A self-centering oil well pump fixed valve

Abstract

A self-centering oil well pump fixed valve comprises: a box body 10, a centering body 30 is installed in the box body 10, an accumulator 20 is installed between the centering body 30 and the liquid outlet of the box body 10, a ball 40 is installed on the centering body 30, the ball 40 and the box body 10 are in point contact, a cavity ring 60 is installed on the centering body 30, a protective cavity is formed between the centering body 30 and the cavity ring 60, a setting ball 50 is installed in the protective cavity, and a box body seat 70 is installed at the liquid inlet of the box body 10. The centering body 30, ball 40 and box body 10 interact with each other to achieve automatic centering, keeping the centroid of the setting ball 50 always relatively consistent with the centroid of the box body seat 70.

Description

Technical Field

[0001] The invention discloses a self-centering oil well pump fixed valve, belonging to the technical field of self-centering oil well pump fixed valves. Background Art

[0002] In order to achieve centralized management of pumping units, oil fields usually arrange multiple pumping wells together on the ground into a platform, so the wellheads of the oil wells are concentrated together on the ground, but the oil wells are drilled obliquely in all directions underground, so there will be an angle between the direction of the oil well and the vertical direction. The angle between the direction of the oil well and the vertical direction is called well inclination, and the maximum angle of well inclination is 90 degrees. That is to say, the well section with a horizontal direction deep underground is called a horizontal well, and almost all oil wells have well inclination. Therefore, high-angle pumps and even horizontal well pumps have become a rigid demand, because conventional pumps cannot be used in oil wells with large well inclination. The fundamental reason is that conventional fixed valves will fail in oil wells with large well inclination and cannot be sealed.

[0003] The specific reasons are as follows: the valve ball of the fixed valve is seated on the valve seat by gravity. When there is a well inclination angle, the fixed valve ball will be biased to one side inside the valve cover due to gravity. When the well inclination angle is greater than 45 degrees, it may not be able to seat on the valve seat. When the horizontal angle is reached, the fixed valve ball stops in one position and no longer works. This problem cannot be solved by existing technology.

[0004] Further reasons are as follows: In the prior art, there is a necessary gap between the valve ball and the valve cover for movement and liquid flow (otherwise the valve ball will not be able to move and liquid will not flow). The traditional valve cover in the prior art is provided with a rib and a liquid flow channel for the valve ball, but there must also be a gap between the rib of the valve cover and the valve ball. It is precisely because of the existence of this gap that the centroid of the valve ball and the centroid of the valve seat are eccentric, and there is also a gap between the radial direction of the valve seat and the valve cover. This gap will aggravate the eccentricity between the valve ball and the valve seat.

[0005] like Figure 1 As shown, among them: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity. This is an ideal fixed valve. After installation, the valve seat 3 is exactly in the center of the valve cover 1 and coincides with the center of the valve ball 2 (but this situation will not happen during the actual assembly process. The direction of the oil well will have a well inclination angle, such as Figure 1 This state basically only exists under ideal conditions. Figure 1 The ideal state shown can be used as a reference for comparison with other working states.

[0006] like Figure 2As shown in the figure, among them: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity. When the well inclination angle reaches 45 degrees, the valve ball 2 is biased to the lower side of the valve cover 1 due to gravity. At this time, the centroid axis of the valve ball 2 no longer coincides with the centroid axis of the valve seat 3. The chamfered corner of the lower part of the inner cavity of the valve cover 1 will interfere with the sealing of the valve ball 2 to the valve seat 3. Affected by this, the valve ball 2 will not be able to return to the correct position and seal with the valve seat 3 accurately and timely. Therefore, when the well inclination angle reaches 45 degrees, it will completely fail to work.

[0007] like Figure 3 As shown, among them: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity, the valve ball 2 is biased to the lower side of the valve cover 1 due to gravity. At this time, the centroid axis of the valve ball 2 no longer coincides with the centroid axis of the valve seat 3. The valve ball 2 completely loses the power generated by gravity to move closer to the valve seat 3 and can no longer rely on gravity to achieve sealing with the valve seat 3, causing the oil pump to fail and be scrapped.

[0008] Therefore, the market is in urgent need of a pump fixing valve that can be used normally in oil wells with large well inclination angles.

