Preparation method and application of high-density solid-free weighting agent

The invention provides a preparation method and application of a high-density solid-free weighting agent, and the preparation method comprises the following steps: S1, dissolving a first soluble weighting material and a second soluble weighting material in a solvent, preferably water, to obtain a solution A; s2, adding a pH regulator into the solution A to obtain a solution B with the pH value of 8-9.5; s3, performing first heat treatment on the solution B to obtain a solution C; s4, cooling the solution C, and adding a tackifier, a deoxidant and a chelating agent into the cooled solution C to obtain a solution D; s5, carrying out second heat treatment on the solution D to obtain a solution E; s6, heating the solution E to remove a liquid phase to obtain a solid phase; and S7, sequentially drying and granulating the solid phase to obtain the high-density solid-free weighting agent. The density of the obtained weighting agent can reach 1.715 g/cm < 3 >; the temperature resistance reaches 180 DEG C, the shieldi