Degradable quick plugging agent

Abstract

The invention relates to a degradable quick plugging agent. The degradable quick plugging agent is composed of three parts, wherein a base solution A is prepared by graft copolymerization of sodium carboxymethylcellulose and acrylamide; a cross-linking agent B is composed of inorganic cross-linking agents CrCl3, FeCl2 and borax; and a base solution C is a gel breaker with a degradation action and composed of H2O2 and NaOH solution. Due to a solid hydrogel generated by the reaction between the base solution A and the cross-linking agent B, the swelling property and retention property of a plugging slurry are enhanced, the success rate of plugging is increased, and the repeatability of plugging is reduced. The plugging agent has high hardness in a working state and can be applied to high-pressure places; when plugging is not needed any more, the gel breaker base solution C can permeate in a plugging gel, and a plugging main body, namely the solid hydrogel, can be decomposed and broken in a period of time and is removed further.

Description

technical field [0001] The present invention belongs to the field of materials. In particular, it relates to a degradable rapid leakage plugging agent. Background technique [0002] All the rapid plugging agents in the current market are powdery substances composed of hard block high-strength cement clinker, chemical admixtures, binders and various auxiliary materials, and some are polyurethane substances. The disadvantage is that it has a certain degree of hydrophobicity, and long-term use will destroy the reaction system, causing secondary water leakage, slow reaction speed, and troublesome post-processing. And some inorganic gel material plugging technologies, such as repeated extrusion cement plugging method, this is a conventional main repair method, used very early, plugging agent is cheap, strong, and can be applied to various temperatures, so far It is still widely used, but it is also a difficult restoration technique. This technology has the following problems: ...

AI Technical Summary

Problems solved by technology

[0002] All the rapid leak stoppage agents in the current market are powdery substances composed of hard block high-strength cement clinker, chemical admixtures, binders and various auxiliary materials. There are also some polyurethane substances. The disadvantage of this type of plugging agent is that it has certain hydrophobicity. Long-term use will destroy the reaction system, resulting in secondary water leakage and slow reaction speed, which is troublesome for post-processing.

And some inorganic gel material plugging technology, such as repeated extrusion cement plugging method, this is a conventional main repair method, used very early, plugging agent is cheap, strong, applicable to various temperatures, so far Still widely used, but also a difficult restoration technique

This technology has the following problems: the plugging agent cannot effectively stay in the plugging layer, and the plugging agent has already leaked after reaching the target layer and before solidification; the plugging agent particles are generally large, resulting in high working pressure, which affects the relevant formation system and New hazards caused by oil recovery systems, etc.

The solidified body formed by the plugging agent is brittle and easy to shrink, and cannot form a firm bond with the surrounding medium, and has poor compatibility with the mud

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