Rotary steering structure of a pulser for oil drilling

Abstract

The utility model discloses a kind of rotatable steering structures of pulser for petroleum drilling, belong to petroleum drilling equipment field.A kind of rotatable steering structures of pulser for petroleum drilling, including hollow shell and the main shaft rotationally connected in hollow shell, further include: fixedly installed in the middle part of main shaft's guide vane, the inner wall of hollow shell is fixedly connected with the guide ring that is compatible with guide vane, and at least four groups of guide block that are compatible with guide vane are fixedly installed on guide ring;The utility model is equipped with the setting of guide vane, and the problem of insufficient impact resistance of traditional uniform thickness blade is solved, and root thin can reduce rotational inertia resistance, tip thick enhances anti-deformation capacity, reduces drilling fluid flow resistance by streamline profile, energy utilization rate is improved, effectively shortens the response delay of guide adjustment, and reinforcing rib structure solves the problem of traditional blade fatigue crack, can extend blade service life, and further satisfy long-term operation demand of deep well.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling equipment technology, and in particular to a rotary guide structure for an oil drilling pulser. Background Technology

[0002] The pulse generator for oil drilling is a core transmission component of the measurement-while-drilling (MSD) or logging-while-drilling (LOD) system. Its function is to transmit in real time directional data (such as inclination angle and azimuth angle), geological parameters (such as gamma rays and resistivity), and engineering parameters (such as temperature and vibration) collected by downhole sensors to the surface. It is usually installed inside the drill collar and transmits binary data streams by encoding mud pressure pulses (positive pulses, negative pulses, or continuous waves). After the surface system decodes these pulse signals, engineers can grasp the downhole drill bit position, formation characteristics, and drilling status, providing a basis for optimizing the trajectory and ensuring safety.

[0003] The pulse generator is integrated into the downhole drilling tool assembly during the drilling process and works in conjunction with various sensors. During drilling, the downhole sensors continuously collect engineering data and geological information. The pulse generator encodes these data into mud pressure pulse signals according to a preset program. The circulating mud column driven by the drilling pump serves as the transmission medium, transmitting the pressure fluctuations to the surface. The high-pressure riser sensor at the wellhead detects these minute pressure changes in real time. The surface computer system decodes the signals and generates a wellbore trajectory map, formation profile, and drilling tool status report.

[0004] The core purpose of rotary steering is to achieve "synchronous rotation of the drill string and direction control" in oil and gas drilling, geological exploration and other engineering projects. Rotary steering adjusts the drill bit direction in real time when the drill string rotates at high speed through a built-in steering actuator. This reduces wellbore friction and failure risk, increases mechanical drilling speed, and controls the trajectory deviation within 0.1 meters through real-time measurement and closed-loop control, accurately hitting target reservoirs such as thin oil layers.

[0005] In existing technologies, some pulsers have certain problems during use. For example, traditional guide impeller blades often use straight plates or simple arc designs, which easily generate turbulence when interacting with drilling fluid, resulting in large fluctuations in guiding force and making it difficult to achieve precise guidance. At the same time, the blade thickness is uniform, which makes it easy to deform under the impact of high-pressure drilling fluid, affecting the guiding accuracy and causing excessive energy loss. On the other hand, some pulsers have pulse holes with equal diameter settings, which leads to a low signal-to-noise ratio of the pulse signal, resulting in unstable pressure pulses. Therefore, we urgently need a rotary guide structure for pulsers used in oil drilling to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to solve the problems of unstable guiding force, excessive energy loss, and unstable pressure pulse in the existing technology, and to propose a rotary guiding structure for a pulse generator used in oil drilling.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A rotary guide structure for an oil drilling pulse generator includes a hollow housing and a main shaft rotatably connected within the hollow housing. It further includes: a guide impeller fixedly installed in the middle of the main shaft; a guide ring adapted to the guide impeller is fixedly connected to the inner wall of the hollow housing; at least four sets of guide blocks with clearance fit to the guide impeller are fixedly installed on the guide ring; when the main shaft rotates, the guide impeller and guide blocks alternately contact to form a guiding eccentric force; a valve seat threadedly connected to the liquid inlet end of the hollow housing; a flow limiting plate is installed on the valve seat; a pulse valve disc is fixedly connected to the main shaft below the valve seat; and a pulse hole adapted to the flow limiting plate is opened on the pulse valve disc; when the main shaft and pulse valve disc rotate, the flow limiting plate and the pulse hole periodically connect or close.

