A non-acid-soluble high-strength channeling and leakage plugging agent and its preparation method

Abstract

The invention discloses a non-acid solution high-strength plugging agent, and a preparation method thereof. The non-acid solution high-strength plugging agent is composed of, by weight, 55 to 60 parts of a curing agent, 3 to 5 parts of an activity improving agent, 2 to 3 parts of a mutual solvent, 0.8 to 1 part of a coupling agent, 1 to 2 parts of furan resin, and 1.5 to 3 parts of a dispersant. The non-acid solution high-strength plugging agent is mixed with an appropriate amount water so as to obtain a slurry; water segregation rate is less than 0.5%; breakthrough pressure gradient is larger than 1.0MPa / cm; stemming ratio is larger than 99.9%; and acid corrosion ratio is less than 1%. The non-acid solution high-strength plugging agent both possesses high strength and acid corrosion ratio, and is capable of satisfying high pressure bearing requirements of oil-water wells after plugging. Corrosion ratio of acidic mediums, such as mud acid, hydrochloric acid, nitric acid, and acetic acid, which are commonly used in oil-water well acidizing plugging removal on the non-acid solution high-strength plugging agent is low; acid resistance of the non-acid solution high-strength plugging agent is relatively high; and a technical problem that damage efficacy lose of plugged parts is easily caused by acidic fluids in oil-water well acidizing operation is solved.

Description

technical field [0001] The invention belongs to the technical field of oilfield chemical plugging, and in particular relates to a non-acid-soluble high-strength plugging agent and a preparation method thereof. Background technique [0002] Under normal circumstances, after long-term development and production, oilfields generally enter a period of high water-cut production. Various measures to increase production and injection are frequent, and the downhole conditions are getting worse year by year. Channeling and casing leaks are injected into non-target layers, resulting in ineffective water injection, or formation water flows back into the production layer along channeling outside the pipe and casing leaks, resulting in flooding of oil wells, seriously affecting oilfield production. In order to solve the above problems, oilfields generally use high-strength materials such as ultra-fine oil well cement and modified ultra-fine oil well cement to seal the channeling outside ...

AI Technical Summary

Problems solved by technology

[0004] However, in the actual oilfield development and production process, soil acid, hydrochloric acid, nitric acid, acetic acid, citric acid and other acidic media are often used to acidify or acid fracturing the reservoir to increase production and injection measures; It generally contains a certain amount of limestone and metal oxides, and calcium hydroxide is produced during the hydration, condensation and solidification process, resulting in poor acid corrosion resistance of the cured product. For example, the acid dissolution rate of ultra-fine oil well cement is about 20%. Modified oil well cement The acid corrosion rate of cement materials is more than 30%, and some are even as high as 90%.

Therefore, when using the existing channeling and plugging agent to seal the channeling outside the pipe or the leakage part of the casing, when the acidification or acid fracturing measures are carried out, the sealing part is often affected by the acidic fluid erosion, resulting in the failure of the channeling and plugging measures.

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