Method for fracking subterranean geological formation with surfactant-containing fluid

Patent metadata

Field	Value
Publication number	US-11866641-B2
Application number	US-202218146205-A
Country	US
Kind code	B2
Filing date	Dec 23, 2022
Priority date	Oct 4, 2019
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A surfactant of formula (I)

wherein each of R 1 and R 2 are independently a hydrogen, an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, R 3 and R 4 are independently an optionally substituted alkyl, an optionally substituted cycloalkyl, or an optionally substituted arylalkyl, x is an integer in a range of 2-8, y is an integer in a range of 1-15, z is an integer in a range of 4-10, n is an integer in a range of 2-5, and A is one of a carboxybetaine group, a sulfobetaine group, or a hydroxy sulfobetaine group. An oil and gas well servicing fluid containing the surfactant and methods of servicing an oil and gas well are also described.

First claim

The invention claimed is:

1. A method of fracking a subterranean geologic formation, comprising:
injecting an oil and gas well servicing fluid into an oil and gas well in the subterranean geologic formation,
wherein the injecting is at a pressure above the fracture point of the subterranean geologic formation;
wherein the oil and gas well servicing fluid comprises:
an aqueous base fluid; and
a surfactant of formula (I)

wherein:
each of R 1 and R 2 are independently H or an optionally substituted C 1 to C 6 alkyl,
R 3 and R 4 are independently an optionally substituted C 1 to C 6 alkyl;
x is 6;
y is an integer in a range of from 7 to 10;
z is 6;
n is an integer in a range of from 3 to 4;
A is an anionic headgroup selected from the group consisting of

wherein the oil and gas well servicing fluid has a total dissolved solids content in a range of from 50,000 to 350,000 ppm,
wherein the surfactant is present in a range of from 0.045 to 2 wt. %, relative to a total weight of the oil and gas well servicing fluid,
wherein the surfactant has a number average molecular weight in a range of from 600 to 1200 g/mol, and
wherein, during the injecting, the surfactant has a concentration in a range of from 3×10 −5 to 5×10 −4 M.

2. The method of claim 1 , wherein each of R 1 and R 2 are independently a hydrogen, or a methyl.

3. The method of claim 1 , wherein each of R 1 and R 2 are a hydrogen.

4. The method of claim 1 , wherein R 3 and R 4 are independently selected from the group consisting of a methyl, an ethyl, and an isopropyl.

5. The method of claim 1 , wherein R 3 and R 4 are a methyl.

6. The method of claim 1 , wherein y is 8.

7. The method of claim 1 , wherein y is 9.

8. The method of claim 1 , wherein n is 3.

9. The method of claim 1 , wherein A is

10. The method of claim 1 , wherein A is

11. The method of claim 1 , wherein A is

12. The method of claim 1 , wherein the carbon-carbon double bond present in formula (I) is in a cis-double bond configuration.

13. The method of claim 1 , wherein the surfactant is selected from the group consisting of

wherein in each structure y is 8 or 9.

14. The method of claim 1 , wherein the surfactant is present in a range of from 0.05 to 0.1 wt. % relative to a total weight of the oil and gas well servicing fluid.

15. The method of claim 1 , wherein the subterranean geologic formation has a temperature in a range of from 30 to 150° C.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Hussain S M Shakil
• Kamal Muhammad Shahzad

Classifications

• C09K8/584 Primary

  characterised by the use of specific surfactants · CPC title

• C07C229/12

  to carbon atoms of acyclic carbon skeletons · CPC title

• C07C305/04

  being acyclic and saturated · CPC title

• C07C305/10

  being further substituted by singly-bound oxygen atoms · CPC title

• C09K8/06

  Clay-free compositions (containing inorganic compounds only C09K8/05) · CPC title