Clay swelling shrinkage agent for oil field and preparation method of clay swelling shrinkage agent

Abstract

The invention discloses a clay swelling shrinkage agent for an oil field and a preparation method of the clay swelling shrinkage agent. The clay swelling shrinkage agent is prepared from the following components of: polyethylene polyamine, benzyl chloride, sodium hydroxide, n-butyl alcohol and an organic metal catalyst. In the novel material for synthesizing the clay swelling shrinkage agent, the amido strongly adsorbs the clay particles, and the long chain with the rigid group enables the swelling clay to be dehydrated and shrunk by winding, wrapping and fixing the clay particles and strongly compressing the double electric layers of the clay particles. Due to the fact that the long chain is of a twisted rigid structure, a twisted comb-shaped structure is formed, the fluid scouring resistance is greatly improved, and meanwhile the use concentration of the product is reduced to a certain degree. After being injected, the agent can be quickly electrically adsorbed with the clay particles, the double electric layers of the clay are strongly compressed, the clay particles are shrunk, the porosity of an oil layer is increased, an oil production throat is recovered and expanded, and the aim of increasing the yield and the injection is achieved; the anti-swelling rate can reach 90%, and the swelling shrinkage rate can reach 35%; a rock core dynamic water injection experiment is simulated, and the experiment lasts for 150 days, the agent is effective, and particle migration is avoided.

Description

technical field [0001] The invention relates to a special product in the technical field of water injection operation in the process of oil recovery in an oil field. Specifically, it relates to a clay expansion agent for oil fields and a preparation method thereof. Background technique [0002] In the process of oilfield exploration and development, clay in shale water-sensitive formations swells with water, resulting in blockage of low-permeability oil production throats, resulting in the following problems: due to blockage of oil production throats, oil cannot be recovered, and formation pressure cannot be balanced by water injection. The injection requirements are met or the injection cannot be made at all, thereby greatly reducing the oil recovery efficiency. [0003] The products currently on the market are all non-rigid structural products using small organic cations generated by substitution of dimethylamine, trimethylamine and unsaturated epoxy groups and alkenyl gr...

AI Technical Summary

Problems solved by technology

[0002] In the process of oilfield exploration and development, clay in shale water-sensitive formations swells with water, resulting in blockage of low-permeability oil production throats, resulting in the following problems: due to blockage of oil production throats, oil cannot be recovered, and formation pressure cannot be balanced by water injection. Injection requirements are met or cannot be injected at all, thus greatly reducing oil recovery efficiency

[0003] The products currently on the market are all non-rigid structural products using small organic cations generated by substitution of dimethylamine, trimethylamine and unsaturated epoxy groups and alkenyl groups, or large cations polymerized by small cations with unsaturated bonds. In order to reduce costs, this type of product is compounded with materials such as inorganic salts such as ammonium chloride and potassium chloride to varying degrees. Insufficiency such as secondary blockage caused by the transfer (it will lose its effect in 30 days or less)

At the same time, due to the strong volatility and low flash point of small molecular amines, it is a serious challenge to safety and environmental protection during production.