A directional well and horizontal well extension tool

Abstract

This invention discloses a directional and horizontal well extension tool, comprising a housing, an impeller rotatably connected inside the housing, a turntable connected above the impeller, a rack eccentrically connected to the turntable, the rack meshing with a gear, a steering gear connected below the gear via a gear shaft, a driving wheel connected to the bottom surface of the steering gear, and the axis of the driving wheel being offset from the axis of the gear; a driven wheel is connected to the lower rear of the housing. The driving principle of this invention is based on the centrifugal force law and the curvilinear force law. The driving wheel oscillates periodically, and the frictional force between the bottom wall and the edge of the driving wheel generates a forward propulsion effect. The alternating lateral component of the frictional force gives the extension tool a unique serpentine movement, thereby solving the technical problems of high drill string friction, severe pressure buildup, and low mechanical drilling speed in directional and horizontal wells.

Description

Technical Field

[0001] This invention relates to the field of oil and gas, shale gas and shale oil drilling technology, and particularly to a directional well and horizontal well extension tool. Background Technology

[0002] Compared to conventional vertical wells, horizontal wells allow for extensive reservoir contact in the horizontal section, significantly improving oil recovery and making them a key technology for unconventional oil and gas development, including shale oil and gas, tight oil and gas, and coalbed methane. However, horizontal well drilling technology generally faces a series of challenges, such as high drill string friction, severe pressure build-up, low mechanical drilling rate, and limited horizontal section extension capacity. Directional and horizontal wells are becoming increasingly important in oil and gas drilling, with horizontal well technology, in particular, becoming a crucial means of improving the efficiency of oil and gas extraction.

[0003] When drilling horizontal and directional wells, due to the large wellbore inclination angle and horizontal displacement, the direction of gravity of the drill string (or drill string) is no longer parallel to the drilling direction (drill pressure direction) of the drill bit, but rather forms an angle (the well inclination angle at the drill bit's location). In this case, only a portion of the drill string's weight acts in the drilling direction of the drill bit, while the remainder acts directly on the well wall, significantly increasing the frictional resistance of the drill string during drilling compared to vertical wells. This frictional resistance is even greater during directional sliding drilling. The increased frictional resistance reduces the effective drill pressure transmitted to the drill bit, leading to and exacerbating pressure drag. The effective working drill pressure drops significantly (even to zero), severely impacting the drill bit's drilling speed. To reduce friction between the tubing string and the well wall and prevent pressure drag, two methods are currently employed: one is adding a micro-vibration tool to the drill pipe, and the other is adding rollers to the tubing string to transform sliding friction into rolling friction. There are many existing drill string friction reduction technologies, but their effectiveness varies. Some of the more effective ones include hydraulic oscillators, drill string torsion drilling systems, and rotary steerable tools. However, the effects of hydraulic oscillators and torsion systems are not ideal, and rotary steerable tools are expensive and have a high risk of getting stuck or buried. Therefore, there is an urgent need to develop a low-cost and efficient directional and horizontal well extension tool. Summary of the Invention

[0004] This invention provides a directional and horizontal well extension tool to address the technical problems of high drill string friction, severe pressure buildup, and low mechanical drilling speed in directional and horizontal wells.

[0005] The present invention is achieved by the following technical solution.

[0006] A directional well and horizontal well extension tool includes a housing, an impeller rotatably connected inside the housing, a turntable connected above the impeller, a rack eccentrically connected to the turntable, the rack meshing with a gear, a steering gear connected below the gear via a gear shaft, a drive wheel connected to the bottom surface of the steering gear, and the axis of the drive wheel being offset from the axis of the gear; a driven wheel is connected to the lower rear part of the housing.

[0007] By adopting the above technical solution, the tool of this application includes a shell, a drive structure, and a guide structure. The drive structure consists of a drive unit and a linkage unit, and the guide structure consists of an interconnected meshing unit, a steering unit, and a drive wheel. When drilling fluid enters the first chamber, the drive unit is driven and rotates. Simultaneously, because the linkage unit is eccentrically connected to the drive unit, it will move regularly with the rotation of the drive unit. During the displacement, it drives the meshing unit to oscillate, which in turn causes the steering unit to oscillate, ultimately driving the drive wheel to oscillate periodically, thus forming a serpentine trajectory. In the above process, the periodic oscillation of the drive wheel causes the friction force between the bottom wall and the edge of the drive wheel to generate a forward pushing effect. The alternating lateral component of the friction force gives the extension tool a unique serpentine movement, ultimately solving the technical problems of high drill string friction, severe pressure buildup, and low mechanical drilling rate in directional and horizontal wells.

[0008] Furthermore, the offset L between the drive wheel axis and the gear axis is less than 100mm.

[0009] Furthermore, the rotation angle α of the drive wheel has a range of: |α|≤45°.

[0010] Furthermore, the angle β between the gear axis and the horizontal line ranges from 45° to 90°.

[0011] Furthermore, the diameter of the driving wheel is smaller than the diameter of the driven wheel.

