Cationic nitrogen-containing heterocycles and their application in wellbore stability

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;
• R1, R2, R3, R4, R5, and R6 are independently a bond to the N-containing heterocycle, a hydrogen radical, X, an unsubstituted alkyl, or an alkyl bearing at least one substituent X;
• X is independently Cl, Br, or I;
• and
• at least one of R1, R3, and R5 is X and the others of R1, R3, and R5 are a bond to the N-containing heterocycle;
• and
• maintaining the reaction mixture in a solvent at a temperature from 0° C. to 50° C. for from 2 hours to 24 hours;
• and
• wherein the cationic polymer has a weight-average molecular weight from 10 kilodaltons (kDa) to 1000 kDa;
• wherein the cationic polymer comprises repeating units of formula (1):
• [A-B] (1)
• where
• A is the substituted benzene or a substituted triazine of formula (2);
• and
• B is the N-containing heterocycle.