CN116641887A - Hydraulic end of a fracturing pump - Google Patents

Abstract

The invention relates to the field of oil and natural gas drilling equipment and engineering technology, in particular to a hydraulic end of a fracturing pump, which includes a main valve box, an auxiliary valve box and a variable-diameter plunger; the main valve box and the auxiliary valve box are connected through The variable-diameter plunger forms cavity 1 between the large-end combined seal and the main valve box, and forms cavity 2 between the small-end combined seal and the auxiliary valve box; cavity 1 and cavity 2 can be The variable diameter plunger moves back and forth to change the volume. In the present invention, the pressure of the first high-pressure medium of the cavity acts on the right end face of the variable-diameter plunger, and the pressure of the second high-pressure medium of the cavity acts on the annular surface of the upper step of the variable-diameter plunger, and the force required for the forward movement of the variable-diameter plunger is variable The force of the right end surface of the diameter plunger is subtracted from the force of the ring surface at the upper step of the variable diameter plunger, thereby greatly reducing the plunger force of the variable diameter plunger, and solving the problem of the existing fracturing pump with a large plunger force. The size of the pump is large and the life of the wearing parts is not high.

Description

Hydraulic end of a fracturing pump

technical field

The invention relates to the field of oil and natural gas drilling equipment and engineering technology, in particular to a hydraulic end of a fracturing pump.

Background technique

In the fracturing operation, the fracturing pump, as the main actuator of the fracturing equipment, is the core component of the fracturing equipment and has an irreplaceable position in the fracturing operation process, and the hydraulic end is the key component of the fracturing pump The function of the component is to convert the mechanical energy of the power end of the fracturing pump into pressure energy. The plunger force is the key parameter of the fracturing pump. For the fracturing pump of the same specification, the smaller the plunger force, The lower the dimensional weight, the longer the life of the consumables.

At present, the plunger force of the fracturing pump is relatively large, the size of the pump is large, and the life of the wearing parts is not high. In order to pursue a smaller pump size and a longer pump life, it is urgent to design a hydraulic end of the fracturing pump.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art, and propose to design a fluid end of a fracturing pump with a smaller plunger force. At the same time, due to the reduced plunger force, the wearing parts of the power end that match it are improved. Life, reducing the overall size of the power end.

The technical scheme that the present invention solves its technical problem to take is:

A hydraulic end of a fracturing pump, comprising a main valve box, an auxiliary valve box and a variable-diameter plunger; the main valve box and the auxiliary valve box are connected through a connecting piece; the variable-diameter plunger is sealed with the main A cavity 1 is formed between the valve boxes, and a cavity 2 is formed between the small end combined seal and the auxiliary valve box; the volume of the cavity 1 and the cavity 2 can change as the variable diameter plunger moves back and forth. The pressure of the high-pressure medium in chamber 1 acts on the right end face of the variable-diameter plunger, and the pressure of the high-pressure medium in chamber 2 acts on the annular surface at the upper step of the variable-diameter plunger, and the force required for the forward movement of the variable-diameter plunger (plunger force ) is the force of the right end surface of the variable diameter plunger minus the force of the annular surface at the upper step of the variable diameter plunger, which greatly reduces the plunger force of the variable diameter plunger.

Further, the first cavity communicates with the first flow channel, the second flow channel and the third flow channel arranged in the main valve box in sequence, and the outlet of the third flow channel is in close contact with the outer wall of the variable-diameter plunger and can communicate with the second cavity .

Further, the second flow channel is parallel to the variable-diameter plunger, and the third flow channel is perpendicular to the variable-diameter plunger, which helps the high-pressure medium liquid flow between the first flow channel, the second flow channel, the third flow channel and the second cavity. circulation.

Further, the main valve box is provided with a discharge valve and a suction valve, the discharge valve and the suction valve are respectively located on both sides of cavity one, and the discharge valve is located between flow channel one and cavity one.

Further, the main valve box is provided with a discharge gland and a suction gland.

