Tubing plug
By introducing a friction mechanism into the oil pipe blocker, the bottom-hole pressure is used to support the tiles to anchor radially outward, solving the problem of difficulty in anchoring when wax or heavy oil is accumulated in the oil pipe, and achieving a better sealing effect.
Patent Information
- Application Number
- CN202421215417.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2024-12-27
- Estimated Expiration
- 2034-05-30
AI Technical Summary
In oil and gas fields, when wax or heavy oil accumulates in the oil pipe, the existing oil pipe blocker relies on gravity to anchor downward, which is prone to poor downward, resulting in poor sealing effect and affecting the blocking effect.
The friction mechanism provides friction with the oil pipe wall, and the bottom-hole pressure makes the anti-overflow bowl rise, driving the center rod upward. The friction mechanism limits the tile axially so that the tile can be anchored to the tile in the radial direction. The inner wall of the oil pipe achieves better sealing effect.
In the case of accumulated wax or heavy oil, the anchoring effect is good, ensuring the sealing effect of the oil pipe blocker, avoiding the downward problems caused by insufficient gravity, and improving the blocking effect.
Smart Images
Figure CN222253904U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of wellbore or well sealing, in particular to an oil pipe plugger. Background Art
[0002] In the field of oil and gas field development, in order to reduce oil and gas layer pollution, maintain formation pressure, and better extract oil and gas, pressurized operation technology is often used for well repair operations. Controlling the sealing technology inside the oil pipe is the core technology of pressurized operation and the key to effectively controlling the fluid in the well from leaking out of the oil pipe. The oil pipe plugger and the oil pipe switch are key devices for pressurized operation. They can seal the fluid in the pipe string without suppressing the well or preventing blowouts, so as to prevent overflow and blowout accidents in the pipe string.
[0003] The Chinese utility model patent with the authorization announcement number CN201883992U and the authorization announcement date of June 29, 2011 discloses a downhole oil pipe plug, which includes a leather cup, a rubber, a spear rod, a slip, and a block. The spear rod is provided with a dovetail, and the slip is provided with a dovetail groove. The slip is installed on the dovetail of the spear rod through the dovetail groove. The block is fixed on the spear rod and is used to limit the slip. During operation, the downhole oil pipe plug is sent to the bottom of the oil pipe by hydraulic pressure for sealing. When the pressure is applied, the rubber is pressed and the leather cup is retracted, so that it can be smoothly lowered to the position where the oil pipe needs to be sealed. After the pressure is released, the leather cup is used to seal the oil pipe, and the slip slides downward under its own weight. The slip and the inclined surface produce relative displacement, anchoring the inner wall of the oil pipe.
[0004] The above-mentioned downhole oil pipe plugger seals the oil pipe through a leather cup and uses two sets of slips to anchor the oil pipe. However, when there is wax or thick oil accumulated in the pipe, the slips rely on gravity to move downward, so there will be a situation where the downward movement is not smooth and the slips cannot reach the inner wall of the oil pipe, resulting in poor anchoring and affecting the plugging effect of the oil pipe plugger. Utility Model Content
[0005] The purpose of the utility model is to provide an oil pipe plugging device to solve the problem that when there is wax or thick oil accumulated in the oil pipe, the plugging device is not anchored well and the plugging effect is affected.
[0006] The oil pipe plug of the utility model adopts the following technical solutions:
[0007] A oil pipe plugger includes a sealing mechanism and an anchoring mechanism, wherein the sealing mechanism includes an anti-overflow leather cup and its attachment, the anchoring mechanism includes a center rod and a cava, the center rod is connected to the attachment, the upper end of the cava is connected to a friction mechanism for cooperating with the oil pipe to provide friction resistance in the up and down directions, the friction mechanism includes a center cylinder seat and a friction body installed on the center cylinder seat, the friction body is an elastic friction body that can be elastically deformed along the radial direction of the center cylinder seat, or is a floating friction body that elastically floats with the center cylinder seat along the radial direction of the center cylinder seat.
[0008] Beneficial effects: The utility model improves the existing oil pipe plug. Specifically, a friction mechanism is used to provide the oil pipe plug with friction with the oil pipe wall. After the oil pipe plug reaches the pumping position, the formation pressure is greater than the hydrostatic column pressure at the oil pipe plug. The anti-overflow leather cup expands due to the pressure difference and moves upward under the action of the bottom hole pressure, driving its attachment upward and driving the center rod upward. The friction mechanism limits the axial position of the slip, and the center rod moves upward, so that the slip is forced to open by the center rod and anchored to the inner wall of the oil pipe along the radial outward support. Since the slip does not slide down by gravity, the anchoring effect is good when there is wax accumulation or thick oil, which can make the oil pipe plug achieve a good sealing effect.
