Cross-linking agent for fracturing fluid with ultralow hydroxypropyl guar concentration and fracturing fluid prepared from cross-linking agent

Abstract

The invention relates to a cross-linking agent for fracturing fluid and preparation method of the cross-linking agent. The cross-linking agent comprises the following components in parts by mass: 450 to 650 parts of water, 150 to 250 parts of salt of organic acid, 100 to 250 parts of boron compound, 50 to 150 parts of polylol and 10 to 50 parts of sodium hydroxide. The method for preparing the cross-linking agent comprises the following steps of: mixing the salt of organic acid and water and adding the mixture into the boron compound, and reacting at the temperature of 70 to 80 DEG C for 2 hours; adding the sodium hydroxide to regulate the pH value to 6 to 8, and reacting at the temperature of 70 to 80 DEG C for 3 hours; adding the polylol, reacting at the temperature of 70 to 80 DEG C for 1 hour, and preparing the cross-linking agent. The invention also relates to fracturing fluid with ultralow hydroxypropyl guar concentration. The fracturing fluid mainly comprises the following components in parts by volume: 96.1 to 98.2 parts of aqueous solution of hydroxypropyl guar and 0.25 to 0.4 part of the cross-linking agent. According to the fracturing fluid, the amount of thickening agent can be reduced, so that the damage and cost are reduced.

Description

technical field [0001] The invention relates to a crosslinking agent for fracturing fluid and a preparation method thereof, as well as a fracturing fluid under the condition of an ultra-low hydroxypropyl guar gum concentration thickener and a preparation method thereof, and belongs to the technical field of petroleum exploitation. Background technique [0002] After nearly a hundred years of research and development of fracturing stimulation fluids, a variety of fracturing fluid systems have been formed, mainly water-based fracturing fluids, emulsified fracturing fluids, foam fracturing fluids, etc., but hydroxypropyl Guar gum is the thickener and a small amount of cross-linking agent is added to form a cross-linked jelly fracturing fluid is still the most commonly used fracturing fluid for oil and gas field development and fracturing at home and abroad. [0003] The damage of hydroxypropyl guar gum fracturing fluid to the reservoir mainly comes from water-insoluble substanc...

AI Technical Summary

Problems solved by technology

[0004] CN 102329602 A discloses an ultra-low concentration fracturing fluid and a preparation method thereof. The disclosed fracturing fluid uses 0.3%-0.35% hydroxypropyl guar gum and an inorganic boron crosslinking agent, which can make the fracturing fluid The maximum temperature resistance reaches 105°C, but the residue content of the gel breaking fluid is 155mg / L, which is high, and the maximum temperature resistance of the fracturing fluid needs to be further improved

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