Cationic nitrogen-containing heterocycles and their application in wellbore stability
AssigneeSaudi Arabian Oil Company
InventorsHasmukh A. Patel, Carl Thaemlitz
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Abstract
In accordance with one or more embodiments of the present disclosure, a method of inhibiting shale formation during water-based drilling of subterranean formations includes introducing a shale inhibitor to the subterranean formation during the water-based drilling, the shale inhibitor comprising a cationic polymer comprising repeating units of [A-B]. A is a substituted benzene or a substituted triazine of formula (2). B is a N-containing heterocycle. The cationic polymer and a method of making the cationic polymer are also described.
Claims20
A method of inhibiting shale formation during water-based drilling of subterranean formations, the method comprising:
- introducing a shale inhibitor to the subterranean formation during the water-based drilling, the shale inhibitor comprising a cationic polymer comprising repeating units of formula (1):
- [A-B] (1)
- where
- A is a substituted benzene or a substituted triazine of formula (2):
- where
- A1, A2, A3, A4, A5, and A6 are independently C or N
- R1, R2, R3, R4, R5, and R6 are independently a bond to B of formula (1), a hydrogen radical, X, an unsubstituted alkyl, or an alkyl bearing at least one substituent X;
- X is independently Cl, Br, or I;
- and
- B is a N-containing heterocycle.
A method of making a cationic polymer, comprising
- introducing a substituted benzene or a substituted triazine of formula (2) to a N-containing heterocycle to obtain a reaction mixture having a molar ratio of the substituted benzene or the substituted triazine of formula (2) to the N-containing heterocycle:
- where
- A1, A2, A3, A4, A5, and A6 are independently C or N;
- R2, R3, R4, R5, and R6 are independently a bond to B of formula (1), a hydrogen radical, X, an unsubstituted alkyl, or an alkyl bearing at least one substituent X;
- X is independently Cl, Br, or I;
- and
- maintaining the reaction mixture in a solvent at a temperature from 0° C. to 50° C. for from 2 hours to 24 hours.
A cationic polymer comprising repeating units of formula (1):
- [A-B] (1)
- where
- A is a substituted benzene or a substituted triazine of formula (2):
- where
- A1, A2, A3, A4, A5, and A6 are independently C or N;
- R1, R2, R3, R4, R5, and R6 are independently a bond to B of formula (1), a hydrogen radical, X, an unsubstituted alkyl, or an alkyl bearing at least one substituent X;
- X is independently Cl, Br, or I;
- and
- B is a N-containing heterocycle.
Dependencies are inferred from the claim text.