[0009] However, the current existing technologies cannot meet the requirements. The existing large well deviated pump fixed valve technology and its shortcomings and defects are specifically described as follows:

[0010] First, the existing large well deviated pump fixed valve technology:

[0011] like Figure 4 As shown, where: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity; 5, spring. This technical method uses spring 5 to force the valve ball 2 to return to its original position. The spring 5 is installed in the traditional fixed valve. The spring force replaces gravity to push the valve ball 2 to the valve seat 3. This method can provide the valve ball 2 with the power to seat, but it cannot solve the following problems: Figure 2 、 Figure 3 The eccentricity problem of the valve ball 2 and the valve seat 3 shown in the figure, and there is also a fatal flaw when using the spring 5: due to the forced reset effect of the spring 5, the valve ball 2 on the lower side will continuously hit the straightening rib of the valve cover 1 and the lower side of the valve seat 3 due to the effect of gravity eccentricity. Over time, the valve ball 2 will impact and wear the lower edge of the seating surface of the valve seat 3 into an elliptical notch, thereby making the seating seal ineffective.

[0012] Therefore, the solution of using the spring 5 to force the valve ball 2 to return to its original position cannot completely solve the problem of using the fixed valve in oil wells with large well deviation angles.

[0013] Second, the existing large well deviated pump fixed valve technology:

[0014] like Figure 5As shown, among them: 1. valve cover; 2. valve ball; 3. valve seat; 4. lower joint; δ, eccentricity; 5. spring; 6. high-hardness straightening rib. As shown in the figure, this technical method is to use spring 5 to force the valve ball 2 to reset + high-hardness straightening rib 6 technology. This technical method is to install high-hardness straightening rib 6 and spring 5 in the traditional fixed valve. The hardness or wear resistance of high-hardness straightening rib 6 is relatively high, and it still cannot solve the eccentricity problem between the valve ball 2 and the valve seat 3. Moreover, the hardness of high-hardness straightening rib 6 cannot be increased indefinitely. The hardness of this high-hardness straightening rib 6 must be lower than the hardness of the valve ball 2. Therefore, adding high-hardness straightening rib 6 will only delay the wear rate but cannot avoid wear. Therefore, the use of high-hardness straightening rib 6 cannot completely solve the problem. At the same time, what is more serious is that the hardness or wear resistance of high-hardness straightening rib 6 will damage the valve ball 2, accelerate the wear of the valve ball 2, and rapidly reduce the roundness accuracy of the valve ball 2, thereby causing poor sealing and premature scrapping.

[0015] Therefore, the solution of using the spring 5 to force the valve ball 2 to return to its original position + the high-hardness straightening rib 6 cannot solve the eccentricity problem, cannot fundamentally solve the impact wear problem, and cannot be widely used in large-angle oil wells.

[0016] Third, the fatal flaw of existing fixed valve technology is that there is a serious eccentricity between the valve ball and the valve seat.

[0017] like Figures 2 to 5 As shown, when the valve seat 3 in the prior art is installed in the valve cover 1, there is a gap between the valve cover 1 in the radial and circumferential directions. This gap causes the valve seat 3 to form a natural eccentricity with the valve cover 1 (with Figure 1 The eccentricity of the valve seat 3 is random and will be biased to any side due to friction during assembly. The direction of this offset is random during the lowering process. After lowering, when the valve seat 3 is positioned upward, a large eccentricity will be formed between the valve cover 1. This eccentricity will be superimposed on the eccentricity between the valve ball 2 and the valve cover 1, forming a large eccentricity δ.

[0018] Fourth, the second fatal flaw commonly found in existing fixed valve technology: loose connections

[0019] like Figures 1 to 5 As shown, existing fixed valve technology generally has the following fatal flaws, namely, frequent disconnection accidents between the valve cover 1 and the lower joint 4. Analysis of its structure reveals the following facts: the valve cover 1, valve seat 3, and lower joint 4 are metal end face hard seals. This structure requires extremely high processing precision, and the surface roughness is generally controlled below 0.8, which poses a great risk of loosening. The specific reasons for loosening are as follows:

[0020] The direct cause of loosening is: too high a finish causes the friction self-locking ability of the end face to decrease;

[0021] The indirect causes of loosening are: the valve ball 2 constantly knocks against the valve seat 3, causing a loosening effect;

[0022] The reason for loosening is that the two sealing end faces of the valve seat 3 form two self-locking surfaces with the end faces of the valve cover 1 and the lower joint 4 respectively. The best way to achieve self-locking is to directly contact and lock with each other. Therefore, to achieve self-locking between the valve cover 1 and the lower joint 4, they must be in direct contact. The valve seat 3 sandwiched between the two destroys this structure. Any loosening of these two self-locking surfaces will cause disengagement. The existence of the valve seat 3 increases the risk of loosening exponentially.

