Supercritical CO2 resistant packer

Abstract

The invention discloses a packer which can be used for a long time under the condition of supercritical CO2. The inner wall of a central tube of the packer is provided with a gas-inject tube, and a spacer ring, rubber barrel mandrels and the central tube are provided with air vents and connected with the gas-inject tube. After the packer is set, a limit screw moves to the uppermost portion of a limit hole, and the air vents are communicated with the gas-inject tube. Chemical inert gases such as N2 or Ar enter into an annular space between rubber barrels through the gas-inject tube via the air vents so that the space is full of N2. The injected inert gases such as N2 or Ar can prevent CO2 from entering into the annular space above the rubber barrels, and accordingly corrosion, softening and damage caused by contacting of the CO2 and the rubber barrels are reduced, protection effect of the rubber barrels is achieved, sealing performance and work cycle of the packer are guaranteed, and meanwhile the injected gases have further compressing effect on the rubber barrel so that the rubber barrel and a casing tube can be attached more closely, and accordingly the packer can have better sealing performance. The supercritical CO2 resistant packer can be used for a long time in corrosive environment, and has high sealing performance.

Description

technical field [0001] The invention belongs to the field of geological storage devices, and more specifically relates to a supercritical CO 2 packer for CO 2 Geological storage, oil production, natural gas and other technical fields, especially suitable for drilling isolation with strong corrosive environment. Background technique [0002] Currently in CO 2 The packers used in geological storage projects are basically derived from oil and gas, geological and mining industries, and can be generally divided into four types: self-sealing, compression, wedge and expansion. Among them, the compression type is the most widely used, and its deformation products are also the most. As the exploration and development of oil reserve reserves is faced with an increasingly harsh natural environment, the working conditions of oil extraction operations are becoming more and more complex. When there are strong corrosive fluids in the formation containing oil and gas, the string The par...

AI Technical Summary

Problems solved by technology

As the exploration and development of oil reserve reserves is faced with an increasingly harsh natural environment, the working conditions of oil extraction operations are becoming more and more complex. When there are strong corrosive fluids in the formation containing oil and gas, the string Corrosion damage to the part of the rubber barrel, especially the seal part, caused the sealing performance and service life of the packer to gradually decline

Currently CO 2 The field of geological storage is an emerging industry, CO 2 CO in geological storage 2 In a supercritical state, it has a strong softening and corrosion effect on rubber and other sealing materials. At the same time, it is also highly corrosive to metal parts when combined with underground salt water. Both the rubber cylinder and the center pipe will be corroded quickly, especially The part of the rubber tube corroded and softened severely and lost its sealing, resulting in CO 2 A leak path is formed through the packer, resulting in a sealed CO 2 the leak

Today CO 2 The packer used in geological storage is still the packer used in the traditional oil and gas production industry, changing the traditional seal material, using fluorine rubber, modified nitrile rubber, Aflas and other sealing materials to replace the traditional sealing original; at the same time, using stainless steel and other corrosion-resistant materials instead of traditional metal parts, improving CO 2 The sealing performance and service life of packer seals in the environment, but limited by the current material science and technology, the degree of service life improvement is limited

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