METHOD FOR OBTAINING CO-SENSITIVE GEL MATERIAL USED FOR SELF-REPAIRING MICROCRACKS IN CEMENT STONE Russian patent published in 2024 - IPC C04B40/00 C04B28/00 C09K8/493 C09K8/467 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to a method for self-healing microcracks in cement stone during cementing of wells in oil and gas fields, in particular to a method for producing a CO₂-sensitive gel material used for self-healing microcracks in cement stone. The method for producing a gel material sensitive to CO₂ used for self-healing of microcracks in cement stone includes the following steps: (1) uniformly mixing the organic monomer with the CO₂-sensitive monomer and dissolving them in deionized water to obtain a solution with pH value controlled by sodium hydroxide in the range of 6~8, the organic monomer being an organic acid containing an unsaturated group, and the CO₂-sensitive monomer being a tertiary amine substance containing an unsaturated group; (2) adding an initiator and a cross-linking agent to the solution, then increasing the temperature of the reaction system to 55~80°C and leaving it to react for 6~10 hours; (3) breaking the product into particles, which are then immersed in deionized water to remove unreacted monomer to obtain gel particles, and then immersing the gel particles in a metal chloride solution, soaking them for 20~30 hours so that double cross-linking occurs; (4) immersing the gel particles in deionized water to remove non-crosslinked metal chloride; and (5) filtering, drying and grinding the product obtained in step (4).

EFFECT: self-removal of microcracks in the cement stone when cementing wells due to its good strength and sensitivity to CO₂, which will ensure safety of the structure when cementing wells.

5 cl, 2 dwg, 1 tbl