Temperature-resistant calcium-resistant polymer filtrate reducer for ultra-deep well and preparation method of temperature-resistant calcium-resistant polymer filtrate reducer

The invention discloses a temperature-resistant and calcium-resistant polymer filtrate reducer for an ultra-deep well and a preparation method of the temperature-resistant and calcium-resistant polymer filtrate reducer. The preparation method sequentially comprises the following steps: adding deionized water and triallyl phosphate into a reactor; filling nitrogen, and dissolving dibenzoyl peroxide in water to serve as a primary polymerization initiator; adding the mixture into a reactor, and carrying out primary polymerization reaction; dissolving sodium persulfate and ammonium persulfate in water to serve as a secondary polymerization initiator; adding a secondary polymerization initiator into the reactor, and then adding dimethyl diallyl ammonium chloride to continue a secondary polymerization reaction; the preparation method comprises the following steps: dissolving 2-acrylamido-2-methylpropanesulfonic acid, acrylamide, styrene and sodium methallyl sulfonate in water; adding into a reactor, and carrying ou