A high pressure piston pump hydraulic end valve box

Abstract

The application discloses a high-pressure plunger pump fluid end valve box, which has a fracturing fluid suction hole, a fracturing fluid discharge hole, a plunger hole and an end cover sealing hole which are connected with the inner cavity of the valve box, the axis of the fracturing fluid suction hole coincides with the axis of the fracturing fluid discharge hole or is parallel to the axis of the fracturing fluid discharge hole, the axis of the plunger hole and the axis of the end cover sealing hole which are vertically distributed coincide or are parallel to each other, and a regular space is arranged in the inner cavity of the valve box along the direction of the axis of the fracturing fluid suction hole or the axis of the fracturing fluid discharge hole. Through the technical scheme, a regular space is introduced into the inner cavity of the fluid end valve box, the shape and direction of the intersection line are changed, the intersection line is lengthened, the stress concentration at the key position is effectively reduced, and the working life of the valve box is significantly prolonged through comparison of the finite element analysis results.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield production equipment, more particularly to a high-pressure plunger pump fluid end valve box. BACKGROUND

[0002] Fracturing technology is a method of forming cracks in oil and gas bearing formations by using liquid pressure, and is a conventional stimulation technology for oil and gas fields, which is widely used. The most important equipment in fracturing construction is a high-pressure plunger pump, which is divided into a power end and a fluid end. The power end converts the energy of a diesel engine or a motor into kinetic energy through a plunger, which is transmitted to the fluid end. The main components of the fluid end are a valve box, a plunger, various valve bodies and valve seats, and sealing accessories. Its function is to suck in liquid and sand particles under normal pressure through the movement of the plunger in the fluid end, and then to discharge the valve box by compressing the liquid to the required pressure and injecting it into the oil and gas well. Figure 1 As shown in the figure, it is a typical five-cylinder fluid end valve box of a high-pressure plunger pump, which includes a fracturing fluid suction hole 1, a fracturing fluid discharge hole 2, a plunger hole 3, and an end cover sealing hole 4. The technical performance of the fluid end is directly related to the construction effect and safety on site, so the high-pressure plunger pump, especially the fluid end, must have the characteristics of high pressure resistance, fatigue resistance, corrosion resistance, strong wear resistance, and long service life.

[0003] However, the main way of unconventional oil and gas development is horizontal well plus staged fracturing. With the development of unconventional oil and gas, the number of high-pressure wells and deep wells in oil and gas production is gradually increasing, and the pressure borne by the fluid end of the high-pressure plunger pump is also increasing. The harsh high-pressure conditions greatly affect the working life of the valve box, and the valve box often fails, which seriously affects the efficiency of the fracturing process and a series of related costs.

[0004] The fluid end valve box is subjected to high-frequency, high-amplitude periodic pressure, and the usual damage is stress corrosion fatigue damage under high stress. Generally, the failure position of the fluid end valve box is concentrated in the positions with high stress concentration in the valve box cavity. Small surface cracks are first generated at these positions, which gradually expand under the action of high-frequency, high-amplitude fatigue stress, until the whole valve box begins to fail or even leaks. Figures 2-4 As shown in the figure, the four positions with significant stress concentration of the valve box are the first existing stress concentration point 13, the second existing stress concentration point 14, the third existing stress concentration point 23, and the fourth existing stress concentration point 24.

[0005] In order to improve the service life of the hydraulic end, the design and manufacture of the overall valve box often adopts measures such as changing the material of the hydraulic end, hardening the inner cavity surface, and self-reinforcing treatment, and the stress concentration parts are reduced by means of structural optimization and production process optimization. These means include the conventional intersecting line chamfering processing for reducing the stress concentration of the key area, that is, the intersecting line is naturally formed after the processing of the fracturing fluid suction hole, the fracturing fluid discharge hole, the plunger hole and the end cover sealing hole, and finally the intersecting line is polished by artificial polishing or special equipment, especially the first existing stress concentration point 13, the second existing stress concentration point 14, the third existing stress concentration point 23 and the fourth existing stress concentration point 24 are chamfered by changing the acute angle to the arc transition to reduce the stress concentration, but as shown in Figure 5 Fig. 1 is a comparison diagram of the naturally generated intersecting line and the polished intersecting line of the valve box during processing, wherein 5 is the naturally generated intersecting line, and 6 is the processed intersecting line. It can be seen that the shape and direction of the intersecting line processed by artificial polishing or special equipment do not change, only the acute angle of the intersecting line is changed to obtuse angle to reduce the stress concentration at the position of the intersecting line, that is, through finite element simulation, it is known that when the chamfer radius increases to a certain extent, the concentrated stress of the first existing stress concentration point 13, the second existing stress concentration point 14, the third existing stress concentration point 23 and the fourth existing stress concentration point 24 will not change significantly.

