Pressure plugging refers to a certain sealing system formed in the shaft or wellhead to control the downhole pressure and prevent the spill of harmful gas or fluid in the well. In the exploration and development of petroleum, natural gas and other oil and gas, pressure sealing technology is widely used in underground operations, and is one of the important means to ensure the stability and effective development of underground.

The sealing technology with pressure is mainly through the sealing operation in the underground, forming a certain sealing system, so as to realize the control and management of the underground shaft. The main purposes of pressure plugging technology include but are not limited to the following:

1. Control downhole pressure: In the process of oil and gas exploitation, the downhole formation pressure is a very important parameter. Through the pressure sealing technology, the underground pressure can be controlled to avoid wellhead explosion and other accidents caused by the out-of-control underground pressure.

2. Prevent harmful gas spillover: In oil and gas exploration and development, harmful gas generation and spillover problems are often encountered. Through the pressure sealing technology, the harmful gas can be effectively prevented from spilling out from the downhole shaft and ensure the stability of the field operators.

3. Maintaining wellbore integrity: The wellbore is an important facility in oil and gas production, and the integrity of the wellbore is crucial to the effective conduct of downhole operations. Pressure plugging technology can maintain the integrity of the well and extend the life of the well.

Pressure plugging technology mainly includes the following common methods and processes:

1. Fracturing and plugging: Through fracturing operations in the downhole wellbore, a certain fracturing zone is formed, so as to control and manage the downhole pressure.

2. Cement sealing: The use of cement to seal, forming a certain cement sealing system to prevent harmful gases or fluids from spilling.

3. Casing plugging: Casing is set in the downhole wellbore, and the downhole pressure is controlled through the casing plugging operation.

4. Blowout preventer plugging: The blowout preventer is set at the wellhead to prevent the wellhead pressure from getting out of control by plugging the blowout preventer.

Pressure plugging technology is of great significance in oil and gas exploration and development, and can effectively ensure the effective underground operation. Through continuous technological innovation and research, pressure plugging technology will be more widely used and promoted in the future, and make greater contributions to the development of the oil and gas industry.