A PDC drill bit with partially movable blades

Abstract

The present invention discloses a PDC drill bit with partially movable blades, including a drill bit body, fixed blades, movable blades, a power conversion mechanism and a transmission mechanism; the power conversion mechanism can be an impeller driven mechanism, a screw motor driven mechanism or an electric motor driven mechanism; the transmission mechanism includes a cam rod, a push rod, a spring, a rotating pin shaft and a fixed pin shaft, and the drill bit body is provided with fixed blades and movable blades, each blade is provided with a PDC tooth, and each movable blade can realize periodic telescopic motion under the action of the transmission mechanism, and at the same time, a combined motion is superimposed with the rotary cutting motion. Under this combined motion, the cutting path of the PDC teeth on the blade will no longer be a circular trajectory but a periodic non-circular trajectory, which can efficiently break the rock ridges generated after the PDC teeth on the fixed blade are cut. This patent can improve the drilling speed and rock breaking efficiency of the drill bit, enhance the drilling stability of the drill bit, and extend the service life of the PDC teeth on the fixed blade, thereby improving the comprehensive performance of the drill bit.

Description

Technical Field

[0001] The invention relates to the field of drilling tools, and in particular to a PDC drill bit with partially movable blades, which is suitable for complex and difficult-to-drill rock formations in deep wells and ultra-deep wells. Background Art

[0002] In recent years, with the advancement of oil and gas resource exploration and development technology and the increasing demand for energy in countries around the world, the exploration field is facing more deep and ultra-deep oil and gas wells. Conventional drill bits have poor adaptability and slow drilling rates when facing deep wells, ultra-deep wells and deep complex and difficult-to-drill rock formations (such as high hardness, high plasticity, dense, and severely heterogeneous formations), which greatly reduces drilling efficiency and increases the overall drilling cost.

[0003] At present, PDC drill bits are widely used in the selection of downhole drilling tools due to their high wear resistance and few moving parts. PDC drill bits rely on poly-gold diamond composite pieces (PDC teeth for short) to shear and crush rocks. In the application of soft to medium-hard formations, the rock breaking efficiency and mechanical drilling speed are very prominent; and with the development of poly-gold diamond composite pieces, the proportion of PDC drill bits used in drilling projects is increasing. However, PDC drill bits still have the following disadvantages: 1) When the strength and hardness of the rock are high, it is difficult for the PDC teeth to eat into the rock to form an effective cutting effect, especially the worn PDC teeth are more difficult to eat into the rock, and the mechanical drilling speed of the drill bit will drop sharply. 2) PDC teeth generate a lot of heat after friction with the rock during the continuous cutting of the rock, causing the temperature at the root of the PDC teeth to rise rapidly. When the temperature rises, the wear rate of the PDC teeth accelerates, resulting in an increase in thermal wear. 3) The wear rate of PDC teeth in different radial areas of PDC drill bits is significantly different. Generally, the wear rate of cutting teeth in the outer area of ​​the drill bit (especially the outer 1 / 3 area of ​​the drill bit radius) is significantly faster than that of teeth in the core area, and the wear balance of cutting teeth is poor, which reduces the overall performance of the drill bit. In short, with the increase of drilling depth, PDC drill bits often show phenomena such as slipping and non-drilling, and the thermal wear of cutting teeth is aggravated and the wear is uneven, which ultimately leads to outstanding problems such as low drilling efficiency and high cost.

[0004] In order to solve the problems of PDC teeth slipping and failure to drill, domestic and foreign experts and scholars have designed and developed a variety of impact rock-breaking tools, such as torque impactors, hydraulic jet impactors, self-excited torsion impact tools, axial and circumferential composite impact tools, hydraulic rotary impact tools, etc. These tools increase the penetration force of PDC cutting teeth by adding axial or circumferential loads to the PDC drill bit. Although this method significantly increases the drilling speed, it aggravates the problem of cutting tooth collapse and can easily have a great impact on the life of the drill bit. Therefore, it is urgent to design and develop a new type of drilling tool to improve the above-mentioned problems of PDC drill bits. Summary of the invention

