Blocking removing solution applied to blocking removal of sandstones of water injection well and preparation method of blocking removing solution

Abstract

The invention discloses a blocking removing solution applied to blocking removal of sandstones of a water injection well and a preparation method of the blocking removing solution. The blocking removing solution is prepared from the following components in parts by weight: 30 to 50 parts of industrial hydrochloric acid (with the mass concentration of 30 percent), 0 to 15 parts of fluorosilicic acid (with the mass concentration of 40 percent), 10 to 20 parts of a multifunctional molecule inclusion agent and the balance of water; the preparation method comprises the following steps: firstly, adding the water, the industrial hydrochloric acid (with the mass concentration of 30 percent), the fluorosilicic acid (with the mass concentration of 40 percent) and the multifunctional molecule inclusion agent in sequence according to the ratio of all the components of the blocking removing solution applied to the blocking removal of the sandstones of the water injection well, uniformly mixing andcompounding to prepare the blocking removing solution. According to the blocking removing solution applied to the blocking removal of the sandstones of the water injection well and the preparation method of the blocking removing solution, disclosed by the invention, can meet the requirements of efficient corrosion of inorganic scales including calcium and magnesium scales, clay grains and the like; the blocking removing solution also has good speed slowing performance and realizes deep blocking removal.

Description

technical field [0001] The invention relates to the technical field of petroleum exploitation, in particular to a plugging removal fluid which is applied to sandstone plugging removal in water injection wells and has a retarding effect and a preparation method thereof. Background technique [0002] In the middle and later stages of water injection well development, due to the gradual increase of water injection pressure, the injection requirements cannot be met. Conventional acidification is generally used for treatment, but the following problems exist: [0003] (1) Excessive acidification causes damage to the rock skeleton, and the solid phase particles are easily stripped and migrated, causing secondary damage to the formation; [0004] (2) Repeated acidification makes the acidification period shorter; [0005] (3) The reaction rate of acid liquid is fast, and the ability to remove plugs in deep parts is poor. [0006] Therefore, how to design a plug-removing fluid that...

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Problems solved by technology

[0003] (1) Excessive acidification causes damage to the rock skeleton, and the solid phase particles are easily stripped and migrated, causing secondary damage to the formation;

[0004] (2) Repeated acidification makes the acidification period shorter;

[0005] (3) The reaction rate of acid liquid is fast, and the ability to remove plugs in deep parts is poor

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