A PDC bit for oil drilling to prevent mud packing and its usage method

Abstract

The present invention relates to a PDC bit for preventing mud packing in oil drilling and its usage method, belonging to the technical field of oil drilling. When mud packing occurs between the cutter wings of the bit, the pressure of the drilling fluid ejected from the head of the bit increases. The increased pressure of the drilling fluid guided by the second diversion channel enters the piston cylinder, pushing the floating piston in the piston cylinder to move upward in the piston cylinder. The connection position between the first diversion channel and the piston cylinder is exposed under the floating piston. The drilling fluid flows from the second diversion channel, the piston cylinder, and the first diversion channel to the side holes and is ejected from the side holes. The drilling fluid flowing out of the side holes can directly impact the sediment on the side of the bit. On the one hand, it can relieve the pressure of the drilling fluid conveying pipeline in the case of bit mud packing, reducing the risk of the mud pump stalling due to the inability of the drilling fluid to circulate. On the other hand, the drilling fluid flowing out of the side holes can directly impact the sediment on the side of the bit, which is beneficial to cleaning the sediment on the side of the bit.

Description

Technical Field

[0001] The invention relates to the technical field of oil drilling, and in particular to a PDC drill bit for anti-mud balling oil drilling and a use method thereof. Background Art

[0002] Polycrystalline Diamond Compact (PDC) drill bits are one of the most commonly used rock-breaking tools in oil and gas drilling projects. PDC drill bits are mostly designed in a blade-wing structure, with PDC teeth arranged on the blade crown of the drill bit body.

[0003] The speed of PDC drill bit is very fast and the impact force is very strong, which makes the drill bit more prone to mud damage. Summary of the invention

[0004] The present invention aims to overcome the problem that viscous sand is sandwiched between the blades on the side of the drill bit, causing the drilling fluid to accumulate at the bottom of the drill bit, resulting in increased pressure in the drilling fluid delivery pipeline and the risk of mud pump shutdown due to inability to circulate the drilling fluid. The purpose of the present invention is to provide a PDC drill bit for anti-mud packing oil drilling and a method of using the same.

[0005] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0006] A PDC drill bit for anti-mud balling oil drilling comprises: a drill body and a blade, wherein at least two blades are provided, the blades are mounted on the drill body head, and PDC teeth are mounted on the blades;

[0007] A flow guide cavity is provided inside the drill body, a spray hole connected to the flow guide cavity is provided at the head of the drill body, and a liquid inlet connected to the flow guide cavity is provided at the lower part of the drill body;

[0008] Side holes are provided on the side wall of the drill body between the cutter wings. A piston cylinder is provided inside the drill body. The upper side of the piston cylinder is connected to the side holes through a first diversion channel. The lower end of the piston cylinder is communicated with a diversion cavity through a second diversion channel. A floating piston is provided inside the piston cylinder. When the floating piston is displaced to the upper part of the piston cylinder, the connection part between the first diversion channel and the piston cylinder is located below the floating piston.

[0009] A ring groove is provided on the side of the drill body. The cutter wings are located above the ring groove. A support ring is slidably installed in the ring groove. A piston rod is connected between the support ring and the floating piston. An extrusion spring is provided between the support ring and the upper side of the ring groove.

[0010] Furthermore, the side holes are arranged at an angle of 60 degrees with the axis of the drill body, and the included angle is oriented towards the tail end of the drill body.

[0011] Furthermore, a driving cavity is provided on the drill body. A spiral liquid guide groove is provided on the inner side wall of the driving cavity. The driving cavity is communicated with the diversion cavity through a pressure relief flow channel. A pressure relief hole is provided at the tail of the drill body, and the pressure relief hole is communicated with the driving cavity.

[0012] Furthermore, a driving shaft is rotatably installed in the driving cavity. A turbine is installed on the driving shaft. The driving shaft extends outside the drill body, and a driving gear is installed at the end. A transmission shaft is rotatably installed along the axial direction on the upper side of the ring groove. One end of the transmission shaft is connected to the driving gear through a gear. A transmission gear is rotatably installed on the support ring. The transmission shaft passes through the transmission gear through a keyway fit. A driven ring is rotatably installed on the support ring. The transmission gear meshes with the driven ring. A discharge screw is rotatably installed on the support ring. The discharge screw is connected to the driven ring through a gear.

