High-rigidity superstructure drill rod with low-frequency multidirectional vibration band gap

Abstract

The invention relates to a high rigidity superstructure drill rod with a low frequency multidirectional vibration band gap, and relates to the technical field of mechanical vibration, the drill rod comprises a base rod, the base rod is in a hollow cylinder shape, a plurality of additional layers are respectively arranged on the base rod along the axial direction, and each additional layer comprises a scatterer ring layer and two soft material ring layers. The soft material ring layer, the scatterer ring layer and the hard ring are periodically arranged to form the local oscillator, when the corresponding waveform excitation frequency is close to the fixed frequency of the local oscillator, the vibration mode of the local oscillator can be activated and amplified into a main mode which is coupled with the vibration mode of the superstructure base rod, and the vibration mode of the local oscillator is coupled with the vibration mode of the superstructure base rod by applying counter-acting force to the superstructure base rod. The vibration mode of the base rod in the waveform propagation direction is restrained, so that the medium-wave propagation mode of the base rod disappears, transverse waves, longitudinal waves and torsional waves cannot be propagated in the super-structure drill rod and are superposed to form a complete band gap, simultaneous control over vibration of the longitudinal waves, the transverse waves and the torsional waves in the low-frequency range in engineering is achieved, and safety and efficiency in drilling operation are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of mechanical vibration technology, and particularly relates to a high-rigidity superstructure drill pipe with low-frequency multidirectional vibration band gap. BACKGROUND

[0002] As the "lifeline" connecting the ground and the underground in drilling equipment, the dynamic behavior and vibration control ability of the drill pipe in the whole life cycle of manufacturing, service and maintenance have become the core elements determining the drilling efficiency, reliability and even economy, and even constitute the key bottleneck restricting the technical breakthrough of ultra-deep wells, complex structure wells and the like, especially with the evolution of drilling operation to deeper strata, higher drilling speed, larger load and more complex geological conditions, the vibration problem derived from the drill string system is increasingly prominent, showing the distinct characteristics of strong nonlinearity and multi-modal coupling.

[0003] As the key component connecting the ground equipment and the downhole drill bit, the drill string system faces a complex dynamic environment during drilling, specifically, when the drill string works in the narrow wellbore filled with drilling fluid, it will be subjected to multi-source excitation actions such as periodic impact generated by rock breaking of the downhole drill bit, frictional resistance generated by contact with the well wall, and vortex-induced vibration generated by the flow of drilling fluid, thereby inducing three basic vibration modes: longitudinal vibration along the axis of the drill string (mainly manifested as the jump drill phenomenon), torsional vibration rotating around the axis (the most typical is stick-slip vibration), and transverse vibration perpendicular to the axis direction (developing into whirling or whipping when severe), and more complexly, in actual working conditions, the three vibration modes are often coupled with each other, forming a complex vibration state of nonlinearity and strong coupling.

[0004] In the prior art, the drill string shock absorption usually adopts two major technologies of active control and passive control, the active control technology relies on external energy supply, monitors the vibration state in real time through a sensor, and applies a reverse control force through an actuator to realize vibration suppression, although the control precision is high, the system is complex, the cost is high, and the adaptability to downhole environment is poor, the passive control technology dissipates vibration energy by installing passive damping elements (such as shock absorbers, dampers, etc.) or optimizing the structure design, although it has the advantages of high reliability and maintenance-free, but for low-frequency, especially below 100Hz, longitudinal-torsional-transverse coupled vibration, due to its physical properties of high vibration energy, long propagation distance and extremely slow attenuation, the control effect is limited, such strong vibration not only significantly reduces the drilling efficiency and the service life of the drill bit, but also is the main cause of engineering accidents such as drill tool fatigue fracture, downhole measurement tool failure, well trajectory out of control, and seriously restricts the technical development of complex structure wells such as deep wells and ultra-deep wells. Therefore, developing a new type of technology and structure capable of effectively suppressing the multidirectional low-frequency vibration of the drill string system has become a key and difficult point in the field of oil drilling engineering that needs to be broken through. SUMMARY

[0005] Therefore, the present application aims to provide a high-stiffness superstructure drill pipe with a low-frequency multidirectional vibration band gap, so as to solve the problem that the prior art has the limitations of narrow control frequency band, single direction and insufficient environmental adaptability when facing the low-frequency, wide-band and multidirectional coupling vibration unique to the drill string system, and is difficult to meet the requirements of modern drilling engineering for vibration suppression.

