Sand blocking valve for screw pump

Abstract

The invention discloses a sand blocking valve for a screw pump, and belongs to the technical field of oil extraction and sand blocking. The outer side and the inner side of one end of the upper connector are connected with the outer pipe and the inner pipe respectively, a valve clack hole is formed in the inner pipe, a plurality of valve clacks are rotationally connected with the inner pipe, a hoop spring is arranged at the movable end of each valve clack, a sand containing cavity is formed between the inner pipe and the outer pipe, the valve clacks rotate to open and close the valve clack holes, and then connection and disconnection between the sand containing cavity and the inner pipe are achieved. The screw pump has the beneficial effects that sand is prevented from entering the screw pump, and the screw pump is effectively protected.

Description

Technical Field

[0001] The invention relates to a sand retaining valve for a screw pump, belonging to the technical field of oil production sand retaining. Background Art

[0002] Currently, most oil well sand control measures involve installing sand control structures at the inlet of the oil pump, which has achieved some success. However, when the pump is stopped, sand in the liquid in the upper tubing string can settle on the upper part of the pump barrel, causing pump sand jams and even requiring pump inspection. This is particularly true for relatively low-power submersible pumps, where excessive sand deposition can burn out the pump motor. Summary of the Invention

[0003] In order to solve the problem that a submersible oil pump cannot be started or the motor is burned due to sand deposited on the pump pipe, the present invention provides a sand retaining valve for a screw pump.

[0004] The technical solution of the present invention is: a sand retaining valve for a screw pump, the outer side and the inner side of one end of the upper joint are respectively connected to the outer tube and the inner tube, a valve flap hole is opened on the inner tube, a plurality of valve flaps are rotatably connected to the inner tube, a hoop spring is provided at the movable end of the valve flap, a sand containing cavity is provided between the inner tube and the outer tube, and the valve flap realizes the opening and closing of the valve flap hole by rotation, thereby realizing the connection and disconnection between the sand containing cavity and the inner tube.

[0005] The outer side and the inner side of one end of the upper joint are respectively threadedly connected with the outer pipe and the inner pipe.

[0006] A rotation limiting device for the valve disc is provided in the inner tube.

[0007] The rotation limiting device is a limiting frame.

[0008] One end of the valve flap is rotatably connected to the inner tube through a rotating shaft.

[0009] A ball valve is provided at the end of the sand containing chamber.

[0010] The ball valve comprises a ball seat fixed between an outer tube and an inner tube, a valve ball is arranged in the ball seat, and a valve cover is arranged on the ball seat, and the valve cover fixes the valve ball in the ball seat.

[0011] The rotating shaft is located at one end of the valve flap hole away from the upper joint.

[0012] The upper joint and the inner tube are both connected to the oil pipe.

[0013] The beneficial effects of the present invention are as follows: after starting the pump, crude oil is transported upward along the oil pipe. Under the impact of the crude oil, the valve disc overcomes the resistance of the hoop spring and rotates toward the valve disc hole, thereby opening the oil pipe and allowing the crude oil to be smoothly lifted to the ground; after stopping the pump, the impact force of the crude oil on the valve disc weakens and disappears, and the valve disc is reset under the action of the hoop spring, and sand falls and deposits on the valve disc in the sand retaining valve. Excessively deposited sand enters the sand containing cavity along the valve disc hole, preventing the sand from entering the screw pump, thereby effectively protecting the screw pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a cross-sectional view of the valve disc in the open state;

[0015] Figure 2 Schematic diagram of the valve disc closed state;

[0016] Figure 3 This is a cross-sectional view of the valve disc in closed state;

[0017] Figure 4 This is an application view of the present invention.

[0018] The reference numerals in the figure are as follows: 1. upper joint, 2. outer tube, 3. inner tube, 4. valve disc hole, 5. valve disc, 6. rotating shaft, 7. limit frame, 8. sand containing chamber, 9. valve cover, 10. ball seat, 11. valve ball, 12. hoop spring. DETAILED DESCRIPTION

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the present invention will be described in detail below in combination with the accompanying drawings and detailed embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0021] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0022] Next, the present invention is described in detail with reference to schematic diagrams. For ease of illustration, cross-sectional views of device structures may be partially enlarged and not to scale when describing the embodiments of the present invention. Furthermore, the schematic diagrams are merely illustrative and should not limit the scope of protection of the present invention. Furthermore, in actual production, three-dimensional dimensions, including length, width, and depth, should be included.

[0023] The following is combined with Figure 1-4 The present invention is described in further detail:

[0024] Example 1

[0025] A sand retaining valve for a screw pump, wherein the outer side and the inner side of one end of the upper joint 1 are respectively provided with an external thread and an internal thread, and are respectively threadedly connected to the outer tube 2 and the inner tube 3, a valve flap hole 4 is opened on the inner tube 3, and a rotating shaft 6 is provided on the inner tube 3 at the bottom end of the valve flap hole 4, and a plurality of valve flaps 5 are rotatably connected to the inner tube 3 through the rotating shaft 6. The rotating shaft 6 is located at the end of the valve flap hole 4 away from the upper joint 1, so that the valve flap 5 flips upward when impacted by crude oil, and a limit frame 7 is provided at the bottom of the rotating shaft 6 to limit the rotation of the valve flap 5. When the inner tube 3 is closed by the valve flap 5, the valve flap 5 rests on the limit frame 7, and a hoop spring 12 is provided at the movable end of the valve flap 5. When the pump is stopped, the valve flap 5 is in a closed state under the action of the hoop spring 12 (such as Figure 2 As shown), a sand containing cavity 8 is provided between the inner tube 3 and the outer tube 2, and the valve flap 5 realizes the opening and closing of the valve flap hole 4 by rotating, thereby realizing the connection and disconnection between the sand containing cavity 8 and the inner tube 3.

