Chelating augmented injection agent for water injection well and preparation method thereof

Abstract

The invention provides a chelating augmented injection agent for a water injection well and a preparation method of the chelating augmented injection agent. The chelating augmented injection agent isprepared from the following raw materials in percentage by mass: 26%-35% of an amino cartankylic acid chelating agent, 10%-14% of a penetrating agent, 12%-16% of an ampholytic surfactant, 14%-18% of anonionic surfactant, 18%-22% of a mutual solvent and the balance of water. The chelating augmented injection agent for the water injection well can be used for treating water injection wells with poor injection water quality, stratum scaling and high residual oil saturation and water injection wells with long-term produced water reinjection, resulting in high water injection pressure and seriousunder-injection of the water injection wells or long-term water injection under-injection wells. The crude oil stripped from the rock surface is dispersed into small oil drops under the action of thesurfactant, and the flowing capacity of the crude oil passing through the throat is improved, so that the reservoir permeability is improved, the stratum is dredged, the oil well liquid supply capacity is recovered, and normal water injection of a water well is realized.

Description

technical field [0001] The invention belongs to the field of low-permeability oil fields, and in particular relates to a chelating injection enhancing agent for water injection wells and a preparation method thereof. Background technique [0002] After the oil field is put into water injection development, because the clay minerals that make up the oil layer expand when exposed to water, and the injected water has a high content of scaling ions, after injection into the formation, as the temperature and pressure change, it is easy to scale in the formation and the residual oil saturation is relatively high. High water injection wells and long-term produced water reinjection cause oil pollution blockage, resulting in high water injection pressure and insufficient water injection volume, which can not be properly allocated, reducing the oil production rate of the oil field, and becoming a major problem restricting the long-term stable production of the oil field. [0003] The ...

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Problems solved by technology

[0004] In order to overcome the problem that the stratum that has been scaled and clay swelled cannot be effectively treated, the present invention provides a chelating depressurization injection booster for water injection wells and a preparation method thereof. The present invention effectively reduces the viscosity of crude oil on the rock surface. Adhesion, change the wettability of rock surface, reduce seepage resistance

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