[0009] Furthermore, slopes are provided on the upper and lower ends of the outer side surface of the floating friction body to prevent the floating friction body from being stuck with the oil pipe.
[0010] Furthermore, the floating friction body is formed into a trapezoidal body by arranging the slope surface, and the top surface of the trapezoidal body constitutes a friction fitting surface.
[0011] Furthermore, a friction body groove is provided on the outer peripheral surface of the central cylindrical seat, and the floating friction body is installed in the corresponding friction body groove.
[0012] Furthermore, snap rings are respectively installed at both ends of the central cylindrical seat, and both ends of the floating friction body are respectively limited by corresponding snap rings.
[0013] Furthermore, a compression spring is provided in the friction body groove, and the compression spring is mounted between the groove bottom of the friction body groove and the floating friction body.
[0014] Furthermore, the center rod is connected to the attachment body through an adapter joint, and the center cylinder seat can be movably sleeved on the center rod, and the upper end can be limited by the adapter joint.
[0015] Furthermore, a connecting window is provided at the lower end of the central cylinder seat, and a slider bent outward is provided at the upper end of the slip and is installed in the corresponding connecting window through the slider.
[0016] Furthermore, the attachment is a hollow attachment.
[0017] Furthermore, the friction force between the friction mechanism and the oil pipe is greater than the gravity of the oil pipe plugger, and the oil pipe plugger also includes a power leather cup for cooperating with the oil pipe pressing device to push the oil pipe plugger downward as a whole. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a structural schematic diagram of an embodiment of the oil pipe plug of the utility model;
[0019] Figure 2 for Figure 1 A schematic diagram of the structure of the central cylinder seat;
[0020] Figure 3 for Figure 1 The structural diagram of the slips in FIG.
[0021] Figure 4 for Figure 1 Schematic diagram of the structure of the central rod.
[0022] Numbers in the figure: 1, pressure cap; 2, center tube, 3, O-ring; 4, anti-overflow leather cup; 5, power leather cup; 6, adapter joint; 7, fixing ring; 8, compression spring; 9, friction block; 10, center cylinder seat; 11, center rod fixing ring; 12, slip, 13, center rod; 100, friction block groove; 101, fixing ring groove; 102, center cylinder seat slip groove; 200, slip shoulder; 201, slip tooth; 300, center rod shoulder; 301, center rod fixing ring groove, 302, center rod slip groove. DETAILED DESCRIPTION
[0023] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.
[0024] Specific implementation of the oil pipe plug of the utility model:
[0025] The prior art discloses an oil pipe plug, which seals the oil pipe with a leather cup, and two groups of slips slide downward by their own weight, so that the slips and the inclined surface produce relative displacement and anchor the inner wall of the oil pipe. However, when there is wax accumulation or thick oil in the pipe, the sliding slips rely on gravity to move downward, so there will be a situation where the downward movement is not smooth, resulting in poor anchoring and affecting the plugging effect of the oil pipe plug. The utility model proposes a solution to the shortcomings of the prior art. The core concept of this solution is to use a friction mechanism to provide the oil pipe plug with friction with the oil pipe wall. After the oil pipe plug is pumped into place, under the action of the bottom hole pressure, the anti-overflow leather cup moves upward, driving the center rod of the anchoring mechanism upward. The friction mechanism limits the slips axially, so that the slips are forced to be opened by the center rod and radially supported and anchored to the inner wall of the oil pipe.
[0026] Based on the above concept, Figure 1 As shown, the oil pipe plug of the present invention includes a sealing mechanism and an anchoring mechanism. The sealing mechanism includes an anti-overflow leather cup 4 and its attachment. The anchoring mechanism includes a center rod 13 and a cava 12. The center rod 13 is connected to the attachment of the anti-overflow leather cup 4. The upper end of the cava 13 is connected to a friction mechanism for cooperating with the oil pipe to provide friction resistance in the up and down directions. The friction mechanism includes a center cylinder seat 10 and a friction body installed on the center cylinder seat. The friction body is an elastic friction body that can be elastically deformed along the radial direction of the center cylinder seat 10, or is a floating friction body that elastically floats with the center cylinder seat along the radial direction of the center cylinder seat 10.
