Calcium methylglycine diacetic acid salt particles and subterranean operations relating thereto

Patent metadata

Field	Value
Publication number	US-2016208160-A1
Application number	US-201314908570-A
Country	US
Kind code	A1
Filing date	Nov 27, 2013
Priority date	Nov 27, 2013
Publication date	Jul 21, 2016
Grant date	—

Abstract

Particles that comprise calcium methylglycine diacetic acid salt (“Ca-MGDA salt”) may be useful for fluid diversion in subterranean operations. In some instances, the particles may be formed in the subterranean formation. For example, a method may involve introducing a treatment fluid into a wellbore penetrating a subterranean formation, wherein the treatment fluid comprises an aqueous base fluid, MGDA or salt thereof, and an acid in an amount of about 3% or greater by weight of the aqueous base fluid; acidizing a portion of the subterranean formation comprising calcium carbonate resulting in a concentration of calcium in the treatment fluid that exceeds about 50,000 ppm; and precipitating a plurality of particles that comprise a Ca-MGDA salt in the portion of the subterranean formation, thereby reducing fluid flow therethrough. In some instances, the particles that comprise Ca-MGDA salt may be included in a treatment fluid before introduction into the subterranean formation.

First claim

The invention claimed is:

1 . A method comprising:
introducing a treatment fluid into a wellbore penetrating a subterranean formation, wherein the treatment fluid comprises an aqueous base fluid, methylglycine diacetic acid (“MGDA”) or salt thereof, and an acid in an amount of about 3% or greater by weight of the aqueous base fluid; acidizing a first portion of the subterranean formation comprising calcium carbonate resulting in a concentration of calcium in the treatment fluid that exceeds about 50,000 ppm; precipitating a plurality of particles that comprise a Ca-MGDA salt in the first portion of the subterranean formation, thereby reducing fluid flow therethrough; and diverting a portion of the treatment fluid or a subsequent treatment fluid from the first portion of the subterranean formation to a second portion of the subterranean formation.

2 . The method of claim 1 further comprising:
contacting the plurality of particles with a second treatment fluid having a pH of about 5.5 or greater; and
dissolving at least a portion of the plurality of particles, thereby increasing fluid flow through the portion of the subterranean formation.

3 . The method of claim 1 , wherein the treatment fluid further comprises calcium before introducing the treatment fluid into the wellbore.

4 . The method of claim 3 , wherein the calcium in the treatment fluid before introducing the treatment fluid into the wellbore is from a calcium salt comprising at least one selected from the group consisting of calcium chloride, calcium bromide, calcium nitrate, calcium sulfate, calcium phosphate, and any combination thereof.

5 . The method of claim 3 , wherein the calcium is at a concentration of about 10,000 ppm to about 50,000 ppm in the treatment fluid before introducing the treatment fluid into the wellbore.

6 . The method of claim 1 , wherein the MGDA or salt thereof is at a concentration of about 0.5 M to about 1.5 M in the treatment fluid.

7 . The method of claim 1 , wherein the wellbore has a bottom hole circulating temperature of about 125° F. or greater.

8 . The method of claim 1 , wherein the plurality of particles have a d50 of about 25 microns to about 100 microns.

9 . The method of claim 1 , wherein introducing the treatment fluid into the wellbore is at a pressure sufficient to create or extend at least one fracture in the subterranean formation.

10 . A method comprising:
introducing a treatment fluid into a wellbore penetrating a subterranean formation, wherein the treatment fluid has a pH of about 1.5 to about 5.5 and comprises an aqueous base fluid, a suspending aid, and a plurality of particles that comprise a Ca-methylglycine diacetic acid (“MGDA”) salt; placing the plurality of particles in a portion of the subterranean formation, thereby reducing fluid flow therethrough; and diverting a portion of the treatment fluid or a subsequent treatment fluid from the portion of the subterranean formation to a second portion of the subterranean formation.

11 . The method of claim 10 further comprising:
contacting the plurality of particles with a second treatment fluid having a pH of about 5.5 or greater; and
dissolving at least a portion of the plurality of particles, thereby increasing fluid flow through the portion of the subterranean formation.

12 . The method of claim 10 , wherein the plurality of particles have a d50 of about 25 microns to about 100 microns.

13 . The method of claim 10 , wherein the plurality of particles are at about 1% to about 30% by weight of the treatment fluid.

14 . The method of claim 10 , wherein the suspending aid comprises at least one of a polymer and a surfactant.

15 . The method of claim 10 , wherein the suspending aid is at about 0.1% to about 20% by weight of the aqueous base fluid.

16 . The method of claim 10 , wherein the treatment fluid further comprises an aqueous-miscible fluid.

17 . A system comprising:
a pump fluidly coupled to a tubular; the tubular containing a treatment fluid that comprises an aqueous base fluid, methylglycine diacetic acid (“MGDA”) or salt thereof, 0 ppm to about 50,000 ppm calcium, and acid in an amount of about 3% or greater by weight of the aqueous base fluid.

18 . A treatment fluid having a pH of about 1.5 to about 5.5 and comprising an aqueous base fluid, a plurality of particles that comprise a Ca-methylglycine diacetic acid (“MGDA”) salt, and a suspending aid.

19 . A system comprising:
a pump fluidly coupled to a tubular; the tubular containing a treatment fluid of claim 16 .

Assignees

• Halliburton Energy Services Inc

Inventors

• Reyes Enrique Antonio
• Smith Christopher Lynn
• Smith Alyssa
• Beuterbaugh Aaron Michael

Classifications

• E21B43/16

  Enhanced recovery methods for obtaining hydrocarbons · CPC title

• C09K8/92

  characterised by their form or by the form of their components, e.g. encapsulated material (C09K8/70 takes precedence) · CPC title

• C09K8/68 Primary

  containing organic compounds · CPC title

• C09K8/74

  combined with additives added for specific purposes · CPC title

• C09K8/72 Primary

  Eroding chemicals, e.g. acids · CPC title