Underground sucker rod indicator diagram testing device

Abstract

The utility model discloses an indicator diagram testing device for an underground sucker rod, which comprises a cylindrical shell, a sealing plug and a testing component, a space between the two threaded counter bores in the shell is an equipment cavity, and sealing plugs are connected in the two threaded counter bores; the sealing plug comprises a connecting part and a sealing part, the connecting part is in threaded connection with the threaded counter bore, and the sealing part is inserted into the equipment cavity and is sealed; the length of the connecting part is smaller than the depth of the threaded counter bore. The sealing element is the sealing plug, is not connected with the oil rod connector, is not a main stress element, has longer service life, prolongs the replacement period, and reduces the use cost.

Description

Technical Field

[0001] The utility model relates to the technical field of oil well testing tools, in particular to a downhole sucker rod dynamometer diagram testing device. Background Art

[0002] The sucker rod is a crucial component of the oil production system in a pumping well. It connects the surface pumping unit to the downhole pump. A single sucker rod is approximately 9 meters long and is threaded together using couplings. The pumping unit drives the rod up and down, transferring mechanical energy to the downhole pump. The force and displacement of the sucker rod are crucial indicators of the well's proper functioning. A common device for testing the force of sucker rods is a ground dynamometer. The ground dynamometer is a curve showing the relationship between the force and displacement of a bare rod during a complete stroke. Its force sensor and displacement sensor are installed at the suspension point of the ground pumping unit. Therefore, it is also called a suspension point dynamometer or a ground dynamometer, or simply a dynamometer for short. This device tests the force and displacement of the top sucker rod of the sucker rod column, which is the bare rod. The force and displacement data obtained from the test are plotted on a coordinate graph with displacement on the horizontal axis and force on the vertical axis. A closed curve is drawn for one complete stroke, which is the dynamometer. The shape of the dynamometer corresponds to the working condition of the pumping well.

[0003] Surface dynamometers have undergone years of research and development and are now technically mature. However, the technology for testing the dynamometer diagram of the sucker rod located underground has been lacking in maturity due to limitations in the well space, the effects of liquids on insulation, and the impact of changes in the sucker rod structure and size on its strength. While there are only a few patented technologies, there are still no widely used products.

[0004] Announcement No.: CN101650239B discloses a downhole sealed load sensor that directly measures the load borne by the rod pump piston rod during its up and down reciprocating motion. The first sealing ring, the second sealing ring and the protective cover are used to seal the elastomer, ensuring the sealing performance of the elastomer and making it unaffected by the high confining pressure downhole, ensuring that the high confining pressure downhole does not cause deformation of the elastomer. Four resistance strain gauges form a differential bridge, effectively eliminating the error caused by bending deformation in load measurement.

[0005] Announcement No.: CN103454030B, discloses a sucker rod mechanical parameter measurement device, which consists of a long joint cabin, a short joint, a double-ring seal, a stress concentration filter and a micro-electric measurement and control system. The double-ring seal is installed in the sealing groove of the long joint cabin, and the micro-electric measurement and control system is placed in its cavity. Strain gauges are attached in the circumferential direction near the wire hole on the outer wall of the long joint cabin to form a bridge circuit for measuring axial force and bending moment. The stress concentration filter is connected to the long joint cabin, and a high-temperature resistant strain gauge is attached to the inner wall of its drum-shaped part to form a radial force bridge measurement circuit.

[0006] Publication No. CN103439037A discloses a downhole rod string power diagram tester for a pumping unit. The tester comprises a load sensor upper connector, a load sensor, a load sensor lower connector, a sensor positioning compartment, a pressure sensor, a data acquisition board, an acceleration sensor, a power supply battery compartment, an upper connector for the power supply battery compartment, and a lower connector for the power supply battery compartment. The tester corrects data collected by the acceleration sensor using a three-dimensional multi-axis correction model to calculate the absolute displacement of the rod string, thereby improving acquisition accuracy and reducing measurement errors. Furthermore, a quadratic integral filtering algorithm is used to isolate drift in the signal, eliminate the impact of rod string vibration on the test, and achieve accurate stroke detection.

