▎ 摘　　要

NOVELTY - High temperature and high density water-based drilling fluid comprises water, bentonite, tackifier, alkalinity regulator, shale inhibition stabilizer, high temperature resistant and environmentally friendly fluid loss agent, shale plugging agent, high temperature resistant and environmentally friendly lubricant, inorganic salt and weighting material, where e.g. high temperature resistant and environmentally friendly fluid loss agent is prepared by mixing 2-acrylamido-2-methylpropanesulfonic acid, N,N-dimethacrylamide, N-vinylpyrrolidone, natural polyphenol plant extract, initiator, inorganic alkaline substance and water, and carrying out copolymerization reaction; and high temperature resistant and environmentally friendly lubricant is prepared by mixing pine oil fatty acid, diethylenetriamine and water for amidation reaction to obtain an amidation product, then mixing amidation product with oleic acid triethanolamine and carrying out polymerization etherification reaction. USE - The drilling fluid is useful in the field of shale well petroleum and natural gas drilling (claimed). ADVANTAGE - The drilling fluid: has excellent rheological properties and biodegradability, strong inhibition, fluid loss control performance, plugging performance and lubricating performance, and can keep the wellbore of shale formations stable for a long time and reduce drilling friction. DETAILED DESCRIPTION - High temperature and high density water-based drilling fluid comprises 100 ml water, 1-2 g bentonite, 0.2-1 g tackifier, 0.3-0.6 g alkalinity regulator, 20-40 g shale inhibition stabilizer, 3-4 g high temperature resistant and environmentally friendly fluid loss agent, 3-5 g shale plugging agent, 2-4 g high temperature resistant and environmentally friendly lubricant, 7-15 g inorganic salt and weighting material, where weight of the weighting material makes the density of the high-temperature high-density water-based drilling fluid 1.8-2.2 g/cm3; high temperature resistant and environmentally friendly fluid loss agent is prepared by mixing 2-acrylamido-2-methylpropanesulfonic acid, N,N-dimethacrylamide, N-vinylpyrrolidone, natural polyphenol plant extract, initiator, inorganic alkaline substance and water, and carrying out copolymerization reaction; and high temperature resistant and environmentally friendly lubricant is prepared by mixing pine oil fatty acid, diethylenetriamine and water for amidation reaction to obtain an amidation product, then mixing amidation product with oleic acid triethanolamine and carrying out polymerization etherification reaction to obtain polymerization etherification product, then mixing polyetherification product, nano-graphite and alcohol.