The invention relates to a
coal gangue-based well cementation material and a preparation method thereof, and belongs to the technical field of oil and gas well cementation
engineering materials. The material is composed of
coal gangue-based high-activity
powder,
magnesium hydroxide,
calcium hydroxide, a reinforcing agent and a well cementation admixture. Wherein the
coal gangue-based high-activity
powder is prepared by calcining and
grinding coal gangue, limestone and siliceous
tailings according to a specific ratio. By optimizing the material composition and adding the
magnesium-based component, the formation of a
stable phase tobermorite in a high-temperature environment (more than or equal to 200 DEG C) is effectively promoted, so that the
well cementing material keeps stable mechanical properties and volume stability at high temperature. Experiments show that the
compressive strength of the material is still kept at 50 MPa or above after the material is aged at 250 DEG C for 28 days, strength decline is avoided, and the material is far superior to a traditional high-temperature
well cementing material. Meanwhile, high-value utilization of
solid waste resources such as
coal gangue is achieved, and remarkable economic and environmental benefits are achieved.