[0006] Therefore, it is an urgent problem for those skilled in the art to provide a high-pressure plunger pump hydraulic end valve box with significantly reduced intersecting line stress concentration. SUMMARY

[0007] Therefore, the present application provides a high-pressure plunger pump hydraulic end valve box, which changes the shape and direction of the intersecting line to effectively reduce the stress concentration at the key position.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0009] A high-pressure plunger pump hydraulic end valve box has a fracturing fluid suction hole, a fracturing fluid discharge hole, a plunger hole and an end cover sealing hole connected in the inner cavity, the fracturing fluid suction hole axis coincides with or is parallel to the fracturing fluid discharge hole axis, and the plunger hole axis and the end cover sealing hole axis distributed vertically coincide or are parallel, and a regular space is arranged in the valve box inner cavity along the direction of the fracturing fluid suction hole axis or the fracturing fluid discharge hole axis.

[0010] Further, the regular space is a cylinder or a cone.

[0011] By adopting the above scheme, the present application has the following beneficial effects:

[0012] On the basis of not changing the general spare parts of the hydraulic end of the fracturing pump used in the existing oil field, through the actual data and failure position statistics of the valve box failure, and in combination with the analysis result of the finite element simulation tool, the structure of the key position of the hydraulic end valve box prone to fatigue, stress corrosion and wear and erosion is optimized, the intersecting line is lengthened, the stress concentration degree of the key position is effectively reduced, and the comparison of the finite element analysis result shows that the structure after the optimization can greatly reduce the stress concentration degree of the key position, and thus the working life of the valve box can be significantly prolonged.

[0013] A high-pressure plunger pump hydraulic end valve box, the valve box has a fracturing fluid suction hole, a fracturing fluid discharge hole, a plunger hole and an end cover sealing hole connected with the inner cavity, the fracturing fluid suction hole axis coincides with the fracturing fluid discharge hole axis or is parallel to the fracturing fluid discharge hole axis, and the plunger hole axis and the end cover sealing hole axis perpendicular to them coincide or are parallel, a spherical space with the intersection of any two orthogonal axes of the fracturing fluid suction hole axis, the fracturing fluid discharge hole axis, the plunger hole axis and the end cover sealing hole axis as the reference is arranged in the inner cavity of the valve box.

[0014] Further, the fracturing fluid suction hole and the plunger hole, the fracturing fluid discharge hole and the plunger hole, the fracturing fluid suction hole and the end cover sealing hole, and the fracturing fluid discharge hole and the end cover sealing hole intersect with each other to form the corresponding intersecting lines of the spherical space.

[0015] Further, the intersecting line is polished to form a circular arc chamfer.

[0016] By adopting the above scheme, the application has the following beneficial effects:

[0017] On the basis of not changing the general spare parts of the hydraulic end of the fracturing pump used in the existing oil field, through the actual data and failure position statistics of the valve box failure, and in combination with the analysis result of the finite element simulation tool, the structure of the key position of the hydraulic end valve box prone to fatigue, stress corrosion and wear and erosion is optimized, the intersecting line is lengthened, the stress concentration degree of the key position is effectively reduced, and the comparison of the finite element analysis result shows that the structure after the optimization can greatly reduce the stress concentration degree of the key position, and thus the working life of the valve box can be significantly prolonged.

