Preparation method of acidic crosslinking agent applied to carboxymethyl guar gum

Abstract

The invention relates to a preparation method of an acidic crosslinking agent applied to carboxymethyl guar gum. An acid technology is usually carried out in a hydraulic fracturing process, which causes secondary damage to a reservoir stratum. The preparation method comprises the following steps of: uniformly mixing 3 parts by weight of citric acid, 57-82 parts by weight of water and 10-20 parts by weight of micromolecular polyhydroxy compound and heating, after the temperature reaches 50 DEG C, slowly adding 5-20 parts by weight of zirconium oxychloride; and keeping the temperature to be 50-55 DEG C, reacting for 3-4 hours, cooling a product to reach room temperature to obtain the acidic crosslinking agent. The cidic crosslinking agent provided by the invention is suitable for an acidic system, and jelly formed by crosslinking is higher in temperature tolerance and is well in sand carrying property, and can be applied to an alkaline-sensitive stratum; a small quantity of citric acid is added in a synthesis process, so that the pH of the whole reaction system is kept constant, the operation step during production is simplified; and the consumption of the organic zirconium crosslinking agent is 0.8 percent, the concentration of a carboxymethyl guar gum water solution is 0.4 percent, and the quantity of residue after crosslinking gelout is 160mg/L.

Description

technical field [0001] The invention relates to a crosslinking agent for oil field carboxymethyl guar gum fracturing system, in particular to a preparation method of an acidic crosslinking agent applied to carboxymethyl guar gum. Background technique [0002] Fracturing is an important method for oil field stimulation. With the development of reservoir stimulation technology, hydraulic fracturing alone cannot fully meet the field requirements. The acidizing process is often accompanied by hydraulic fracturing, which will cause secondary damage to the reservoir. In an acidic environment, it can effectively inhibit the expansion and migration caused by the negative typical of the clay surface, strengthen the molecular force between layers, and stabilize the clay layer. On the other hand, the fracturing fluid is acidic, which can remove plugs and increase the permeability of the reservoir. Contents of the invention [0003] The purpose of the present invention is to provid...

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Problems solved by technology

[0002] Fracturing is an important method for increasing production in oilfields. With the development of reservoir stimulation technology, hydraulic fracturing alone cannot fully meet field requirements.

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