[0013] Furthermore, a first baffle is fixedly installed on the support ring, and a second baffle is fixed on the upper side of the ring groove. The first baffle is slidably inserted into the second baffle.

[0014] Furthermore, a first connection end, a second connection end, and a third connection end are provided on the piston cylinder. The first connection end is located at the lower part of the piston cylinder and is communicated with the second diversion channel. The second connection end is located at the upper side of the piston cylinder. The third connection end is located at the upper part of the piston cylinder. Both the second connection end and the third connection end are communicated with the first diversion channel.

[0015] Furthermore, the second diversion channel is perpendicular to the axis of the diversion cavity.

[0016] A method for using a PDC bit for anti-sludging in oil drilling is as follows: Install the bit on the drill pipe on the drilling platform. Connect the liquid inlet on the bit to the drilling fluid delivery pipeline, and perform drilling operations.

[0017] The beneficial effects of the present invention are:

[0018] 1. When there is mud caking between the cutter blades of the drill bit, the pressure of the drilling fluid ejected from the head of the drill bit increases. The second diversion channel guides the increased pressure of the drilling fluid into the piston cylinder, pushing the floating piston in the piston cylinder upward. The connection position between the first diversion channel and the piston cylinder is exposed under the floating piston. The drilling fluid flows from the second diversion channel, the piston cylinder, and the first diversion channel to the side holes and is ejected from the side holes. The drilling fluid flowing out of the side holes can directly impact the sediment on the side of the drill bit, which is beneficial to cleaning the sediment on the side of the drill bit.

[0019] 2. The drilling fluid entering the drive chamber through the pressure relief channel flows along the liquid guide groove on the inner side wall of the drive chamber. Under the impact force of the drilling fluid, the turbine in the drive chamber is pushed to rotate, and then the drive shaft is driven to rotate. The rotation of the drive shaft drives the drive gear to rotate. The drive gear drives the transmission shaft to rotate. The rotation of the transmission shaft drives the transmission gear on the support ring to rotate, and then drives the discharge screw on the support ring to rotate. The discharge screw is used to push the mud at the tail of the drill bit upward to relieve the blockage of the material around the drill bit.

[0020] 3. When there is no mud caking on the drill bit and the drilling fluid around it has good fluidity, the discharge screw is withdrawn from the gap between the cutter blades. The resistance of the drilling fluid flowing between the cutter blades is reduced. When the drill bit has mud caking, the discharge screw can be pushed into the gap between the cutter blades, and the rotation of the discharge screw is used to push the mud flowing between the cutter blades. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic structural diagram of the present invention;

[0022] Figure 2 It is a schematic installation diagram of the support ring of the present invention;

[0023] Figure 3 It is a schematic connection diagram of the piston rod and the support ring of the present invention;

[0024] Figure 4 It is a schematic connection diagram of the first diversion channel, the second diversion channel and the piston cylinder of the present invention;

[0025] Figure 5 It is a schematic connection diagram of the transmission shaft and the transmission gear of the present invention;

[0026] Figure 6 It is a schematic structural diagram of the piston cylinder of the present invention;

[0027] Figure 7 It is a schematic structural diagram of the drive chamber of the present invention.

[0028] In the figure: 1, drill body; 2, cutter blade; 12, diversion cavity; 101, first diversion channel; 102, second diversion channel; 13, liquid inlet; 14, spray hole; 21, side hole; 22, support ring; 23, piston cylinder; 24, floating piston; 25, annular groove; 26, piston rod; 27, compression spring; 31, drive cavity; 32, liquid guide groove; 33, pressure relief channel; 34, pressure relief hole; 41, drive shaft; 42, turbine; 43, drive gear; 44, transmission shaft; 45, transmission gear; 46, discharge screw; 47, driven ring; 51, first connection end; 52, second connection end; 53, third connection end; 61, first baffle; 62, second baffle. Detailed implementation mode

[0029] In order to make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below with reference to specific illustrations.