[0012] Furthermore, the upper surface of the turntable is eccentrically provided with a turntable shaft, one end of the rack is sleeved on the turntable shaft, and the other end forms teeth that mesh with the gear.

[0013] Furthermore, the outer casing is provided with a partition that divides the outer casing into upper and lower chambers, with the impeller located in the lower chamber and the turntable located in the upper chamber.

[0014] Furthermore, the lower end of the impeller is rotatably connected to the bottom wall of the housing, and the upper end of the impeller passes through the partition and engages with the rotating disk shaft hole.

[0015] This application has the following beneficial effects.

[0016] The driving principle of this invention is based on the centrifugal force law and the curvilinear force law. The drive wheel oscillates periodically, and the frictional force between the bottom wall and the edge of the drive wheel generates a forward propulsion effect. The alternating lateral component of the frictional force gives the extension tool a unique serpentine movement, thus solving the technical problems of high drill string friction, severe pressure buildup, and low mechanical drilling speed in directional and horizontal wells. This invention has an ingenious structure and strong practicality. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the internal structure of the present invention;

[0019] Figure 3 This is a front view of the internal structure of the present invention;

[0020] Figure 4 This is a top view of the internal structure of the present invention;

[0021] Figure 5 This is a schematic diagram of the connection between the impeller and the turntable of the present invention;

[0022] Figure 6 This is a schematic diagram of the driving force of the present invention;

[0023] Figure 7 This is a schematic diagram showing the angle between the gear axis and the horizontal line of the present invention;

[0024] Figure 8 This is a schematic diagram of the serpentine trajectory of the tool of this invention;

[0025] Figure 9 This is a schematic diagram of the impeller structure of the present invention;

[0026] Figure 10 This is a schematic diagram of the structure of the turntable of the present invention.

[0027] Among them, 1. outer shell; 12. partition plate; 2. impeller; 3. turntable; 31. turntable shaft; 4. rack; 5. gear; 6. gear shaft; 7. steering gear; 8. driving wheel; 9. driven wheel; 10. serpentine trajectory. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0029] like Figure 1-10 As shown, a directional well and horizontal well extension tool includes a housing 1, a drive structure and a guide structure.

[0030] The outer shell 1 is used to provide installation space for the internal structure and to protect it; the outer shell 1 is provided with a partition 12, which divides the outer shell 1 into a first chamber and a second chamber arranged in an upper and lower manner; the bottom of the outer shell 1 is provided with a passive wheel 9.

[0031] The drive structure consists of an interconnected drive unit and a linkage unit. The drive unit is rotatably assembled into the first chamber and is driven to rotate by the drilling fluid entering the first chamber. Specifically, the drive unit includes an impeller 2 and a turntable 3. The impeller 2 is rotatably connected to the first chamber. More specifically, one end of the impeller 2 is connected to the bottom wall of the outer casing 1, and the other end is connected to the bottom of the turntable 3 via a through-plate 12. The upper end of the impeller 2 forms a square shaft, and the bottom of the turntable 3 forms a square hole. The square shaft and square hole cooperate to transmit rotation. When the drilling fluid enters the first chamber, the drilling fluid drives the impeller 2 to rotate, and the turntable 3 rotates synchronously, thereby realizing the linkage process of driving the other structures. The linkage part is eccentrically connected to the drive part and placed in the second chamber. Specifically, the linkage part includes a rack 4, which is eccentrically connected to the upper surface of the turntable 3. More specifically, the upper surface of the turntable 3 is eccentrically provided with a turntable shaft 31. One end of the rack 4 is sleeved on the turntable shaft 31, and the other end has teeth that mesh with the gear 5. When the turntable 3 rotates, the rack 4 moves synchronously. During the movement of the rack 4, it continuously drives the guide structure to swing, thereby realizing the periodic swing of the drive wheel 8.

[0032] The guiding structure consists of an interconnected meshing part, a steering part, and a drive wheel 8. The meshing part and the linkage part are meshed together. When the drive part rotates, the linkage part drives the steering part to oscillate through the meshing part, thereby causing the drive wheel 8 to oscillate and forming a serpentine trajectory. Specifically, the meshing part is a gear 5, which meshes with a rack 4. When the rack 4 moves, the gear 5, as a force-bearing structure, is driven to oscillate periodically, thereby causing the rest of the guiding structure to oscillate synchronously, ultimately achieving the periodic oscillation of the drive wheel 8. The steering part includes a gear shaft 6 and a steering gear 7. The upper end of the gear shaft 6 is connected to the gear 5 via a keyway. When the gear 5 oscillates, the gear shaft 6 oscillates synchronously. The lower end of the steering gear 7 is fitted with a square hole and a square shaft to the gear shaft 6. When the gear shaft 6 oscillates, the steering gear 7 oscillates synchronously. The drive wheel 8 is connected to the bottom of the steering gear 7. When the steering gear 7 oscillates, the drive wheel 8 oscillates synchronously to form a serpentine trajectory. It should be noted that the drive wheel axis does not intersect with the gear axis, meaning there is an offset between the drive wheel axis and the gear axis, and the offset L ranges from L < 100mm (e.g., Figure 3 As shown in the figure, the direction of the drive wheel offset is the direction of tool extension.

