Integral-assembling type heat-insulating oil pipe connection structure

Abstract

The invention discloses an integral-assembling type heat-insulating oil pipe connection structure which comprises a box coupling, a factory end of an outer pipe, and a user end of the outer pipe, wherein the insides of the factory end and user end of the outer pipe are respectively hermetically welded with a pipe-body inner pipe, and a pipe-end inner pipe is arranged between a factory end of the pipe-body inner pipe and a user end of the pipe-body inner pipe, the two ends of the pipe-end inner pipe are connected with the factory end and user end of the pipe-body inner pipe by a seal butt joint structure, and a closed pipe-end heat-insulating cavity is formed between the pipe-end inner pipe and the factory end of the pipe-body inner pipe as well as the factory end of the outer pipe, the box coupling, the user end of the pipe-body inner pipe and the user end of the outer pipe; the inside of the pipe-end heat-insulating cavity is provided with a heat-insulating sleeve; and a seal structure is formed between the factory end of the pipe-body inner pipe and the pipe-end inner pipe as well as the user end of the pipe-body inner pipe, and can reduce the heat conduction, heat convection and radiation effects of the connecting part of the box coupling, thereby reducing the heat loss of the connecting part of the box coupling and improving the sealing performance of the connecting part of the box coupling, and the seal structure can prevent the occurrence of a problem that the box coupling is easy to corrode at high temperature.

Description

【Technical field】 [0001] The invention relates to a connection structure of heat-insulated oil pipe joints for thermal recovery of heavy oil, in particular to a connection structure of vacuum heat-insulated oil pipe joints. 【Background technique】 [0002] Crude oil with high viscosity and high specific gravity is called heavy oil. The viscosity of heavy oil changes significantly with temperature. Tests show that for heavy oil, if the temperature increases by 8-9 °C, its viscosity can be reduced by half. Therefore, for the exploitation and transportation of heavy oil, heat is often used to reduce its viscosity; injecting steam into the underground heavy oil layer is the main technical measure for heavy oil exploitation in the petroleum industry, commonly known as "steam huff and puff method for thermal recovery of heavy oil" or " steam driven method". [0003] When injecting high-temperature (200°C-350°C) steam into the ground, in order to reduce the loss of heat and reduce...

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Problems solved by technology

[0006] For the above purpose, the applicant disclosed a joint connection structure of heat-insulated oil pipe in application number 201010513674.3, which can not only reduce the heat loss at the joint joint of heat-insulated oil pipe, but also ensure the sealing performance here. Eliminate the possibility of Cl at the joints caused by high temperature - , CO 2 corrosion defects

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