Clay anti-swelling agent

Abstract

The invention discloses a clay anti-swelling agent mainly including the following three substances: ammonium salt, polyols and potassium formate, wherein the mass percentage of the ammonium salt is 20-60.0%, the mass percentage of the polyols is 2.0-30.0% and the mass percentage of the potassium formate is 2.0-10%, and the balanced being water. The clay anti-swelling agent is excellent in temperature resistance, is excellent in anti-swelling property and is suitable for low-permeability reservoirs.

Description

technical field [0001] The patent belongs to the technical field of petroleum engineering and relates to a clay antiswelling agent. Background technique [0002] Clay minerals widely exist in oil reservoirs, and 97% of the oil reservoirs in the world contain clay minerals to varying degrees. Usually when the reservoir contains 5% to 20% clay, it is considered to be an oil layer with higher clay content. If improper measures are taken during the development process, clay minerals will expand, disperse, and migrate, thereby blocking the throat of the formation pore structure, reducing the permeability of the formation, and causing formation damage, especially for low-permeability reservoirs. In order to reduce the damage to the reservoir, clay stabilizers are often added in oilfields to improve the hydration expansion and dispersion migration of clay. [0003] According to different chemical structures, clay stabilizers can be divided into: inorganic salts, inorganic multi-c...

AI Technical Summary

Problems solved by technology

Most of the organoclay stabilizers currently used are straight-chain type. When the molecular weight is large, it is easy to block the pores of medium and low permeability formations. When the molecular weight is small, the anti-swelling effect is poor and the validity period is short.

[0007] Although the existing clay stabilizers have the ability of temperature resistance and clay stabilization to a certain extent, they have deficiencies in high temperature resistance, salt resistance, long-term performance and use in medium and low permeability reservoirs

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