[0007] The above-mentioned prior art is different from the structure of this patent. The cylindrical shell of this patent lengthens the coupling and forms an equipment cavity of the required length in the middle of it. The cylindrical shell does not change the wall thickness, thread model, material and processing technology of the coupling, ensuring that its strength and fatigue resistance during underground use are similar to those of the coupling. The sealing plug provided ensures that the test components in the equipment cavity are protected from insulation problems caused by underground liquid intrusion, and are affected by collision and extrusion, making it easier to assemble and implement. The seal of the above-mentioned prior art is directly connected to the oil rod, and there is a risk of insufficient strength and fatigue resistance. The seal of this patent is separated from the oil rod joint and is not the main force-bearing part. It has a longer service life and a long-term sealing effect that is better than the above-mentioned prior art.

[0008] In short, the technical solutions of the above-disclosed technologies, the technical problems to be solved and the beneficial effects produced are all different from those of the present utility model. Regarding the more technical features, technical problems to be solved and the beneficial effects of the present utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0009] In view of the above-mentioned defects in the prior art, the purpose of the present invention is to provide a downhole sucker rod dynamometer diagram testing device.

[0010] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0011] A downhole sucker rod dynamometer test device comprises a cylindrical shell with threaded countersunk holes at both ends of the shell, a sealing plug, and a test assembly; the space between the two threaded countersunk holes in the shell is an equipment cavity, and both threaded countersunk holes are connected to sealing plugs; the sealing plug comprises a connecting portion and a sealing portion, the connecting portion being threadedly connected to the threaded countersunk hole, the sealing portion being inserted into the equipment cavity and sealing; the length of the connecting portion is less than the depth of the threaded countersunk hole.

[0012] Furthermore, a sealing ring groove is provided on the outer wall of the sealing portion, a sealing ring is provided in the sealing ring groove, and the sealing ring seals the outer wall of the sealing portion and the inner wall of the equipment cavity.

[0013] Furthermore, the sealing plug is provided with an axially penetrating sealing opening, and a plug is provided at one end of the sealing opening away from the equipment cavity.

[0014] Furthermore, a tool countersunk hole is provided on the end surface of the sealing portion away from the equipment cavity.

[0015] Furthermore, the plug is threadedly connected to the sealing port and sealed.

[0016] Furthermore, the sealing plug is completely screwed into the threaded countersunk hole, and the remaining threaded section of the threaded countersunk hole is used to connect the sucker rod joint.

[0017] Furthermore, the cylindrical shell is formed by lengthening the coupling to form a device cavity of required length in the middle thereof.

[0018] Furthermore, the test assembly includes a test unit, a strain gauge, and a battery;

[0019] Specifically, the strain gauge is adhered and fixed to the wall of the device cavity, the strain gauge is connected to the test unit through a high-temperature resistant wire, and the test unit is connected to the battery through a high-temperature resistant wire.

[0020] Furthermore, the strain gauge is an axial force strain gauge, and at least two strain gauges are provided.

[0021] Furthermore, the test unit includes a programmable controller, a storage, and an acceleration sensor. The programmable controller is used for control, the acceleration sensor is used for testing acceleration and calculating displacement data, and the storage is used for storing test data.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The utility model lengthens the coupling to form a cylindrical space inside the coupling, and then designs a sealing plug so that the test unit can be installed in the coupling.

[0024] 2. The utility model adopts the structure of a mature conventional coupling. The lengthening of the coupling does not affect its mechanical strength and fatigue resistance. The structure is simple. The test unit is installed in the cylindrical shell to prevent the test unit from being hit and worn by the rod and pipe. The provision of a sealing plug and blockage can prevent well fluid from invading the equipment cavity and protect the insulation performance of the test component. After the cylindrical shell is removed from the well, the test unit can be taken out for data playback, and the entire device can be reused.