Further, the discharge gland and the suction gland are provided with threaded glands, and the threaded glands are connected to the main valve box for fixing the discharge gland and the suction gland.

Further, a combined sealing box and an oil seal are arranged between the end of the auxiliary valve box and the variable-diameter plunger, and a combined sealing gland is set outside the combined sealing box to realize the sealing between the end of the auxiliary valve box and the variable-diameter plunger.

Further, a hoop is provided at the end of the variable diameter plunger.

Further, a sealing ring is provided between the main valve box and the auxiliary valve box to enhance the sealing performance between the main valve box and the auxiliary valve box.

Further, the working principle of the hydraulic end of the fracturing pump is: when the variable-diameter plunger moves forward, the cavity becomes smaller, and the high-pressure medium liquid is discharged through the flow channel by opening the discharge valve. At the same time, a part of the high-pressure medium liquid Through the first flow channel, through the second flow channel, and then through the third flow channel, the high-pressure medium liquid is introduced into the cavity two, and the pressure of the high-pressure medium in the cavity one acts on the right end surface of the variable-diameter plunger, forming a direction opposite to that of the variable-diameter plunger. At the same time, the pressure of the high-pressure medium in the second cavity acts on the annular surface of the upper step of the variable-diameter plunger, forming a force in the same direction as the movement direction of the variable-diameter plunger, and the force required for the movement of the variable-diameter plunger (column Plug force) is the force of the right end surface of the variable diameter plunger minus the force of the annular surface at the upper step of the variable diameter plunger, thereby reducing the plunger force; when the variable diameter plunger moves backward, the cavity becomes larger, Negative pressure is generated, the suction valve is opened, the high-pressure medium liquid enters, the first cavity becomes larger, the second cavity becomes smaller, and the high-pressure medium liquid in the second cavity is discharged.

Technical effect of the present invention:

Compared with the prior art, a fluid end of a fracturing pump of the present invention has the following advantages:

1. The pressure of the first high-pressure medium in the cavity of the present invention acts on the right end face of the variable-diameter plunger, and the pressure of the high-pressure medium of the second cavity acts on the annular surface at the upper step of the variable-diameter plunger. Saili;

2. The reduction of the plunger force reduces the force of the connecting rod on the power end of the driving fluid end, reduces the pressure ratio of the bearing bush, and reduces the lateral force of the crosshead, thereby reducing the weight of the power end and the inertial force of the moving parts, improving The wearing parts of the power end improve the service life of the wearing parts of the power end;

3. When the variable-diameter plunger moves forward, especially in the high-pressure working condition of the hydraulic end of the fracturing pump, the pressure of chamber 1 and chamber 2 is the same, that is, the pressure at both ends of the big-end combination seal is the same, which significantly improves the big-end combination Seal stress conditions can increase the service life of combined seals and reduce maintenance costs;

4. When the plunger moves backward, it can also provide the discharge function of high-pressure medium liquid;

5. The invention adopts a long stroke, which can reduce the crankshaft speed and improve the life of wearing parts.

Description of drawings

Fig. 1 is a side view of the hydraulic end of the fracturing pump of the present invention;

Fig. 2 is a longitudinal sectional view of the fluid end shaft of the fracturing pump of the present invention;

Fig. 3 is a schematic diagram of the structure of the variable diameter plunger of the present invention.

In the figure, 1. Main valve box; 2. Auxiliary valve box; 3. Reducing plunger; 4. Discharge valve; 5. Suction valve; 6. Discharge gland; 7. Threaded gland; 8. Suction gland; 9. Spring bracket; 10. Big end combined seal; 11. Small end combined seal; 12. Combined sealing box; 13. Oil seal; 14. Combined sealing gland; 15. Connecting piece; 16. Clamp; 17. Sealing ring ;A, cavity one; B, flow channel one; C, flow channel two; D, flow channel three; E, cavity two.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings.

Example 1:

As shown in FIG. 1 , a hydraulic end of a fracturing pump involved in this embodiment includes a main valve box 1 , an auxiliary valve box 2 and a variable-diameter plunger 3 .