[0030] Embodiment 1

[0031] As Figure 1 , Figure 3 , Figure 4 shown, a PDC bit for anti-sludging oil drilling includes: a drill body 1 and cutter blades 2. At least two cutter blades 2 are provided, and the cutter blades 2 are installed at the head of the drill body 1, and PDC teeth are installed on the cutter blades 2;

[0032] A diversion cavity 12 is provided inside the drill body 1, a spray hole 14 communicating with the diversion cavity 12 is provided at the head of the drill body 1, and a liquid inlet 13 communicating with the diversion cavity 12 is provided at the lower part of the drill body 1;

[0033] Side holes 21 are provided on the side wall of the drill body 1 between the cutter blades 2. A piston cylinder 23 is provided inside the drill body 1. The upper side part of the piston cylinder 23 is connected to the side holes 21 through a first diversion channel 101, and the lower end of the piston cylinder 23 is communicated with the diversion cavity 12 through a second diversion channel 102. A floating piston 24 is provided inside the piston cylinder 23. When the floating piston 24 moves to the upper part of the piston cylinder 23, the connection part between the first diversion channel 101 and the piston cylinder 23 is located below the floating piston 24;

[0034] An annular groove 25 is provided on the side of the drill body 1. The cutter blades 2 are located above the annular groove 25. A support ring 22 is slidably installed in the annular groove 25. A piston rod 26 is connected between the support ring 22 and the floating piston 24. A compression spring 27 is provided between the support ring 22 and the upper side of the annular groove 25;

[0035] The number of cutter blades 2 can preferably be 3 - 8. Here, 6 cutter blades 2 are taken as an example;

[0036] When the drill bit is drilling, when a smooth flow channel can be formed between the head and the tail of the drill bit, at this time, under the action of the compression spring 27, the support ring 22 moves along the axis of the ring groove 25 to the lower part of the ring groove 25. The support ring 22 pulls the piston rod 26, driving the floating piston 24 to move. The floating piston 24 blocks the connection between the first diversion channel 101 and the second diversion channel 102. At this time, the drilling fluid flowing through the diversion cavity 12 is ejected from the head of the drill body 1 through the spray holes 14. The drilling fluid will move from the head of the drill bit along the gap between the cutter wings 2 towards the tail of the drill bit, which can pre-cool the cutter wings 2 in direct contact with the rock formation at the head of the drill bit and promote the movement of drill cuttings at the head of the drill bit towards the tail of the drill bit;

[0037] When there is mud wrapping between the cutter wings 2, the drilling fluid ejected from the head of the drill bit is blocked when passing through the cutter wings 2, and the pressure of the drilling fluid at the lower part of the drill bit increases, which in turn increases the internal pressure of the diversion cavity 12. As the internal pressure of the diversion cavity 12 increases, under the pressure, the pressure of the drilling fluid entering the second diversion channel 102 and the piston cylinder 23 increases. Under the action of the drilling fluid pressure, the floating piston 24 is pushed to move upwards in the piston cylinder 23. When the floating piston 24 moves to the upper part of the connection between the first diversion channel 101 and the piston cylinder 23, the first diversion channel 101 is connected to the second diversion channel 102 through the piston cylinder 23. At this time, the drilling fluid entering the piston cylinder 23 can be ejected from the side holes 21 through the first diversion channel 101. The drilling fluid ejected from the side holes 21 can directly impact the sediment wrapped between the cutter wings 2 on the side of the drill bit. On the one hand, it can relieve the pressure of the drilling fluid delivery pipeline in the case of mud wrapping on the drill bit, reducing the risk of the mud pump stalling due to the inability of the drilling fluid to circulate. On the other hand, the drilling fluid flowing out of the side holes 21 can directly impact the sediment on the side of the drill bit, which is beneficial to cleaning the sediment on the side of the drill bit;

[0038] When the mud wrapping phenomenon on the side of the drill bit is alleviated and a normal flow channel can be formed between the head and the tail of the drill bit, and the drilling fluid can be normally ejected from the spray holes 14 at the head of the drill bit, the pressure in the diversion cavity 12 decreases. As the pressure in the diversion cavity 12 decreases, the pressure in the second diversion channel 102 and the piston cylinder 23 also decreases accordingly. Under the push of the compression spring 27 to move the support ring 22 and the piston rod 26, the floating piston 24 is driven to move, blocking the connection between the first diversion channel 101 and the second diversion channel 102 again. At this time, it can continue to ensure that the drilling fluid is ejected from the head of the drill bit.

