Methods of inhibiting corrosion of metals from acid stimulation of an oil and gas well

Patent metadata

Field	Value
Publication number	US-11518932-B2
Application number	US-201916418585-A
Country	US
Kind code	B2
Filing date	May 21, 2019
Priority date	May 21, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A method of inhibiting corrosion of metal surfaces of piping, tubing, heat exchangers and other metal equipment during acid stimulation of an oil and gas well is provided. The method includes introduction of an acidic treatment fluid containing an inorganic acid and a corrosion inhibitor of formula I into the oil and gas well.

First claim

The invention claimed is:

1. A method of inhibiting corrosion of metal during acid stimulation of an oil and gas well, the method comprising:
treating the oil and gas well with an acidic treatment fluid comprising 10 to 28 wt. % of an inorganic acid and from 0.001 wt. % to 0.045 wt. % of a corrosion inhibitor of formula I in water, each based on a total weight of the acidic treatment fluid,

wherein R 1 to R 5 are hydrogen and the compound of formula (I) is N′—(3-phenylallylidene) hydrazinecarbothiohydrazide (PHCT).

2. The method of claim 1 , wherein the acidic treatment fluid further comprises at least one secondary corrosion inhibitor selected from the group consisting of a cinnamaldehyde compound, an alkoxylated fatty amine, and an imidazoline compound.

3. The method of claim 1 , wherein the acidic treatment fluid further comprises from 0.001 wt. % to 0.5 wt. % of an intensifier, based on a total weight of the acidic treatment fluid, wherein the intensifier is at least one selected from the group consisting of CuI, KI and NaCl.

4. The method of claim 1 , wherein the acidic treatment fluid further comprises from 0.001 wt. % to 0.5 wt. % of a surfactant, based on a total weight of the acidic treatment fluid.

5. The method of claim 4 , wherein the surfactant is sodium dodecyl sulfate.

6. The method of claim 1 , wherein the acidic treatment fluid further comprises from 5 vol. % to 20 vol. % of an organic solvent, based on a total volume of the acidic treatment fluid, and wherein the organic solvent is at least one selected from the group consisting of acetone, methyl ethyl ketone, methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, and diethylene glycol.

7. The method of claim 1 , wherein the inorganic acid is HCl and wherein the acidic treatment fluid comprises from 14 wt. % to 16 wt. % HCl, based on a total weight of the acidic treatment fluid.

8. The method of claim 1 , wherein the oil and gas well is treated with the acidic treatment fluid at a temperature of from 25° C. to 180° C.

9. The method of claim 1 , wherein the metal is carbon steel.

10. The method of claim 1 , wherein a corrosion rate of the metal is from 16 millimeters per year (mm/y) to 100 mm/y when exposed to an acidic treatment fluid having 15 wt. % of the inorganic acid at 90° C.

11. The method of claim 1 , wherein
the acidic treatment fluid further comprises:
from 0.001 wt. % to 0.5 wt. % of an intensifier selected from the group consisting of CuI, KI and NaCl,
from 0.001 wt. % to 0.5 wt. % of a surfactant, and
from 5 vol. % to 20 vol. % of an organic solvent, selected from the group consisting of acetone, methyl ethyl ketone, methanol, ethanol, propanol, isopropanol, n-butanol, isobutanol, ethylene glycol, and diethylene glycol,
each based on a total weight of the acidic treatment fluid, and
a corrosion inhibition efficiency of the method is from 92% to 99.5%.

12. The method of claim 11 , wherein the surfactant is sodium dodecyl sulfate.

Assignees

• Univ King Fahd Pet & Minerals

Inventors

• Quraishi Mumtaz Ahmad
• Ansari Kashif Rahmani
• Chauhan Dheeraj Singh

Classifications

• C09K8/74 Primary

  combined with additives added for specific purposes · CPC title

• C09K8/54

  Compositions for in situ inhibition of corrosion in boreholes or wells · CPC title

• C23F11/16

  Sulfur-containing compounds · CPC title

• C09K2208/32

  Anticorrosion additives · CPC title

• C23F11/04

  in markedly acid liquids · CPC title