Active anti-swelling and swelling-shrinkage agent and preparation method and application thereof

Abstract

The invention provides an active anti-swelling and swelling-shrinkage agent and a preparation method and application thereof. Water is added to a closed container, cation modified starch, dimethyl diallyl ammonium chloride and epoxy chloropropane are sequentially added, a reaction is conducted for 3 h under the 100-DEG-C constant-temperature condition, after the container is cooled to 40 DEG C, ethidene diamine, potassium peroxodisulfate and urea are added, the mixture is stirred to be uniform, and raw materials are obtained; the raw materials are taken, potassium chloride or ammonium chloride is added, 1-2 parts of fluorinated surfactant is added, the balance is water, the mixture is stirred to be uniform, and a product is obtained; the product is diluted into a solution with the mass concentration of 2-5%, and the solution is injected into an oil layer to be used. The active anti-swelling and swelling-shrinkage agent has an obvious anti-swelling effect, water injection efficiency is improved, and the water injection amount meets injection allocation requirements.

Description

Technical field [0001] The invention relates to the technical field of oil field development, in particular to an active anti-swelling agent for protecting oil reservoirs, reducing pressure and removing plugging, and a preparation method and application thereof. Background technique [0002] With the development of oilfields, the application of anti-swelling agents has become more and more extensive, and there are more and more types. According to different structures and different chemicals used, the development in this area can be roughly divided into three stages:( 1) From the 1950s to the late 1960s, inorganic salts were mainly used to stabilize soil; (2) In the 1970s, cationic surfactants and inorganic polynuclear polymers were mainly used to stabilize clay; (3) After the 1980s, the use of cationic Research and experiment on organic polymer stabilized clay. [0003] Most of the existing anti-swelling agents use polyhydroxy cationic polymers alone. If the inorganic stabilizer ...

AI Technical Summary

Problems solved by technology

[0004] The limitation of existing anti-swelling agents is that most of them have no shrinkage-swelling effect, and additional operational measures need to be taken for the water-sensitive damage that has already occurred, which not only increases new reservoir damage but also reduces economic benefits

Although some inventions have shrinkage and expansion effects, they have no surface activity. When used in low-permeability reservoirs or reservoirs with water-locking damage, surfactants need to be injected at the same time, which increases operating costs and workload.

Although the traditional surface active anti-swelling agent has surface activity, the first problem is that it does not have shrinkage and swelling effect, and the second problem is that it will cause wetting reversal, so it cannot be used in oil well operations