Temporary plugging agent for fracturing and preparation method thereof

Abstract

The invention belongs to the technical field of oilfield production, and in particular relates to a temporary plugging agent for fracturing and a preparation method thereof. The components and parts by weight are: 38 parts of hydroxypropyl cellulose and 15 parts of polyvinyl butyral , 16.5 parts of zinc oxide, 27 parts of urea-formaldehyde resin, 6 parts of hexamethylene tetraammonium, 14 parts of calcium hypochlorite. Mix hydroxypropyl cellulose, polyvinyl butyral, zinc oxide, urea-formaldehyde resin, hexamethylenetetraammonium and calcium hypochlorite at room temperature at 25°C, and then add the mixture slowly under stirring After stirring in water for 30 minutes, the temporary plugging agent for fracturing can be obtained. This temporary plugging agent can withstand a pressure difference of 40.6MPa after waiting for 2 hours in the wellbore at 60°C. After the gel is broken, the viscosity of the gel-breaking fluid is less than 5mPa·S, and all of it can be discharged to the ground through the flowback process.

Description

Technical field: [0001] The invention belongs to the technical field of oilfield production, and in particular relates to a temporary plugging agent for fracturing and a preparation method thereof. Background technique: [0002] With the continuous development of oil and gas resources in my country, the geological conditions of reservoirs are becoming more and more complex, and the difficulty of exploitation is also increasing. In recent years, for reservoirs with strong heterogeneity, low permeability, and ultra-low permeability, in order to further improve the stimulation efficiency and achieve uniform stimulation, the temporary plugging and diversion technology has been proposed, which is to add temporary plugging and diversion in real time during the hydraulic fracturing process. It can temporarily plug the artificial fractures that have been formed, force the fractures to crack and expand in other directions, and open new fractures under high pressure to increase the co...

AI Technical Summary

Problems solved by technology

Among them, polymers and plugging pellets are the most widely used. Among them, the polymer temporary plugging agent has a good plugging effect due to its firm chemical cross-linked network structure, but there is a phenomenon of slow or even difficult gel breaking. If it is not thorough, it will cause a certain degree of damage to the formation; the plugging ball has the characteristics of high plugging strength and small deformation, but the disadvantage is that it is easy to fall off and the plugging effect is poor. Difficult to dissolve

The above-mentioned temporary plugging agents cannot effectively seal the fractures during the fracturing process, and cannot effectively break the gel and flow back, causing permanent damage to the reservoir