Temperature-sensitive swelling microcapsule anti-gas-channeling agent and anti-gas-channeling cement slurry system

Abstract

The present invention discloses a temperature-sensitive swelling microcapsule anti-gas-channeling agent and an anti-gas-channeling cement slurry system. The temperature-sensitive expansion microcapsule anti-gas-channeling agent preparation method comprises: adding 3-4 parts of acrylonitrile, 0.4-0.5 part of methyl acrylate and 2-3 parts of methyl methacrylate to a beaker, adding 1-2 parts of lauroyl peroxide as an initiator, 10-30 parts of a low boiling point solvent as a foaming agent, and 0.1-0.2 part of 1, 4-butanediol dimethacrylate as a cross-linking agent, carrying out stirring dissolving, transferring into a glass reaction kettle, adding 20-25 parts of nano-silica as a dispersant and 300-350 parts of deionized water, carrying out a constant temperature water bath reaction for 20-24 h at a temperature of 60-70 DEG C under nitrogen protection, cooling, washing, and drying. The anti-gas-channeling cement slurry system comprises 100 parts of oil well cement, 1.5-2 parts of a fluid loss additive, 2-3 parts of a dispersant, 0.1-1 part of an anti-gas-channeling agent, 0-3 parts of a retarder, 0.2 part of a defoamer, 0-50 parts of a density adjuster, and 44 parts of water. According to the present invention, with the temperature-sensitive expansion microcapsule anti-gas-channeling agent and the anti-gas-channeling cement slurry system, the cement stone volume shrinkage can be effectively made up, the stratum fluid can be sealed, the channeling can be prevented, the occurrence of the annulus pressure phenomenon can be prevented, and the service life of the oil well can be prolonged.

Description

technical field [0001] The invention relates to a temperature-sensitive expansion microcapsule anti-gas channeling agent in the field of well cementing slurry and its application in preparing an anti-gas channeling cement slurry system. Background technique [0002] The volume shrinkage in the cement hydration process of oil wells is the main reason for the poor bonding quality of the cement annulus interface, the channeling of oil, gas and water in the well, the pollution of the oil layer, and the pressure in the annular space after production. This has not yet been well resolved. Cementing technical problems. The volume shrinkage of the cement slurry in the plastic state will reduce the pore pressure of the cement slurry column (gelation weight loss), and the volume shrinkage after solidification will cause problems in the cement sheath, the formation and the casing, forming micro-gap, 95% of the shrinkage The volume shrinkage of the cement slurry is 2.6%-5.0% of the tota...

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Problems solved by technology

But existing anti-gas channeling agent has the following problems: gas-generating class anti-gas-channeling agent (such as KQ series), has the uncontrollable defective of gas generation; agent and preparation method thereof CN103834374A) the addition amount is relatively large, and demulsification will also occur when the storage temperature is low, which affects the effect of preventing gas channeling; polyvinyl alcohol cannot be used in high-temperature and high-salt environments; (Zheng Guosheng et al. Research and Application of Plastic Expansion Anti-Channeling Cement Slurry System. [J]. Petroleum Drilling and Production Technology, 2013,35(5):52-55) The main component is calcium sulfate, and the main disadvantage is insufficient expansion performance , expansion time and expansion well depth are uncontrollable

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