Large amounts of hydrocarbons are located in deeper formations where higher temperatures are experienced, hence designing a proper drilling fluid to tolerate such conditions has represented a challenging task for researchers in the field. The current work is focused on evaluating the effectiveness of poly(prop-2-enamide-sodium 2-acrylamido-2-methyl propane sulphonate-ethenyl ethanoate), designated as CP4 and poly(prop-2-enamide-sodium-prop-2-enoate-

Tight environmental regulations coupled with the constant need to enhance water-based drilling mud performance for use in deeper formation where it can withstand high temperature, high pressure and high saline condition have always been an existential issue during drilling operations. This research compared the performance of biodiesel produced from waste vegetable oil with that of white oil 5#, used as additives in mud formulations. Their effectiveness was tested at high temperature high pressure, in the presence of monovalent and divalent electrolytes. The mud density, rheological behavior, yield point, fluid loss under high temperature and pressure, and cake thickness were examined.

Abstract.1 A fluid loss reducer polymer (polymer-FLR) was synthesized using acrylamide, hydroxyethyl methacrylate, N-vinyl pyrrolidone, and N,N-dimethyl acrylamide by free radical polymerization, followed by partial hydrolysis. Its composition was confirmed using FTIR and 1 H NMR spectroscopy. API mud fluid loss reduction of polymer-FLR was about 10-fold lower than the blank. High temperature, high pressure fluid loss reduction of about 9-fold were achieved compared with the blank.