[0025] 3. The seal of the utility model is a sealing plug, which is not connected to the oil rod joint and is not a main force-bearing component. It has a longer service life, extends the replacement cycle, and reduces the cost of use. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a structural diagram of a downhole sucker rod dynamometer test device of the utility model;

[0027] Figure 2 This is a schematic structural diagram of the cylindrical shell in the utility model;

[0028] Figure 3 This is a schematic structural diagram of the sealing plug in the utility model;

[0029] Figure 4 It is a structural schematic diagram of the sucker rod joint in the utility model.

[0030] In the figure: 1. Cylindrical shell; 2. First sucker rod joint; 3. Second sucker rod joint; 4. First sealing plug; 5. Second sealing plug; 6. First plugging; 7. Second plugging; 8. Test unit; 9. First strain gauge; 10. Second strain gauge; 11. Battery; 12. High-temperature resistant wire; 101. First threaded countersunk hole; 102. Second threaded countersunk hole; 103. Equipment cavity; 201. First sucker rod wrench square; 202. External thread of first sucker rod joint; 401. External thread of first sealing plug; 402. First sealing ring groove. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] The axial force on the sucker rod coupling is the same as that on the connected sucker rod, and the axial movement is also the same. If the strain gauges, circuits, storage and batteries for testing the force and displacement of the sucker rod are set inside the inner hole of the coupling, the test data will be the same as that of the sucker rod. The space in the inner hole of the coupling is larger, which becomes an optional space for installing the test unit. The coupling length commonly used in the industry is designed and manufactured based on the thread length required to connect two sucker rods. The national standard GB / T 43303-2023, "Sucker Rods for Petroleum and Natural Gas Drilling and Production Equipment," specifies coupling dimensions. Taking a 22mm nominal coupling as an example, its length is 101.6mm. The minimum diameter of the internal thread in the inner bore is 27.43mm, corresponding to a sucker rod external thread length of 41.28mm. After the two sucker rods are connected with the coupling, there is still 101.6-2*41.28=19.04mm of space left in the coupling's inner bore. Increasing the coupling's length creates a larger internal space, creating a circular space with a 27.43mm diameter for accommodating a test unit. Both the diameter and length are met, and the coupling's thick wall protects the test unit, eliminating the need to consider the impact of collision and friction between the sucker rod and the inner wall of the tubing. A sealing feature within the coupling further mitigates issues such as well fluid immersion.

[0033] Example 1:

[0034] See also Figures 1 to 4 The utility model provides a downhole sucker rod dynamometer test device, comprising a cylindrical shell 1, the center of the cylindrical shell 1 is through, a second threaded countersunk hole 102 is provided at the axial front end of the cylindrical shell 1, and a first threaded countersunk hole 101 is provided at the axial rear end of the cylindrical shell 1, and an equipment cavity 103 is between the first threaded countersunk hole 101 and the second threaded countersunk hole 102.

[0035] The cylindrical shell 1 is a component connecting two sucker rods and is cylindrical in shape. Its length and aperture meet the space requirements of the test unit 8. The wall surface of the equipment cavity 103 of the cylindrical shell 1 is smooth.

[0036] A first sealing plug 4 is threadedly connected in the first threaded countersunk hole 101. The first sealing plug 4 includes a first connecting part and a first sealing part. The first connecting part is provided with a first sealing plug external thread 401. The first connecting part is threadedly connected to the first threaded countersunk hole 101. The first sealing part is fixed at one end of the first connecting part close to the equipment cavity 103. The first sealing part is inserted into the equipment cavity 103. A first sealing ring groove 402 is provided on the outer wall of the first sealing part. A first sealing ring is provided in the first sealing ring groove 402. The first sealing ring seals the outer wall of the first sealing part with the inner wall of the equipment cavity 103. At most 2 sealing ring grooves and sealing rings can be provided on the outer wall of the first sealing part; the first sealing plug 4 is provided with an axially through first sealing port, and a first plug 6 is provided at the end of the first sealing port away from the equipment cavity 103. The end face of the first sealing part away from the equipment cavity 103 is provided with a first tool countersunk hole.

