Impact of low‐molecular‐weight poly(4‐styrenesulfonic acid‐co‐maleic acid) sodium salt on filtration and rheological parameters of nanoparticles‐enhanced drilling fluid

Abstract

Abstract The thermally stable drilling fluid is the need of the oil and gas industry. The impetus for producing appropriate drilling fluid lies in the addition of novel polymeric additives. The addition of polymer improves the filtration and rheological properties of the drilling fluid. Poly(4‐styrene sulfonic acid‐co‐maleic acid) sodium salt (PSSM), a low‐molecular‐weight polymer, exhibited filtration and rheological control in the water‐based drilling fluid system containing bentonite and hydroxyethyl cellulose. The polymer was characterized using a thermogravimetric technique and found to be stable up to 250°C. The optimum concentration for PSSM is 1.0 w/v% as fluid loss from the drilling fluid reduced by ~63% on addition of 1.0 w/v% PSSM and by ~75% on addition of 2.0 w/v% PSSM. The addition of CuO and ZnO nanoparticles (NPs) to the PSSM‐induced drilling fluid further improved the rheological and filtration properties at elevated temperature. The thermal aging studies confirm the stability of the drilling mud up to 110°C in the presence of NPs. The addition of PSSM and NPs significantly improved the mud performance due to PSSM interactions with NPs and other mud additives even at high temperatures which suggests the applicability of these mud formulations for challenging high‐temperature wells.