Pipe pillar of multi-pipe injecting and washing technique of well controlling and inverse well-flushing integration

Abstract

The invention discloses a pipe pillar of a multi-pipe injecting and washing technique of well controlling and inverse well-flushing integration. A top packer, a first isolation packer, a second isolation packer and a third isolation packer are arranged in a sleeve pipe. A positioning insertion seal is arranged in the top packer, an annulus flow-back preventing check valve, a bridge type passageway, a lifting device and an outer oil pipe hang are sequentially connected to the upper portion of the positioning insertion seal. An inner oil pipe hang, a safety valve and a first insertion seal which are sequentially connected are arranged in a corrosion prevention oil pipe. A second insertion seal, a first pipe with a hole, a seal light cylinder, a third insertion seal, a check valve, a second pipe with a hole, a fourth insertion seal and a bull plug are sequentially connected to the lower portion of the positioning insertion seal. A fifth insertion seal is arranged in the seal light cylinder, the upper portion of the fifth insertion seal communicates with the annulus flow-back preventing check valve, and the lower portion of the fifth insertion seal communicates with the check valve. According to the pipe pillar of the multi-pipe injecting and washing technique of well controlling and inverse well-flushing integration, well-flushing and accurate water distribution within three layers of a super-large slope well and a horizontal water injecting well can be achieved, and the pipe pillar is suitable for a directional well (including a large slope well and the horizontal well).

Description

technical field [0001] The invention relates to the technical field of downhole water injection in oil fields, in particular to an integrated multi-tube injection and washing process string for well control backwashing. Background technique [0002] The concentric multi-pipe split injection process uses two layers of concentric tubing to divide the injection well into three injection layers. Because the pressure system of each injection channel is independent, it has the advantages of satisfying multi-media injection, large pressure difference between injection layers, and not limited by well deviation. It is widely used in Bohai Oilfield. The process has been applied since 2001, and the following two shortcomings have been found: one is that the pipe string does not have the function of flushing wells, and after long-term water injection, the pipe string cannot be lifted and caused major repairs; the other is that the pipe string does not have well control and protection ca...

AI Technical Summary

Problems solved by technology

The process has been applied since 2001, and the following two shortcomings have been found: one is that the pipe string does not have the function of flushing wells, and after long-term water injection, the pipe string cannot be lifted and caused major repairs; the other is that the pipe string does not have well control and protection capabilities. The increasing awareness of water injection safety and protection of the marine environment does not match, which affects the promotion of the technology. The above situations all affect the injection time and water injection effect of water injection wells

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