[0027] Among the above-mentioned components, the attachment body of the anti-overflow leather cup 4 of the sealing mechanism is the central tube 2. Preferably, the central tube 2 is a hollow tube to achieve the effect of weight reduction. In other embodiments, it can also be solid. A pressure cap 1 is connected to the upper end of the central tube 2. The pressure cap 1 and the upper end of the central tube 2 are connected by threads. The anti-overflow leather cup 4 is mounted on the upper end of the central tube 2. An O-ring 3 is provided between the pressure cap 1 and the anti-overflow leather cup 4. A power leather cup 5 is provided below the anti-overflow leather cup 4. The power leather cup 5 is used to cooperate with the oil pipe pressure equipment to push the oil pipe plug downward as a whole. The power leather cup 5 is mounted on the lower end of the central tube 2. An adapter joint 6 is provided at the lower end of the central tube 2 below the power leather cup 5. The adapter joint 6 and the lower end of the central tube 2 are connected by threads. In this embodiment, the central tube 2 is connected to the adapter joint 6 and the pressure cap 1 by threads, and the threads here serve as a connection. In other embodiments, welding, forced assembly, etc. can also be used for connection. When the tubing plug is lowered into the well, hydraulic pumping pressure acts on the inner cavity of the power cup 5. The internal pressure of the power cup 5 is higher than the external pressure, causing it to expand and press against the inner wall of the tubing, generating a cutoff pressure differential that pushes the tubing plug downward. After the plug reaches the designed position, pumping stops. The formation pressure is greater than the hydrostatic column pressure at the tubing plug. The difference between the formation pressure and the hydrostatic column pressure acts on the inner cavity of the overflow prevention cup 4. The overflow prevention cup 4 expands due to the pressure differential, sealing the annulus between the tubing plug and the tubing.
[0028] In this embodiment, the friction body is a floating friction body, specifically a friction block 9. In other embodiments, it can also be an elastic friction body that can undergo elastic deformation, such as a friction body made of rubber or a friction body made of elastic strip steel. Figure 1 As shown, the upper and lower ends of the outer side of the friction block 9 are provided with slopes to prevent the friction block 9 from getting stuck with the oil pipe. The friction block 9 is formed into a trapezoidal body by providing the slopes, and the top surface of the trapezoidal body constitutes the friction fitting surface with the oil pipe wall. Snap rings are respectively installed at both ends of the center cylinder seat 10, and the two ends of the friction block 9 are respectively limited by the corresponding snap rings. In this embodiment, the snap ring is a fixed ring 7, and the fixed ring 7 is preferably a C-shaped ring. Figure 2 As shown, the lower end of the center cylinder seat 10 is provided with a connection window. In this embodiment, the connection window is a center cylinder seat slip groove 102. The center cylinder seat 10 is mounted on the center rod 13. The outer peripheral surface of the center cylinder seat 10 is provided with a friction block groove 100, a center cylinder seat slip groove 102 and a fixed ring groove 101. The fixed ring 7 is installed in the fixed ring groove 101. After assembly, it is welded and fixed to the center cylinder seat 10. The friction block 9 is installed in the friction block groove 100. The friction block 9 can make limited radial movement in the friction block groove 100. A compression spring 8 is provided in the friction block groove 100. The compression spring top is installed between the bottom of the friction block groove 100 and the friction block 9. The friction block 9 is tightly attached to the inner wall of the oil pipe due to the elastic force of the compression spring 8. When the oil pipe plug moves, the friction block 9 generates friction with the oil pipe. The friction force is greater than the self-weight of the oil pipe plug.
[0029] like Figure 1 、 Figure 3 、 Figure 4 As shown, the upper end of the center rod 13 is threadedly connected to the adapter joint 6. The center cylinder seat 10 movably fits over the center rod 13, with the upper end restrained by the adapter joint 6. A center rod shoulder 300 is provided at the center of the center rod 13. A center rod retaining ring groove 301 is provided on the outer side of the center rod shoulder 300, and the center rod retaining ring 11 is installed in conjunction with the center rod shoulder 300. The center rod slip groove 302 for the retaining slip 12 is provided on the center rod shoulder 300. The lower end of the center rod 13 is provided with a conical surface that matches the lower conical surface of the slip 12. The center rod retaining ring 11 is a C-shaped ring that is welded to the center rod 13 after assembly. The slip 12 has an outwardly bent slider at its upper end, which is installed in the center cylinder seat slip groove 102 via the slider. The slider is a slip shoulder 200. The outer side of the lower end of the slip 12 is equipped with upwardly angled teeth 201. The slip 12 is assembled within the center barrel seat slip groove 102 and the center rod slip groove 302. The two slip grooves limit the slip 12 axially. There are three slips 12, and their simultaneous operation prevents the two slips from being synchronized during anchoring, which can cause the plug's overflow cup to be misaligned and out of position within the oil pipe, resulting in an unsatisfactory sealing effect. When the plug is inserted into the well, the upper end surface of the center barrel seat 10 abuts against the lower end surface of the adapter 6 due to the friction between the friction block 9 and the oil pipe. At this time, the slip 12 is in a freely suspended state. After the plug reaches the predetermined position, pumping stops, the overflow cup 4 expands and seals, and the plug is subjected to an upward thrust due to the pressure differential. The center rod 13 moves upward, and the slips 12 are radially supported and anchored to the inner wall of the oil pipe. The greater the upward thrust, the greater the anchoring force.