[0018] The utility model provides a kind of high-pressure plunger pump fluid end valve box, the valve box has the fracturing fluid suction hole, fracturing fluid discharge hole, plunger hole and end cover sealing hole with inner cavity being connected, the fracturing fluid suction hole axis coincides with the fracturing fluid discharge hole axis or parallel, and the plunger hole axis and the end cover sealing hole axis vertically distributed coincide or parallel;The fracturing fluid suction hole and the plunger hole, the fracturing fluid discharge hole and the plunger hole, the fracturing fluid suction hole and the end cover sealing hole, the fracturing fluid discharge hole and the end cover sealing hole respectively two two intersection form first interpenetrating line, and one or several places of the first interpenetrating line are cut or polished according to predetermined profile to form straightened second interpenetrating line.

[0019] Further, the predetermined profile is the line segment of straight line and the two circular arc segments at its two ends.

[0020] Further, the predetermined profile is the line segment of multiple circular arc segments.

[0021] By adopting the above scheme, the beneficial effects of the present application are:

[0022] The shape and direction of one or several places of the first interpenetrating line naturally generated in valve box processing are changed by processing and reforming to play the role of dispersing stress concentration, so as to straighten the first interpenetrating line, change the shape and direction of the first interpenetrating line to obtain the second interpenetrating line, realize the effect of expanding pressure bearing area and reducing stress concentration level, and improve the service life of the valve box. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present application, and other drawings can also be obtained according to the provided drawings without creative labor for those skilled in the art.

[0024] Figure 1 The drawing is the schematic diagram of the appearance of the existing high-pressure plunger pump fluid end;

[0025] Figure 2 The drawing is Figure 1 The drawing is the schematic diagram of the inner cavity of the fluid end valve box in the utility model;

[0026] Figure 3 The drawing is Figure 2 The drawing is the schematic diagram of the inner cavity section of the fluid end valve box in the utility model;

[0027] Figure 4 The drawing is Figure 2 The drawing is the schematic diagram of the inner cavity section of the fluid end valve box in the utility model;

[0028] Figure 5The drawing is a shape comparison schematic diagram of natural generated intersecting lines (first intersecting lines) and processed intersecting lines (first intersecting lines);

[0029] Figure 6 The drawing is a schematic diagram of the inner cavity of the fluid end valve box in the embodiment 1 of the present application;

[0030] Figure 7 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 6 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0031] Figure 8 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 6 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0032] Figure 9 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 6 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0033] Figure 10 The drawing is a schematic diagram of the inner cavity of the fluid end valve box in the embodiment 2 of the present application;

[0034] Figure 11 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 10 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0035] Figure 12 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 10 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0036] Figure 13 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 10 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0037] Figure 14 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0038] Figure 15 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0039] Figure 16 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0040] Figure 17 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application; Figure 14 The drawing is a schematic diagram of the inner cavity of the fluid end valve box provided by the present application;

[0041] In the diagram: 1-Fracturing fluid intake hole, 2-Fracturing fluid discharge hole, 3-Plunger hole, 4-End cap sealing hole, 5-Naturally generated intersection line, 6-Processed intersection line, 13-First existing stress concentration point, 14-Second existing stress concentration point, 23-Third existing stress concentration point, 24-Fourth existing stress concentration point, 131-First stress concentration point, 141-Second stress concentration point, 231-Third stress concentration point, 241-Fourth stress concentration point, 132-First stress concentration point, 142-Second stress concentration point, 232-Third stress concentration point, 242-Fourth stress concentration point, 5A-First intersection line, 6A-First intersection line completed by conventional processing, 13A-Existing stress concentration point, 133A-Stress concentration point. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1:

[0044] like Figure 6 As shown in the figure, an embodiment of the present invention discloses a hydraulic end valve box for a high-pressure plunger pump. The valve box has a fracturing fluid inlet 1, a fracturing fluid outlet 2, a plunger hole 3, and an end cap sealing hole 4 connected in the inner cavity. The axis of the fracturing fluid inlet 1 coincides with or is parallel to the axis of the fracturing fluid outlet 2. The axis of the plunger hole 3, which is perpendicular to it, coincides with or is parallel to the axis of the end cap sealing hole 4. A regular space is opened in the inner cavity of the valve box along the direction of the axis of the fracturing fluid inlet 1 or the axis of the fracturing fluid outlet 2. Through the above technical solution, without changing the existing general spare parts of the hydraulic end of the fracturing pump used in oilfields, the structure of the key locations of the hydraulic end valve box that are prone to fatigue, stress corrosion and wear erosion is optimized by combining the actual failure data and failure location statistics of the valve box with the analysis results of the finite element simulation tool. A regular space is introduced inside the hydraulic end valve box, and the shape and direction of the intersection line are changed. The intersection line is lengthened, which effectively reduces the stress concentration at the key locations. The comparison of finite element analysis results shows that the optimized structure can significantly reduce the stress concentration at the key locations, thus significantly extending the service life of the valve box.