[0033] When the drilling fluid passes through the lower chamber (the first chamber) of the extension tool, it drives the impeller 2 to rotate. The impeller 2 and the turntable 3 transmit rotation through a square hole and a square shaft, so that the impeller 2 drives the turntable 3 to rotate. The turntable 3 is connected to the rack 4 through the turntable shaft 31. The rack 4 moves back and forth under the drive of the turntable 3. The rack 4 meshes with the gear 5. Under the movement of the rack 4, the gear 5 rotates left and right. The gear 5 and the gear shaft 6 are connected by a key and a groove. The gear shaft 6 rotates clockwise or counterclockwise under the drive of the gear 5. The gear shaft 6 and the steering gear 7 transmit torque through a square shaft and a square hole. The steering gear 7 swings left and right under the drive of the gear shaft 6. The driving wheel 8 is arranged on the steering gear 7. Thus, the driving wheel 8 swings left and right under the drive of the drilling fluid, and the axis of the driving wheel does not intersect with the axis of the gear, that is, there is an offset between the axis of the driving wheel and the axis of the gear, and the value range of the offset L is: L < 100 mm. The offset direction of the driving wheel 8 is the tool extension direction. The driving wheel 8 swings periodically. The frictional force of the bottom well wall on the edge of the driving wheel 8 can produce a forward pushing effect. The alternating lateral component of the frictional force makes the extension tool have a unique form of serpentine swimming (as Figure 8 shown), thereby solving technical problems such as high drill string friction, serious pipe sticking, and low mechanical drilling speed in directional wells and horizontal wells.

[0034] More preferably, the value range of the rotation angle α of the driving wheel 8 is: │α│≤45°. It is stipulated that the counterclockwise rotation direction is the positive direction. As Figure 6 shown, since the tool extension power comes from the frictional force component F 1X of the tool, when α is 45°, the frictional force component is the largest at this time, and the driving force for the tool to extend forward is the largest, reducing the friction between the drill strings and reducing the occurrence of pipe sticking phenomenon of the drill strings.

[0035] More preferably, the diameter of the driving wheel 8 is smaller than the diameter of the driven wheel 9, that is, d1 < d2, where d1 is the diameter of the driving wheel 8 and d2 is the diameter of the driven wheel 9. The diameter of the driving wheel 8 being smaller than the diameter of the driven wheel 9 can reduce the turning radius of the tool, thereby reducing the Y-direction displacement of the extension tool (as Figure 6 shown), reducing the energy consumption of the tool extension, and thus improving the energy utilization rate of the tool in the extension direction.

[0036] More preferably, the value range of the angle β between the line of the gear shaft 6 and the horizontal line is: 45°≤β≤90°. As Figure 7 shown, since the angle β affects the magnitude of the frictional force component along the extension direction and follows a cosine law, therefore, limiting the angle β between 45° and 90° can increase the driving frictional force of the tool.

[0037] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A directional well, horizontal well extension tool comprising a housing (1), characterized in that: The impeller (2) is rotatably connected in the shell (1), the upper portion of the impeller (2) is connected with the rotating disc (3), the rotating disc (3) is eccentrically connected with the rack (4), the rack (4) is engaged with the gear (5), the lower portion of the gear (5) is connected with the steering gear (7) through the gear shaft (6), the bottom surface of the steering gear (7) is connected with the driving wheel (8), and the driving wheel axis is offset from the gear axis; the lower portion of the shell (1) is connected with the driven wheel (9); The included angle β between the gear axis and the horizontal line is 45°≤β≤90°; The upper surface of the rotating disc (3) is eccentrically provided with the rotating disc shaft (31), one end of the rack (4) is sleeved on the rotating disc shaft (31), and the other end is provided with the teeth engaged with the gear (5); The lower end of the impeller (2) is rotatably connected to the bottom wall of the shell (1), and the upper end of the impeller (2) penetrates the partition plate (12) and is matched with the shaft hole of the rotating disc (3).

2. A directional well, horizontal well extension tool according to claim 1, characterized in that: The offset amount L between the driving wheel axis and the gear axis is less than 100 mm.

3. A directional well, horizontal well extension tool according to claim 1, characterized in that: The rotation angle α of the driving wheel (8) is│α│≤45°.

4. A directional well, horizontal well extension tool according to claim 1, characterized in that: The diameter of the driving wheel (8) is less than the diameter of the driven wheel (9).

5. A directional well, horizontal well extension tool according to claim 1, characterized by: The shell (1) is provided with the partition plate (12) for dividing the shell (1) into two chambers, the impeller (2) is located in the lower chamber, and the rotating disc (3) is located in the upper chamber.

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