Fracturing and imbibition method for low-permeability reservoir

Abstract

The invention discloses a fracturing and imbibition method for a low-permeability oil reservoir, and belongs to the technical field of oil reservoir development. The method comprises the following steps: preparing a first liquid amount of dry layer energizing fluid, a second liquid amount of gel fracturing fluid with a first sand content, and a foaming type imbibition agent with a target concentration, and injecting the dry layer energizing fluid into an adjacent dry layer of a target oil layer under the condition that the injection pressure of the target oil layer is greater than the fracture pressure of the target oil layer, and gel fracturing fluid and a foaming type imbibition agent are sequentially injected into the target oil layer. According to the technical scheme provided by the embodiment of the invention, the dry layer energizing fluid is adopted, the bottom layer energy of the target oil layer is increased, the gel fracturing fluid is adopted, the underground flowing environment of crude oil can be improved, the flow conductivity is improved, the foaming type imbibition agent is adopted, and the foaming type imbibition agent can be converted into a foam state from a liquid state under the crude oil shearing condition, so that the foaming type imbibition agent can be converted into the foam state from the liquid state. The displacement distance of crude oil can be reduced, the backflow difficulty of the crude oil is reduced, and the purpose of improving the recovery efficiency is achieved.

Description

technical field [0001] The application relates to the technical field of reservoir development, in particular to a fracturing and imbibition method for low-permeability reservoirs. Background technique [0002] In the case of limited potential for increasing domestic conventional energy production, the development of unconventional energy has gradually received great attention from the petroleum industry. For example, the production of low-permeability reservoirs and tight reservoirs. However, the recovery factors of low-permeability oil reservoirs and tight oil reservoirs have always been low due to the limitations of their own low-permeability reservoir properties and the current construction technology. Therefore, for low-permeability reservoirs and tight reservoirs, how to enhance oil recovery is a problem worth considering. [0003] At present, the method to enhance the recovery of low-permeability reservoirs is usually to implement volume fracturing and imbibition oi...

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Problems solved by technology

[0004] However, since the injection pressure is usually high during the fracturing injection process, the crude oil is likely to be driven to the deep part of the oil layer. Moreover, the common imbibition solution currently used is poor in demulsification after emulsification with crude oil, so that the crude oil in the deep oil layer is Due to the high seepage resistance, it is difficult to flow back in large quantities and efficiently, which affects the recovery of crude oil

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