Bypass sand setting water injection well check valve

Abstract

According to the bypass sand setting water injection well check valve, an outer communication slotted hole is formed in the side wall of the upper section of a sand setting cylinder, a blind hole drilled from bottom to top is formed in a valve body, an inner communication slotted hole is formed in the side wall of the upper section of the valve body, the valve body is placed in the sand setting cylinder, the inner communication slotted hole corresponds to the outer communication slotted hole, and the inner communication slotted hole is communicated with the blind hole. The valve body and the sand setting cylinder are welded at the position of the external communication slotted hole, the check valve is installed on the valve body, the check valve is fixed on the valve body through the fixing screwed plug, the check valve is an inverted one-way control valve, and liquid flow can only flow through the check valve downwards from the blind hole to enter the sand setting cylinder. Liquid flow cannot flow upwards into the blind hole from the interior of the inner sand setting cylinder through the check valve, a sand setting channel is formed between an inner hole of the sand setting cylinder and the valve body, the upper portion of the valve body is conical, the lower connector is installed on the lower portion of the sand setting cylinder, and the lower portion of the lower connector is provided with oil pipe threads connected with a field tail pipe. Oil pipe threads connected with the lower portion of the water injection tubular column are arranged on the upper portion of the sand setting cylinder.

Description

Technical Field

[0001] The utility model is a tool for oilfield injection wells, which is a check valve used for pressure testing and setting of injection well strings. Specifically, it is a bypass sand-settling injection well check valve. Background Art

[0002] The check valve at the bottom of the injection string is installed at the bottom of the injection string. The function of the check valve at the bottom of the injection string is to seal the injection string, which can be used for pressure testing of the injection string to verify the sealing performance of the injection string. In addition, it is used to cooperate with the setting of the injection packer. At the same time, it is required to meet the requirement that the washing water injected from the casing enters the injection string through the check valve at the bottom of the injection string and returns to the ground (washing the well). Currently, the check valve at the bottom of the injection string is fixed at the bottom of the injection string and is lowered into the well during operation with the injection string. The liquid can only enter from the lower part of the valve ball in the check valve to the upper part of the valve ball, and cannot flow from the upper part of the valve ball to the lower part of the valve ball.

[0003] During the injection process of the injection well, due to pressure fluctuations or opening and closing of the well, sometimes the bottom hole pressure is lower than the formation pressure. At this time, the formation fluid will flow reversely into the wellbore, which is called formation backflow. When the formation backflows, it will carry out formation sand and flow into the injection string and sink to the check valve at the bottom of the string, causing the check valve to be blocked. For example, the Chinese patent: 201920877543X "A Check Valve for Injection Wells" will have the problem of being blocked. After the check valve is buried by sand, the washing channel is blocked, and the long-term normal injection of the injection well cannot be guaranteed.

[0004] The Chinese patent 2020220042987 "A Check Valve for Injection Wells with a Sand-Settling Channel" has a sand-settling channel, which can sink the sand into the sand-settling tail pipe at its lower part. However, the sand-settling channel of this structure is formed by two groups of symmetric communication holes, and the sand-settling channel is small, which is not conducive to the sinking of sand, and it is easy to have sand accumulated on the upper port of the sand-settling channel, losing the function of preventing sand blockage by sand settling. Summary of the Invention

[0005] The purpose of the utility model is to provide a sand-preventing and sand-carding oil pump with a partial-hole oil inlet and sand-settling device, which overcomes the deficiencies of the prior art, has a large flow area of the sand-settling channel, prevents sand blockage of the sand-settling channel, and increases the production cycle of the injection string.

[0006] The object of the utility model is achieved as follows: It includes a valve body, a check valve, a fixed plug, a sand settling cylinder, and a lower joint. An external communication slot hole is formed on the upper side wall of the upper section of the sand settling cylinder. The valve body is provided with a blind hole drilled from bottom to top. An internal communication slot hole is arranged on the upper side wall of the valve body. The valve body is placed inside the sand settling cylinder. The internal communication slot hole corresponds to the external communication slot hole. At the external communication slot hole, the valve body and the sand settling cylinder are welded. After the valve body and the sand settling cylinder are welded into one body, the liquid outside the external communication slot hole can only enter the blind hole through the internal communication slot hole and cannot enter the sand settling cylinder through the weld seam. The check valve is installed on the valve body and is fixed on the valve body by the fixed plug. The upper port of the check valve communicates with the blind hole. The valve ball in the check valve is inverted on the lower port of the valve seat inside it by a spring or buoyancy, making the check valve an inverted one-way control valve. The liquid flow can only flow downward from the blind hole through the check valve into the sand settling cylinder, and the liquid flow cannot flow upward from the inside of the sand settling cylinder through the check valve into the blind hole. A sand settling channel is formed between the inner hole of the sand settling cylinder and the valve body. The upper part of the valve body is conical. The lower joint is installed at the lower part of the sand settling cylinder. The lower part of the lower joint has tubing threads for connecting with the on-site tail pipe. The upper part of the sand settling cylinder has tubing threads for connecting with the lower part of the water injection string. The lower part of the fixed plug has a wrench tool insertion mechanism, enabling the tool to be inserted from the lower part of the sand settling cylinder to tighten the fixed plug on the lower part of the check valve.

