Fractured oil and gas reservoir hot fluid mixing and injecting in-situ residual oil water plugging process and device

Abstract

The invention belongs to the technical field of oil and gas development, and particularly relates to a fractured oil and gas reservoir hot fluid mixing and injecting in-situ residual oil water plugging process and device. An existing water shutoff agent is not well matched with an oil reservoir environment, and has the problems of sensitivity and pollution. The invention provides a fractured oil and gas reservoir hot fluid mixing and injecting in-situ residual oil water plugging process which comprises the following steps: performing oil-water separation on crude oil to obtain low-water-content crude oil, performing oil-residue separation on the low-water-content crude oil to obtain oil residues, mixing and injecting and diluting the oil residues to obtain a water plugging agent, and performing water-oil separation on the oil residues to obtain the fractured oil and gas reservoir hot fluid mixing and injecting in-situ residual oil water plugging. And mixing high-pressure gas and a water plugging agent to obtain a dispersed injection state water plugging agent, and injecting the dispersed injection state water plugging agent into the stratum. The problems that an existing water shutoff agent is not well matched with the oil reservoir environment, has sensitivity and pollution and is prone to being washed away by subsequent water drive can be solved.

Description

technical field [0001] The application belongs to the technical field of oil and gas development, and in particular relates to a process and a device for water plugging with in-situ residual oil by thermal fluid mixing in fractured oil and gas reservoirs. Background technique [0002] Fractured oil and gas reservoirs refer to oil and gas reservoirs in which the reservoir space and percolation channels are mainly fractures. The origin of fractures is diverse, mainly structural fractures, and the reservoirs are generally tight and brittle rock formations with impermeability and poor permeability. For fractured oil and gas reservoirs, single-well water injection can effectively supplement formation energy and improve oil recovery. [0003] Oil well water plugging methods mainly include mechanical water plugging and chemical water plugging. By plugging the highly permeable effluent layer of the oil well, the ineffective circulation of the injected fluid is reduced, the sweeping...

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Problems solved by technology

[0003] Oil well water plugging methods mainly include mechanical water plugging and chemical water plugging. By plugging the high-permeability liquid layer of oil wells, the invalid circulation of injection fluid can be reduced, the sweep efficiency can be improved, and the development effect can be improved. At present, the chemical water plugging method is more commonly used. In the process of application, foreign inorganic water blocking agents and organic synthetic water blocking agents are mainly used. The non-selective blocking effect of water blocking agents makes it impossible to block water channeling to a high degree; the current application effect and validity period of water blocking agents Usually lower than the profile control agent, and it is easy to be washed away by subsequent water flooding, and the water plugging effect is poor

In addition, foreign water shutoff agents cannot be recycled and reused after being injected into the formation, and the cost of water shutoff is high; some water shutoff agents have compatibility problems with the formation, which damages the reservoir

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