The main valve box 1 and the auxiliary valve box 2 are connected through a connecting piece 15; the variable diameter plunger 3 forms a cavity A through the large end combined seal 10 and the main valve box 1, and the small end combined seal 11 is connected with the main valve box 1. A chamber 2E is formed between the auxiliary valve boxes 2; the volume of the chamber 1A and the chamber 2E can change as the variable diameter plunger 3 moves back and forth; the discharge port and the suction port of the main valve box 1 are respectively set to discharge Valve 4 and suction valve 5; the discharge valve 4 communicates with flow channel 1 B, flow channel 2 C, and flow channel 3 D arranged in the main valve box 1 in sequence, and the discharge valve 4 is located between flow channel 1 B and cavity 1 Between A, the outlet of the flow channel 3D is in close contact with the outer wall of the reducing plunger 3 and can communicate with the cavity 2E. As a preference, the second flow channel C is parallel to the variable diameter plunger, and the third flow channel D is perpendicular to the variable diameter plunger, which helps the high-pressure medium liquid flow through the first B flow channel, the second flow channel C, and the third flow channel D. , The circulation between cavity two and E.

A discharge gland 6 and a suction gland 8 are respectively arranged on both sides of the cavity A; a threaded gland 7 is provided at the discharge gland 6 and the suction gland 8, and the threaded gland 7 is connected with the main valve box 1 , used to fix the discharge gland 6 and the suction gland 8.

A combined sealing box 12 and an oil seal 13 are arranged between the end of the auxiliary valve box 2 and the variable diameter plunger 3, and a combined sealing gland 14 is arranged outside the combined sealing box 12 to realize the connection between the end of the auxiliary valve box 2 and the variable diameter plunger 3. between the seal; the end of the variable diameter plunger 3 is provided with a clamp 16; a sealing ring 17 is provided between the main valve box 1 and the auxiliary valve box 2 to strengthen the gap between the main valve box 1 and the auxiliary valve box 2 sealing performance.

The working principle of the hydraulic end of the fracturing pump described in the present invention:

When the variable-diameter plunger 3 moves forward, the cavity A becomes smaller, and the high-pressure medium liquid opens the discharge valve 4 and is discharged through the flow channel B. At the same time, a part of the high-pressure medium liquid passes through the flow channel B and then through the flow channel C , and then through the flow channel 3D, the high-pressure medium liquid is introduced into the cavity 2E, and the pressure of the high-pressure medium in the cavity 1A acts on the right end surface of the variable-diameter plunger 3, forming a force opposite to the direction of movement of the variable-diameter plunger 3, At the same time, the pressure of the high-pressure medium in cavity 2E acts on the annular surface at the upper step of the variable-diameter plunger 3, forming a force in the same direction as the movement direction of the variable-diameter plunger 3, and the force required for the movement of the variable-diameter plunger 3 (column Plug force) needs to overcome the force of the right end surface of the variable diameter plunger 3 minus the force of the ring surface at the upper step of the variable diameter plunger 3, thereby reducing the plunger force. The plunger force of the variable-diameter plunger 3 is reduced, so that the connecting rod force of the power end equipped with the driving fluid end is reduced, the pressure ratio of the bearing bush is reduced, and the lateral force of the crosshead is reduced, thereby reducing the weight of the power end and moving parts The inertial force improves the power end wearing parts and improves the service life of the power end wearing parts.

When the variable-diameter plunger 3 moves forward, especially under high-pressure conditions, the pressures of chamber 1 A and chamber 2 E are the same, that is, the pressure at both ends of the big-end combination seal 10 is the same, which can significantly improve the pressure of the big-end combination. The stress condition of the seal 10 can improve the service life of the combined seal and reduce the maintenance cost. When the variable-diameter plunger 3 moves backward, the first chamber A becomes larger, generating negative pressure, the suction valve 5 opens, and the high-pressure medium liquid enters, the first chamber A becomes larger, and the second chamber E becomes smaller, and the second chamber E becomes smaller. E High-pressure medium liquid is discharged.

