Patent ID: 11913319
Assignee: SAUDI ARABIAN OIL COMPANY
Field: Civil engineering (Other fields)
Classification: CPC E  C | IPC C  E

Claim 0:
1. A method of acidizing a sandstone formation in Earth crust, comprising:
pumping ammonium salts and nitrite salt through a wellbore into a subterranean formation, wherein the subterranean formation comprises a sandstone formation, and wherein the ammonium salts comprise an ammonium salt not having fluoride and an ammonium salt having fluoride;
generating heat, nitrogen gas, and hydrofluoric acid from reaction of the ammonium salts with the nitrite salt in the subterranean formation;
pumping an acid through the wellbore into the subterranean formation after conclusion of pumping the ammonium salts and the nitrite salt through the wellbore into the subterranean formation;
generating heat, nitrogen gas, and hydrofluoric acid from reaction of the ammonium salts with the nitrite salt and the acid in the subterranean formation; and
acidizing the sandstone formation with the hydrofluoric acid, wherein the acidizing comprises dissolving quartz in the sandstone formation with the hydrofluoric acid.