[0037] Specifically, the length of the first connecting portion is smaller than the depth of the first threaded countersunk hole 101 .

[0038] Specifically, a first tool groove is provided at one end of the first sealing port away from the first sealing port, and the first sealing port is threadedly connected to the first sealing port to form a seal.

[0039] Preferably, the first seal 6 is screwed together with the first sealing opening for sealing. If the screwing sealing effect is poor, the seal can be wrapped with a raw tape.

[0040] Another preferred embodiment is that a first sealing countersunk hole is provided at one end of the first sealing port away from the equipment cavity 103, one end of the first plug 6 in the first sealing port is a first sleeve, a first conical rubber sealing head is provided in the first sleeve, and by screwing in the first plug 6, the first conical rubber sealing head is compacted and sealed with the bottom hole of the first sealing countersunk hole.

[0041] A second sealing plug 5 is threadedly connected in the second threaded countersunk hole 102, and the second sealing plug 5 includes a second connecting part and a second sealing part. The second connecting part is provided with a second sealing plug external thread, and the second connecting part is threadedly connected to the second threaded countersunk hole 102. The second sealing part is fixed at one end of the second connecting part close to the equipment cavity 103, and the second sealing part is inserted into the equipment cavity 103. A second sealing ring groove 402 is provided on the outer wall of the second sealing part, and a second sealing ring is provided in the second sealing ring groove 402. The second sealing ring seals the outer wall of the second sealing part with the cavity wall of the equipment cavity 103. The outer wall of the second sealing part can be provided with at most 2 sealing ring grooves and sealing rings; the second sealing plug 4 is provided with an axially penetrating second sealing port, and a second plug 7 is provided at the end of the second sealing port away from the equipment cavity 103, and a second tool countersunk hole is provided on the end face of the second sealing part away from the equipment cavity 103.

[0042] Specifically, the length of the second connecting portion is smaller than the depth of the second threaded counterbore 102 .

[0043] Specifically, a second tool groove is provided at one end of the second sealing port away from the second sealing port, and the second sealing port is threadedly connected to the second sealing port to form a seal.

[0044] Preferably, the second seal 7 is screwed together with the second sealing opening for sealing. If the screwing sealing effect is poor, the seal can be wrapped with raw tape.

[0045] Another preferred embodiment is that a second sealing countersunk hole is provided at one end of the second sealing port away from the equipment cavity 103, one end of the second plug 7 in the second sealing port is a second sleeve, a second conical rubber sealing head is provided in the second sleeve, and by screwing in the second plug 7, the second conical rubber sealing head is compacted and sealed with the bottom hole of the second sealing countersunk hole.

[0046] A test unit 8, a first strain gauge 9, a second strain gauge 10, and a battery 11 are provided in the device cavity 103; the first strain gauge 9 and the second strain gauge 10 are respectively adhered and fixed to the wall of the device cavity 103, and the first strain gauge 9 and the second strain gauge 10 are connected to the test unit 8 through a high-temperature resistant wire 12, and the test unit 8 is connected to the battery 11 through a high-temperature resistant wire 12.

[0047] The first strain gauge 9 and the second strain gauge 10 are axial force strain gauges.

[0048] The sealing openings of the first sealing plug 4 and the second sealing plug 5 are used to allow excess thermal paste to overflow, and the plugging is used to completely seal the openings to prevent well fluid from invading the equipment cavity 103 .

[0049] Among them, the tool countersunk holes of the first sealing plug 4 and the second sealing plug 5 are used to completely screw the first sealing plug 4 and the second sealing plug 5 into the first threaded countersunk hole 101 and the second threaded countersunk hole 102, and the remaining threaded sections of the first threaded countersunk hole 101 and the second threaded countersunk hole 102 are used to connect the first sucker rod joint 2 and the second sucker rod joint 3.

