Treatment of subterranean formations

Patent metadata

Field	Value
Publication number	US-11987751-B2
Application number	US-202017429795-A
Country	US
Kind code	B2
Filing date	Feb 11, 2020
Priority date	Feb 12, 2019
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

A method of treating a subterranean formation by contacting the formation with the following: (a) ammonium compound; (b) an oxidizing agent selected from a perchlorate or a nitrite or combinations thereof; and (c) sulfamic acid.

First claim

The invention claimed is:

1. A method of treating a subterranean formation, the method comprising:
(a) introducing an ammonium compound into the formation;
(b) introducing an oxidizing agent into the formation, wherein said oxidizing agent is selected from a perchlorate and a nitrite or combinations thereof;
(c) introducing sulfamic acid as a solution or slurry in water into the formation; and
(d) contacting the formation with said ammonium compound, said oxidizing agent and said sulfamic acid;
wherein said ammonium compound reacts with said oxidizing agent and/or said sulfamic acid to generate a gas in the formation;
wherein said sulfamic acid reacts to produce a gas, wherein the gas produced includes nitrogen atoms originating in the sulfamic acid; and
wherein a ratio (B) defined as the number of moles of ammonium compound divided by the total number of moles of sulfamic acid contacted with the formation is greater than 0 and is 10 or less.

2. The method according to claim 1 , wherein the method comprises treating the formation to create or enhance a fracture in the formation.

3. The method according to claim 2 , wherein in the method the sum of the wt % of a formulation (F1) comprising said ammonium compound, a formulation (F2) comprising said oxidizing agent and a formulation (F3) comprising said sulfamic acid introduced into the formation is at least 98 wt %, of the total weight of materials introduced into the formation.

4. The method according to claim 1 , wherein said oxidizing agent comprises a nitrite which, optionally, is sodium nitrite.

5. The method according to claim 1 , wherein said ammonium compound and said oxidizing agent are contacted so they react and nitrogen and carbon dioxide are generated in the formation.

6. The method according to claim 1 , wherein a ratio (A) defined as the number of moles of ammonium compound divided by the number of moles of nitrite contacted with the formation and/or reacted in the formation is in the range 0.05 to 2.0.

7. The method according to claim 1 , wherein said ammonium compound is selected from ammonium fluoride, ammonium chloride, ammonium bromide, ammonium iodide, ammonium nitrate, ammonium sulfate, ammonium hydrogen sulfate, ammonium carbonate, ammonium carbamate, ammonium bicarbonate, ammonium hydroxide, ammonium acetate, ammonium borates, ammonium chromate, ammonium dichromate, ammonium cyanides, ammonium glutamate, ammonium molybdate, ammonium oxalate, ammonium hydrogen oxalate, ammonium phosphate monobasic, ammonium phosphate dibasic, ammonium thiosulfate, ammonium formate, ammonium sulfamate, ammonium sulfite, ammonium persulfate, ammonium sulfide, ammonium tartrate dibasic, ammonium thiocyanate, ammonium dihydrogen phosphate and ammonium glycinate or mixtures thereof.

8. The method according to claim 1 , wherein said ammonium compound includes, in addition to a NH 4 + moiety, a second moiety which is arranged to generate a gas on reaction with said oxidizing agent and/or said sulfamic acid.

9. The method according to claim 8 , wherein said second moiety comprises a sulfamate, carbonate or bicarbonate moiety.

10. The method according to claim 1 , wherein a ratio (C) defined as the number of moles of ammonium compound divided by the sum of the number of moles of sulfamic acid which react with other materials contacted with the formation to produce a gas is greater than 0 and is 10 or less.

11. The method according to claim 1 , wherein said ammonium compound is provided as a slurry, an emulsion or a solution; and wherein the method comprises selecting an aqueous solution of said oxidizing agent.

