Pdc bit for rock breaking by shock oscillation with pressure pulse

Abstract

The present application belongs to the field of oil drilling technology, and discloses a PDC drill bit for rock breaking by pressure pulse impact oscillation. The specific technical scheme is as follows: the PDC drill bit for rock breaking by pressure pulse impact oscillation is composed of an upper threaded joint, a shell, a jet pulse block and a drill bit. The jet pulse block is composed of a fluid inlet, a left feedback channel outlet, a right feedback channel outlet, a left fluid channel, a right fluid channel, a left backflow feedback inlet, a left backflow annular fluid channel, a right backflow feedback inlet, a right backflow annular fluid channel, a fluid outlet and a fluid outlet cavity. After the drilling fluid passes through the upper threaded joint, it enters the jet pulse block from the fluid inlet, and then passes through the fluid outlet and flows out from the drill bit water eye. When the drilling fluid passes through the jet pulse block, the flow direction of the drilling fluid will change periodically due to the action of the feedback channel, and a pressure pulse will be generated, forming impact oscillation, and thus accelerating the rock breaking and drilling of the drill bit. The present application has the function of improving the rock breaking efficiency of the drill bit by relying on pressure pulse impact oscillation.

Description

Technical Field

[0001] This invention belongs to the field of oil drilling technology, specifically relating to a PDC drill bit that uses pressure pulses to achieve impact oscillation rock breaking. Background Technology

[0002] In modern oil and gas drilling engineering, the drill bit comes into direct contact with the formation during the drilling process. The rock is broken up under the combined action of drilling pressure and drilling torque, forming a regular wellbore. During the drilling process, the working performance of the drill bit has a significant impact on drilling efficiency and production costs. Stable drill bit performance will greatly extend its service life, reduce the number of tripping operations, and save economic costs. Therefore, the development of high-performance drill bits has always been an important research direction in the field of oil and gas technology and equipment.

[0003] Currently, conventional oil and gas resource exploration and development has entered a mature stage. Even shallow oil and gas reserves with favorable conditions are decreasing as extraction progresses, leading to a gradual shift in oil and gas development towards unconventional resources such as shale gas and coalbed methane. Well structures are becoming increasingly complex, including deep wells, ultra-deep wells, and extended reach directional wells. Formation environments are also becoming increasingly harsh, with high-temperature geothermal wells, a prime example, differing from traditional formations. Under these new oil and gas resource conditions, especially in horizontal and extended reach well drilling technologies, there is a demand for efficient rock breaking by the drill bit, increased mechanical drilling speed, and shortened drilling cycles. The challenges facing drilling engineering are gradually increasing, placing new demands on drill bit technology development.

[0004] Therefore, improving the rock-breaking efficiency of drill bits and ensuring the stability of drill bit operation are key issues in the development of modern drill bits. Summary of the Invention

[0005] The purpose of this invention is to provide a PDC drill bit that improves rock-breaking efficiency by relying on pressure pulses to achieve impact oscillation.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by this invention is as follows: the outlets of the left and right feedback channels are symmetrically distributed about the axis of the jet pulse block; the left and right fluid channels are symmetrically distributed about the axis of the jet pulse block; the height of the left return annular fluid channel in the axial position is higher than that of the right return annular fluid channel; the left and right return annular fluid channels are tangent to the left and right return feedback inlets, respectively, to ensure that the drilling fluid enters tangentially when entering the feedback channel inlet.

[0007] Preferably, the upper threaded connector serves to fix the jet pulse block axially. After the upper threaded connector is fitted with the outer shell, the mating part between the upper threaded connector and the outer shell is welded to ensure axial positioning and sealing.

[0008] Preferably, the fluid outlet cavity is a circular structure, tangent to the outlet of the left return annular fluid channel and the outlet of the right return annular fluid channel, respectively; a fluid outlet is opened at the center of the fluid outlet cavity, and a groove is opened on the circumferential surface of the jet pulse block, which communicates with the fluid outlet, so that the drilling fluid can flow into the drill bit through the fluid outlet and along the groove; two fan-shaped grooves are opened on the circumferential surface of the jet pulse block, which cooperate with the fan-shaped column inside the shell. The height of the fan-shaped column is greater than the depth of the fan-shaped groove, so that there is a gap between the bottom section of the jet pulse block and the shell, which facilitates the outflow of drilling fluid.

[0009] Preferably, there is a height difference between the left return annular fluid channel and the right return annular fluid channel, so that the drilling fluid first reaches the left return annular fluid channel and then the right return annular fluid channel, and there is a time difference in the arrival of the drilling fluid in the left and right annular fluid channels; there is also a time difference in the entry of the drilling fluid into the feedback channel through the return annular fluid channel, so the drilling fluid will generate periodic pressure pulses under the action of the feedback channel.

