High-temperature-resistant soilless-phase calcium-based drilling fluid as well as preparation method and application thereof

The invention belongs to the technical field of oilfield chemical drilling fluids, and discloses a high-temperature-resistant soilless-phase calcium-based drilling fluid as well as a preparation method and application thereof. The drilling fluid contains one or more of water, calcium chloride, an anti-calcium filtrate reducer and an anti-calcium tackifier, and relative to 100 mL of water, the content of the calcium chloride is 1-35 parts by weight; the anti-calcium filtrate reducer is modified starch and/or sulfonate copolymer; the anti-calcium tackifier comprises one or more of modified xanthan gum, a vinyl polymer and an acrylamide copolymer. The soilless-phase calcium-based drilling fluid has the temperature resistance of 150 DEG C and better suspension stability under the condition of high-concentration calcium chloride content, and the problem that the filter loss of the drilling fluid is difficult to control under the conditions of high-concentration calcium chloride and high temperature is solved by th