Pressure plugging is a common oil and gas well construction technology, which is mainly used for stability control and downhole accident response during downhole operation. It refers to the installation of pressure equipment at the wellhead, through adjusting the wellhead pressure valve and plugging device to achieve the control and plugging of downhole pressure. The technology of sealing with pressure plays an important role in the construction and maintenance of oil and gas Wells. This paper will introduce the technology of sealing with pressure in detail from the aspects of technical principle, process flow and equipment application.

First, technical principles

Pressure plugging technology is a kind of construction technology to control downhole fluid pressure by setting pressure valve and plugging device at the wellhead of oil and gas well. Its main principle is to control the underground pressure through the pressure valve and plug at the wellhead, so as to ensure the stability of the construction process and the effective operation of the underground equipment. The pressure valve and plugging device can adjust the pressure and plugging effect as needed to ensure that the pressure at the wellhead is within a stable range to avoid downhole pressure loss and accidents.

Second, the process flow

A typical process flow with pressure plugging technology consists of the following steps:

1. Preparation work: including checking and maintaining the wellhead equipment, confirming the stability of the working area, preparing the required tools and materials, etc.

2. Install a pressure valve: Install a pressure valve at the wellhead, which is usually fixed on the wellhead equipment by threaded connection or flange connection.

3. Install the plug: Install the plug under the pressure valve, and control the pressure of the downhole fluid by adjusting the opening of the plug.

4. Pressure test: After the installation of the pressure valve and the plug, the pressure test is carried out to confirm the tightness and reliability of the pressure valve and the plug.

5. Plugging operation: According to the needs of downhole pressure, adjust the opening of the plug to achieve the control and plugging of downhole pressure.

Third, equipment application

Pressure plugging technology requires the use of a series of equipment to achieve, mainly including the following aspects:

1. With pressure valve: used to control the pressure of the wellhead, adjust the opening as needed to ensure that the downhole pressure is in a stable range.

2. Plug: installed under the pressure valve, by adjusting the opening to control the pressure of downhole fluid.

3. Sealing material: used for the sealing effect of the plugging device, the common sealing materials are colloids, cement, etc.

4. Pressure gauge: It is used to monitor the change of downhole pressure in real time to ensure the effective control of wellhead with pressure valve and plug.

To sum up, pressure plugging technology is an important oil and gas well construction technology, through the setting and adjustment of pressure valve and plugging device, to achieve the control and plugging of downhole pressure. It plays a vital role in the construction and maintenance of oil and gas Wells, ensuring the stability of the construction process and the normal operation of downhole equipment. With the deepening of oil and gas exploration and development, pressure sealing technology will be more widely used and developed.