A kind of anti-swelling agent for acidification and preparation method thereof

Abstract

The invention relates to an acidizing anti-swelling agent and a preparation method thereof. The preparation method comprises the following steps of: feeding organic amine and epoxy chloropropane according to the molar ratio of (1:1)-(1:3), simultaneously adding 5-100% of solvent and 1-5% of catalyst according to the total weight of the organic amine and the epoxy chloropropane, stirring and heating to 10-100 DEG C, stopping reaction after carrying out backflow for 2-10 hours, thus obtaining a polyquaternium intermediate; and reacting thiocarbamide with the polyquaternium intermediate according to the molar ratio of (0.5:1)-(3:1) for 0.5-10 hours at the temperature of 10-100 DEG C, so as to obtain thiocarbamide-based polyquaternium product. The acidizing anti-swelling agent has anti-swelling and corrosion inhibition functions, the raw material sources are wide, the product is uniform and stable, has good economical efficiency and can be easily put into industrial production, the anti-swelling rate is higher than 80%, and the corrosion inhibition rate is higher than 50%. The acidizing anti-swelling agent is applied to anti-swelling construction of fracture acidizing of clay and has a structural formula shown in the specification.

Description

technical field [0001] The invention relates to an oilfield chemical agent used in the construction of petroleum and natural gas exploitation—clay anti-swelling agent, especially an acidizing clay anti-swelling agent with corrosion inhibition function and its preparation method, which is mainly used for water injection, acidification and well killing in the liquid. Background technique [0002] The formation often contains a certain amount of clay minerals, mainly kaolinite, montmorillonite, illite and chlorite. These clay minerals are mostly composed of silicon-oxygen tetrahedrons and aluminum-oxygen octahedrons, and the interlayer surfaces are all oxide layers, with weak bonding. When in contact with water, water can enter between the crystal layers, and the exchangeable cations on the surface of the crystal layers dissociate and diffuse in the water, forming a diffuse electric double layer. When clay encounters water or water-based substances in the process of water inj...

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Problems solved by technology

[0013] The clay anti-swelling agent and acidifying clay anti-swelling agent reported in the above documents or patents can effectively inhibit clay swelling and migration, or play an important role in acidifying anti-swelling and water injection anti-swelling, but due to organic cationic polymers in the past The anti-swelling agent only has the function of anti-swelling, but does not have the ability to inhibit corrosion. Therefore, it is necessary to add an acidizing corrosion inhibitor in the acidizing operation, so that there are many types of injection agents in the oilfield, and the compatibility between the injection agents is uneven. The incompatibility of the agent will lead to the decline of the use effect and even the pollution of the formation

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