[0006] The present application is implemented by the following technical solutions:

[0007] A high-stiffness superstructure drill pipe with a low-frequency multidirectional vibration band gap comprises a base rod, which is arranged in a hollow cylindrical shape, and a plurality of additional layers arranged on the base rod in the axial direction, wherein the additional layers comprise a scatterer ring layer and two soft material ring layers.

[0008] The two soft material ring layers are both wrapped on the base rod, and the scatterer ring layer is sleeved on the two soft material ring layers, and a hard ring is arranged between the two soft material ring layers and in the scatterer ring layer.

[0009] Further, the inner diameter of the base rod is 120 mm, the thickness of the base rod is not less than 7 mm and not greater than 10 mm, and the length of the base rod is 12000 mm.

[0010] Further, the thickness of the soft material ring layer is the same as that of the scatterer ring layer, and the thickness of the soft material ring layer and the scatterer ring layer is greater than that of the hard ring.

[0011] Further, the hard rings are equidistantly arranged on the base rod, and the distance L1 between the outer walls of the base rod and the distance L2 between the inner walls of the hard rings and the scatterer ring layer are equal, i.e. L1=L2.

[0012] Further, the length of the scatterer ring layer is equal to the distance between the two farthest ends of the two soft material ring layers, i.e. the scatterer ring layer completely covers the two soft material ring layers.

[0013] Further, the inner wall of the soft material ring layer is fixedly connected with the outer wall of the base rod, the inner wall of the scatterer ring layer is fixedly connected with the outer wall of the soft material ring layer, and the two ends of the hard ring are fixedly connected with the ends of the soft material ring layer corresponding in position.

[0014] Further, the base rod is made of steel, the plurality of soft material ring layers are all made of rubber, and the density of the plurality of soft material ring layers is not less than 1300 kg / m 3 , the plurality of scatterer ring layers are all made of copper, and the density of the plurality of scatterer ring layers is not less than 8950 kg / m 3 , and the plurality of hard rings are all made of steel, and the density of the plurality of hard rings is not less than 7780 kg / m 3 .

[0015] The application has the advantages that:

[0016] The high-rigidity superstructure drill rod with low-frequency multidirectional vibration band gaps has the advantages that: the periodic coating of soft material ring layers and scatterer ring layers on the rod body can provide good mechanical protection for the base rod, reduce the influence caused by the erosion of solid particles in the drilling fluid and the collision and scraping between the base rod and the well wall, the hard ring with a suitable thickness is arranged in cooperation to form a local oscillator, when the corresponding waveform excitation frequency is close to the fixed frequency of the local oscillator, the vibration mode of the local oscillator will be activated and amplified to become a main mode, and the vibration mode of the base rod along the waveform propagation direction is coupled through the application of a counterforce to the superstructure base rod, so that the wave propagation mode in the base rod disappears, and the transverse wave, the longitudinal wave and the torsional wave cannot propagate in the superstructure drill rod and superimposed to form a complete band gap, thereby realizing the control of the longitudinal wave, the transverse wave and the torsional wave vibration in the low-frequency range in engineering, and improving the safety and efficiency in drilling operation.

[0017] Additional advantages, objects, and features of the application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following specification or can be learned from practice of the application. The objects and other advantages of the application can be realized and attained by the structure particularly pointed out in the description below. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a front view structural schematic diagram of the base rod of the application;

[0019] Figure 2 It is a front view structural schematic diagram of the superstructure rod unit of the application;

[0020] Figure 3 It is a mounting structural schematic diagram of the soft material ring layer and the hard ring of the application;

[0021] Figure 4 It is a side sectional view structural schematic diagram of the application;

[0022] Figure 5 It is a front sectional view structural schematic diagram of the application;

[0023] Figure 6 It is a structural schematic diagram of the soft material ring layer and the hard ring of the application;

[0024] Figure 7 It is a transverse wave band gap energy band structure diagram of the superstructure rod in the embodiment of the application;

[0025] Figure 8 It is a transverse wave band gap boundary characteristic mode vibration mode diagram of the superstructure rod in the embodiment of the application;

[0026] Figure 9A transverse excitation transmission characteristic diagram of the superstructure rod of the embodiment in the present application;

[0027] Figure 10 A longitudinal wave band gap energy band structure diagram of the superstructure rod of the embodiment in the present application;

[0028] Figure 11 A longitudinal wave band gap boundary characteristic modal shape diagram of the superstructure rod of the embodiment in the present application;

[0029] Figure 12 A longitudinal excitation transmission characteristic diagram of the superstructure rod of the embodiment in the present application;

[0030] Figure 13 A torsional wave band gap energy band structure diagram of the superstructure rod of the embodiment in the present application;

[0031] Figure 14 A torsional wave band gap boundary characteristic modal shape diagram of the superstructure rod of the embodiment in the present application;

[0032] Figure 15 A torsional excitation transmission characteristic diagram of the superstructure rod of the embodiment in the present application;

[0033] Figure 16 A complete band gap energy band structure diagram of the superstructure rod of the embodiment in the present application.

