Hale Arthur Herman
• Farinas Moya Mauricio Jose
• Verbist Guy Lode Magda Maria
• Mowad Benjamin
• Kerkar Prasad Baloo

Classifications

• E21B43/267 Primary

  reinforcing fractures by propping · CPC title

• C04B2111/00284

  Materials permeable to liquids · CPC title

• C09K8/80

  Compositions for reinforcing fractures, e.g. compositions of proppants used to keep the fractures open · CPC title

• C09K8/845

  containing inorganic compounds · CPC title

• C09K8/665

  containing inorganic compounds (proppants C09K8/80) · CPC title