[0023] Fifth, summary of practical problems existing in current existing technologies:

[0024] like Figures 1 to 5 The key issues of traditional fixed valve technology and existing large well deviation fixed valve technology are as follows:

[0025] There is a large eccentricity between the valve ball 2 and the valve cover 1;

[0026] There is a large eccentricity between the valve seat 3 and the valve cover 1, which is superimposed on the eccentricity between the valve ball 2 and the valve cover 1 to form an eccentricity δ;

[0027] The valve ball 2 will continuously bounce, hit and wear the valve cover 1 and valve seat 3 under the impact of the liquid flow. Under the action of the gravity of the valve ball 2 and the eccentricity δ, severe eccentric wear will occur, resulting in eccentric wear of the lower part of the valve cover 1 and elliptical wear of the valve seat 3.

[0028] The presence of the valve seat 3 often causes tripping accidents between the valve cover 1 and the lower joint 4;

[0029] Therefore, in order to solve the problem of large well inclination fixed valve, it is necessary to properly solve the above fundamental problems.

[0030] The purpose of the present invention is to solve the problems and shortcomings of existing products, and to propose a self-centering oil pump fixed valve. The main purpose is to solve the eccentricity problem of the valve ball 2 and the valve seat 3, solve the knocking wear problem between the valve ball 2 and the straightening ribs of the valve cover 1, and solve the problem of the valve ball 2 hitting the lower edge of the valve seat 3. The technical solution of the present invention completely solves the normal operation problem of the oil pump under large well inclination. In order to solve all the above problems, the present invention provides a self-centering oil pump fixed valve. The present invention has successively improved dozens of solutions. After more than ten years of optimization design and hundreds of tests and experiments, it finally solved all the above problems using the simplest structure within the effective space. Summary of the Invention

[0031] The problem to be solved by the present invention is achieved by the following technical solutions:

[0032] A self-centering oil well pump fixed valve comprises: a housing 10, a centering body 30 mounted within the housing 10, an accumulator 20 mounted between the centering body 30 and the liquid outlet of the housing 10, a ball 40 mounted on the centering body 30, the ball 40 and the housing 10 being in point contact, a cavity ring 60 mounted on the centering body 30, a protective cavity formed between the centering body 30 and the cavity ring 60, a setting ball 50 mounted within the protective cavity, and a housing seat 70 mounted on the housing 10. The centering body 30, ball 40, and housing 10 interact to achieve automatic centering, keeping the centroid of the setting ball 50 always relatively consistent with the centroid of the housing seat 70. The technical principle is as follows:

[0033] First, the centering body 30, the ball 40, and the housing 10 constitute a bearing-type centering structure, which is durable and reliable and can maintain the centering accuracy for a long time. The entire surface of the housing 10 does not contact the setting ball 50, thus completely solving the problems of eccentricity and wear caused by gravity.

[0034] Secondly, the setting ball 50 is protected in the protection cavity, thereby limiting the setting ball 50 from bouncing and impacting and causing damage, and completely solving the problem of bouncing and impacting.

[0035] Third, the number of balls 40 is 2-15, which is equivalent to more than 2-15 bearings supporting the centering body 30 at the same time, which can ensure that the axis of the centering body 30 is stable and the centroids of the sealing ball 50 and the box seat 70 are completely coincident and relatively consistent.

[0036] Fourthly, the centroids of the setting ball 50 and the housing seat 70 are consistent, so the setting ball 50 is positively opposed to the housing seat 70, and the setting ball 50 is positively contacted for setting and positively disengaged for opening, thereby completely solving the problem of wear and failure of the seating cover in the prior art.

[0037] Fifth, the "valve seat" structure in the prior art is eliminated, and a new housing seat 70 is adopted to achieve sealing. The housing 10 and the housing seat 70 are in direct contact to achieve self-locking, which completely solves the problems of loose connection and tripping in the conventional prior art.

[0038] Sixth, the balls 40 are distributed in groups of 3 to 10 per circle on the centering body 30 .

[0039] Seventh, the number of the balls 40 in each group on the centering body 30 is 1-10.

[0040] Eighth, the centering body 30 can rotate around the axis and can also slide along the axis in the housing 10.

