The invention relates to the technical field of
heavy oil reservoir exploitation, in particular to a device and a method for realizing
viscosity-reducing huff-puff exploitation of heavy oil by injecting
natural gas into a well and pressurizing. According to the technical scheme, a
gas supply pipeline is tripped into an annular space between a sleeve and a pump cylinder, the upper end of the
gas supply pipeline is connected with a
natural gas injection device on the ground, and the lower end of the
gas supply pipeline is communicated with a gas inlet of an underground
natural gas booster pump; a gas injection packer is installed on the lower middle side of a pump cylinder, an oil inlet hole is formed in the
pipe wall of the lower side of the gas injection packer, and the lower end of the gas injection packer is connected with an underground natural gas
booster pump through a transition adapter. The device has the advantages that the pressure of natural gas can be increased in a
relay mode, the natural gas is dynamically mixed and dissolved in thickened oil, the
viscosity of the natural gas is remarkably reduced, the natural gas is increased along with
volume expansion, flowing to a shaft is facilitated, in addition, the foam oil effect can be formed, and the functions of reducing
viscosity and increasing yield of a thickened oil reservoir are achieved; and the total operation cost is lower than the steam
thermal recovery cost, and the safety is also greatly improved.