Filtrate reducer for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection, drilling fluid, and uses thereof

摘要

A filtrate reducer for temperature-resistant calcium-resistant water-based drilling fluid used in oil and gas reservoir protection, a drilling fluid, and uses of the filtrate reducer and the drilling fluid are described. The filtrate reducer contains structural units represented by formulas (1), (2), and (3) herein. The water-based drilling fluid contains the filtrate reducer, and exhibits good inhibitive, rheological, filtrate reducing, and reservoir protection performance when it is applied in the drilling process in a high-temperature high-calcium deep salt-gypsum formation.