[0034] In the figure: 1, base rod; 2, soft material ring layer; 3, scatterer ring layer; 4, hard ring. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts are within the scope of protection of the present application.

[0037] It should be noted that: similar numbers and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0038] In the above description of the present application, it should be noted that the terms "one side", "the other side" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed during use, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0039] In addition, the term "same" and the like do not mean that the components must be absolutely the same, but there can be slight differences. The term "vertical" only means that the positional relationship between the components is more vertical than "parallel", and does not mean that the structure must be completely vertical, but can be slightly inclined.

[0040] Please refer to Figure 1 Figure 3 The present application provides a technical solution: a high-stiffness superstructure drill rod with a low-frequency multidirectional vibration band gap, comprising a base rod 1, the base rod 1 is set as a hollow cylindrical type, a plurality of additional layers are arranged on the base rod 1 along the axial direction respectively, the additional layers comprise a scatterer ring layer 3 and two soft material ring layers 2, a hard ring 4 is arranged between the two soft material ring layers 2, the inner wall of the soft material ring layer 2 is fixedly connected with the outer wall of the base rod 1, the inner wall of the scatterer ring layer 3 is fixedly connected with the outer wall of the soft material ring layer 2, and the two ends of the hard ring 4 are fixedly connected with the end portions of the soft material ring layers 2 corresponding in position.

[0041] Specifically, in order to achieve excellent engineering bearing force, one embodiment of the superstructure rod is as follows:

[0042] The length of the base rod 1 is set to 12000mm, which can be directly replaced or integrated as a single drill rod, the length of the soft material ring layer 2 is set to 967.5mm, and the thickness is 55mm, when the drill rod is twisted and vibrates, the soft material ring layer 2 will be sheared and deformed, when longitudinal vibration occurs, it will be compressed or stretched, and the stress wave length in the drill rod is very long, the appropriate thickness enables the local oscillator to effectively interact with these long wave vibrations, thereby ensuring the effectiveness of the low-frequency vibration in the physical scale, the length of the scatterer ring layer 3 is set to 2365mm, and the thickness is 55mm, the scatterer ring layer 3 occupies most of the length of the base rod 1, so that the vibration wave is within the influence range of the high-quality unit during propagation, ensuring the width of the band gap and the effectiveness of the suppression effect, the length of the hard ring 4 is set to 430mm, and the thickness is 20mm, which is used as an excitation mass block to dissipate the energy of multidirectional vibration (longitudinal-torsional-lateral).

[0043] In combination with Table 1, the base rod 1 is made of steel, and its density is 7780kg / m 3With an elastic modulus of 216,000 MPa and a Poisson's ratio of 0.33, the high elastic modulus gives the base rod 1 extremely strong load-bearing capacity and torsional resistance. It can withstand complex working conditions such as high-pressure drilling fluid column pressure at the bottom of the well and formation reaction load during drilling, avoiding deformation or fracture due to external forces. At the same time, the hollow design forms a high-pressure drilling mud circulation channel, realizing the extended functions of cooling the drill bit, carrying cuttings and balancing formation pressure, meeting the core operational requirements of drill pipe in extreme downhole environments.

[0044] The soft material ring layer 2 is made of rubber with a density of 1300 kg / m³. 3 With an elastic modulus of 2.05 MPa and a Poisson's ratio of 0.43, the low elastic modulus and high Poisson's ratio of rubber give the soft material ring layer 2 excellent elastic deformation ability. When the superstructure rod vibrates, it has good buffering performance. Utilizing its high damping characteristics, it can dissipate energy while blocking waves, thus achieving more efficient vibration reduction.

