Self-healing agent for oil well cement and its preparation method and testing method

Abstract

The invention discloses a self-repair agent of oil well cement and relates to the field of oil well cement additives of drilling engineering. The self-repair agent comprises a framework material, a grafting functional monomer, a multifunctional group radiation sensitizer and a separant, wherein the framework material is one or more of methyl vinyl silicone rubber, butadiene rubber, isoprene rubber and nitrile rubber; the grafting functional monomer is one or more of vinyl acetate and methyl methacrylate; the multifunctional group radiation sensitizer is triethylene glycol dimethacrylate; and the separant is one or more of white carbon black, calcium stearate, KH-550 and KH-570. The invention also discloses a preparation method of the self-repair agent of oil well cement and a test method of the self-repair agent of oil well cement. The self-repair agent of oil well cement has the advantages of being automatically responsive to oil and gas, good in ability to repair, wide in application range, free of special construction demand and the like, and can meet the demand on self-repair ability of a well cementing cement sheath in a complex environment under the well.

Description

technical field [0001] The invention relates to the field of well cementing cement additives for drilling engineering, in particular to a self-repairing agent for oil well cement and a preparation method thereof. Background technique [0002] Oil and gas well cementing is to seal adjacent oil, gas and water layers and protect the downhole casing. After the cement slurry is solidified into stone, a vertical hydraulic isolation system is formed. Therefore, it must be scrapped during the entire life of the oil and gas well. After that, effective interlayer isolation can be realized. [0003] Oil and gas well cementing cement is a brittle material with congenital defects like building cement-based materials. During oil and gas well stimulation operations and long-term exploitation, under the combined effects of downhole pressure, temperature, formation load and other factors, the integrity of the cement sheath will be affected. Inevitably damaged, micro-cracks and micro-gaps wi...

AI Technical Summary

Problems solved by technology

At present, the existing cement sheath self-repair technologies include the following five categories: ① seepage and crystallization, which requires a water environment and has a slow reaction repair rate; Special heating process, cumbersome process; ③ Polymer solidification, high cost, no multiple repair ability; ④ Flexible crystal expansion, low expansion rate, insufficient repair ability; ⑤ Thermally reversible cross-linked polymer, complex construction process

Images