A kind of oxidized gel breaker for polymer injection well and preparation method thereof

Abstract

The invention discloses an oxidized gel breaker for a polymer injection well and a preparation method of the oxidized gel breaker, and belongs to the field of tertiary oil recovery. The oxidized gel breaker comprises the following components in percentage by weight: 12%-25% of persulfate oxidizing agents, 3.1%-8.5% of alkaline pH regulating agents, 0.5%-2% of corrosion inhibitors, 2%-5% of mutual solvents and the balance of water. The oxidized gel breaker for the polymer injection well has the characteristics of high oxidized gel breaking rate and low corrosivity, can efficiently remove the oxidized gel breaker formation plugging caused by aldehyde cross-linked polymer gelation, chromium cross-linked polymer gelation, a polyacrylamide high-molecular solution and the like, has the advantages of high technical adaptability, wide application range, high oxidative decomposition and gel breaking rate, good plugging-removing and injection-increasing effect, low corrosivity on steel equipment and high safety, meets the requirement for primary standard and can meet the requirement for large-dose extrusion injection plugging-removing construction of the polymer injection well and solve the technical problem of high corrosivity of an original oxidized gel breaker on the steel equipment and a down-hole pipe column.

Description

technical field [0001] The invention specifically relates to an oxidized gel breaker for polymer injection wells and a preparation method thereof, belonging to the technical field of tertiary oil recovery. Background technique [0002] Under normal circumstances, after natural exploitation and water injection development of an oil field, there are still 60-70% of the remaining oil in the ground that cannot be recovered. In order to continue to exploit this part of the remaining oil and further enhance the recovery factor, the polymer flooding technology has been applied on a large scale industrially and has achieved remarkable results, and has become the leading technology for inhibiting the decline of crude oil production and controlling and stabilizing oil production in the later stage of oilfield development. [0003] However, in the process of polymer flooding, due to the adsorption, retention and mechanical trapping of polymers in the formation porous media, it is very ...

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Problems solved by technology

[0005] The first is that the original plugging agents such as hydrogen peroxide, potassium permanganate, steady-state chlorine dioxide, new ecological chlorine dioxide, DOC-8, HJS-1, etc. caused formation damage caused by polymer polyacrylamide commonly used in oilfield polymer flooding. The effect of plugging and plugging removal is good, and its oxidation gel breaking rate is above 95%, but the effect of plugging and plugging removal in the formation caused by aldehyde cross-linked polymer gel is poor, and its oxidation gel breaking rate is below 30%, which cannot achieve plugging removal For attention

[0006] Second, the original oxidative gel breaker severely corrodes construction equipment and downhole pipe strings, such as hydrogen peroxide, potassium permanganate, steady-state chlorine dioxide, new ecological chlorine dioxide, DOC-8, HJS-1 and other chemical agents are all Strong oxidant, strong chemical oxidation, highly corrosive to steel equipment and pipe strings, often causes corrosion of construction equipment and downhole pipe strings during construction, and even completely scraps construction equipment and measure wells, making it difficult to effectively guarantee construction safety

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