Patent ID: 9702235
Date: 2017-07-11
CPC Classifications: C09K,E21B

Claim:
1. A process for producing mineral oil from an underground mineral oil deposit comprising at least one oil-bearing stratum L into which at least one injection well and at least one production well have been sunk, comprising the following process steps: (1) injecting at least one aqueous formulation F which exhibits an increase in viscosity at or above a critical temperature T (2) after step (1), directly or indirectly heating at least a portion of the aqueous formulation F injected in step (1) by injecting steam into the mineral oil deposit, (3) producing mineral oil through at least one production well, wherein the temperature of the aqueous formulation F on injection in step (1) is below the critical temperature T K , and step (2) is conducted at least until at least a portion of the aqueous formulation F injected in step (1) has been heated to a temperature of at least T K ; wherein mineral oil is withdrawn from the at least one production well during step (1), and step (2) is commenced as soon as aqueous formulation F injected through the at least one injection well is detected in the mineral oil withdrawn.