Selective high-molecular fracture catalyst as well as preparation method and application thereof

Abstract

The invention discloses a selective high-molecular fracture catalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: filling water into a reaction kettle and increasing the temperature to 50 DEG C; adding an organic phosphate chelating agent in to the reaction kettle and reacting for 1 h; adding a reducing agent and reacting for 30 min; finally, adding a boron removal catalyst, increasing the reaction temperature to 50 to 90 DEG C, and reacting for 3 h. The selective high-molecular fracture catalyst provided by the invention is mainly applied to gel breakage of fracturing fluid in an oil field, and the usage amount is 0.05 to 0.1% of the total mass of the fracturing fluid. The selective high-molecular fracture catalyst has the beneficial effects that gel can be broken radically, the price is reasonable, and the catalyst does not have corrosivity and is free from influence of a great amount of co-existence salt; all ingredients contained in the product supplement one another, the boron removal catalyst lowers the activation energy of boron to ensure that the fracturing fluid is unstable in boron cross-linking performance and is degraded unceasingly so as to achieve the effects of hydration and gel breakage at last, the reducing agent can lower activation energy and serves as a low-temperature activating agent to prevent oxygen corrosion, and the organic phosphate chelating agent can prevent scaled and treated water from being compatible with follow-up water.

Description

technical field [0001] The invention relates to a catalyst and its preparation method and application, in particular to a selective polymer fragmentation catalyst, its preparation method and application, and belongs to the field of polymer chemistry. Background technique [0002] There are a lot of jelly in the fracturing fluid flowback fluid, so the discharge of fracturing fluid flowback fluid will cause serious pollution. In addition, if the jelly enters the sewage treatment system, it will cause problems such as blockage of the filter system and failure of fiber balls, which will directly affect the effect of water treatment. [0003] At present, in the gel breaking technology of oilfield fracturing fluid flowback fluid, oxidizers-ammonium persulfate, enzymes, and acids are usually used to complete the hydration gel breaking of fracturing fluid flowback fluid. But, adopt existing method to break glue, there are some following problems: [0004] 1. The oxidizing agent - ...

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Problems solved by technology

[0004] 1. The oxidizing agent - ammonium persulfate is a very traditional product. Its ability to release oxygen is reduced at low temperature and cannot completely break the gel; in addition, its compensatory product, sulfate, will react with barium, strontium, etc. in the water to form precipitates, which will block the formation

[0005] 2. Enzyme is a kind of microorganism, which is selective and can completely break the glue, but it is expensive and makes it difficult to apply

[0006] 3. Acid, because of its corrosiveness to on-site facilities, its use is limited; in addition, acid is also a raw material for sulfate-reducing bacteria, which can generate divalent sulfur, causing equipment corrosion and electrochemical reactions

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