Adsorption of polymers used in drilling fluids on the inner surfaces of carbon steel pipes

Polymers in drilling fluids tend to adhere to the inside surfaces of metal pipes, improving the lubricity characteristics of the fluid. The present study evaluated the adsorption of polymers from their aqueous solutions on metal surfaces by means of visual observation and contact angle measurements. The polymers tested were xanthan gum, starch, and partially hydrolyzed polyacrylamide (PHPA). The contact angle measurements were carried out to enable calculating the adhesion and adsorption energy. The visual observation, although not furnishing quantitative data, agreed with the results of the contact angle measurements. The results show that the tendency of these polymers to be adsorbed on metal surfaces varies as follows: starch > PHPA > xanthan gum. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers