Fe<sub>3</sub>O<sub>4</sub>/poly (acrylic acid) nanoparticles as modifiers for improving rheological and filtration properties of water-based drilling fluids

<p>Drilling fluid is a vital element and is often regarded as the “blood” in the oil industry. Although traditional oil-based drilling fluids have advantages in some harsh cases, the high cost and environmental pollution faced with them limit its application. Water-based drilling fluids (WBDFs) with environmental friendly, low cost, and high performance are important for drilling engineering to solve the problems of low efficiency and wellbore instability caused by poor rheological properties and large filtration loss in drilling operations. In this paper, Fe<sub>3</sub>O<sub>4</sub> nanoparticles modified by poly (acrylic acid) (PAA) through 3-(trimethoxysilyl) proryl methacrylate (TMSPMA) were introduced into WBDFs for enhancing their rheological and plugging performance. Rheological tests indicated that the consistency coefficient (K) of the Fe<sub>3</sub>O<sub>4</sub>/PAA nanoparticles/WBDFs decreased at a higher concentration. Incorporated nanoparticles with a concentration of 0.05 wt %, the WBDFs will exhibit good shear-thinning behavior. The results showed that the best performance for Fe<sub>3</sub>O<sub>4</sub>/PAA nanoparticles being as a filtration additive in WBDFs was achieved at concentration as low as 0.1 wt %. These results demonstrated that Fe<sub>3</sub>O<sub>4</sub>/PAA nanoparticles are effective additives for WBDFs.</p>