[0045] The scatterer ring layer 3 is made of copper with a density of 8950 kg / m³. 3 With an elastic modulus of 110,000 MPa and a Poisson's ratio of 0.34, the high density of the scatterer ring layer 3 allows it to act as a mass block, forming a mass-spring type local resonant unit with the soft material ring layer 2. This opens up sub-bandgap spaces for transverse, longitudinal, and torsional waves in the low-frequency range of 44.30 Hz to 81.14 Hz (as shown in the figure below). Figure 7 , Figure 10 , Figure 13 As shown in the figure, the medium elastic modulus and good ductility of copper can ensure the structural strength of the scatterer ring layer 3 itself and avoid damage in drilling fluid erosion or well wall friction. At the same time, it can adapt to the vibration response of the soft material ring layer 2 and ensure the stability of the resonance effect.

[0046] The hard ring 4 is made of steel, with a length of 430mm and a thickness of 20mm. The high rigidity of the steel material allows the hard ring 4 to act as a rigid excitation mass block. When the superstructure rod undergoes lateral bending vibration, the hard ring 4 can apply cyclic compressive and shear loads to the soft material ring layers 2 on both sides, further stimulating multi-mode deformation of the soft material and enhancing the dissipation of lateral vibration energy. At the same time, the hard ring 4 can enhance the overall structural stability of the additional layer, preventing the soft material ring layer 2 from excessive deformation or falling off due to long-term vibration. Furthermore, the compatibility between the steel material and the base rod 1 ensures that the hard ring 4 can be firmly connected to the soft material ring layer 2 through adhesive bonding and other processes, forming an integrated high-rigidity structure. This improves the overall load-bearing capacity of the superstructure rod and meets the comprehensive requirements of high rigidity and long service life for drill pipes in engineering fields such as oil drilling and production.

[0047] Table 1 Structural Material Parameters

[0048] Material Density / (kg-m-3) Elastic modulus / (Mpa) Poisson's ratio Steel 7780 216000 0.33 Rubber 1300 2.05 0.43 Copper 8950 110000 0.34

[0049] To filter and suppress low-frequency vibrations, the above-mentioned scheme was optimized and improved by referring to... Figures 4 to 6 Two soft material ring layers 2 are both wrapped around the base rod 1. The scatterer ring layer 3 is fitted on the two soft material ring layers 2. The length of the scatterer ring layer 3 is equal to the distance between the two far ends of the two soft material ring layers 2. The hard ring 4 is set inside the scatterer ring layer 3. The hard ring 4 is set in the middle of the base rod 1. The distance L1 between the hard ring 4 and the outer wall of the base rod 1 is equal to the distance L2 between the hard ring 4 and the inner wall of the scatterer ring layer 3, that is, L1 = L2.

[0050] Specifically, the base rod 1, soft material ring layer 2, scatterer ring layer 3, and hard ring 4 are arranged axially. When the transverse wave excitation frequency, longitudinal wave excitation frequency, and torsional wave excitation frequency are close to the natural frequency of the local oscillator, the vibration mode of the local oscillator is activated and amplified into the dominant mode. This corresponds to the local oscillator vibrating in the direction perpendicular to the axial direction, vibrating in the axial direction, and vibrating in the torsional direction. At this time, the base rod 1 is in a static state, and the vibration mode of the local oscillator dominates the response of the superstructure rod. Coupled with the vibration mode of the superstructure base rod 1, a reaction force is applied to the superstructure base rod 1 to suppress its vibration modes in the directions perpendicular to the axial direction, axial direction, and torsional direction (corresponding to...). Figure 8 Medium mode A, Figure 11 Medium mode C, Figure 14 The intermediate mode (E) causes the wave propagation mode of the base rod 1 to disappear. Transverse waves, longitudinal waves, and torsional waves cannot propagate in the local resonant superstructure drill rod, forming transverse wave, longitudinal wave, and torsional wave band gaps, which begin to suppress vibration.

[0051] When the transverse, longitudinal, and torsional vibration excitations exceed their respective specific frequencies, the transverse, longitudinal, and torsional vibration modes of the superstructure base rod are activated and amplified into the dominant modes of the superstructure rod. This manifests as the base element vibrating along the perpendicular, axial, and torsional directions, respectively. At this time, the local oscillator is at rest, and the wave modes of the novel local resonant drill rod base rod 1 dominate the response of the superstructure rod (corresponding to...). Figure 8 Medium mode B, Figure 11 Mode D Figure 14 Mode F), so transverse waves, longitudinal waves, and torsional waves can propagate in the local resonant drill pipe according to this mode, and the band gap is closed.

