Method for plugging large-scale cracks of fractured reservoir

Abstract

The invention discloses a plugging method for a large-scale crack of a fractured reservoir, and belongs to the field of oilfield exploitation. Comprising the following steps: preparing gel particle aqueous solution; injecting a plurality of gel particle aqueous solutions into the simulated large-scale crack, and selecting the adaptive particle size of the gel particles; preparing gel particles meeting the adaptive particle size into gel particle aqueous solutions with different concentrations, injecting the gel particle aqueous solutions into the simulated large-scale crack at different injection speeds and by always keeping the mass flow rate as a fixed value, and selecting an adaptive concentration and an adaptive injection speed; injecting a gel particle aqueous solution meeting adaptive particle size and adaptive concentration into the actual large-scale crack at an adaptive injection speed to obtain a gel particle medium channel; calculating the permeability of the gel particle medium channel; selecting an adaptive polymer body gel system matched with the gel particle medium channel; and injecting the adaptive polymer body gel system into the gel particle medium channel. By means of the method, it can be ensured that the whole large-scale crack channel is evenly and compactly blocked.

Description

technical field [0001] The present application relates to the technical field of oilfield exploitation, in particular to a method for plugging large-scale fractures in fractured oil reservoirs. Background technique [0002] Fractured oil reservoirs account for a large proportion of oil production at home and abroad. In the initial stage of production, fractures can greatly increase the production of oil wells, especially in low-permeability oil fields, often need to use fracturing technology to form large-scale artificial fractures. However, in the stage of water injection development, especially when the injection-production well pattern is adjusted, large-scale fractures will become the source of water channeling. At this time, in order to efficiently develop such reservoirs, it is necessary to seal the fractured water channeling zones. [0003] Plugging large-scale fractures requires a plugging agent with high strength, good migration ability, and long-term stable exist...

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Problems solved by technology

[0004] The embodiment of the present application provides a method for plugging large-scale fractures in fractured oil reservoirs, which solves the problem that the existing plugging methods for large-scale fractures in fractured oil reservoirs cannot simultaneously meet the requirements of high plugging strength, good migration capacity and problems with long-term stability

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