[0026] After the pump is started, crude oil is transported upward along the inner tube 3. Under the impact of the crude oil, the valve disc 5 overcomes the resistance of the hoop spring 12 and rotates upward toward the valve disc hole 4, thereby opening the inner tube 3 and allowing the crude oil to be smoothly lifted to the ground. After the pump is stopped, the impact of the crude oil on the valve disc 5 weakens and disappears. The valve disc 5 is reset under the action of the hoop spring 12, and the sand falls and deposits on the valve disc 5 in the sand retaining valve. Excessive sand deposited enters the sand holding chamber 8 along the valve disc hole 4. The limit frame 7 limits the valve disc 5 from rotating beyond its stroke and also plays a supporting role, preventing the valve disc from tilting downward due to the excessive sand deposited. The reset valve disc 5 prevents the sand from entering the screw pump, effectively protecting the screw pump. After the pump is pumped again, the valve disc 5 is pushed open by the crude oil again. Most of the sand on the valve disc 5 is pushed into the sand holding chamber 8, and a small part is lifted to the ground together with the crude oil.

[0027] Example 2

[0028] As a supplement to Example 1, a ball valve is provided at the bottom of the sand holding chamber 8. The ball valve includes a ball seat 10 fixed between the outer tube 2 and the inner tube 3. A valve ball 11 is disposed in the ball seat 10. A valve cover 9 is provided on the ball seat 10. The valve cover 9 secures the valve ball 11 in the ball seat 10. The upper end of the upper joint 1 and the lower end of the inner tube 3 are both connected to the oil pipe to form a conveying channel. The oil pipe is located within the casing. A packer is provided between the oil pipe and the casing. The packer divides the space between the oil pipe and the casing into several sections. When the liquid in the pipeline stops flowing, the sand in the liquid will deposit on the sand retaining valve, achieving segmented sand retention. In the past, without sand retaining valves, the sand accumulated together and was heavy. The limited capacity of the screw pump made it impossible to displace the deposited sand all at once. The segmented design ensures that the sand stored in each section is much less than that in an unsegmented environment, allowing the screw pump to easily break through each sand blockage section. During installation, the number of sand retaining valves in the entire pipeline can be designed according to actual conditions.

[0029] When there is too much sand deposited in the sand holding chamber 8 and it needs to be cleaned, a sand flushing fluid is injected into the annular space between the oil pipe and the casing. Due to the effect of the packer, the sand flushing fluid will not enter the formation, so that the sand flushing fluid will flush the valve ball 11 and further pass through the valve cover 9, flushing the sand in the sand holding chamber into the inner tube 3 through the valve disc chamber 4. The sand flushing fluid carries the sand upward along the inner tube 3 and is finally transported to the surface.

[0030] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A sand retaining valve for a screw pump, characterized in that: The outer side and the inner side of one end of the upper joint (1) are connected to the outer tube (2) and the inner tube (3) respectively. A valve flap hole (4) is opened on the inner tube (3). A plurality of valve flaps (5) are rotatably connected to the inner tube (3). A hoop spring (12) is provided at the movable end of the valve flap (5). A sand containing cavity (8) is provided between the inner tube (3) and the outer tube (2). The valve flap (5) is rotated to open and close the valve flap hole (4), thereby realizing the connection and disconnection between the sand containing cavity (8) and the inner tube (3).

2. The sand retaining valve for a screw pump according to claim 1, characterized in that: The outer side and the inner side of one end of the upper joint (1) are respectively threadedly connected to the outer tube (2) and the inner tube (3).

3. The sand retaining valve for a screw pump according to claim 1, characterized in that: A rotation limiting device for the valve flap (5) is provided in the inner tube (3).

4. The sand retaining valve for a screw pump according to claim 3, characterized in that: The rotation limiting device is a limiting frame (7).

5. The sand retaining valve for a screw pump according to claim 1, characterized in that: One end of the valve flap (5) is rotatably connected to the inner tube (3) via a rotating shaft (6).

6. The sand retaining valve for a screw pump according to claim 1, characterized in that: A ball valve is provided at the end of the sand holding chamber (8).

7. The sand retaining valve for a screw pump according to claim 6, characterized in that: The ball valve comprises a ball seat (10) fixed between an outer tube (2) and an inner tube (3), a valve ball (11) being arranged in the ball seat (10), a valve cover (9) being arranged on the ball seat (10), and the valve cover (9) fixing the valve ball (11) in the ball seat (10).

8. The sand retaining valve for a screw pump according to claim 5, characterized in that: The rotating shaft (6) is located at an end of the valve flap hole (4) away from the upper joint (1).

9. The sand retaining valve for a screw pump according to claim 1, characterized in that: The upper joint (1) and the inner tube (3) are both connected to the oil pipe.

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