Wellhead pressure control device for oil well

Abstract

The utility model belongs to the field of oil exploitation equipment, and particularly discloses an oil well mouth pressure control device which comprises an upper connector and a lower connector which are coaxially arranged up and down, a spherical groove with an upward opening is formed in the lower connector, a rubber plug matched with the spherical groove is arranged in the lower connector, the rubber plug is provided with a channel, and the lower end of the upper connector abuts against the upper end of the rubber plug. The upper connector or the lower connector is provided with a pressing adjusting mechanism used for pressing the rubber plug downwards, the inner side wall of the channel is provided with at least two attaching ring parts, the attaching ring parts are distributed upwards at intervals from the bottom of the channel and protrude inwards in the radial direction of the channel, and the protruding heights of the attaching ring parts are sequentially increased from bottom to top. By the adoption of the scheme, mainly from the two aspects of a rubber plug structure and a pressing structure, on one hand, a multi-point-position face sealing structure is formed through the rubber plug, the static sealing reliability is improved, and on the other hand, loosening is effectively relieved or prevented through the pre-tightening spring, that is, dynamic sealing under conventional operation is improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of petroleum equipment, concretely relates to an oil well wellhead pressure control device. BACKGROUND

[0002] Because the oil pumping well also has the condition of sudden pressure increase, so it needs to carry out well sealing operation when carrying out wellhead operation, and the oil pumping rod of the oil well mainly relies on the rubber valve well sealing operation when replacing the packing box packing, and the traditional rubber valve low pressure structure valve, due to the different oilfield well bottom geological structure and time elapse, when the oil well suddenly increases after the self-blowing well turns into the oil pumping well, the sealing failure is extremely easy, and the blowout accident appears.

[0003] The traditional rubber plug shape is not suitable, and it also causes the problems of poor sealing effect, short service life and the like, so the prior art proposes a new structure with the patent number of CN208669255U and the name of "oil pumping rod spherical sealing device", which can play a good sealing and has a good reset ability, but the applicant finds in the research that the sealing structure mainly relies on the linear sealing of the inner lower edge to the oil pumping rod, the local pressure is large, and if the corresponding position rubber plug or oil pumping rod is deformed, the sealing performance is greatly reduced, on the other hand, due to the motion resonance influence of the oil pumping rod in the normal working process, the compression mechanism is easy to loosen, the single radial sealing performance is weak, and there is a great pressure relief risk in the normal oil production operation. UTILITY MODEL CONTENTS

[0004] Therefore, the utility model provides an oil well wellhead pressure control device to solve the problems of poor sealing reliability and pressure relief risk in the prior art.

[0005] Its technical scheme is as follows:

[0006] An oil well wellhead pressure control device, comprising an upper joint and a lower joint coaxially arranged, the lower joint has a spherical surface groove with an opening upward in the inside, and is provided with a rubber plug matched therewith, the rubber plug has a channel, the lower end of the upper joint abuts against the upper end of the rubber plug, and the upper joint or the lower joint is provided with a compression adjusting mechanism for pressing the rubber plug, and the key lies in that the inner wall of the channel has at least two abutting ring parts, the abutting ring parts are distributed upward from the bottom of the channel at intervals, and protrude inward along the radial direction of the channel, and the protruding height increases from bottom to top in sequence.

[0007] When the well sealing operation is needed, the rubber plug is pressed by the compression adjusting mechanism, so that the rubber plug at the lower edge of the channel and the at least one abutting ring part contact with the oil pumping rod, multi-position surface sealing is formed, the sealing performance is greatly provided, even if the single position is deformed, the sealing performance is not immediately affected, the sealing reliability and the overall service life are improved.

[0008] As preferred: the vertical section of the fitting ring part is isosceles trapezoidal or right trapezoidal, when being isosceles trapezoidal, the inner side of the fitting ring part corresponds to the upper base, when being right trapezoidal, the inner side of the fitting ring part corresponds to the oblique leg. Relatively speaking, the isosceles trapezoidal scheme is more beneficial to demolding and has better structural stability, and the right trapezoidal scheme can compensate the shrinkage of the lower side by using the slope, so that the face seal of multiple parts is more easily formed.

[0009] As preferred: the thickness of the fitting ring part gradually increases from bottom to top. By using the above scheme, the height of the upper protrusion gradually increases, and increasing the thickness can ensure better strength stability and prolong the deformation period.

[0010] As preferred: a radial sealing ring is arranged between the lower end of the upper joint and the upper end of the rubber plug.

[0011] As preferred: an axial sealing ring is arranged between the side wall of the upper joint and the side wall of the lower joint. By using the above scheme, the overall sealing performance can be further improved in cooperation with the radial sealing ring.

[0012] As preferred: the upper joint has an outer step, the compression adjusting mechanism comprises a compression sleeve and a bearing, the bearing is supported on the outer step, the lower end of the compression sleeve is threadedly connected with the outer side of the upper end of the lower joint, and the upper end of the compression sleeve is in abutment with the upper side of the bearing.

