Anti-swelling shrinking agent

Abstract

The invention discloses an anti-swelling shrinking agent which is an ethylene diamine diacetate solution. This solution avoids the adverse factor that traditionally bridge blinding occurs in capturing of large cations, also overcomes the adverse factor that small cations are low in charge density and short in effective life, has a good clay stabilizing function and is also well capable of shrinking swelled clay. The anti-swelling shrinking agent composited by adding magnesium chloride and / or amino trimethylene phosphonic acid has better anti-swelling and shrinking effects. A liquid of the anti-swelling shrinking agent is clear and crystal, has anti-swelling agent higher than 95% and shrinking rate higher than 35%, and is applicable to preventing and solving the clay swelling problem caused in oilfield development.

Description

technical field [0001] The invention belongs to the technical field of clay anti-expansion, and in particular relates to an anti-expansion and contraction agent, which is used to solve the problem of clay expansion caused by oilfield development. Background technique [0002] In oilfield development, drilling, cementing, perforating, fracturing, acidizing, and water injection operations all have foreign fluids entering the oil layer. Due to the inconsistency between the foreign fluid and formation water, the original balance in the formation is destroyed. Clay minerals Water absorption swelling, dispersion, migration occurs, the effective pores of the formation become smaller, and even the throats are blocked, resulting in a decrease in the permeability of the oil layer, which seriously affects the oil production of oil production wells and water injection of water injection wells. [0003] The research on domestic clay anti-swelling agent can be divided into three stages. F...

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Problems solved by technology

[0006] The purpose of the present invention is to provide an anti-swelling and shrinking agent, which is used to solve the problem of clay swelling caused by oil field development, and solves the problem that the existing anti-swelling agent has poor anti-swelling effect and does not have the function of shrinking and swelling the expanded clay.

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