An annular bottom pressurizer

Abstract

The invention relates to an annulus bottom pressurizer. The annulus bottom pressurizer comprises a shell, a seat pressure subassembly and a rubber plug, wherein the structure of the shell is a hollow tube section; a limiting portion is arranged on the inner wall of the shell; the seat pressure subassembly is arranged in the shell; the limiting portion limits downward movement of the seat pressure subassembly; the seat pressure subassembly comprises a plug core and a drainage channel penetrating in the plug core; and the rubber plug can be matched with the plug core so as to block the drainage channel. When the rubber plug blocks the drainage channel and pressure on the rubber plug is not smaller than ultimate pressure, the plug core moves downwards. By the annulus bottom pressurizer, the bottom of an annulus can be pressurized effectively and stably.

Description

technical field [0001] The invention relates to the technical field of cementing engineering in the petroleum industry, in particular to a pressurizer at the bottom of an annulus. Background technique [0002] At present, liner hangers with top seals are widely used in well cementing operations in oil and gas production layers. The top seal liner hangers can effectively seal off the annulus, thereby preventing operation hazards caused by pressure in the annulus, and are especially suitable for high-temperature, high-pressure containing The natural gas cementing of corrosive gas provides a favorable technical guarantee for ensuring the safety of the wellhead. [0003] However, there is a problem that the packer swells and seals after the replacement of the slurry, resulting in the closure of the annulus, so it is not possible to pressurize the wellhead to wait for solidification, especially it cannot compensate for the pressure loss caused by the weight loss of the cement slu...

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Problems solved by technology

[0003] However, there is a problem that the packer swells and seals after the replacement of the slurry, resulting in the closure of the annulus, so the wellhead pressurization method cannot be used to wait for solidification, especially the pressure loss caused by the weight loss of the cement slurry in the cementing of high-pressure gas wells cannot be compensated. , so that the gas layer at the bottom hole cannot be effectively pressed and stabilized. In severe cases, gas channels will be formed, which will affect the cementing quality of the production layer.

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