Chemical plugging remover suitable for ternary composite flooding injection well

Abstract

The invention relates to a chemical plugging remover suitable for a ternary composite flooding injection well. The method mainly solves problems of poor effect and short validity period when measuressuch as changing stratum injection fluid, acidizing and blocking removal of a common water injection well and the like are applied to a ternary compound flooding injection well. The chemical pluggingagent consists of three parts, namely a precursor, a main agent and an after agent, wherein the precursor consists of 10-15 percent of a polymer degradation agent and 90-85 percent of water; the mainagent consists of 7-10 percent of hydrochloric acid, 3-5 percent of acetic acid, 3-5 percent of ammonium fluoride, 1.0-2.0 percent of triethanolamine, 0.5-1.0 percent of an imidazoline quaternary ammonium salt corrosion inhibitor and 85.5-77 percent of water; the after agent consists of 1.0-3.0 percent of organic phosphonic acid, 0.5-1.0 percent of hexamethylene tetraammonium and 98.5-96.0 percentof water, wherein the components are measured in percentage by weight. The chemical plugging remover suitable for the ternary composite flooding injection well aims at various plugging substances such as scale, polymer, alkali and the like in the ternary composite flooding injection well, has functions of degrading polymer, dissolving scale, complexing, metal ions and the like, and has the advantages of good stability, low corrosivity and safe use.

Description

Technical field: [0001] The invention relates to a plug-removing agent in the field of oil recovery, in particular to a chemical plug-removing agent suitable for three-element compound flooding injection wells. Background technique: [0002] Field tests show that ASP flooding can increase the recovery rate by 20 percentage points compared with water flooding, and it is an important replacement technology for the sustainable development of high water-cut oilfields. During the development of ASP flooding, due to the injection of alkali, surfactant, and polymer, the overall injection condition has deteriorated, and the injection pressure of a considerable number of wells has approached or reached the fracture pressure of the oil layer, and the injection pressure has to be lowered. The rate affects the effect of ASP flooding. The root cause of this situation is that the near-wellbore area of ​​the injection well is blocked. The plugging substances at the bottom of the ASP floo...

AI Technical Summary

Problems solved by technology

[0003] The present invention aims to overcome the problem of poor effectiveness of existing plugging removers for water flooding and polymer flooding existing in the background technology, and provides a chemical plugging remover suitable for ASP flooding injection wells, which is suitable for ASP flooding injection wells. The chemical plugging agent for composite flooding injection wells is aimed at various blockages such as scale, polymer and alkali in ASP flooding injection wells. It has the functions of degrading polymers, dissolving scale, complexes and metal ions, etc. low, safe to use

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