12. The method according to claim 1 , wherein:
the sum of the total weight in grams (g) of ammonium compound, oxidizing agent and sulfamic acid introduced into the formation is herein referred to as SUM-W;
the sum of the total volume in cm 3 of gas generated by reaction of ammonium compound, oxidizing agent and said sulfamic acid is herein referred to as SUM-V;
wherein, in the method, the Reaction Efficiency is defined as SUM-V divided by SUM-W;
wherein the Reaction Efficiency is at least 100 cm 3 /g and is less than 300 cm 3 /g.

13. The method according to claim 1 , wherein said ammonium compound is ammonium bicarbonate and the method comprises producing pulses of pressure within the formation by controlling contact and/or amounts of ammonium bicarbonate, oxidizing agent and/or sulfamic acid within the formation.

14. The method according to claim 1 , wherein said ratio (B) is less than 2.0.

15. A method of treating a subterranean formation, the method comprising:
(a) introducing an ammonium compound into the formation;
(b) introducing an oxidizing agent into the formation, wherein said oxidizing agent is selected from a perchlorate and a nitrite or combinations thereof;
(c) introducing sulfamic acid as a solution or slurry in water into the formation; and
(d) contacting the formation with said ammonium compound, said oxidizing agent and said sulfamic acid;
wherein said ammonium compound reacts with said oxidizing agent and/or said sulfamic acid to generate a gas in the formation;
wherein said sulfamic acid reacts to produce a gas, wherein the gas produced includes nitrogen atoms originating in the sulfamic acid; and
wherein a ratio (H) defined as the number of moles of oxidizing agent divided by the total number of moles of sulfamic acid contacted with the formation is in the range 0.5-10.

16. The method according to claim 15 , wherein said ratio (H) is in the range 0.75 to 3.5.

17. The method according to claim 15 , wherein said oxidizing agent comprises a nitrite which, optionally, is sodium nitrite.

18. A method of treating a subterranean formation, the method comprising:
(a) introducing an ammonium compound into the formation;
(b) introducing an oxidizing agent into the formation, wherein said oxidizing agent is selected from a perchlorate and a nitrite or combinations thereof;
(c) introducing sulfamic acid as a solution or slurry in water into the formation; and
(d) contacting the formation with said ammonium compound, said oxidizing agent and said sulfamic acid;
wherein said ammonium compound reacts with said oxidizing agent and/or said sulfamic acid to generate a gas in the formation;
wherein said sulfamic acid reacts to produce a gas, wherein the gas produced includes nitrogen atoms originating in the sulfamic acid;
wherein a ratio (B) defined as the number of moles of ammonium compound divided by the total number of moles of sulfamic acid contacted with the formation is greater than 0 and is 10 or less; and
wherein a ratio (H) defined as the number of moles of oxidizing agent divided by the total number of moles of sulfamic acid contacted with the formation is in the range 0.5-10.

19. The method according to claim 18 , wherein said ratio (B) is less than 2.0 and said ratio (H) is in the range 0.75 to 3.5.

20. The method according to claim 19 , wherein said oxidizing agent comprises a nitrite.

21. The method of treating a subterranean formation according to claim 19 , to generate gas within the formation so as to create or enhance a fracture in the formation, undertake a ‘Huff and Puff’ operation or reduce proppant settling, wherein said ammonium compound includes, in addition to a NH 4 + moiety, a second moiety which generates carbon dioxide or nitrogen on reaction with said oxidizing agent and/or said sulfamic acid;
wherein:
the sum of the total weight in grams (g) of ammonium compound, oxidizing

Assignees

• Innospec Ltd

Inventors

• Mcrobbie Ian Malcolm
• Trenholme William

Classifications

• C09K8/665 Primary

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

• C06B29/00

  Compositions containing an inorganic oxygen-halogen salt, e.g. chlorate, perchlorate · CPC title

• C06B31/02

  the salt being an alkali metal or an alkaline earth metal nitrate · CPC title

• E21B43/2405

  in association with fracturing or crevice forming processes (E21B43/247 takes precedence) · CPC title

• E21B43/2605

  using gas or liquefied gas · CPC title