Independent safe long-acting double-pipe water injection pipe column

Abstract

The invention discloses an independent safe long-acting double-pipe water injection pipe column. The independent safe long-acting double-pipe water injection pipe column comprises an independently arranged inner pipe and an independently arranged outer pipe. The inner pipe is arranged in the outer pipe coaxially. An inner pipe center cavity serves as an inner water injection channel communicating to a lower oil layer. An annulus formed between the inner pipe and the outer pipe serves as an outer water injection channel communicating to an upper oil layer. The annulus positions between the upper end of the inner pipe, the upper end of the outer pipe as well as the upper end outer wall of the outer pipe and a sleeve are all provided with safety control devices which are an inner pipe safety valve, an annulus safety valve and an annulus safety packer correspondingly. The inner pipe safety valve, the annulus safety valve and the annulus safety packer control the three axial channels of the inner pipe, the inner inner-outer-pipe annulus and the outer pipe and sleeve annulus correspondingly, and whole sealing during the shaft emergency condition is achieved. The lower end of the inner pipe is connected with an inner water injection pipe column body. The lower end of the outer pipe is connected with an outer water injection pipe column body. Through the independent safe long-acting double-pipe water injection pipe column, the problems of unreliable safety control, not-in-place inner and outer pipe flow separation, liable failure of an outer pipe and unbalanced pipe column stress existing in the prior art are mainly solved.

Description

technical field

[0001] The invention relates to an underground water injection pipe string for oil production; in particular, it is an independent safe and long-lasting double-pipe water injection pipe string. Background technique

[0002] At present, the water injection technology used in offshore water injection wells is mainly hollow type layered water injection technology and concentric double pipe water injection technology. The former uses concentric measurement and adjustment integration technology to conduct online measurement and adjustment of water injection wells. However, due to constraints such as well deviation restrictions, high bottom hole pressure, and high temperature, the success rate of surveying and adjustment has been greatly affected, and the urgent need for offshore refined water injection has been restricted. Although the current concentric double-pipe water injection can be deployed on the ground, it has the characteristics of simple measurement an...

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