[0009] In order to generate a stable guiding force, preferably, at least four sets of blades are fixedly connected to the guide impeller, and the four sets of blades are arranged equidistantly along the circumference of the main shaft.

[0010] To further enhance the structural strength of the blades, the blades are arranged in a fan shape, the flow-guiding surface of the blades is arc-shaped, and the back flow surface is fixedly connected with reinforcing ribs for improving the structural strength of the blades.

[0011] To generate a stable and precise guiding eccentric force, preferably, the gap between the guide impeller and the guide block is in the range of 0.5mm-2mm.

[0012] To provide reliable pulse signal transmission, preferably, the gap between the valve seat and the pulse valve disc is in the range of 0.2mm-0.8mm.

[0013] In order to generate pulse fluctuations, preferably, the number of current limiting plates and pulse holes is at least four sets, and the four sets of current limiting plates and pulse holes are all equidistantly arranged along the circumference of the main shaft.

[0014] To create a throttling effect, the cross-sectional projection of the pulse orifice is further arranged in a stepped shape, with the orifice diameter ratio of the inlet end to the outlet end being 2:1.

[0015] To provide support for the main shaft, preferably, an annular support platform is fixedly connected to the inner wall of the hollow housing, and the main shaft is rotatably connected to the annular support platform through a thrust bearing.

[0016] In order to drive the blades and pulse valve disc to rotate, preferably, a drive motor is fixedly connected to the end of the hollow housing away from the valve seat, and the output end of the drive motor is fixedly connected to the end of the main shaft. When the drive motor works, the pulse valve disc and blades on the main shaft rotate.

[0017] Compared with the prior art, this utility model provides a rotary guide structure for an oil drilling pulser, which has the following advantages:

[0018] 1. The rotary guide structure of this oil drilling pulse generator, through the setting of the guide impeller, the blade thickness gradually changes from 5mm at the root to 10mm at the tip along the radial direction. This design specifically solves the problem of insufficient impact resistance of traditional blades with uniform thickness. The thinner root reduces rotational inertia resistance, while the thicker tip enhances the resistance to deformation. The streamlined profile reduces drilling fluid flow resistance, improves energy utilization, effectively shortens the guidance adjustment response delay, and the reinforcing rib structure solves the fatigue crack problem of traditional blades, which can extend the service life of the blades and thus meet the long-term operation requirements of deep wells.

[0019] 2. The rotary guide structure of this oil drilling pulser solves the problem of insufficient pressure pulse intensity by setting a stepped pulse orifice. The abrupt change from a large orifice at the inlet to a small orifice at the outlet creates a stronger throttling effect, which enables the drilling fluid to generate a more obvious pressure change when passing through the pulse orifice. This ensures that the pressure pulse intensity is stable within the design range of 0.5-2MPa, and guarantees the clarity and reliability of the pulse signal even under complex drilling fluid conditions.

[0020] The parts not covered in this device are the same as or can be implemented using existing technologies. This invention solves the problem of insufficient impact resistance of traditional uniform thickness blades, improves energy utilization, effectively shortens the guidance adjustment response delay, and solves the problem of insufficient pressure pulse intensity. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the rotary guide partial cross-sectional structure of a pulse generator for oil drilling proposed in this utility model.

[0022] Figure 2 This is a schematic diagram of a rotary guide partial structure of a pulse generator for oil drilling proposed in this utility model.

[0023] Figure 3 This is a schematic diagram of the rotary guide blade structure of a pulse generator for oil drilling proposed in this utility model.

[0024] Figure 4 This is a schematic diagram of the rotary guide ring structure of a pulse generator for oil drilling proposed in this utility model;

[0025] Figure 5 This is a schematic diagram of the rotary guide pulse valve disc structure of a pulse generator for oil drilling proposed in this utility model;

[0026] Figure 6 This is a schematic diagram of the rotary guide valve seat structure of a pulse generator for oil drilling proposed in this utility model.