[0005] The purpose of the present invention is to solve the problems existing in the above-mentioned PDC drill bit and propose a PDC drill bit with partially movable blades, wherein the movable blades can realize periodic radial contraction movement, and the motion trajectory of the PDC teeth on the fixed blades can be converted into a periodic non-circular trajectory (such as Figure 6 As shown), the non-circular trajectory of the movable blade is superimposed on the circular trajectory of the original fixed blade (as shown Figure 7 The invention can not only ensure that the PDC teeth on the fixed blade can effectively cut into the rock, but also significantly reduce the wear rate of the PDC teeth, increase the service life of the PDC drill bit and the mechanical drilling speed, and reduce the cost of the entire drilling project. The purpose of the invention is achieved through the following technical solutions:

[0006] The present invention is a PDC drill bit with a partially movable blade, which includes a drill body, a water hole or a fixed nozzle, a fixed blade, a movable blade, a transmission mechanism, a power conversion mechanism, a housing, and a drill joint section. The transmission mechanism includes: a cam rod, a push rod, a spring, a rotating pin shaft, and a fixed pin shaft. A movable blade is also arranged between the fixed blades, and the movable blade and the fixed blade are evenly arranged on the drill body. The power of the movable blade comes from drilling fluid; the drilling fluid flows through the power conversion mechanism, prompting the power conversion mechanism to perform a rotational motion, and at the same time drives the cam rod in the transmission mechanism to rotate; the cam is meshed with the push rod and the push rod is compressed and rebounded by the spring to obtain a periodic radial expansion and contraction motion, and finally the power is transmitted to the movable blade through the rotating pin shaft. The PDC teeth on the movable blade can effectively cut the rock ridges generated by the rotary cutting of the PDC teeth on the fixed blade during the radial expansion and contraction process, thereby effectively reducing the wear of the PDC teeth on the fixed blade and extending the service life of the PDC teeth.

[0007] As a preferred embodiment, the power conversion mechanism can adopt an impeller type, a screw motor type and an electric motor type drive mechanism to realize the rotational movement of the torsional transmission mechanism.

[0008] As a preferred embodiment, the power conversion mechanism includes: a guide wheel 51, a guide wheel cap 52, a bearing 53, a guide wheel shaft 54, and an impeller 55. The drilling fluid flows through the guide wheel to impact the impeller to rotate. The guide wheel is fixed on the housing, and a stepped surface is provided in the housing to realize the axial positioning of the transmission structure. The guide wheel rod and the guide wheel cap are connected by threads. The guide wheel rod is assembled with the guide wheel through a deep groove ball bearing to realize the positioning and rotation functions. The guide wheel rod and the impeller are connected by threads, and the thread rotation direction between the guide wheel rod and the impeller is opposite to the rotation direction of the impeller to prevent it from falling off during operation; then the impeller, the guide wheel rod, and the guide wheel cap can be positioned and rotated as a whole through the bearing. The drilling fluid flows through the guide wheel, and the guide wheel impacts the impeller to rotate. The impeller and the cam rod are connected by threads to transmit power to the cam rod, and the impeller speed and torque can be adjusted by adjusting the drilling fluid displacement and pressure.

[0009] Furthermore, the guide wheel diverts the drilling fluid through the guide ring at the upper end, and changes the flow direction of the drilling fluid through the guide wheel blades. The guide wheel blades have a certain helix angle; the helix angle of the impeller blades and the helix angle of the guide wheel blades are opposite to each other to enhance the impact of the fluid on the impeller blades. The drilling fluid flows through the guide wheel blades and impacts the impeller blades, and the impeller, the guide wheel rod and the guide wheel cap rotate in the bearing.

[0010] Furthermore, the impeller and the cam rod are connected by threads, and the direction of the threads between the cam rod and the impeller is opposite to the direction of rotation of the impeller to prevent it from falling off during operation; the impeller rotation torque can be transmitted to the cam rod. The cam profile of this design adopts a sine curve, which is characterized by: there is no rigid and flexible impact when meshing with the push rod, the meshing is smooth, and the vibration of the drill tool can be minimized. A spring device is provided between the three push rods and the drill body. The push rod is compressed under the action of the cam and rebounds under the action of the spring, so that the telescopic movement of the push rod can be realized. In addition, the push rod passes through the preset hole on the drill body and is hinged with the movable blade by rotating the pin shaft, so that the telescopic movement of the push rod can be transmitted to the bottom of the movable blade.

