High temperature and salt resistant filtrate reducer ATJQ-4 is a white powder polymer product, which is suitable for all kinds of fresh water, salt water and seawater drilling fluid systems. lts temperature resistance is up to 210 'C. ATJQ-4 can be well used in combination with other water-based drilling fluid treatment agents often used in the industry. Practice has proved that, It is a high-quality high-temperature and high-pressure filtration control chemical agent for water-based drilling and completion fluid system.