[0052] The periodic arrangement of the structure makes the local resonance effect of each unit more pronounced. The resonant coupling formed by the elastic deformation of the soft material ring layer 2 and the vibration of the scatterer ring layer 3 will generate reverse waves inside the structure, which will interfere with the longitudinal, transverse, and torsional waves propagating in the base rod 1, causing the three sub-bandgap superposition (e.g. Figure 16(As shown in the shaded area), within this frequency range, the propagation of elastic waves is significantly attenuated, forming a fully bandgap structure that can simultaneously suppress all vibration modes (longitudinal-transverse-torsional coupling). Ultimately, this effectively suppresses low-frequency vibrations coupled in the longitudinal-torsional-transverse three directions. At the same time, the stiffness characteristics of the materials of each component work together to ensure the overall load-bearing capacity of the superstructure rod, meeting the dual requirements of load-bearing and vibration reduction in engineering applications.

[0053] Specifically, such as Figure 7 In the diagram, A and B represent the open and closed positions of the shear wave bandgap, respectively. Figure 8 A and B respectively represent Figure 7 The mode shapes corresponding to the opening and closing positions of the midband gap. Figure 9 This indicates that the transverse vibration within the transverse wave bandgap is in a state of continuous attenuation, such as... Figure 10 In the diagram, C and D represent the open and closed positions of the P-wave bandgap, respectively. Figure 11 C and D in the text represent Figure 10 The mode shapes corresponding to the opening and closing positions of the midband gap. Figure 12 This indicates that the longitudinal vibration within the P-wave bandgap is in a state of continuous attenuation, such as... Figure 13 In the diagram, E and F represent the torsional wave bandgap opening and closing positions, respectively. Figure 14 E and F represent respectively Figure 13 The mode shapes corresponding to the opening and closing positions of the midband gap. Figure 15 This indicates that the torsional vibration within the band gap range of the torsional wave is in a state of continuous attenuation.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A high stiffness superstructure drill pipe with a low frequency multi-directional vibrational bandgap comprising a base pipe (1) characterised in that: The base rod (1) is provided as a hollow cylindrical type, and a plurality of additional layers are arranged on the base rod (1) along the axial direction respectively, and the plurality of additional layers respectively comprise a scattering body ring layer (3) and two soft material ring layers (2); The two soft material ring layers (2) are both wrapped on the base rod (1), the scattering body ring layer (3) is sleeved on the two soft material ring layers (2), a hard ring (4) is arranged between the two soft material ring layers (2), and the hard ring (4) is arranged in the scattering body ring layer (3).

2. A high stiffness superstructured drill pipe with low frequency multidirectional vibrational band gap according to claim 1, characterized in that: The inner diameter of the base rod (1) is 120 mm, the thickness of the base rod (1) is not less than 7 mm and not greater than 10 mm, and the length of the base rod (1) is 12000 mm.

3. The high stiffness superstructure drill pipe with low frequency multidirectional vibration band gap of claim 1, wherein: The thickness of the soft material ring layer (2) is the same as the thickness of the scattering body ring layer (3), and the thickness of the soft material ring layer (2) and the scattering body ring layer (3) is greater than the thickness of the hard ring (4).

4. The high stiffness superstructure drill pipe with low frequency multidirectional vibration band gap of claim 1, wherein: The hard ring (4) is equidistantly arranged on the base rod (1), and the spacing L1 between the hard ring (4) and the outer wall of the base rod (1) is equal to the spacing L2 between the hard ring (4) and the inner wall of the scattering body ring layer (3), that is, L1=L2.

5. The high stiffness superstructure drill pipe with low frequency multidirectional vibration band gap of claim 1, wherein: The length of the scattering body ring layer (3) is equal to the distance between the two farthest ends of the two soft material ring layers (2), that is, the scattering body ring layer (3) completely covers the two soft material ring layers (2).

6. The high stiffness superstructure drill pipe with low frequency multidirectional vibrational band gap of claim 1, wherein: The inner wall of the soft material ring layer (2) is fixedly connected with the outer wall of the base rod (1), the inner wall of the scattering body ring layer (3) is fixedly connected with the outer wall of the soft material ring layer (2), and the two ends of the hard ring (4) are respectively fixedly connected with the end portions of the soft material ring layers (2) corresponding in position.

7. The high stiffness superstructure drill pipe with low frequency multidirectional vibration band gap of claim 1, wherein: The base rod (1) is made of steel, the soft material ring layers (2) are made of rubber, and the density of the soft material ring layers (2) is not less than 1300kg / m 3 The scatterer ring layers (3) are made of copper, and the density of the scatterer ring layers (3) is not less than 8950kg / m 3 The hard rings (4) are made of steel, and the density of the hard rings (4) is not less than 7780kg / m 3 .

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