Hydrophobic modified hydroxypropyl guar fracturing liquid cross-linking agent and preparation method thereof

Abstract

The invention relates to a cross-linking agent able to crosslink hydrophobic modified hydroxypropyl guar and a preparation method thereof. Presently at home and abroad, water-based fracturing liquids are more likely to be employed in fracturing of most reservoirs, and the practice has the following disadvantages that: (1) a fracturing liquid system with routine guar gum as the densifier is only suitable for intermediate and low temperature stratums, so that a limitation exists for high temperature wells with a temperature over 150DEG C; (2) generally, fracturing liquids needs more additives, thus causing damage to stratums to a certain degree. The cross-linking agent of the invention comprises by weight: 150-200 parts of water, 140-160 parts of glycol, 60-70 parts of boric acid, 60-80 parts of zirconium oxychloride, 180-200 parts of acetic acid, 20-240 parts of monoethanolamine, and 50-180 parts of sodium hydroxide. In an enclosed container, the final product can be produced. The cross-linking agent of the invention can form a fracturing liquid with a densifier, and the formed fracturing liquid can resist a temperature higher than 150DEG C. The cross-linking agent and the densifier fracturing liquid system in the invention have the characteristic of low interfacial tension.

Description

technical field [0001] The invention relates to synthesizing a cross-linking agent capable of cross-linking with hydrophobically modified hydroxypropyl guar gum through chemical reaction and a preparation method thereof. Background technique [0002] Due to the reliability and economy of the technology, water-based fracturing fluids are mainly used in the fracturing of most reservoirs at home and abroad, and Changqing Oilfield is no exception. Conventional water-based fracturing fluids mainly use the alkaline cross-linking system of guar gum series, which has the following deficiencies: [0003] ① The fracturing fluid system using conventional guar gum as the thickener is only suitable for medium and low temperature formations, and has limitations for high temperature wells above 150 °C; [0004] ②The fracturing fluid generally needs to add more additives, which will cause damage to the formation to a certain extent; [0005] The above factors have greatly affected the ef...

AI Technical Summary

Problems solved by technology

[0003] ① The fracturing fluid system using conventional guar gum as the thickener is only suitable for medium and low temperature formations, and has limitations for high temperature wells above 150 °C;

[0004] ②The fracturing fluid generally needs to add more additives, which will cause damage to the formation to a certain extent;

[0005] The above factors have greatly affected the effect of fracturing stimulation, especially for oil and gas production, which tends to be more and more deep wells, resulting in the need for thickeners with stronger temperature resistance in fracturing technology