Pressure plugging is a common technique used to control and plug the wellhead pressure and ensure the stable operation of oil and gas Wells. It plays an important role in oil and gas drilling and completion. By using a pressure packer and a plugging agent, the wellhead pressure can be effectively controlled and the hole can be plugged when needed.

The principle of sealing with pressure can be summarized in the following aspects:

Pressure control: The on-pressure plugging technology controls the wellhead pressure through the use of on-pressure sealers. A pressure packer is a device that can pressurize and decompress the wellhead, which can prevent the wellhead pressure from exceeding the stable range and ensure the stable operation of the wellhead. When the wellhead pressure is too high, the pressure stopper can reduce the wellhead pressure by releasing the pressure. When the wellhead pressure is too low, the pressure packer can maintain the stability of the wellhead pressure by increasing the pressure.

2. Selection of plugging agent: There are many choices of plugging agents used in sealing technology with pressure, such as cement slurry, polyurethane, etc. Selecting the right plugging agent takes into account a number of factors, including wellhead pressure, wellbore temperature, and reliability of the plugging agent. After the plugging agent is injected into the hole, it quickly solidifies to form a plugging body, which seals the hole and prevents oil and gas from flowing into the wellbore.

3. Plugging agent injection: In the process of plugging with pressure, plugging agent needs to be injected into the hole through the pipeline. When plugging agent is injected, the injection rate and pressure need to be controlled to ensure that the plugging agent can be evenly distributed in the hole and can effectively plug the well head. To achieve this, equipment such as injection pumps can be used for injection, and the operation can be adjusted by monitoring the wellhead pressure and injection speed to ensure the sealing effect.

4. Curing and strength of the plugging body: After the plugging agent is injected into the hole, it takes a certain amount of time to fully cure and form a solid plugging body. The curing speed and strength of the sealer are related to the properties and temperature of the sealer. In actual operation, it is necessary to determine the curing time of the plugging agent according to the specific situation, and carry out relevant monitoring and testing to ensure the quality and strength of the plugging body.

Pressure plugging technology is of great significance in the process of oil and gas drilling and completion. It can effectively control the wellhead pressure, ensure the sealing of the wellhead, prevent oil and gas leakage and wellhead accidents. At the same time, the pressure sealing technology can also be used for wellhead maintenance and reconstruction to improve the operating efficiency and stability of the wellhead. Therefore, pressure plugging technology is an indispensable technology in oil and gas development.