[0011] Furthermore, a fixed pin is provided in the middle of the movable blade, and the pin is fixed on the drill bit body. The telescopic movement of the push rod at the bottom of the movable blade drives the bottom of the movable blade to swing around the fixed pin, and the cutting teeth at the top of the movable blade also swing back and forth in a circular arc around the pin, and superimposed with the circular motion of the downhole drilling tool to form a periodic non-circular (trigonometric function) motion trajectory.

[0012] A 1mm wide long gap is also provided at the contact position between the top of the movable blade and the drill bit body, so that when the movable blade swings back and forth around the fixed pin, drilling fluid will flow out from the long gap, continuously cleaning the cuttings between the inner side of the movable blade and the drill bit body; and due to the impact of the drilling fluid, a high-pressure area is formed between the gaps, and cuttings are not easy to enter, thereby ensuring the reciprocating motion of the movable blade, reducing the risk of the movable blade being stuck by cuttings, and enhancing the reliability of this design.

[0013] The wear speed of PDC teeth at different radial positions on the PDC drill bit body is significantly different. The wear speed of the cutting teeth in the radially outer area of ​​the drill bit body is significantly faster than that of the cutting teeth in the core area, especially the PDC cutting teeth located at the crown about 1 / 3 of the radial outer side of the PDC drill bit. Since the cutting diameter of the cutting teeth at this position is large and its own cutting speed is faster than that of the cutting teeth in the core of the drill bit, it is subject to the most load and wear when cutting and breaking rocks. Therefore, the length of the movable blade is set to 2 / 3 of the radius of the PDC drill bit, and the movable blade is arranged in the area of ​​severe wear of the PDC teeth on the radially outer side of the drill bit body, which can minimize the wear of the PDC teeth on the fixed blade in this area.

[0014] The working principle of a PDC drill bit with partially movable blades (impeller type) is as follows:

[0015] S1. The drilling fluid flows through the guide wheel, and after being divided by the guide wheel ring, it obliquely impacts the impeller blades through the guide wheel blades, so that the impeller obtains a larger speed and torque.

[0016] S2. The impeller drives the cam rod to rotate, and the cam engages with the push rod to transmit power to the push rod. The push rod realizes radial telescopic movement under the joint action of the cam and the spring.

[0017] S3. Rotate the pin shaft to connect the push rod with the bottom of the movable blade to achieve hinge connection. During the extension and retraction of the push rod, the bottom of the movable blade swings around the fixed pin shaft, and then the top of the blade also swings under the action of the lever structure, achieving periodic radial extension and retraction movement.

[0018] Compared with the prior art, the present invention is beneficial in that:

[0019] 1) Compared with the existing PDC drill bit, this PDC drill bit not only has the circular rotary cutting of the fixed blade, but also has the non-circular trajectory cutting of the movable blade. There are two cutting and rock breaking methods in one drill bit, which greatly improves the drilling efficiency.

[0020] 2) The radial telescopic movement of the movable blade can effectively cut the rock ridges generated by the fixed blade, making it easier for the PDC teeth on the fixed blade to bite into the rock, effectively avoiding the slipping and non-drilling phenomenon of traditional PDC drill bits.

[0021] 3) The length of the movable blade is 2 / 3 of the radius of the PDC drill bit, and the movable blade is arranged in the area of ​​the drill bit body radially outside where the PDC teeth are severely worn, which can effectively reduce the wear of the PDC teeth on the fixed blade and extend the service life of the drill bit.

[0022] 4) Compared with existing impact PDC drill bits, it can significantly improve the PDC tooth load problem, extend the service life of PDC teeth, improve the reliability of the drill bit, and thus reduce drilling costs.

[0023] 5) When facing deep wells, ultra-deep wells and deep difficult-to-drill rock formations (such as high hardness, high plasticity, dense, severe heterogeneity, etc.), the periodic movement of the movable blade can be adjusted by the drilling fluid flow, making the drill bit more adaptable to different formations.

