Reagent for breaking and removing boron cross-linking agent and preparation method thereof

Abstract

The invention discloses an reagent for breaking and removing a boron cross-linking agent. The reagent comprises the following components in percentage by weight: 0.01 to 0.1 percent of peroxide, 0.01 to 0.05 percent of a gel breaking activator, 0.02 to 0.06 percent of a saccharide accelerant, 0.08 to 0.016 percent of a demulsifier, 0.08 to 1 percent of a bactericide and 0.2 to 0.3 percent of a pH regulator, with the balance being water. The invention further discloses a preparation method of the reagent for breaking and removing the boron cross-linking agent. The agent is prepared by mixing the peroxide, the gel breaking activator, the saccharide accelerant, the demulsifier, the bactericide, the pH regulator and the water. The reagent can effectively break and remove the boron cross-linking agent, rapid viscosity can be reduced to a low degree within a short time, gel breaking time is short, the viscosity can be reduced to about 2 after 60 min, and gel breaking efficiency is high; and meanwhile, common agents such as the peroxide and the gel breaking activator are adopted, so treatment cost is low, an application range is wide, and the actual use requirements are met.

Description

technical field [0001] The invention relates to the field of oilfield chemicals, in particular to a medicament for breaking boron crosslinking agents in an oilfield fracturing fluid system and a preparation method thereof. Background technique [0002] In the field of petroleum exploitation, fracturing refers to a method of forming cracks in oil and gas layers by using hydraulic action during the process of oil or gas extraction, also known as oil layer hydraulic fracturing. Fracturing is artificially creating fractures in the formation, improving the flow environment of oil underground, increasing the production of oil wells, and playing an important role in improving the flow conditions at the bottom of oil wells, slowing down interlayers and improving the production status of oil layers. [0003] Fracturing is an important link in the exploration and development engineering sequence of medium and low permeability oilfields. After the fracturing operation is completed, the...

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Problems solved by technology

[0005] The biological method adopts biological enzyme gel breaker, which is a green and environmentally friendly gel breaker, which can significantly improve the reduction of gel breaking residue, but it is less sensitive to heat than the enzyme activity temperature range, and the enzyme activity is low , the biodegradation is slow, and when the temperature is higher than the enzyme's adaptation temperature range, the enzyme will completely lose its activity

[0006] The chemical method mainly uses oxidants such as potassium persulfate and ammonium persulfate. When the temperature is high, the peroxide decomposes into highly active free radicals, destroys the main chain structure of the polymer, and achieves the purpose of gel breaking. The higher the temperature, the stronger the reactivity of the oxidant. However, when the temperature is lower than 50°C, the gel-breaking effect of the oxidant decreases significantly.

The current gel-breaking system under low temperature conditions requires a large dose of activator, and has disadvantages such as narrow application range, long gel-breaking time, and incomplete gel-breaking hydration.

[0007] Therefore, the current gel breakers cannot meet the actual needs of use.

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