Sand flushing and plugging removal pipe string

Abstract

The invention provides a pipe string for sand flushing and plugging removal, which can clean the sand produced in the well and ensure the output of the oil well. Sand flushing and plugging removal pipe string, including center pipe, upper joint, packer, bridge joint and lower joint; the upper joint is connected to the upper end of the central pipe to form an annular space with the central pipe, and the upper joint is provided with a connecting The liquid inlet of the space outside the space and the upper joint; the packer is connected with the upper joint to form an annulus with the central pipe; the bridge joint is connected with the other end of the packer, and the inner wall of the upper end of the bridge joint is connected to the center Annulus is formed between the tubes; a central hole and an eccentric hole are provided in the bridge joint; the upper end of the central hole communicates with the inner cavity of the central pipe, and the lower end is blocked, and the bridge joint also has a connecting center hole and the outside of the bridge joint The upper end of the eccentric hole communicates with the annular space surrounded by the central pipe, the upper joint, the packer and the bridge joint, and the lower end of the eccentric hole communicates with the lower joint; the central hole and the eccentric hole are connected by the central pipe Separated, not connected to each other.

Description

technical field [0001] The invention relates to the technical field of sand washing tools for oil wells, in particular to a pipe string for sand washing and plugging removal. Background technique [0002] The oil well in the prior art pumps the crude oil in the oil layer into the oil well when it is working. With the increase of the pressure difference inside and outside the oil well, the flow velocity of the crude oil flowing into the well will also increase, and the drag force on the rock becomes larger. When dragging When the force is greater than the tensile strength of the rock, the rock will be damaged by stretching and become sand grains, which will flow into the oil well with the crude oil; When the pressure exceeds the shear stress of the rock, the rock will be sheared and broken into sand grains. As the crude oil flows into the oil well, these sand grains will produce sand in the well after entering the oil well. [0003] The sand particles in the oil well will co...

AI Technical Summary

Problems solved by technology

[0003] The sand in the oil well will continue to deposit at the bottom of the well, forming a sand column. When the sand column is too high, it will block the oil outlet channel; and the sand will also wear out various oil production pumps and pipelines, reduce pump efficiency, and reduce production or even stop production of the oil well.

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