[0007] The beneficial effects of the utility model are as follows: The sand settling channel is concentrated on one side of the sand settling cylinder, forming a bypass-shaped sand settling channel. This sand settling channel is relatively concentrated, and the sand will not accumulate or form a sand bridge, overcoming the problems existing in the prior art, preventing sand blockage of the sand settling channel, increasing the production cycle of the water injection string. The check valve is of an inverted structure, and the sand will not sink onto the check valve, having significant economic benefits. Brief Description of the Drawings

[0008] Attached Figure 1 is a cross-sectional view of the utility model.

[0009] Attached Figure 2 is Figure 1 the right view of Detailed Description of the Embodiment

[0010] The following combines with the attached Figure 1 to describe the embodiments of the utility model.

[0011] From Figure 1It can be seen that the embodiments of the present utility model include a valve body 2, a check valve 3, a fixed plug 4, a sand settling cylinder 5, and a lower joint 6. An external communication slot hole 5-2 is formed on the upper side wall of the sand settling cylinder 5. The valve body 2 is provided with a blind hole 2-1 drilled from bottom to top. An internal communication slot hole 2-2 is arranged on the upper side wall of the valve body 2. The valve body 2 is placed inside the sand settling cylinder 5. The internal communication slot hole 2-2 corresponds to the external communication slot hole 5-2. At the external communication slot hole 5-2, the valve body 2 and the sand settling cylinder 5 are welded. After the valve body 2 and the sand settling cylinder 5 are welded into one body, the liquid outside the external communication slot hole 5-2 can only enter the blind hole 2-1 through the internal communication slot hole 2-2 and cannot enter the sand settling cylinder 5 through the weld seam. The check valve 3 is installed on the valve body 2. The check valve 3 is fixed on the valve body 2 by the fixed plug 4. The upper port of the check valve 3 communicates with the blind hole 2-1. The valve ball in the check valve 3 is inverted on the lower port of the valve seat inside it by a spring or buoyancy, making the check valve 3 an inverted one-way control valve. The liquid flow can only flow downward from the blind hole 2-1 through the check valve 3 into the sand settling cylinder 5, and the liquid flow cannot flow upward from the inside of the sand settling cylinder 5 through the check valve 3 into the blind hole 2-1. A sand settling channel 5-1 is formed between the inner hole of the sand settling cylinder 5 and the valve body 2. The upper part of the valve body 2 is conical. The lower joint 6 is installed at the lower part of the sand settling cylinder 5. The lower part of the lower joint 6 has tubing threads for connecting to the on-site tail pipe. The lower part of the fixed plug 4 has a tool insertion mechanism for an installation wrench, enabling the tool to be inserted from the lower part of the sand settling cylinder 5 to tighten the fixed plug 4 at the lower part of the check valve 3. The upper part of the sand settling cylinder 5 is connected to a reducer joint 1. The upper part of the reducer joint 1 has tubing threads for connecting to the lower part of the water injection string.

[0012] The present utility model is installed at the lower part of the water injection string. The lower part of the lower joint is connected to a sand settling tail pipe, and a plug is installed at the bottom of the sand settling tail pipe to keep the water injection string in a sealed state. During well flushing, the flushing water enters the blind hole (2-1) through the external communication slot hole 5-2 and the internal communication slot hole 2-2 and then flows downward. The flushing water flows through the check valve 3 to flush the water injection string. When sand is ejected from the formation in reverse, the formation sand can sink to the tail pipe through the sand settling channel 5-1. The tail pipe connected to the lower part of the lower joint is the tubing used on site.

Claims

1. A bypass sand settling water injection well check valve, comprising a valve body (2), a check valve (3), a fixed plug (4), a sand settling cylinder (5), and a lower joint (6), wherein: An external connecting slot (5-2) is provided on the upper side wall of the sand settling cylinder (5), a blind hole (2-1) drilled from bottom to top is provided on the valve body (2), an internal connecting slot (2-2) is provided on the upper side wall of the valve body (2), the valve body (2) is placed in the sand settling cylinder (5), the internal connecting slot (2-2) corresponds to the external connecting slot (5-2), the valve body (2) and the sand settling cylinder (5) are welded at the external connecting slot (5-2), after the valve body (2) and the sand settling cylinder (5) are welded into one body, liquid outside the external connecting slot (5-2) can only enter the blind hole (2-1) through the internal connecting slot (2-2), and cannot enter the sand settling cylinder (5) through the weld, and a check valve (3) is installed on the valve body (2), and the check valve (3) is fixed The plug (4) is fixed on the valve body (2). The upper port of the check valve (3) is communicated with the blind hole (2-1). The valve ball in the check valve (3) is inverted on the lower port of the valve seat therein by a spring or buoyancy, so that the check valve (3) is an inverted one-way control valve. Liquid can only flow downward from the blind hole (2-1) through the check valve (3) to the sand settling cylinder (5). Liquid cannot flow upward from the inside of the inner sand settling cylinder (5) through the check valve (3) into the blind hole (2-1). A sand settling channel (5-1) is formed between the inner hole of the sand settling cylinder (5) and the valve body (2). The lower joint (6) is installed at the lower part of the sand settling cylinder (5). The lower part of the lower joint (6) has a tubing thread connected to the on-site tail pipe, and the upper part of the sand settling cylinder (5) has a tubing thread connected to the lower part of the water injection pipe column.

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