Preparation and performance evaluation of heat resistant and salt resistant anionic fluid loss reducer for water-based drilling fluid

In this investigation, a new micro-crosslinked anionic polymer resistant to elevated temperature and high salinity, PKDASN, was synthesized using 3-chloropropyltriethoxysilane (KMB703), N, N-Dimethylacrylamide (DMAM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), N-vinyl caprolactam (NVCL), and sodium (4-vinyl phenyl)methanesulfonate (SVM) employing free radical polymerization in a water-based solution. The structure of PKDASN was analyzed using Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy, while its microstructure was analyzed using scanning electron microscopy. Thermogravimetric analysis showed that the pyrolysis temperature of PKDASN was above 294 degrees C. Adding KMB703 enables the polymer to form a dense and stable spatial network. This intensified polymer network could interact with bentonite via intermolecular force and Coulomb force and form a dual grid structure, which presents impressive stability and control of filtration in saltwater. This is mainly achieved through creating a "silane coupling layer" on the particle surface by KMB703, which facilitates the crosslinking and aggregation of the polymer, thereby reinforcing the polymer's framework. This implies that under high-temperature conditions of 230 degrees C, 3 wt% PKDASN can improve the filtration effectiveness of drilling fluids and exhibit resistance to 15 wt% NaCl contamination. American Petroleum Institute filtration(FLAPI) and High temperature and high pressure filtration(FLHTHP) values were 4.6 and 23.0 mL, respectively. Therefore, this investigation provides a novel approach to utilizing the designated silane agent for the advancement of filtration loss additives in drilling fluids resistant to elevated temperature and high salinity. A novel micro-crosslinked anionic polymer resistant to 230 degrees C and 15 wt% NaCl, PKDASN, was synthesized using 3-chloropropyltriethoxysilane, N, N-dimethyl acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, N-vinyl caprolactam, and sodium (4-vinyl phenyl)methanesulfonate employing free radical polymerization. The polymer effectively adsorbed on the surface of bentonite particles through strong electrostatic interactions and hydrogen bonding, forming both a protective layer and network, thus reducing filtration. image