[0027] In the diagram: 1. Hollow shell; 2. Main shaft; 3. Guide impeller; 4. Guide ring; 5. Guide block; 6. Valve seat; 7. Flow limiting plate; 8. Pulse valve disc; 9. Pulse orifice; 10. Blade; 11. Reinforcing rib; 12. Annular support platform; 13. Drive motor. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0029] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] Example:

[0031] Reference Figures 1-6 A rotary guide structure for an oil drilling pulser includes a hollow housing 1 and a main shaft 2 rotatably connected inside the hollow housing 1. An annular support platform 12 is fixedly connected to the inner wall of the hollow housing 1. The main shaft 2 is rotatably connected to the annular support platform 12 through a thrust bearing. A drive motor 13 is fixedly connected to the end of the hollow housing 1 away from the valve seat 6, and the output end of the drive motor 13 is fixedly connected to the end of the main shaft 2. The drive motor 13 is a hydraulic drive motor.

[0032] Here, the hollow shell 1 is made of high-strength alloy material, which has excellent pressure resistance and corrosion resistance, and can work stably in harsh downhole environments. It has a through drilling fluid channel along the axial direction. The channel diameter is designed to be 120-180mm according to the conventional drilling fluid flow requirements to ensure smooth flow of drilling fluid.

[0033] Furthermore, the spindle 2 is made of 42CrMo alloy steel, which has high strength, good toughness and fatigue resistance. The surface of the spindle is nitrided, and the hardness reaches HRC55-60, which effectively improves its wear resistance and corrosion resistance. The spindle passes through the drilling fluid channel, and one end is rotatably connected to the annular support platform 12 through a thrust bearing. The other end is connected to the output end of the drive motor 13. When the drive motor 13 works, the spindle 2 rotates accordingly.

[0034] It also includes a guide impeller 3 fixedly installed in the middle of the main shaft 2. At least four sets of blades 10 are fixedly connected to the guide impeller 3. The four sets of blades 10 are arranged equidistantly along the circumference of the axis of the main shaft 2. The blades 10 are arranged in a fan shape. The flow-guiding surface of the blades 10 is arc-shaped. The back flow surface is fixedly connected to a reinforcing rib 11 for improving the structural strength of the blades 10.

[0035] Here, the thickness of the blades 10 on the guide impeller 3 gradually increases radially, from 5 mm at the root to 10 mm at the tip, in order to improve the impact resistance of the blades 10 when rotating at high speed and being subjected to drilling fluid impact. The guide impeller 3 preferably has 4 blades 10, which are evenly distributed around the circumference of the main shaft 2. The front surface of the blades 10 is arc-shaped, which can reduce the flow resistance of the drilling fluid. The reinforcing ribs 11 on the back surface effectively enhance the structural strength of the blades 10.

[0036] The inner wall of the hollow shell 1 is fixedly connected with a guide ring 4 that is adapted to the guide impeller 3, and at least four sets of guide blocks 5 that are clearance-fitted with the guide impeller 3 are fixedly installed on the guide ring 4. The gap between the guide impeller 3 and the guide blocks 5 is 0.5mm-2mm. When the main shaft 2 rotates, the guide impeller 3 and the guide blocks 5 alternately contact to form a guiding eccentric force.

[0037] It is important to note that the gap between the guide impeller 3 and the guide block 5 is 1mm. Within this gap range, the blades 10 on the guide impeller 3 can smoothly and alternately contact the guide block 5 on the inner wall of the guide ring 4 during rotation, generating a stable and precise guiding eccentric force. This also effectively reduces the leakage of drilling fluid from the edge of the blades 10 to the inner wall of the guide ring 4, allowing more drilling fluid to act on the blades 10, enhancing the guiding force generation effect, and ensuring that the blades 10 and the guide block 5 will not undergo rigid collisions due to complex downhole conditions such as vibration and impact. At the same time, a small amount of drilling fluid leakage is allowed to a certain extent, which can play an auxiliary lubrication role, reduce the frictional resistance between the blades 10 and the guide block 5, and extend the service life of the equipment.

