WATER-BASED DRILLING FLUID FOR PROTECTING FRACTURED RESERVOIRS, AND PREPARATION METHOD AND USE THEREOF

摘要

The present invention relates to the technical field of petroleum drilling, and discloses a water-based drilling fluid for protecting fractured reservoirs and preparation method and use thereof. The drilling fluid includes: bentonite, a tackifier, a diluent, a filtrate reducer, an anti-collapse agent, a reservoir protectant composition, a lubricant, and water, wherein, the reservoir protectant composition comprises at least one of a polymer elastic granule, a synthetic fiber and a film former; the polymer elastic granule comprises an intermediate product, an alkali, a salt, and water in specific contents; the intermediate product is prepared from raw materials including acrylamide, a cationic monomer, a cross-linker, an initiator, a toughener, and water in specific contents. The drilling fluid provided in the present invention has a temperature-resistant property up to 200° C. or above, achieves a high temporary plugging success ratio, has a unidirectional plugging characteristic, and attains an outstanding reservoir protection effect.