[0024] 6) Compared with traditional PDC drill bits, the reciprocating extension and contraction of the top of the movable blade is superimposed on the circular motion to form a periodic non-circular motion trajectory. The non-circular trajectory of the movable blade and the original circular trajectory of the fixed blade form a cross-cutting of the rock ridge, which can improve the bottom hole trajectory of the drill bit and enhance the cutting efficiency of the PDC teeth on the fixed blade.

[0025] 7) The power comes from the drilling fluid, and the power conversion is realized by the power conversion mechanism, which has the characteristics of simple structure, high conversion efficiency and high reliability.

[0026] 8) The cam profile is set as a sine curve. When the cam and the push rod are engaged, there is no rigid or flexible impact, the engagement is smooth, and the vibration of the drilling tool can be minimized.

[0027] 9) The PDC drill bit has a simple internal structure, easy parts processing and simple assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0029] Attached Figure 1 It is a partial cutaway schematic diagram of the present invention;

[0030] Attached Figure 2 It is a schematic diagram of the external three-dimensional structure of a PDC drill bit with partially movable blades;

[0031] Attached Figure 3 It is a top view of a PDC drill bit with partially movable blades;

[0032] Attached Figure 4 It is a half-section view of a PDC drill bit (impeller type) with partially movable blades;

[0033] Attached Figure 5 It is a schematic diagram of the drill body structure;

[0034] Attached Figure 6 Schematic diagram of the cutting trajectory of a PDC tooth on a single movable blade of a PDC drill bit with partially movable blades (the thin solid line in the figure is the cutting trajectory of the PDC tooth on the fixed blade, and the thick solid line is the cutting trajectory of the PDC tooth on the movable blade);

[0035] Attached Figure 7 Schematic diagram of the cutting trajectory of the PDC teeth on the full blade of a PDC drill bit with partially movable blades (the thin solid line in the figure is the cutting trajectory of the PDC teeth on the fixed blade, and the thick solid line is the cutting trajectory of the PDC teeth on the movable blade);

[0036] Attached Figure 8 Schematic diagram of the left limit position of the movable blade PDC teeth of a PDC drill bit with partially movable blades (solid lines in the figure are fixed blade cutting teeth, and dotted lines are movable blade cutting teeth);

[0037] Attached Fig. 9It is a schematic diagram of the right limit position of the movable blade PDC teeth of a PDC drill bit with partially movable blades (the solid line in the figure is the fixed blade cutting teeth, and the dotted line is the movable blade cutting teeth);

[0038] Attached Fig.10 It is a schematic diagram of the transmission structure of a PDC drill bit (impeller type) with partially movable blades;

[0039] Attached Fig.11 It is a schematic diagram of the cam rod structure of a PDC drill bit with partially movable blades;

[0040] In the above drawings: 1-drill bit body; 11-long slit; 12-water hole or fixed nozzle; 2-fixed blade; 21-PDC tooth; 3-movable blade; 4-transmission mechanism: 41-cam rod; 42-push rod; 43-spring; 44-rotating pin; 45-fixed pin; 5-power conversion mechanism; 51-guide wheel; 52-guide wheel cap; 53-bearing; 54-guide wheel shaft; 55-impeller; 6-housing; 7-drill bit joint section. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Refer to the following Figures 1 to 11 The PDC drill bit with movable blades according to some embodiments of the present application is described. Figure 1 , 2 As shown, a PDC drill bit with partially movable blades includes a drill body 1, fixed blades 2, movable blades 3, a transmission mechanism 4, a power conversion mechanism 5, a housing 6 and a drill joint section 7. The transmission mechanism 4 includes: a cam rod 41, a push rod 42, a spring 43, a rotating pin 44 and a fixed pin 45. The movable blade 3 is arranged between the fixed blades 2, and the movable blades and the fixed blades are evenly arranged on the drill body. PDC teeth 21 are arranged on each blade. The fixed blade tooth arrangement adopts the conventional PDC drill bit tooth arrangement principle, and the tooth spacing on the movable blade is twice the diameter of the PDC tooth.

