Anti-leakage well flushing packer

Abstract

The invention discloses an anti-losing well-flushing packer. The packer comprises an upper joint, an upper shell, a center pipe, a lower shell and a lower joint which are sequentially connected from top to bottom; a packing cup assembly is arranged on the outer side of the center pipe, and a one-way switch valve is arranged inside a cylinder jointly formed by the lower shell and the lower joint; an overflowing hole communicated with the center pipe is formed in the side wall of the upper shell, and a suction opening communicated with the center pipe and the one-way switch valve at the same time is formed in the side wall of the lower shell; and the one-way switch valve comprises a flow dividing body, a valve cover, a stainless steel valve ball and a valve ball spring. The flow dividing body is fixed to the inner wall of the lower joint, the valve cover is connected to the top of the flow dividing body, and the stainless steel valve ball is arranged on the opening in the top of the flow dividing body; and a step is arranged on the inner wall of the flow dividing body, and the valve ball spring is arranged between the stainless steel valve ball and the step of the inner wall of the flow dividing body. According to the anti-losing well-flushing packer, during oil well flushing, flushing fluid can be effectively prevented from being lost and entering a stratum, the packer is reliable in sealing, wear-resisting, creep-resisting and capable of effectively preventing a ball seat from being buried by sand, and during well repairing work, oil can be drained.

Description

technical field [0001] The invention relates to a packer for oil fields, in particular to a packer for preventing leakage and flushing wells. Background technique [0002] During the oilfield development process, due to the need for thermal washing to remove wax or pump card to clean well and release jam, well washing is required to maintain normal production. In the process of well flushing, due to the low formation pressure and energy shortage of some oil wells, it is inevitable that the well flushing fluid will be injected into the formation, which will not only cause temporary or permanent damage to the formation, prolong the production recovery period or sharply reduce production, but also It also increases the consumption of well-flushing fluid, reduces the efficiency of well-flushing, and increases the operating cost. Due to serious formation leakage, some wells cannot establish circulation during well flushing, and it is difficult for oil wells to maintain normal pr...

AI Technical Summary

Problems solved by technology

In the process of well flushing, due to the low formation pressure and energy shortage of some oil wells, it is inevitable that the well flushing fluid will be poured into the formation, which will not only cause temporary or permanent damage to the formation, prolong the production recovery period or sharply reduce production, but also It also increases the amount of flushing fluid, reduces the efficiency of flushing, and increases operating costs

Due to serious formation leakage, some wells cannot establish circulation during well flushing, and it is difficult for oil wells to maintain normal production

[0003] However, in the existing well flushing packer, due to the interference fit between the cup and the casing, the cup is fully opened by the pressure of the liquid column on it every time a single lifting string is connected to pick up the elevator in the process of lowering the pipe string. Wear with the casing, especially when passing through the casing collar, the wear is more serious, causing the wear and tear failure after the cup is sealed to the predetermined position, the proper sealing effect cannot be achieved, and leakage occurs during well cleaning

At the same time, the existing well flushing packer cannot drain the oil when the pipe string is pulled out during the workover operation, which is likely to cause well site pollution; when used in sand production wells, sand buried ball seats are prone to occur, and the ball seat cannot be opened to affect normal production.

[0004] Due to the above technical deficiencies, none of the existing well flushing packers has been popularized and applied. Therefore, there is an urgent need for a leak-proof well flushing packer that is wear-resistant, sand-proof, and oil-draining.

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