Preparation method of potassium persulfate microcapsule gel breaker

Abstract

The invention discloses a preparation method of a potassium persulfate microcapsule gel breaker. The method includes: (1) preparing a 5-20 mass% gelatin solution; (2) under 45DEG C constant temperature and constant speed stirring, measuring liquid paraffin into a three-mouth flask, adding a stabilizer, and mixing the substances evenly into a continuous phase medium; (3) weighing potassium persulfate powder and slowly adding it into the continuous phase medium, conducting 45DEG C constant temperature water bath stirring to disperse the substances evenly so as to form a stable suspension system; (4) slowly adding the gelatin solution into the suspension system, conducting 45DEG C constant temperature stirring at a uniform speed to form a stable latex solution; (5) transferring the latex solution into ice bath to performing constant speed stirring, adding a dehydrating agent isopropanol and a crosslinking agent formaldehyde; and (6) removing the upper oil phase, and subjecting the lower solid microcapsule to washing, pumping filtration and drying. The method provided by the invention has reliable principle and is easy to operate, the prepared microcapsule gel breaker has good sphericity, uniform and controllable particle size distribution, high effective content, and slow-release property, can be used for gel breaking of oil field water-based fracturing fluid, and has broad market prospect.

Description

technical field [0001] The invention relates to a preparation method of a potassium persulfate microcapsule gel breaker for water-based fracturing in the process of oil and natural gas exploration and development. Background technique [0002] Gel breaker is an important additive to improve the gel breaking effect of fracturing fluid and reduce the damage of fracturing fluid to the reservoir in the exploration and reconstruction of oil and gas reservoirs. Before the 1990s, the gel-breaking system of fracturing fluid was relatively simple, mainly using conventional persulfate. With the improvement of people's awareness of protecting the reservoir and reducing the damage to the conductivity of the supporting fractures of the reservoir, it is necessary to ensure that the fracturing fluid reaches a certain pumping viscosity, and it is also necessary to quickly reduce the viscosity of the fluid after fracturing, so the proposed Capsule breakers are used to solve this problem. ...

AI Technical Summary

Problems solved by technology

[0007] Due to the high preparation cost and complicated operation of the capsule gel breaker at present, the demand for industrial application is large, and a large amount of import is required. Combined with the current water-based fracturing fluid construction, persulfate is commonly used, but if it is used directly, it will damage the reservoir environment and the reservoir. Conductivity

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