Method for filling oil-gas well of fractured oil-gas reservoir with isolation particles to reduce water and increase oil production

A method for filling an oil and gas well of a fractured oil and gas reservoir with pack-off particles to reduce water and increase oil production, the oil and gas well having a wellbore within which a screen pipe is provided, wherein a packer is provided at the top of the screen pipe, and the packer is provided with a filling channel for injecting filling liquid, wherein the method comprises the following steps:

• (b1) continuously injecting a filling liquid carrying pack-off particles into an annular space and a fracture via the filling channel provided on the packer, until (i) a stratum crack/fracture extension pressure is reached or exceeded, (ii) an injection amount per unit injection pressure is close to zero, or (iii) a preset filling amount of pack-off particles is reached;
• (b2) reducing an injection rate of the filling liquid, and allowing a filling pressure to be smaller than the stratum crack/fracture extension pressure, continuously injecting the filling liquid carrying pack-off particles until the annular space is fully filled with the pack-off particles or the preset filling amount of pack-off particles is reached;
• and
• (b3) closing the filling channel and launching production, wherein the preset filling amount of pack-off particles is determined by:
• V≥ρ·L0
• wherein V is the preset filling amount of pack-off particles, L0 is a total length of the wellbore of the production section;
• and ρ is a filling density, and when the oil and gas well is a horizontal well, ρ has a value of 0.01-1.0 m3/m, and when the oil and gas well is a vertical well, ρ has a value of 0.01-5.0 m3/m.