[0043] The power of the movable blade comes from the drilling fluid. The drilling fluid flows through the power conversion mechanism 5, causing the power conversion mechanism 5 to rotate, and at the same time driving the cam rod 41 in the transmission mechanism 4 to rotate; the cam rod 41 is meshed with the push rod 42, and the push rod 42 is compressed and rebounded by the spring 43 to obtain periodic radial expansion and contraction movement, and finally the power is transmitted to the movable blade 3 through the rotating pin 44. The PDC teeth on the movable blade 3 can effectively cut the rock ridges generated by the rotary cutting of the PDC teeth on the fixed blade 2 during the radial expansion and contraction process, thereby effectively reducing the wear of the PDC teeth on the fixed blade and extending the service life of the PDC teeth.

[0044] The power conversion mechanism 5 and the transmission mechanism 4 jointly drive the movable blade 3 to realize periodic radial telescopic motion, so that the PDC teeth on the movable blade 3 form a periodic non-circular cutting motion trajectory.

[0045] Preferably, a plurality of movable blades 3 are arranged on the drill bit body 1, and the movable blades 3 can realize periodic telescopic motion, so that the PDC teeth on the movable blades 3 can realize rotational chip cutting motion and radial telescopic motion at the same time, and the two are superimposed to form a periodic non-circular motion trajectory; the non-circular trajectory of the movable blade wing 3 is superimposed on the circular trajectory of the original fixed blade wing 2 to form cross-cutting on the rock.

[0046] Preferably, the power conversion mechanism 5 can adopt a single-stage or multi-stage impeller drive, a screw motor drive or an electric motor drive mechanism to achieve the rotational movement of the transmission mechanism 4.

[0047] As a preference, Figure 4 As shown, the power conversion mechanism 5 can be designed with an impeller structure, and the power conversion mechanism 5 includes: a guide wheel 51, a guide wheel cap 52, a bearing 53, a guide wheel shaft 54, and an impeller 55. The drilling fluid first flows through the guide wheel 51. A guide wheel ring is provided on the upper part of the guide wheel 51, which can evenly divert the drilling fluid. The guide wheel blades have a certain helical angle. The drilling fluid is accelerated by the guide wheel 51 and then obliquely impacts the impeller blades. The drilling fluid flows through the guide wheel 51 to impact the impeller 55 to rotate. The impeller 55 and the cam rod 41 are connected by a thread to transmit power to the transmission mechanism, driving the cam of the cam rod 41 to achieve periodic rotation. The cam is engaged with the push rod 42, and the push rod 42 achieves telescopic movement under the joint action of the cam and the spring 43. The movable blade wing 3 is a lever mechanism that can rotate around the fixed pin shaft 45. The spring 43 is periodically compressed and rebounded, so that the movable blade wing 3 swings periodically around the fixed pin shaft 45 under the lever structure, and the top of the movable blade wing 3 can obtain periodic radial telescopic movement.

[0048] As a preferred embodiment, the cam profile curve can be a sine curve, a cosine curve or a quintic polynomial motion curve, and the PDC teeth on the movable blade obtain a sine, cosine or quintic polynomial motion trajectory. This cam profile line has no rigid and flexible impact, and is suitable for this high-speed cam mechanism, so that the cam rod rotates smoothly and reduces the impact vibration of the drill bit.

[0049] As a preference, Figure 5 As shown, a 1 mm wide long slit 11 is provided at the contact position between the top of the movable blade 3 and the drill body 1, and the drilling fluid can flow out from the long slit when the drill is working.

[0050] A nozzle 12 is provided in front of each blade and in the center of the drill bit. (This design is a 6-inch drill bit, and the nozzle diameter can be 8 to 12 mm).

[0051] Preferably, the tooth arrangement of the fixed blade wing 2 is the same as that of a conventional PDC tooth, the length of the movable blade wing 3 is 2 / 3 of the radius of the PDC drill bit, and the movable blade wing 3 is arranged in the area of ​​the drill bit body 1 radially outward where the PDC teeth are severely worn. The top contour line of the movable blade wing 3 is an arc with the fixed pin 45 as the center, and the main body of the movable blade wing 3 and the fixed pin 45 form a lever structure. While the movable blade wing 3 swings around the fixed pin 45, the top of the movable blade wing 3 swings back and forth in an arc around the fixed pin 45.