[0041] The present invention has the following beneficial effects compared with the prior art:

[0042] The sealing ball 50 of the present invention is self-centering with respect to the housing seat 70. The centering body 30, the ball 40 and the housing 10 form a bearing-type centering structure to achieve centering and positioning. The structure is sturdy, durable and reliable. The centroid of the sealing ball 50 always remains relatively consistent with the centroid of the housing seat 70. The sealing ball 50 will not bounce or collide in the protective cavity. The sealing ball 50 is positively opposed to the sealing ring of the housing seat 70, and contacts the sealing in a positive direction and opens in a positive direction. This completely solves the long-standing problem that has plagued the traditional existing technology for many years, and the overall structure is simpler, more scientific and reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] like Figure 1 As shown, among which: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity, the figure shown is the ideal working state of the traditional technology fixed valve, attached Figure 1 Provides a comparative reference for other states.

[0044] like Figure 2 As shown, where: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity, as shown Figure 2 This is the state of the traditional technology fixed valve when the well inclination angle is 45 degrees. Figure 2 It is not the technical content of the present invention.

[0045] like Figure 3 As shown, among them: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity, is the state of the traditional technology fixed valve when the well inclination angle is 90 degrees, Figure 3 It is not the technical content of the present invention.

[0046] like Figure 4 As shown, among which: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity; 5, spring, Figure 4 This is an existing technology that uses a spring 5 to force the valve ball 2 to return to its original position, and is not the technical content of the present invention.

[0047] like Figure 5 As shown, among them: 1, valve cover; 2, valve ball; 3, valve seat; 4, lower joint; δ, eccentricity; 5, spring; 6, high hardness straightening rib, which is the existing technology of using spring 5 to force the valve ball 2 to return to its original position + high hardness straightening rib 6, Figure 5 It is not the technical content of the present invention.

[0048] like Figure 6 As shown, among them: 10, box body; 20, accumulator; 30, centering body; 40, ball; 50, setting ball; 60, cavity ring; 70, box body seat, as shown Figure 6 This is a structural schematic diagram of a self-centering oil well pump fixed valve according to the present invention, which is a working state of the self-centering oil well pump fixed valve when it is set.

[0049] like Figure 7 As shown, among them: 10, box body; 20, accumulator; 30, centering body; 40, ball; 50, setting ball; 60, cavity ring; 70, box body seat, as shown Figure 7 This is a structural schematic diagram of a self-centering oil well pump fixed valve according to the present invention, which is a working state of the self-centering oil well pump fixed valve when it is opened. DETAILED DESCRIPTION

[0050] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0051] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the present invention.

[0052] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0053] like Figure 6 、 Figure 7 As shown, the first embodiment of the present invention provides a self-centering oil well pump fixed valve, comprising: a housing 10, a centering body 30 is installed in the housing 10, an accumulator 20 is installed between the centering body 30 and the liquid outlet of the housing 10, a ball 40 is installed on the centering body 30, the ball 40 and the housing 10 are in point contact, a cavity ring 60 is installed on the centering body 30, a protective cavity is formed between the centering body 30 and the cavity ring 60, a setting ball 50 is installed in the protective cavity, and a housing seat 70 is installed on the housing 10. The centering body 30, the ball 40 and the housing 10 interact with each other to achieve automatic centering, keep the centroid of the setting ball 50 always relatively consistent with the centroid of the housing seat 70, thereby completely solving the problem of eccentricity and forming a self-centering oil well pump fixed valve.

[0054] Preferably, the centering body 30 and the cavity ring 60 together form a protective cavity, and the setting ball 50 is located in the protective cavity.

[0055] Preferably, the number of circles of the balls 40 distributed in the axial direction of the centering body 30 is 2-15.

[0056] Preferably, the housing seat 70 can form a setting seal with the setting ball 50.

[0057] Preferably, the balls 40 are distributed in groups of 3 to 10 per circle on the centering body 30 .

[0058] Preferably, the number of the balls 40 in each group on the centering body 30 is 1-10.

[0059] Preferably, the centering body 30 can rotate around the axis and slide along the axis in the housing 10 .

[0060] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

[0061] In the description of the present invention, it should be noted that the term "motion" should be understood in a broad sense. It can be movement by pulling or dragging by external force, movement by relying on its own kinetic energy, or movement by relying on the interaction force of electromagnetic or magnetic energy. In specific implementation, it can be regarded as phase motion between the two. When the moving object is stationary, it can be the movement of the object relative to it.

