CTAB grafted PAM gel and its application in drilling fluid

Cetyltrimethyl ammonium bromide (CTAB) grafted Polyacrylamide (PAM) gel has been used to control fluid loss for high performance drilling fluid with increased thermal stability. PAM complex was prepared by treating PAM with CTAB by green chemistry techniques. Characterization of PAM complex was carried out using FTIR, scanning electron microscope (SEM). Dispersed inhibitive drilling fluid system was formulated using PAM complex in KCl solution with attapulgite (as viscosifier), chrome free lignosulphate (as dispersant) and oxygen scavenger. rheology of an inhibitive drilling fluid has been studied using Fann VG meter, Mud balance, API fluid loss apparatus. Mud cake was analysed using SEM, EDX to study the PAM complex linkage with attapulgite. Addition of PAM complex improves the rheology of the mud system with increased fluid retention capacity. PAM complex is stable upto 160 °C, where generally PAM degrades thermally resulting in performance decrease of desirable rheological properties and filtration control of the fluid. PAM complex is believed to form coacervate phase which increases the fluid retention capacity of the system, from effective bridging with attapulgite, high salt tolerance, moderate temperature stability, in the inhibitive mud system.