[0010] The present invention has the following beneficial effects: (1) The addition of a pressure pulse oscillation section enhances the rock-breaking efficiency of the drill bit by adding the function of impact oscillation based on pressure pulses, on the basis of the original rock-breaking function. (2) The pressure pulses generated by the drilling fluid after passing through the jet pulse block have the characteristics of periodicity and high stability, which improves the drilling stability of the drill bit. (3) Separating the drill bit from the pressure pulse oscillation section allows the pressure pulse oscillation section to be used continuously, facilitates the replacement of the drill bit, and reduces the overall processing requirements. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of a PDC drill bit that uses pressure pulses to achieve impact oscillation rock breaking according to an embodiment of the present invention;

[0012] Figure 2 yes Figure 1 AA section view;

[0013] Figure 3 yes Figure 1 BB section view;

[0014] Figure 4 yes Figure 1 CC section view;

[0015] Figure 5 yes Figure 1 DD cross-sectional view;

[0016] Figure 6 yes Figure 1 EE section view;

[0017] Figure 7 This is a schematic diagram of the bottom structure of the outer shell;

[0018] Figure 8 This is a schematic diagram of the jet pulse block structure.

[0019] The meanings of the reference numerals in the attached figures are as follows: 1. Upper threaded connector, 2. Fluid inlet, 3. Left feedback channel outlet, 4. Right feedback channel outlet, 5. Left fluid channel, 6. Right fluid channel, 7. Left reflux feedback inlet, 8. Left reflux annular fluid channel, 9. Right reflux feedback inlet, 10. Right reflux annular fluid channel, 11. Fluid outlet, 12. Outer shell, 13. Fluid outlet cavity, 14. Jet pulse block, 15. Drill bit, 20. Groove, 21. Fan-shaped groove, 22. Fan-shaped column, 23. Bolt connection hole. Detailed Implementation

[0020] The invention will now be further described with reference to the accompanying drawings.

[0021] like Figure 1 The PDC drill bit shown is characterized in that: the PDC drill bit for rock breaking by impact oscillation using pressure pulses includes an upper threaded connector 1, a housing 12, a jet pulse block 14, and a drill bit 15.

[0022] The upper threaded connector 1 is connected to the outer shell 12 by threads and axially positions the jet pulse block 14. After the positioning connection, the mating part of the upper threaded connector 1 and the outer shell 12 is welded and ground to ensure sealing and axial positioning stability.

[0023] The pulse jet block 14 includes a fluid inlet 2, a left feedback channel outlet 3, a right feedback channel outlet 4, a left fluid channel 5, a right fluid channel 6, a left reflux feedback inlet 7, a left reflux annular fluid channel 8, a right reflux feedback inlet 9, a right reflux annular fluid channel 10, a fluid outlet 11, a fluid outlet cavity 13, a groove 20, a fan-shaped groove 21, and a bolt connection hole 23. The left fluid channel 5 and the right fluid channel 6 are symmetrical about the central axis of the pulse jet block 14. When the drilling fluid first enters the pulse jet block 14 through the fluid inlet 2, it can achieve uniform flow distribution in the left and right fluid channels.

[0024] Both the left return annular fluid channel 8 and the right return annular fluid channel 10 are circular designs and are tangent to the inlet of the feedback channel. The distance from the left return annular fluid channel 8 to the fluid inlet 2 is shorter than the distance from the right return annular fluid channel 10 to the fluid inlet 2. When the drilling fluid first enters the jet pulse block 14, it can reach the left return annular fluid channel 8 more quickly.

[0025] The left feedback channel outlet 3 and the right feedback channel outlet 4 are symmetrical about the central axis of the jet pulse block 14. In the axial direction, the left feedback channel outlet 3 and the right feedback channel outlet 4 are at the same height. The distance from the left feedback channel outlet 3 to the left return annular fluid channel 8 is shorter than the distance from the feedback channel outlet 4 to the right return annular fluid channel 10. Therefore, there is a time difference when the return drilling fluid reaches the left and right feedback channel outlets. When the left return drilling fluid passes through the left feedback channel outlet 3, it will push the drilling fluid that subsequently passes through the fluid inlet 2 to the right fluid channel 6. After a certain time difference, the right return drilling fluid passes through the right feedback channel outlet 4, which will push the drilling fluid that subsequently passes through the fluid inlet 2 to the left fluid channel 5. This process completes the change of the drilling fluid flow direction and generates a pressure pulse.

[0026] The fluid outlet cavity 13 is a circular structure, which is tangent to the outlets of the left return annular fluid channel 8 and the right return annular fluid channel 10, respectively. A circular hole for the fluid outlet 11 is opened at the center of the fluid outlet cavity, and the drilling fluid flows to the drill bit 15 through the fluid outlet 11.

[0027] The jet pulse block 14 is connected by bolts. There are three bolt connection holes 23 at the center of the central axis of the jet pulse block 14, the center of the left return annular fluid channel 8 and the center of the right return annular fluid channel 10, for connecting the jet pulse block 14.