[0013] As preferred: a pre-tightening spring is arranged between the compression sleeve and the lower joint, the pre-tightening spring is arranged along the axial direction of the upper joint, the upper and lower ends of the pre-tightening spring are in abutment with the compression sleeve and the lower joint respectively, and the pre-tightening spring is in a compressed state. By using the elasticity of the spring to tighten the upper joint and the compression sleeve, the influence of vibration during normal operation is weakened, and pressure leakage caused by loosening of the compression sleeve is prevented.

[0014] Compared with the prior art, the oil well wellhead pressure control device has the following beneficial effects:

[0015] The oil well wellhead pressure control device provided by the utility model mainly starts from the structure of the rubber plug and the compression adjusting mechanism, forms a multi-point face seal structure by using the rubber plug to improve the static seal reliability, and effectively alleviates or prevents loosening by using the pre-tightening spring, that is, improves the dynamic seal under normal operation. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a structural schematic view of the utility model;

[0017] Figure 2 is Figure 1 is an exploded view;

[0018] Figure 3This is the installation diagram;

[0019] Figure 4 A schematic cross-sectional view of the fitting ring portion;

[0020] Figure 5 It is another cross-sectional schematic diagram of the fitting ring portion.

[0021] Figure markings: 1-upper joint; 10-outer step; 2-lower joint; 20-spherical groove; 3-preload spring; 4-rubber plug; 40-channel; 41-fitting ring; 5-tightening adjustment mechanism; 50-tightening sleeve; 51-bearing; 52-handle; 6-radial sealing ring; 7-axial sealing ring; 8-sucker rod. DETAILED DESCRIPTION

[0022] The present invention will be described in further detail below with reference to the accompanying drawings.

[0023] refer to Figure 1 and Figure 5 The oil well wellhead pressure control device shown mainly includes an upper joint 1 and a lower joint 2 coaxially arranged in the upper and lower parts. The lower joint 2 has a spherical groove 20 with an opening facing upward (the upper and lower parts in this application are referred to as relative positions during specific installation), and is equipped with a corresponding rubber plug 4. The rubber plug 4 has a channel 40, which is mainly through-through for the sucker rod to pass through. The lower end of the upper joint 1 abuts against the upper end of the rubber plug 4. A compression adjustment mechanism 5 for pressing the rubber plug 4 downward is provided on the upper joint 1 or the lower joint 2. In this way, when the compression adjustment mechanism 5 is pressed downward, the lower part of the rubber plug 4 can be retracted inward to fit and seal with the sucker rod.

[0024] The key to this application is to further optimize the structure of the rubber plug 4, as shown in the following example: Figures 3 to 5 As shown, the inner wall of the channel 40 has at least two fitting ring portions 41, which are spaced apart from each other upward from the bottom of the channel 40. They are annular protrusions that protrude radially inward along the channel 40, and their protrusion heights increase from bottom to top. During implementation, the inner diameter of the channel 40 and the protrusion height of the fitting ring portion 41 need to be determined according to the diameter of the sucker rod to ensure that when the lower edge of the channel 40 is in contact with the sucker rod, at least one or two inner sides of the fitting ring portions 41 on the upper part are in contact with the sucker rod, thereby achieving multi-point surface sealing. During long-term use, the wear on the lower edge of the channel 40 is relatively the greatest, and with the help of the sealing of the upper fitting ring portion 41, it can continue to be used, thereby extending its service life.

[0025] refer to Figure 4 and Figure 5 In specific implementation, the vertical cross-section of the fitting ring portion 41 is in the shape of an isosceles trapezoid or a right-angled trapezoid, such as Figure 4 As shown, when it is an isosceles trapezoid, the inner side of the fitting ring portion 41 is the upper base of the trapezoid, as shown in FIG. Figure 5As shown, when it is a right-angled trapezoid, the inner side of the fitting ring portion 41 corresponds to the slanted waist of the trapezoid. In this way, when the rubber plug is pressed down and retracted, the slanted waist surface is gradually straightened to better fit with the sucker rod 8, thereby achieving better sealing performance.

[0026] like Figures 3 to 5 As shown, in the specific implementation, in order to ensure that the fitting ring portion 41 can fit the sucker rod as much as possible, the upper fitting ring portion 41 must bulge inward more. In order to ensure that it has better supporting strength and pressure resistance, the thickness of the fitting ring portion 41 (referring to the thickness along the axial direction of the channel) increases from bottom to top.

[0027] In addition, in order to further improve the sealing performance during normal oil production and well sealing operations, a radial sealing ring 6 is provided between the lower end of the upper joint 1 and the upper end of the rubber plug 4. Figure 3 As shown, the lower end of the upper joint 1 is consistent with the upper end face of the plug 4, and the two are in contact with each other. The radial sealing ring 6 is close to the middle of the contact part of the two. In this way, even if the radial inner and outer sides of the plug 4 are worn, they can be sealed by the radial sealing ring 6, which is mainly used to prevent the pressurized gas from overflowing outward through the contact surface of the two.