[0045] Specifically, the regular space is a cylinder or a cone.

[0046] Specifically, the fracturing fluid suction hole 1 and the plunger hole 3, the fracturing fluid discharge hole 2 and the plunger hole 3, the fracturing fluid suction hole 1 and the end cover sealing hole 4, and the fracturing fluid discharge hole 2 and the end cover sealing hole 4 are intersected with each other to form a regular space corresponding to the intersecting line.

[0047] Specifically, the intersecting line is polished to form a circular arc chamfer.

[0048] As shown in Figure 7 , the positions of the third stress concentration point 231 and the fourth stress concentration point 241 are greatly changed compared to the positions of the third existing stress concentration point 23 and the fourth existing stress concentration point 24. The intersecting line processed according to the embodiment is elongated, effectively reducing the stress concentration at the key positions.

[0049] As shown in Figure 8 , the positions of the first stress concentration point 131 and the second stress concentration point 141 are greatly changed compared to the positions of the first existing stress concentration point 13 and the second existing stress concentration point 14. The intersecting line processed according to the embodiment is elongated, effectively reducing the stress concentration at the key positions.

[0050] As shown in Figure 9 , the left side of the figure is the shape and direction of the intersecting line in the conventional valve box cavity, and the right side is the shape and direction of the intersecting line after the embodiment is taken. By comparison, it can be known that the intersecting line after the embodiment is taken can effectively disperse the stress concentration area in the liquid end valve box cavity, and play a role in reducing the stress concentration of the four key areas.

[0051] Example 2:

[0052] As shown in Figure 10As shown, the embodiment of the present application discloses a high-pressure plunger pump fluid end valve box, the valve box has a fracturing fluid suction hole 1, a fracturing fluid discharge hole 2, a plunger hole 3 and an end cover sealing hole 4 which are connected with the inner cavity, the axis of the fracturing fluid suction hole 1 coincides with or is parallel to the axis of the fracturing fluid discharge hole 2, the axis of the plunger hole 3 and the axis of the end cover sealing hole 4 which are vertically distributed coincide or are parallel, and a spherical space is arranged in the inner cavity of the valve box, the spherical space is based on the intersection of any two orthogonal axes of the axis of the fracturing fluid suction hole 1, the axis of the fracturing fluid discharge hole 2, the axis of the plunger hole 3 and the axis of the end cover sealing hole 4. Through the above technical scheme, without changing the general spare parts of the fracturing pump fluid end used in the existing oil field, through the actual failure data and the failure position statistics of the valve box, combined with the analysis result of the finite element simulation tool, the structure of the key position where fatigue, stress corrosion and wear erosion are prone to occur is optimized, a spherical space is introduced into the fluid end valve box, the shape and direction of the intersecting line are changed, the intersecting line is lengthened, the stress concentration of the key position is effectively reduced, and the working life of the valve box is significantly prolonged through the comparison of the finite element analysis result.

[0053] Specifically, the fracturing fluid suction hole 1 and the plunger hole 3, the fracturing fluid discharge hole 2 and the plunger hole 3, the fracturing fluid suction hole 1 and the end cover sealing hole 4, and the fracturing fluid discharge hole 2 and the end cover sealing hole 4 intersect with each other to form the intersecting lines corresponding to the spherical space.

[0054] Specifically, the intersecting line is polished to form a circular arc chamfer.

