Method of staged refracturing for fractured well

A method of staged refracturing for a fractured well, comprising:

• re-perforating a target wellbore to form a new perforation, wherein the target wellbore has an old perforation, and a position of the new perforation is different from a position of the old perforation;
• dividing the target wellbore into at least two fracturing stages, and refracturing the fracturing stages in sequence, wherein the refracturing comprises:
• injecting a fracturing fluid into a current fracturing stage of the target wellbore to stimulate new and old fractures;
• injecting a fluid containing a plugging agent into the current fracturing stage of the target wellbore for plugging the perforations in the fracturing stage, the perforations comprising the new perforation and the old perforation;
• and
• determining a perforation plugging effect based on fracturing monitoring data, the perforation plugging effect comprising successful plugging and failed plugging, wherein the fracturing monitoring data is a bottom hole pressure which is obtained by monitoring of a wellhead pressure and calculation using a wellbore flow model;
• when the bottom hole pressure reaches or exceeds a formation rock breakdown pressure, determining that the perforation plugging effect is successful plugging completing the refracturing of the current fracturing stage, and refracturing a next fracturing stage;
• and when the bottom hole pressure fails to reach the formation rock breakdown pressure, determining that the perforation plugging effect is failed plugging, continuing to inject the fluid containing the plugging agent into the fracturing stage of the target wellbore until the perforation plugging effect is successful plugging.