PROCESS FOR TREATING SUBTERRANEAN OIL-BEARING FORMATIONS COMPRISING CARBONATE ROCKS Russian patent published in 2018 - IPC C09K8/584 C09K8/60 C09K8/68 C09K8/74 C09K8/86 

FIELD: soil or rock drilling; mining.

SUBSTANCE: present invention relates to a method for treating subterranean oil-bearing formations comprising carbonate rocks in which the process includes at least the following steps: injecting an aqueous composition comprising at least one cationic surfactant (S) into at least a portion of the oil-bearing formation, allowing the composition to interact with oil-wet surfaces in the formation, wherein the cationic surfactant (S) has general formula (I) [R¹-N(R²)(R³)(R⁴)]^{+ 1}/_mX^m- (I), and R¹, R², R³, R⁴ and X^m- have the following values: R¹: a group selected from the group of R^1a and R^1b, in which R^1a is an aliphatic linear or branched hydrocarbon radical containing from 10 to 22 carbon atoms, and R^1b is an aliphatic linear or branched hydrocarbon radical containing from 10 to 22 carbon atoms substituted with 1 to 3 OH groups, and R², R³ and R⁴ can be the same or different and are selected from the group of R^2a, R^3a, R^4a: alkyl groups containing from 1 to 4 carbon atoms,R^2b, R^3b, R^4b: OH- substituted alkyl groups containing from 1 to 4 carbon atoms, and R^2c, R^3c, R^4c: alkyl ether groups of formula -CH₂CH₂OCH₂CH₂OH and -CH₂CH₂OCH₂CH₂OCH₂CH₂OH, and X^m- is an anion in which m is 1, 2 or 3,provided that at least one of the groups R¹, R², R³ and R⁴ contains an OH group and the total number of OH groups in the surfactant (S) is from 1 to 4. Invention is developed in dependent claims of the invention.

EFFECT: technical result is an increase in the efficiency of treatment of subterranean formations.

16 cl, 3 tbl