[0028] The jet pulse block 14 has a groove 20 on its circumferential surface, which is connected to the fluid outlet 11, allowing the drilling fluid to flow along the fluid outlet 11 to the drill bit 15; the jet pulse block 14 has a fan-shaped groove 21 symmetrical about the groove 20 on its circumferential surface, which is used for circumferential fixation of the jet pulse block.

[0029] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A PDC drill bit that uses pressure pulses to achieve impact oscillation rock breaking, characterized in that: The PDC drill bit for impact oscillation rock breaking via pressure pulse consists of an upper threaded connector (1), a shell (12), a jet pulse block (14), and a drill bit (15); wherein the jet pulse block (14) includes a fluid inlet (2), a left feedback channel outlet (3), a right feedback channel outlet (4), a left fluid channel (5), a right fluid channel (6), a left return feedback inlet (7), a left return annular fluid channel (8), a right return feedback inlet (9), a right return annular fluid channel (10), a fluid outlet (11), a fluid outlet cavity (13), a groove (20), a fan-shaped groove (21), and a bolt connection hole (23); The left fluid channel (5) and the right fluid channel (6) are symmetrical about the central axis of the jet pulse block (14), ensuring that the drilling fluid can flow evenly to the left and right fluid channels when it first enters the jet pulse block (14). The distance between the left return annular fluid channel (8) and the fluid inlet (2) is closer than the distance between the right return annular fluid channel (10) and the fluid inlet (2). When the drilling fluid enters the jet pulse block (14), it will first reach the left return annular fluid channel (8) and then pass through the right return annular fluid channel (10). There is a time difference when the drilling fluid reaches the left and right return rings, thus forming a periodic pressure pulse. The left feedback channel outlet (3) and the right feedback channel outlet (4) are at the same axial height. The distance from the left feedback channel outlet (3) to the left return annular fluid channel (8) is shorter. After the drilling fluid passes through the left return annular fluid channel (8), it can reach the left feedback channel outlet (3) faster and push the drilling fluid that subsequently passes through the fluid inlet (2) to the right fluid channel (6). When the drilling fluid in the right fluid channel (6) flows out from the right feedback channel outlet (4), it pushes the drilling fluid that subsequently passes through the fluid inlet (2) to the left, thus completing the change of direction of one cycle of drilling fluid. The left return annular fluid channel (8) and the right return annular fluid channel (10) are designed in a circular shape and are tangent to the left return feedback inlet (7) and the right return feedback inlet (9) respectively, ensuring that the drilling fluid enters the feedback inlet tangentially and that a sufficient amount of drilling fluid enters the feedback channel through the feedback inlet.

2. The PDC drill bit for impact oscillation rock breaking via pressure pulse as described in claim 1, characterized in that: The jet pulse block (14) is composed of two semi-cylindrical pieces that are mirror-symmetrical and connected by bolts in the bolt connection hole (23). Drilling fluid channels are opened on the axial section of the jet pulse block (14), including fluid inlet (2), left feedback channel outlet (3), right feedback channel outlet (4), left fluid channel (5), right fluid channel (6), left return feedback inlet (7), left return annular fluid channel (8), right return feedback inlet (9), right return annular fluid channel (10), fluid outlet (11), and fluid outlet cavity (13).

3. The PDC drill bit for impact oscillation rock breaking via pressure pulse as described in claim 1, characterized in that: The jet pulse block (14) has a groove (20) on its circumferential surface, which is connected to the fluid outlet (11). After the drilling fluid flows out through the fluid outlet (11), it enters the drill bit (15) through the groove (20) on the jet pulse block (14) and finally flows out through the water hole of the drill bit (15).

4. The PDC drill bit for impact oscillation rock breaking via pressure pulse as described in claim 1, characterized in that: The lower end of the jet pulse block (14) has two fan-shaped grooves (21) of the same size for circumferential positioning of the jet pulse block (14). The two fan-shaped grooves (21) are symmetrically distributed about the groove (20), and the included angle between the fan-shaped grooves (21) and the groove (20) is 45°. The upper threaded connector (1) and the outer shell (12) perform axial positioning of the jet pulse block (14).

5. The PDC drill bit for impact oscillation rock breaking via pressure pulse as described in claim 4, characterized in that: The lower end of the outer shell (12) has four evenly distributed fan-shaped pillars (22), which cooperate with the fan-shaped grooves (21) at the lower end of the jet pulse block (14) to provide circumferential positioning for the jet pulse block (14). The height of each fan-shaped pillar (22) is greater than the depth of the fan-shaped grooves (21) on the jet pulse block (14), so that the bottom of the jet pulse block (14) and the outer shell (12) will not come into contact with each other, allowing the drilling fluid to flow smoothly into the drill bit (15) through the grooves (20).

6. The PDC drill bit for impact oscillation rock breaking via pressure pulse as described in claim 1, characterized in that: The fluid outlet cavity (13) is a circular structure, which is tangent to the outlets of the left return annular fluid channel (8) and the right return annular fluid channel (10) respectively, and a fluid outlet (11) is opened at the center of the fluid outlet cavity (13).

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