The working principle of soluble bridge plugs mainly involves the following steps:

1. Transportation and positioning: Transport soluble bridge plugs to the predetermined position in the wellbore through cables or tubing.

2. Setting tool: Use gunpowder blasting, hydraulic setting or mechanical setting tools to generate pressure, which is transmitted to the pushing cylinder of the bridge plug through the outer cylinder of the setting tool, and then squeeze the soluble rubber cylinder and the slip.

3. Setting process: When the thrust reaches a certain value, cut the release pin to separate the setting tool from the soluble bridge plug. At this point, the locking device on the center pipe of the soluble bridge plug is activated, causing the slip to break and be embedded on the inner wall of the casing. The rubber cylinder expands and seals, completing the sealing process.

4. Release and dissolution: After the sealing is completed, the thread of the release ring is cut, releasing the soluble bridge plug. Then, under the action of the well fluid, the soluble bridge plug gradually dissolves, achieving the purpose of sealing or sealing the formation.

The structure of soluble bridge plugs includes components such as a central tube, anchoring mechanism, sealant cylinder, and release ring. These components are connected through gap fitting or threaded connections to ensure the correct position and sealing effect of the bridge plug in the wellbore