In-fissure diversion fracturing temporary blocking agent for low-permeability oilfield, and preparation method and application thereof

Abstract

The invention relates to an in-fissure diversion fracturing temporary blocking agent for a low-permeability oilfield, and a preparation method and application thereof. The temporary blocking agent is prepared by the following steps of: mixing 92 mass percent of bone glue powder, 0.2 mass percent of benzoic acid, 5 mass percent of modified starch, 1.3 mass percent of hydroxyethyl cellulose, 1.0 mass percent of F-containing surfactant and 0.5 mass percent of cross-linking agent; adding polyoxyethylene diacrylate with concentration of between 5 and 100mg / L and an initiator with concentration of between 100 and 500mg / L and reacting at the temperature of 80 DEG C under the pressure of 1.2MPa for gelling; and granulating, applying oil and drying, wherein the maximum expansion ratio is 1.33; the agent has high temperature resistance stability and stable adhesion; the maximum elongation is 64 percent; the breakthrough pressure gradient reaches 30.0MPa / m; the viscosity is 35mPa.s after the agent is completely dissolved at the temperature of 60 DEG C; and the agent can be completely flowed back under the action of the carrying of fracturing liquid.

Description

Technical field: [0001] The invention relates to an in-fracture steering fracturing temporary plugging agent applied to repeated fracturing reconstruction of low-permeability oilfield reservoirs, a preparation method and application thereof. Background technique: [0002] In low-permeability oilfields, conventional refracturing technology is usually used to tap the formation potential and increase the single-well production of oil wells. This technology is mainly to re-add a certain amount of proppant to the formation, realize the re-placement of proppant in the original fracture, and improve the fracture conductivity. To achieve the purpose of increasing production. This technology still has certain limitations while increasing production: First, the implementation of conventional refracturing technology for wells with high formation energy and a history of effective water injection will lead to excessive extension of artificial fractures, and eventually cause water cut in ...

AI Technical Summary

Problems solved by technology

This technology still has certain limitations while increasing production: First, the implementation of conventional refracturing technology for wells with high formation energy and a history of effective water injection will lead to excessive extension of artificial fractures, and eventually cause water cut in oil wells to rise after refracturing Second, for low-yield and low-efficiency wells located in the waterline direction of the injection-production well pattern, in order to avoid excessive extension of artificial fractures along the waterline direction, conventional refracturing is usually small in scale, and no new fractures are formed after fracturing. In the oil drainage area, the fracturing effect is poor; third, for the oil wells at the edge of the reservoir, due to the lack of a perfect injection-production well pattern, a reasonable injection-production relationship has not been established, and the level of formation energy is kept low, resulting in routine repetition Fracturing is less effective

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