[0050] Among them, the test unit 8 is controlled by a programmable controller, which can be a single-chip microcomputer; the test unit 8 uses an acceleration sensor to test acceleration and obtains displacement through calculation; the test unit 8 is provided with a storage for storing test data and replaying the test data after taking it out from the well.

[0051] The battery 11 is a high temperature resistant battery of available model such as ER26500S, a 6.5Ah capacity model, with a diameter of 25.4mm, a length of 50mm, and a maximum operating temperature of 145°C.

[0052] The first sucker rod joint 2 includes a first sucker rod joint external thread 202 and a first sucker rod wrench 201. The first sucker rod joint external thread 202 is screwed and tightened with the internal thread of the cylindrical shell 1 by applying torque to the first sucker rod wrench 201 using a wrench tool.

[0053] The second sucker rod joint 3 includes a second sucker rod joint external thread and a second sucker rod wrench. The second sucker rod joint external thread is screwed and tightened with the internal thread of the cylindrical shell 1 by applying torque to the second sucker rod wrench using a wrench tool.

[0054] Example 2:

[0055] Based on Example 1, this embodiment provides a specific downhole sucker rod dynamometer diagram testing device.

[0056] The cylindrical shell 1 was tested for tensile strength using a material testing machine, and the test value was no less than the requirements of the relevant standard GBT 43303-2023 "Sucker Rods for Petroleum and Natural Gas Drilling and Production Equipment". A fatigue performance test was performed using a fatigue testing machine, and the fatigue performance met the requirements of the relevant standard GBT 43303-2023 "Sucker Rods for Petroleum and Natural Gas Drilling and Production Equipment" of 1 million times without damage; other properties such as centering and thread structure were processed according to the requirements of the relevant standard GBT 43303-2023 "Sucker Rods for Petroleum and Natural Gas Drilling and Production Equipment"; the machinery and tools required for processing are very mature and easy to implement.

[0057] Example 3:

[0058] Based on Example 1 or Example 2, this embodiment provides a method for using a downhole sucker rod dynamometer diagram testing device, comprising the following steps:

[0059] The first strain gauge 9 and the second strain gauge 10 of the test unit are respectively pasted on the middle cavity wall of the equipment cavity 103, and high-temperature resistant wires 12 are led out from the first strain gauge 9 and the second strain gauge 10 to connect with the test unit 8. After the test unit 8 and the battery 11 are connected with the high-temperature resistant wires 12, they are installed into the equipment cavity 103. The computer is connected to the test unit 8, and the programmable controller of the test unit 8 is set, and the clock of the test unit 8 and the test and sleep time intervals are set. The memory is cleared and the test function is started. At this time, the test unit 8 starts working and tests according to the set test parameters and sleep time intervals. The test data is stored in the memory. The duration of the test work depends on the power supply capacity of the battery 11. The power of the battery 11 can provide the test unit with more than one month of work. When the power of the battery 11 is insufficient to meet the needs of the test unit 8, the test function is automatically terminated, but the test data in the memory is still saved.

[0060] After completing the setup, disconnect the connection line and inject thermal paste into the equipment cavity. Fill the thermal paste as much as possible to reduce the space occupied by air. Install sealing rings on the two sealing plugs respectively and screw them in from both ends of the cylindrical shell 1. When screwing in, the sealing port on the sealing plug opens and the excess thermal paste inside overflows from the sealing port. After the sealing plug is screwed in to the bottom, screw the plug into the sealing port on the sealing plug and tighten it to complete the installation of the test unit.

[0061] The cylindrical shell 1 is screwed together with the sucker rod whose dynamometer diagram needs to be tested, tightened, and lowered into the well. While the test component in the cylindrical shell 1 is in the well, force and acceleration tests are performed according to the set test and sleep intervals, and the test data is stored in the memory. When the battery power of the test unit is lower than the circuit requirement, the test work stops, but all the data of the previous tests are continuously stored in the memory. After the cylindrical shell is taken out during oil well operation, the plug is unscrewed, the sealing plug is unscrewed, the test unit is taken out, connected to the computer, and the test data stored in the memory is read for data playback and analysis.