[0052] The working principle of the present invention is as follows: the drilling fluid flows through the guide wheel, and after being diverted under the action of the guide wheel ring, it obliquely impacts the impeller blades through the guide wheel blades, so that the impeller obtains a larger rotation speed and torque; the impeller drives the cam rod to rotate, and the cam engages with the push rod to transmit power to the push rod, and the push rod realizes radial telescopic movement under the joint action of the cam and the spring; the push rod is connected to the bottom of the movable blade by rotating the pin shaft to realize hinge connection, and during the extension and retraction of the push rod, the bottom of the movable blade swings around the fixed pin shaft, and then the top of the blade also swings accordingly under the action of the lever structure, thereby realizing periodic radial telescopic movement.

[0053] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions described in the above embodiments may still be modified, or some or all of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PDC drill bit with partially movable blades, comprising a drill bit body (1), fixed blades (2), movable blades (3), a transmission mechanism (4) and a power conversion mechanism (5), characterized in that: The fixed blade (2) and movable blade (3) of the PDC drill bit are both provided with PDC teeth (21); the movable blade (3) is distributed on the drill bit body (1); the power conversion mechanism (5) drives the movable blade (3) through the transmission mechanism (4) to realize periodic radial telescopic movement; so that the PDC teeth on the movable blade (3) form a periodic non-circular cutting motion trajectory; the PDC drill bit with partially movable blades is characterized in that: the power conversion mechanism (5) can adopt a single-pole or multi-stage impeller drive type, a screw motor drive type and an electric motor drive type mechanism to realize the rotational movement of the transmission mechanism (4); the movable blade (3) is movable The force comes from drilling fluid; the drilling fluid flows through the guide wheel (51) to impact the impeller (55) to rotate, and the impeller (55) and the cam rod (41) are connected by a thread to transmit power to the transmission mechanism, driving the cam of the cam rod (41) to achieve periodic rotation, the cam is engaged with the push rod (42), and the push rod (42) achieves telescopic movement under the joint action of the cam and the spring (43); the movable blade (3) is a lever mechanism that rotates around the fixed pin shaft (45), and the spring (43) is periodically compressed and rebounded, so that the movable blade (3) is periodically swung around the fixed pin shaft (45) under the lever structure, and the top of the movable blade (3) obtains periodic radial telescopic movement.

2. A PDC drill bit with a partially movable blade as claimed in claim 1, characterized in that: A plurality of movable blades (3) are provided and evenly arranged on the drill bit body (1); the non-circular trajectory of the movable blade (3) is superimposed on the circular trajectory of the original fixed blade (2) to form cross cutting on the rock.

3. A PDC drill bit with a partially movable blade as claimed in claim 1, characterized in that: The guide wheel (51) is provided with a guide wheel ring on its upper part, and the guide wheel ring evenly distributes the drilling fluid; The guide wheel blades have a certain helical angle, and the drilling fluid is accelerated by the guide wheel (51) and then obliquely impacts the impeller blades.

4. A PDC drill bit with a partially movable blade as claimed in claim 1, characterized in that: The cam profile on the cam rod (41) is a sine curve, a cosine curve or a quintic polynomial motion curve.

5. A PDC drill bit with a partially movable blade as claimed in claim 1, characterized in that: A long slit (11) with a width of 1 mm is provided at the contact position between the top of the movable blade (3) and the drill bit body (1), and drilling fluid flows out from the long slit when the drill bit is working.

6. A PDC drill bit with a partially movable blade as claimed in claim 1, characterized in that: The tooth arrangement of the fixed blade (2) is the same as that of conventional PDC teeth, the length of the movable blade (3) is 2 / 3 of the radius of the PDC drill bit, and the movable blade (3) is arranged in a region of the drill bit body (1) radially outward where the PDC teeth are severely worn.

7. A PDC drill bit with partially movable blades as claimed in claim 1, characterized in that: The top contour line of the movable blade wing (3) is an arc with the fixed pin shaft (45) as the center, and the main body of the movable blade wing (3) and the fixed pin shaft (45) form a lever structure; while the movable blade wing (3) swings around the fixed pin shaft (45), the top of the movable blade wing (3) swings back and forth in an arc around the fixed pin shaft (45).

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