[0030] The method of using the oil pipe plug of the utility model is as follows:
[0031] Before use, the overflow prevention cup 4 and the power cup 5 that match the inner diameter of the oil pipe must be assembled. The outer diameter of the overflow prevention cup 4 and the power cup 5 is 0.3 to 0.4 mm larger than the inner diameter of the oil pipe at the predetermined position of the plug. When in use, the oil pipe plug is placed in the oil pipe. First, the oil pipe plug is hydraulically pumped. The amount of pumped liquid is calculated based on the volume of the oil pipe above the predetermined position of the oil pipe plug. After the pump is stopped, the overflow prevention cup 4 is supported on the inner wall of the oil pipe under the pressure difference between the formation pressure and the hydrostatic column pressure, sealing the annulus between the oil pipe plug and the oil pipe. The overflow prevention cup 4 moves upward under the action of the bottom hole pressure, driving the central pipe 2 upward, the adapter 6 moves upward accordingly, and finally drives the central rod 13 upward. The slips 12 are forced to open along the central rod 13 to achieve an anchoring effect. It can be observed at the wellhead that the liquid in the oil pipe no longer overflows, achieving a positioning and plugging effect in the oil pipe.
Claims
1. An oil pipe plug, comprising a sealing mechanism and an anchoring mechanism, wherein the sealing mechanism comprises an anti-overflow leather cup and its attachment, and the anchoring mechanism comprises a center rod and a slip, wherein the center rod is connected to the attachment, characterized in that: The upper end of the cava is connected to a friction mechanism for cooperating with the oil pipe to provide friction resistance in the up and down directions. The friction mechanism includes a center cylinder seat and a friction body installed on the center cylinder seat. The friction body is an elastic friction body that can be elastically deformed along the radial direction of the center cylinder seat, or a floating friction body that elastically floats with the center cylinder seat along the radial direction of the center cylinder seat.
2. The oil pipe plug according to claim 1, characterized in that: The upper and lower ends of the outer side surface of the floating friction body are both provided with slope surfaces to prevent the floating friction body from being stuck with the oil pipe.
3. The oil pipe plug according to claim 2, characterized in that: The floating friction body is formed into a trapezoidal body by arranging the slope surface, and the top surface of the trapezoidal body constitutes a friction fitting surface.
4. The oil pipe plug according to claim 1, 2 or 3, characterized in that: The outer peripheral surface of the central cylinder seat is provided with a friction body groove, and the floating friction body is installed in the corresponding friction body groove.
5. The oil pipe plug according to claim 4, characterized in that: Snap rings are respectively installed at both ends of the central cylinder seat, and both ends of the floating friction body are limited by corresponding snap rings.
6. The oil pipe plug according to claim 4, characterized in that: A compression spring is arranged in the friction body groove, and the compression spring is mounted between the groove bottom of the friction body groove and the floating friction body.
7. The oil pipe plug according to claim 1, characterized in that: The central rod is connected to the attachment body through an adapter joint, and the central tube seat can be movably sleeved on the central rod, and the upper end can be limited by the adapter joint.
8. The oil pipe plug according to claim 1, characterized in that: A connecting window is provided at the lower end of the central cylinder seat, and a sliding block bent outward is provided at the upper end of the slip and installed in the corresponding connecting window through the sliding block.
9. The oil pipe plug according to claim 1, characterized in that: The attachment is a hollow attachment.
10. The oil pipe plug according to claim 1, characterized in that: The friction force between the friction mechanism and the oil pipe is greater than the gravity of the oil pipe plugger. The oil pipe plugger also includes a power leather cup used to cooperate with the oil pipe pressing equipment to push the oil pipe plugger downward as a whole.