The above-mentioned specific embodiments are only specific cases of the present invention, and the scope of patent protection of the present invention includes but is not limited to the above-mentioned specific embodiments, any appropriate changes made to it by any person of ordinary skill in the technical field that conforms to the claims of the present invention Or modification, all should fall into the patent protection scope of the present invention.

Claims (10)

1. A fracturing pump fluid end which characterized in that: comprises a main valve box (1), an auxiliary valve box (2) and a reducing plunger (3); the main valve box (1) is connected with the auxiliary valve box (2) through a connecting piece (15); the variable-diameter plunger (3) forms a first cavity (A) between the main valve box (1) and the large-end combined seal (10), and forms a second cavity (E) between the small-end combined seal (11) and the auxiliary valve box (2); the first cavity (A) and the second cavity (E) can change in volume along with the forward and backward movement of the reducer plunger (3).

2. The frac pump fluid end of claim 1, wherein: the first cavity (A) is sequentially communicated with the first runner (B), the second runner (C) and the third runner (D) which are arranged in the main valve box (1), and the outlet of the third runner (D) is tightly attached to the outer wall of the reducing plunger (3) and can be communicated with the second cavity (E).

3. The frac pump fluid end of claim 2, wherein: the second flow passage (C) is parallel to the variable-diameter plunger (3), the third flow passage (D) is perpendicular to the variable-diameter plunger (3), and high-pressure medium liquid can flow among the first flow passage (B), the second flow passage (C), the third flow passage (D) and the second cavity (E).

4. The frac pump fluid end of claim 2, wherein: the main valve box (1) is internally provided with a discharge valve (4) and a suction valve (5), the discharge valve (4) and the suction valve (5) are respectively positioned at two sides of the first cavity (A), and the discharge valve (4) is positioned between the first flow passage (B) and the first cavity (A).

5. The frac pump fluid end of claim 4, wherein: the main valve box (1) is provided with a discharge gland (6) and a suction gland (8).

6. The frac pump fluid end of claim 5, wherein: screw thread glands (7) are arranged at the positions of the discharge gland (6) and the suction gland (8), and the screw thread glands (7) are connected with the main valve box (1).

7. The frac pump fluid end of claim 1, wherein: a combined sealing box (12) and an oil seal (13) are arranged between the end part of the auxiliary valve box (2) and the reducing plunger (3), and a combined sealing gland (14) is arranged on the outer side of the combined sealing box (12).

8. The frac pump fluid end of claim 1, wherein: the end part of the reducing plunger (3) is provided with a clamp (16).

9. The frac pump fluid end of claim 1, wherein: a sealing ring (17) is arranged between the main valve box (1) and the auxiliary valve box (2).

10. A frac pump fluid end according to any one of claims 1 to 9, wherein: the working principle of the hydraulic end of the fracturing pump is as follows: when the variable diameter plunger (3) moves forwards, the cavity I (A) is reduced, the high-pressure medium liquid opens the discharge valve (4) to be discharged through the flow passage I (B), meanwhile, a part of the high-pressure medium liquid passes through the flow passage I (B), passes through the flow passage II (C) and then passes through the flow passage III (D), the high-pressure medium liquid is introduced into the cavity II (E), the pressure of the high-pressure medium of the cavity I (A) acts on the right end surface of the variable diameter plunger (3) to form acting force opposite to the moving direction of the variable diameter plunger (3), meanwhile, the pressure of the high-pressure medium of the cavity II (E) acts on the annular surface at the upper step of the variable diameter plunger (3) to form acting force in the same direction as the moving direction of the variable diameter plunger (3), and the acting force required by the movement of the variable diameter plunger (3) is the acting force of the annular surface at the upper step of the variable diameter plunger (3), so that the plunger force is reduced; when the reducing plunger (3) moves backwards, the first cavity (A) is enlarged, negative pressure is generated, the suction valve (5) is opened, high-pressure medium liquid enters, the first cavity (A) is enlarged, the second cavity (E) is reduced, and the high-pressure medium liquid in the second cavity (E) is discharged.