[0062] Working principle and working process:

[0063] like Figure 6 、 Figure 7 As shown, a self-centering oil well pump fixed valve includes: a box body 10, a centering body 30 is installed in the box body 10, an accumulator 20 is installed between the centering body 30 and the liquid outlet of the box body 10, a ball 40 is installed on the centering body 30, and the ball 40 and the box body 10 are in point contact. A cavity ring 60 is installed on the centering body 30, and a protective cavity is formed between the centering body 30 and the cavity ring 60. A setting ball 50 is installed in the protective cavity, and a box body seat 70 is installed on the box body 10. The centering body 30, ball 40 and box body 10 interact with each other to achieve automatic centering, keeping the centroid of the setting ball 50 always relatively consistent with the centroid of the box body seat 70.

[0064] like Figure 6As shown, when the oil well pump is lowered into the well, the setting ball 50 is in contact with the box body seat 70 and is in the setting state;

[0065] like Figure 7 As shown, after the oil well pump is lowered into the well, it starts pumping normally. When it enters the upstroke, the cavity above the fixed valve forms a vacuum negative pressure in the pump. The state of the fixed valve of the self-centering oil well pump is as follows: Figure 7 As shown, the well fluid pushes the setting ball 50 and simultaneously moves the centering body 30, the cavity ring 60, the ball 40, and the accumulator 20 along the axis of the inner hole of the casing 10. The setting ball 50 disengages from the casing seat 70, and the fixed valve of the self-centering oil well pump switches from the setting state to the open state, and the well fluid enters the oil well pump through the inner hole of the centering body 30.

[0066] When the wellbore pump is in the downstroke, when the well fluid stops flowing upward, the accumulator 20 pushes the centering body 30, the ball 40, the setting ball 50, and the cavity ring 60 to move closer to the box body seat 70 at the same time, and the setting ball 50 sits on the box body seat 70 to re-set the seal and restore the wellbore to the original state. Figure 6 In the state shown, the well fluid in the pump chamber above the fixed valve of the self-centering oil well pump enters the tubing above the plunger through the inner hole of the plunger assembly.

[0067] Normal oil production is achieved through the reciprocating alternation of up and down strokes.

[0068] During the entire process, the setting ball 50 is enclosed in the protective cavity and does not contact the housing 10. The centroid axes of the setting ball 50 and the housing seat 70 completely coincide with each other, thus achieving automatic centering.

[0069] like Figure 6 、 Figure 7 As shown, the setting ball 50 is in the protection cavity and will not bounce or collide.

[0070] like Figure 6 、 Figure 7 As shown, the present invention eliminates the component structure of the 'valve seat' in the prior art, and instead directly connects the new housing 10 with the housing seat 70 to achieve direct self-locking, and the self-locking performance is reliable and firm.

[0071] like Figure 6 、 Figure 7 As shown, the setting and opening actions of the present invention are achieved by the positive contact and positive separation of the setting ball 50 and the box body seat 70.

[0072] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. A self-centering oil well pump fixed valve, characterized in that: include: A housing (10) is provided with a centering body (30) installed in the housing (10), an accumulator (20) is installed between the centering body (30) and the liquid outlet of the housing (10), a ball (40) is installed on the centering body (30), the ball (40) and the housing (10) are in point contact, a cavity ring (60) is installed on the centering body (30), a protective cavity is formed between the centering body (30) and the cavity ring (60), a sealing ball (50) is installed in the protective cavity, a housing seat (70) is installed at the liquid inlet of the housing (10), and the centering body (30), the ball (40) and the housing (10) interact with each other to achieve automatic centering, so that the centroid of the sealing ball (50) is always relatively consistent with the centroid of the housing seat (70).

2. The self-centering oil well pump fixed valve according to claim 1, characterized in that: The number of circles of the balls (40) distributed in the axial direction of the centering body (30) is 2-15.

3. The self-centering oil well pump fixed valve according to claim 1, characterized in that: The number of distribution groups of the balls (40) per circle on the centering body (30) is 3-10 groups.

4. The self-centering oil well pump fixed valve according to claim 1, characterized in that: The number of the balls (40) in each group on the centering body (30) is 1-10.

5. The self-centering oil well pump fixed valve according to claim 1, characterized in that: The centering body (30) can rotate around the axis and can also slide along the axis in the housing (10).

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