[0038] Here, the inner wall of the guide ring 4 is provided with four protruding guide blocks 5. When the blades 10 on the guide impeller 3 rotate with the main shaft 2, the blades 10 and guide blocks 5 alternately contact each other. Since the guide blocks 5 are circumferentially protruding and uniformly shaped on the inner wall of the guide ring 4, when the blades 10 contact the guide blocks 5 at different positions during rotation, they will be subjected to reaction forces from different directions but of uniform magnitude. At the instant the blades 10 and guide blocks 5 contact each other, the blades 10 at the contact point exert an impact force on the guide blocks 5. At this time, the guide blocks 5 will generate a reaction force of equal magnitude and opposite direction on the blades 10. Since the guide blocks 5 are distributed in different circumferential positions, this reaction force will form a resultant force in the radial direction, namely, radial eccentric force. This radial eccentric force is transmitted to the main shaft 2 through the blades 10 on the guide impeller 3, thereby driving the hollow shell 1 to produce a guide offset as a whole. The frequency of the guide eccentric force can be precisely controlled, thereby achieving precise adjustment of the guide offset angle. The higher the rotation speed, the higher the frequency of the eccentric force and the higher the guide accuracy.

[0039] A valve seat 6 is threaded to the liquid inlet end of the hollow housing 1. A flow limiting plate 7 is installed on the valve seat 6. A pulse valve disc 8 is fixedly connected to the main shaft 2 below the valve seat 6. The pulse valve disc 8 has a pulse hole 9 that matches the flow limiting plate 7. The gap between the valve seat 6 and the pulse valve disc 8 is 0.2mm-0.8mm. The cross-sectional projection of the pulse hole 9 is stepped. The ratio of the diameter of the inlet end to the outlet end is 2:1. When the main shaft 2 and the pulse valve disc 8 rotate, the flow limiting plate 7 and the pulse hole 9 periodically connect or close. There are at least four sets of flow limiting plates 7 and pulse holes 9. The four sets of flow limiting plates 7 and pulse holes 9 are all equidistantly arranged along the circumference of the axis of the main shaft 2.

[0040] Here, the pulse valve disc 8 is interference-fitted with the spindle 2 to ensure that the two rotate synchronously during high-speed rotation. The edge of the pulse valve disc 8 is provided with several pulse holes 9 evenly distributed circumferentially. The pulse holes 9 are designed with stepped holes, and the diameter of the hole near the drilling fluid inlet end is larger than that of the outlet end. This structure can form a throttling effect, causing the drilling fluid to generate pressure changes when passing through the pulse holes 9. For example, the diameter of the hole at the inlet end is 20 mm and the diameter of the hole at the outlet end is 10 mm.

[0041] Furthermore, except for the area where the flow restrictor plate 7 is installed, the entire valve seat 6 is hollow to ensure the flow of drilling fluid. The flow restrictor plate 7 is made of hard alloy material, which has extremely high hardness and wear resistance, and can maintain stable performance under long-term scouring of high-pressure drilling fluid. When the spindle 2 drives the pulse valve disc 8 to rotate, the pulse orifice 9 and the flow restrictor plate 7 periodically connect and close, causing the drilling fluid pressure to generate pulse fluctuations of 0.5-2MPa, thereby realizing the signal transmission of downhole data.

[0042] It is important to note that the preferred gap between the valve seat 6 and the pulse valve disc 8 is 0.5mm. On the one hand, if the gap is too small, the pulse valve disc 8 and the valve seat 6 are prone to friction or even collision during the high-speed rotation of the pulse valve disc, which will aggravate wear, shorten its service life, and may also cause the rotation of the pulse valve disc 8 to be obstructed, affecting the normal generation and transmission of pulse signals, and in severe cases, may cause equipment failure. On the other hand, if the gap is too large, the drilling fluid will generate a large amount of leakage when passing through the gap between the pulse valve disc 8 and the valve seat 6, resulting in a weakening of the drilling fluid pressure pulse intensity, affecting the accurate transmission of downhole data, making it difficult for the surface receiving equipment to receive clear and accurate pulse signals, thereby reducing the accuracy and reliability of the entire measurement while drilling system.