[0055] As shown in the figure, Figure 11 The positions of the third stress concentration point 232 and the fourth stress concentration point 242 are greatly changed compared with the positions of the third existing stress concentration point 23 and the fourth existing stress concentration point 24, the intersecting line processed according to the embodiment is lengthened, and the stress concentration of the key position is effectively reduced.

[0056] As shown in the figure, Figure 12 The positions of the first stress concentration point 132 and the second stress concentration point 142 are greatly changed compared with the positions of the first existing stress concentration point 13 and the second existing stress concentration point 14, the intersecting line processed according to the embodiment is lengthened, and the stress concentration of the key position is effectively reduced.

[0057] As shown in the figure, Figure 13 The left side of the figure is the shape and direction of the intersecting line in the cavity of the conventional valve box, and the right side is the shape and direction of the intersecting line after the embodiment is adopted, and through comparison, it can be known that the intersecting line after the embodiment is adopted can effectively disperse the stress concentration area in the inner cavity of the fluid end valve box, and plays a role in reducing the stress concentration of the four key areas.

[0058] Embodiment 3:

[0059] As shown in Figures 1-4 , the embodiment of the present application discloses a high-pressure plunger pump fluid end valve box, the valve box has a fracturing fluid suction hole 1, a fracturing fluid discharge hole 2, a plunger hole 3 and an end cover sealing hole 4 which are connected with the inner cavity, the axis of the fracturing fluid suction hole 1 coincides with or is parallel to the axis of the fracturing fluid discharge hole 2, and the axis of the plunger hole 3 and the axis of the end cover sealing hole 4 which are vertically distributed coincide or are parallel; the fracturing fluid suction hole 1 and the plunger hole 3, the fracturing fluid discharge hole 2 and the plunger hole 3, the fracturing fluid suction hole 1 and the end cover sealing hole 4, and the fracturing fluid discharge hole 2 and the end cover sealing hole 4 respectively intersect with each other to form a first intersecting line 5A, and one or more places of the first intersecting line 5A are cut or polished according to a predetermined contour to form a straightened second intersecting line. Through the above technical solution, the shape and direction of one or more places of the first intersecting line 5A naturally generated in the valve box processing are changed by machining modification to play a role in dispersing stress concentration, thereby straightening the first intersecting line 5A, changing the shape and direction of the first intersecting line 5A to obtain the second intersecting line, realizing the effect of expanding the pressure bearing area and reducing the stress concentration level, and improving the service life of the valve box.

[0060] As shown in Figure 15 , specifically, the predetermined contour is a line segment composed of a straight line segment and two circular arc segments at both ends of the straight line segment.

[0061] As shown in Figure 16 , specifically, the predetermined contour is a line segment composed of a plurality of circular arc segments.

[0062] As shown in Figure 17 , specifically, the existing stress concentration point 13A of the first intersecting line 5A is cut or polished according to a predetermined contour to obtain a second intersecting line and a stress concentration point 133A, Figure 6 the straight line segment of the predetermined contour in Figure 7 the middle circular arc segment of the predetermined contour can straighten the first intersecting line 5A, thereby expanding the pressure bearing area and reducing the stress concentration level, thereby improving the service life of the valve box.

[0063] In the specification, each embodiment is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts are described in the method part.

[0064] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A hydraulic end valve box for a high-pressure plunger pump, characterized in that, The valve box has a fracturing fluid intake hole (1), a fracturing fluid discharge hole (2), a plunger hole (3), and an end cap sealing hole (4) connected in the inner cavity. The axis of the fracturing fluid intake hole (1) coincides with or is parallel to the axis of the fracturing fluid discharge hole (2). The axes of the plunger hole (3) and the end cap sealing hole (4), which are perpendicular to each other, coincide with or are parallel to each other. The fracturing fluid intake hole (1) and the plunger hole (3), the fracturing fluid discharge hole (2) and the plunger hole (3), the fracturing fluid intake hole (1) and the end cap sealing hole (4), and the fracturing fluid discharge hole (2) and the end cap sealing hole (4) intersect each other to form a first intersection line (5A). One or more of the first intersection lines (5A) are cut or ground according to a predetermined contour to form a straightened second intersection line. The predetermined contour is a line consisting of a straight line segment and two circular arc segments at its two ends.

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