Low-temperature gel breaker and preparation method thereof

Abstract

The invention discloses a low-temperature gel breaker for polymer fracturing fluid. The low-temperature gel breaker is prepared from the following raw materials in parts by weight: peroxides: 10-15 parts of dibenzoyl peroxide, 3-5 parts of ammonium persulfate and 1-3 parts of hydrogen peroxide; active additives: 4-6 parts of sodium gluconate, 1-2 parts of potassium iodide, 3-5 parts of hexamethylenetetramine and 0.1-4 parts of triethanolamine; a solvent: 150-180 parts of water. A preparation method of the low-temperature gel breaker comprises the following steps: (1) preparing the peroxides, namely, weighing raw material components according to a weight ratio, putting the peroxides into a reaction kettle, adding water, and stirring for 30 minutes; (2) preparing the active additives, namely, adding the sodium gluconate, sequentially feeding potassium iodide, hexamethylenetetramine and triethanolamine, continuously stirring for 60 minutes, so as to obtain a finished product. The low-temperature gel breaker disclosed by the invention has the benefits that structures of polymer fracturing fluid and guanidine gel fracturing fluid can be effectively decomposed, thorough gel breakage at the temperature as low as 20 DEG C can be achieved, and the low-temperature gel breaker has the characteristics of small use amount, rapid gel breakage, thorough gel breakage, high simplicity in use and the like. A use method of a cross-linking agent prepared from the low-temperature gel breaker is completely in accordance with that of a conventional gel breaker, so that high convenience can be brought to on-site construction.

Description

technical field [0001] The invention relates to an oil and gas field fracturing fluid system, in particular to a gel breaker in the system, specifically a low-temperature gel breaker and a preparation method thereof. Background technique [0002] Reservoir hydraulic fracturing, referred to as oil reservoir fracturing or fracturing, is a technology developed in the 1940s to improve the seepage characteristics of oil reservoirs. It is an important technological measure for increasing production of oil and gas wells and increasing injection of water injection wells. It uses surface high-pressure pumps to inject high-viscosity liquid into the well at a displacement that greatly exceeds the absorption capacity of the formation, and then forms high pressure near the bottom of the well. After the pressure exceeds the formation stress near the bottom of the well and the tensile strength of the rock, fractures are formed in the formation. Continue to inject the fluid with proppant i...

AI Technical Summary

Problems solved by technology

Therefore, a gel breaker should be added to the water-based fracturing fluid. However, conventional peroxide gel breakers are only suitable for formation temperatures above 50°C. When the formation temperature is lower than 50°C, the gel breaking effect will be significantly reduced. Low temperature breaker has important practical significance

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