[0043] In this invention, when oil drilling operations begin, the drive motor 13 starts under the action of the drilling fluid hydraulic system, driving the main shaft 2 to rotate. The rotation of the main shaft 2 is transmitted to the guide impeller 3 and the pulse valve disc 8 through the spline, causing them to rotate synchronously. During the rotation of the blades 10 on the guide impeller 3 with the main shaft 2, the blades 10 alternately contact the guide blocks 5 on the inner wall of the guide ring 4. Since the guide blocks 5 are evenly distributed circumferentially on the inner wall of the guide ring 4 and have the same shape, when the blades 10 contact different guide blocks 5 during rotation, they will be subjected to reaction forces from different directions but of uniform magnitude. These reaction forces form a resultant force in the radial direction, namely radial eccentric force. This eccentric force is transmitted to the main shaft 2 through the guide impeller 3, thereby causing the hollow shell 1 to produce a guide offset as a whole, realizing the adjustment of the drilling direction. By adjusting the output speed of the drive motor 13, the frequency of the guide eccentric force can be changed, thereby precisely controlling the guide offset angle and meeting the requirements of the drilling direction under different drilling conditions.

[0044] Simultaneously, the pulse valve disc 8 rotates synchronously under the drive of the spindle 2. When the pulse orifice 9 on the pulse valve disc 8 periodically connects and closes with the flow limiting plate 7 on the valve seat 6, the flow area of ​​the drilling fluid changes periodically, thereby causing the drilling fluid pressure to generate pulse fluctuations of 0.5-2MPa. These pressure pulses are transmitted to the surface through the drilling fluid. After the receiving equipment on the surface receives the pulse signal, it can obtain various downhole measurement data, such as steering parameters and formation information, after decoding and processing.

[0045] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A rotary steering structure of a pulser for oil drilling, comprising a hollow housing (1) and a main shaft (2) rotatably connected in the hollow housing (1), characterized in that, Also includes: A guide impeller (3) is fixedly installed in the middle of the main shaft (2). The inner wall of the hollow shell (1) is fixedly connected with a guide ring (4) that is compatible with the guide impeller (3). At least four sets of guide blocks (5) that are clearance-fitted with the guide impeller (3) are fixedly installed on the guide ring (4). When the main shaft (2) rotates, the guide impeller (3) and the guide blocks (5) alternately contact to form a guide eccentric force. A valve seat (6) is threaded to the liquid inlet end of the hollow shell (1). A flow limiting plate (7) is installed on the valve seat (6). A pulse valve disc (8) is fixedly connected to the main shaft (2) and located below the valve seat (6). A pulse hole (9) adapted to the flow limiting plate (7) is opened on the pulse valve disc (8). When the main shaft (2) and the pulse valve disc (8) rotate, the flow limiting plate (7) and the pulse hole (9) periodically connect or close.

2. A rotary steering structure for a pulse generator for oil drilling according to claim 1, characterized in that, At least four sets of blades (10) are fixedly connected to the guide impeller (3), and the four sets of blades (10) are arranged equidistantly along the circumference of the main shaft (2).

3. The rotary steering structure of a pulser for oil drilling according to claim 2, wherein The blade (10) is arranged in a fan shape, the flow-guiding surface of the blade (10) is arc-shaped, and the back flow surface is fixedly connected with a reinforcing rib (11) for improving the structural strength of the blade (10).

4. The rotary steering structure of a pulser for oil drilling according to claim 1, wherein The gap between the guide impeller (3) and the guide block (5) is in the range of 0.5mm-2mm.

5. The rotary steering structure of a pulser for oil drilling according to claim 1, wherein The gap between the valve seat (6) and the pulse valve disc (8) is in the range of 0.2mm-0.8mm.

6. The rotary steering structure of a pulser for oil drilling according to claim 1, wherein The number of the current limiting plate (7) and pulse hole (9) is at least four sets, and the four sets of current limiting plate (7) and pulse hole (9) are arranged equidistantly along the circumference of the main shaft (2).

7. The rotary steering structure of a pulser for oil drilling according to claim 6, characterized in that, The cross-sectional projection of the pulse hole (9) is arranged in a stepped shape, and the ratio of the diameter of the inlet end to the outlet end is 2:

1.

8. The rotary steering structure of a pulser for oil drilling according to claim 1, wherein The inner wall of the hollow shell (1) is fixedly connected to an annular support platform (12), and the main shaft (2) is rotatably connected to the annular support platform (12) through a thrust bearing.

9. The rotary guide structure of a pulse generator for oil drilling according to claim 1, characterized in that, The hollow housing (1) is fixedly connected to a drive motor (13) at the end away from the valve seat (6), and the output end of the drive motor (13) is fixedly connected to the end of the main shaft (2). When the drive motor (13) is working, the pulse valve disc (8) and blades (10) on the main shaft (2) rotate.

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