Treatment of subterranean formations
AssigneeInnospec Limited
InventorsIan Malcolm McRobbie, William Trenholme
Life of this patent
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Abstract
A method of treating a subterranean formation by contacting the formation with the following (a) ammonium bicarbonate; (b) and oxidizing agent selected from a perchlorate or a nitrite or combinations thereof; and (c) an acid (AA).
Claims21
A method of treating a subterranean formation to generate gas within the formation so as to create or enhance a fracture in the formation, the method comprising:
- (i) contacting the subterranean formation with the following:
- (a) ammonium bicarbonate;
- (b) an oxidizing agent which is a nitrite;
- and
- (c) an acid (AA);
- wherein a ratio (A) defined as the number of moles of ammonium bicarbonate divided by the number of moles of nitrite contacted with the formation and/or reacted in the formation is in the range 0.1 to 2.0;
- (ii) directing said ammonium bicarbonate, said nitrite and said acid (AA) towards a region of said formation it is desired to fracture;
- and
- (iii) fracturing the formation in a region adjacent to, or within, an area where gas is produced by reaction of said ammonium bicarbonate, said nitrite and said acid (AA).
A method of treating a subterranean formation to generate gas within the formation so as to create or enhance a fracture in the formation, the method comprising:
- (i) contacting the subterranean formation with the following:
- (a) ammonium bicarbonate;
- (b) an oxidizing agent which is sodium nitrite;
- (c) an acid (AA) selected from sulfamic acid and ammonium bisulfate;
- and
- mixtures of sulfamic acid and ammonium bisulfate;
- wherein a ratio (A) defined as the number of moles of ammonium bicarbonate divided by the number of moles of nitrite contacted with the formation and/or reacted in the formation is in the range 0.3 to 0.6;
- wherein a ratio (E) defined as the number of moles of ammonium bicarbonate divided by the sum of the number of moles of sulfamic acid and ammonium bisulfate contacted with the formation ranges from 0.01 to 4;
- and
- wherein a ratio (K) defined as the number of moles of nitrite divided by the sum of the number of moles of sulfamic acid and ammonium bisulfate which react with materials contacted with the formation, to produce a gas is in the range 0.1 to 10;
- (ii) directing said ammonium bicarbonate, said nitrite and said acid (AA) towards a region of said formation it is desired to fracture;
- and
- (iii) fracturing the formation in a region adjacent to, or within, an area where gas is produced by reaction of said ammonium bicarbonate, said nitrite and said acid (AA).
A method of treating a subterranean formation to generate gas within the formation so as to create or enhance a fracture in the formation, the method comprising:
- (i) contacting the subterranean formation with the following:
- (a) ammonium bicarbonate;
- (b) an oxidizing agent which is a nitrite;
- and
- (c) an acid (AA);
- (ii) directing said ammonium bicarbonate, said nitrite and said acid (AA) towards a region of said formation it is desired to fracture;
- and
- (iii) fracturing the formation in a region adjacent to, or within, an area where gas is produced by reaction of said ammonium bicarbonate, said nitrite and said acid (AA);
- wherein a ratio (B) defined as the number of moles of ammonium bicarbonate divided by the total number of moles of acid contacted with the formation and/or reacted with bicarbonate and oxidizing agent in the formation is in the range 0.01 to 4;
- and
- wherein a ratio (H) defined as the number of moles of nitrite divided by the total number of moles of acid contacted with the formation is in the range 0.5 to 5.
Dependencies are inferred from the claim text.