[0028] On this basis, an axial sealing ring 7 is provided between the side wall of the upper joint 1 and the side wall of the lower joint 2. Figure 2 and Figure 3 As shown, there is an overlapping section between the upper joint 1 and the lower joint 2, and the axial sealing ring 7 is mounted on the upper joint 1. After long-term use, the surface of the rubber plug 4 may not be completely in contact with the spherical groove 20, resulting in the pressurized gas overflowing from between the spherical groove 20 and the rubber plug 4. The axial sealing ring 7 can further seal it.

[0029] The upper joint 1 has an annular outer step 10, and the compression adjustment mechanism 5 includes a compression sleeve 50 and a bearing 51. The bearing 51 is supported on the outer step 10. The lower end of the compression sleeve 50 is threadedly matched with the outer side of the upper end of the lower joint 2, and the inner side of the upper end of the compression sleeve 50 is against the upper side of the bearing 51. During operation, hold a handle 52 with both hands to rotate the compression sleeve to cause axial displacement. When the compression sleeve 50 is rotated forward, the upper joint 1 can be pressed down through the bearing 51, and the upper joint 1 simultaneously presses down the plug 4. When the compression sleeve 50 is rotated backward, the pressure on the upper joint 1 disappears, and the plug 4 can be reset by relying on its own elasticity.

[0030] In order to facilitate the screwing operation of the compression sleeve 50 , a symmetrically arranged handle 52 is provided on the compression sleeve 50 . The handle 52 is arranged along the radial direction of the compression sleeve 50 .

[0031] In order to improve the reliability of normal oil production operations, prevent the vibration of the wellhead device caused by the pumping rod from affecting the compression sleeve 50, and ensure the stability of the connection position of the compression sleeve 50 and the lower joint 2 under normal conditions to prevent it from loosening, a preload spring 3 is provided between the compression sleeve 50 and the lower joint 2. Figure 3 As shown, the preload spring 3 is arranged along the axial direction of the upper joint 1 and is sleeved on the outside of the outer step 10. Its upper and lower ends are respectively against the compression sleeve 50 and the lower joint 2, and the preload spring 3 is in a compressed state.

[0032] In order to facilitate quick installation and connection, the upper part of the lower joint 1 and the lower part of the lower joint 2 are respectively provided with female buckles or male buckles to facilitate connection with other wellhead devices.

[0033] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention. Such changes fall within the scope of protection of the present invention.

Claims

1. An oil well wellhead pressure control device, comprising an upper joint (1) and a lower joint (2) coaxially arranged above and below, wherein the lower joint (2) has a spherical groove (20) with an upward opening and is provided with a corresponding rubber plug (4), the rubber plug (4) having a channel (40), the lower end of the upper joint (1) abutting against the upper end of the rubber plug (4), and a compression adjustment mechanism (5) for pressing down the rubber plug (4) is provided on the upper joint (1) or the lower joint (2), characterized in that: The inner side wall of the channel (40) has at least two fitting ring portions (41), which are spaced apart and distributed upward from the bottom of the channel (40) and protrude radially inwardly along the channel (40), with the protrusion height increasing sequentially from bottom to top.

2. The oil wellhead pressure control device according to claim 1, characterized in that: The vertical cross-section of the fitting ring portion (41) is in the shape of an isosceles trapezoid or a right-angled trapezoid. When it is in the shape of an isosceles trapezoid, the inner side of the fitting ring portion (41) corresponds to the upper base. When it is in the shape of a right-angled trapezoid, the inner side of the fitting ring portion (41) corresponds to the oblique waist.

3. The oil wellhead pressure control device according to claim 1 or 2, characterized in that: The thickness of the fitting ring portion (41) increases sequentially from bottom to top.

4. The oil well wellhead pressure control device according to claim 1 or 2, characterized in that: A radial sealing ring (6) is provided between the lower end of the upper joint (1) and the upper end of the rubber plug (4).

5. The oil wellhead pressure control device according to claim 4, characterized in that: An axial sealing ring (7) is provided between the side wall of the upper joint (1) and the side wall of the lower joint (2).

6. The oil wellhead pressure control device according to claim 1 or 2, characterized in that: The upper joint (1) has an outer step (10), and the compression adjustment mechanism (5) includes a compression sleeve (50) and a bearing (51), wherein the bearing (51) is supported on the outer step (10), the lower end of the compression sleeve (50) is threadedly engaged with the outer side of the upper end of the lower joint (2), and the inner side of the upper end of the compression sleeve (50) is in contact with the upper side of the bearing (51).

7. The oil wellhead pressure control device according to claim 6, characterized in that: A preload spring (3) is provided between the compression sleeve (50) and the lower joint (2). The preload spring (3) is arranged along the axial direction of the upper joint (1), and its upper and lower ends respectively abut against the compression sleeve (50) and the lower joint (2). The preload spring (3) is in a compressed state.

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