[0062] Example 4:

[0063] Based on Example 3, this embodiment provides a specific application example for testing the dynamometer diagram of a well pump.

[0064] A cylindrical shell 1 is used for screwing with a nominal size 22mm sucker rod. The length of the cylindrical shell 1 is 340mm, and the minimum diameter of the internal thread in the inner hole is 27.43mm. A 70mm long internal thread is processed at both ends of the coupling. The internal hole diameter is 27.97mm. The circular equipment cavity 103 is processed inside and the first strain gauge 9, the second strain gauge 10, the test unit 8, the battery 11 and other components for testing force and acceleration are placed. There is no need to consider the collision and friction between the sucker rod and the inner wall of the oil pipe. Thermal paste is filled and a sealing plug is set to make the space for installing the test unit a sealed space to solve the problem of being soaked by well fluid.

[0065] All components not discussed in detail in this application and the connection methods of the components in this application are well-known technologies in the technical field and can be directly applied without further explanation.

[0066] In this utility model, the term "plurality" refers to two or more, unless otherwise specified. Terms such as "installed," "connected," "connected," and "fixed" should be interpreted broadly. For example, "connected" can mean fixed, removable, or integral; "connected" can mean directly or indirectly through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this utility model based on specific circumstances.

[0067] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by terms such as "up", "down", "left", "right", "front" and "back" are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit 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.

[0068] Throughout this specification, terms such as "one embodiment," "some embodiments," and "specific embodiments" mean that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A downhole sucker rod dynamometer test device, comprising a cylindrical housing with threaded countersunk holes at both ends of the housing, characterized in that: Also included are sealing plugs and test components; The space between the two threaded countersunk holes in the housing is a device cavity, and both threaded countersunk holes are connected to sealing plugs; The sealing plug includes a connecting portion and a sealing portion, wherein the connecting portion is threadedly connected to the threaded countersunk hole, and the sealing portion is inserted into the equipment cavity and seals; The length of the connecting portion is smaller than the depth of the threaded countersunk hole.

2. A downhole sucker rod dynamometer test device according to claim 1, characterized in that: A sealing ring groove is provided on the outer wall of the sealing portion, a sealing ring is provided in the sealing ring groove, and the sealing ring seals the outer wall of the sealing portion and the inner wall of the equipment cavity.

3. A downhole sucker rod dynamometer test device according to claim 1, characterized in that: The sealing plug is provided with an axially penetrating sealing port, and a plug is provided at one end of the sealing port away from the equipment cavity.

4. A downhole sucker rod dynamometer test device according to claim 1, characterized in that: The end surface of the sealing portion away from the equipment cavity is provided with a tool countersunk hole.

5. A downhole sucker rod dynamometer test device according to claim 3, characterized in that: The plug is threadedly connected to the sealing port and is sealed.

6. A downhole sucker rod dynamometer test device according to claim 1, characterized in that: The sealing plug is completely screwed into the threaded countersunk hole, and the remaining threaded section of the threaded countersunk hole is used to connect the sucker rod joint.

7. A downhole sucker rod dynamometer test device according to claim 1, characterized in that: The cylindrical shell is a coupling for setting the equipment cavity.

8. A downhole sucker rod dynamometer test device according to any one of claims 1 to 7, characterized in that: The test assembly includes a test unit, a strain gauge, and a battery; The strain gauge is adhered and fixed to the wall of the equipment cavity, the strain gauge is connected to the test unit through a high-temperature resistant wire, and the test unit is connected to the battery through a high-temperature resistant wire.

9. A downhole sucker rod dynamometer test device according to claim 8, characterized in that: The strain gauge is an axial force strain gauge, and at least two of the strain gauges are provided.

10. A downhole sucker rod dynamometer test device according to claim 8, characterized in that: The test unit includes a programmable controller, a storage, and an acceleration sensor. The programmable controller is used for control. The acceleration sensor is used for testing acceleration and calculating displacement data. The storage is used for storing test data.

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