Decompression and augmented injection agent for water injection well of low-permeability reservoir and preparation method thereof

Abstract

The invention belongs to the technical field of oil and gas fieldchemistry and discloses a decompression and augmented injection agent for a water injection well of a low-permeability reservoir. The decompression and augmented injection agent comprises the following components by weight percent: 30%-35% of bisoctyl dimethyl ammonium chloride, 3%-7% of a fluorocarbon surfactant, 3%-5% of a non-ionic surface active agent, 5%-10% of ethylene diamine tetra (methylene phosphonic acid) sodium, 2%-5% of dimethyl ketoxime and 38-57% of water. The invention also provides a preparation method for the decompression and augmented injection agent. The decompression and augmented injection agent takes water solution as a transmitting medium and forms an ultrathin molecular film by depositing on the rock surface; the decompression and augmented injection agent has a function of changing the core wettability and clay anti-swelling property; the decompression and augmented injection agent also has multiple effects of corrosion inhibition, scale inhibition, sterilization, and the like, can effectively prevent the influence on the formation porosity caused by injected water corrosion products, scaling, bacteria, and the like, and can greatly promote the water injection effect of the water injection well of the low permeability reservoir. Being as a novel decompression and augmented injection agent with excellent decompression and augmented injection effects, the decompression and augmented injection agent has wide market prospect.

Description

technical field [0001] The invention belongs to the technical field of oil and gas field chemistry, and in particular relates to a pressure-reducing injection-increasing agent for low-permeability reservoir water injection wells, which is mainly used in low-permeability oil fields and water injection wells with high water injection pressure to reduce water injection pressure and increase water injection volume. Background technique [0002] During the development of low-permeability oil and gas fields, water injection is difficult and high water injection pressure is a common problem. By changing the wettability of the rock surface, increasing the permeability of the water phase, reducing the injection pressure, and increasing the amount of water injected are generally pursued in the development of low-permeability reservoirs. In low-permeability reservoirs, chemical agents are used to improve rock interface wettability and inhibit clay expansion and migration, so as to achi...

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Problems solved by technology

[0005] The technical problem to be solved by the present invention: the existing conventional depressurizing and increasing injection agents have single effect and uneven effects, and poor applicability, which provides an opportunity for developing a new type of depressurizing and increasing injection agent for water injection wells with high efficiency and low permeability

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