[0039] Embodiment 2

[0040] On the basis of Embodiment 1, as Figure 1 、 Figure 2 、 Figure 5 、 Figure 7As shown, the side hole 21 is set at an angle of 60 degrees with respect to the axis of the drill body 1, and the included angle is oriented towards the tail end of the drill body 1. The drilling fluid ejected from the side hole 21 sprays towards the tail of the drill body 1 at an angle of 60 degrees along the side wall of the drill body 1, which can push the mud on the side wall of the drill body 1 towards the tail of the drill body 1 and promote the flow of the mud around the drill body 1;

[0041] A driving cavity 31 is provided on the drill body 1. A spiral liquid guide groove 32 is provided on the inner side wall of the driving cavity 31. The driving cavity 31 is communicated with the diversion cavity 12 through a pressure relief flow channel 33. A pressure relief hole 34 is provided at the tail of the drill body 1, and the pressure relief hole 34 is communicated with the driving cavity 31; When the drill bit is being drilled, regardless of whether there is mud caking on the drill bit, the pressure relief hole 34 and the pressure relief flow channel 33 can discharge the drilling fluid from the tail of the drill bit. This part of the drilling fluid can push the mud in the well above the tail of the drill bit to flow upward, preventing the mud from settling. Moreover, by setting the pressure relief hole 34 and the pressure relief flow channel 33, when the spray hole 14 at the head of the drill bit is blocked, the pressure relief hole 34 and the pressure relief flow channel 33 can also normally discharge the drilling fluid, and when there is mud caking on the drill bit, it can relieve the problem of sudden increase in the pressure of the drilling fluid conveying pipeline;

[0042] A drive shaft 41 is rotatably installed in the drive cavity 31. A turbine 42 is installed on the drive shaft 41. The drive shaft 41 extends outside the drill body 1, and a drive gear 43 is installed at the end. A drive shaft 44 is rotatably installed along the axial direction on the upper side of the annular groove 25. One end of the drive shaft 44 is connected to the drive gear 43 through a gear. A transmission gear 45 is rotatably installed on the support ring 22. The drive shaft 44 passes through the transmission gear 45 through a keyway fit. A driven ring 47 is rotatably installed on the support ring 22. The transmission gear 45 meshes with the driven ring 47. A discharge screw 46 is rotatably installed on the support ring 22. The discharge screw 46 is connected to the driven ring 47 through a gear;

[0043] The drilling fluid entering the drive cavity 31 from the pressure relief flow channel 33 flows along the liquid guide groove 32 on the inner side wall of the drive cavity 31. Under the impact force of the drilling fluid, it pushes the turbine 42 in the drive cavity 31 to rotate, and then drives the drive shaft 41 to rotate. The rotation of the drive shaft 41 drives the drive gear 43 to rotate. The drive gear 43 drives the drive shaft 44 to rotate. The rotation of the drive shaft 44 drives the transmission gear 45 on the support ring 22 to rotate. The transmission gear 45 drives the discharge screw 46 to rotate through the driven ring 47, and uses the discharge screw 46 to push the mud at the tail of the drill bit upward to relieve the blockage around the drill bit.

[0044] Embodiment 3

[0045] On the basis of Embodiment 2, as Figure 1 、 Figure 2 、 Figure 3 、 Figure 4 、 Figure 6As shown in the figure, a first connection end 51, a second connection end 52, and a third connection end 53 are provided on the piston cylinder 23. The first connection end 51 is located at the lower part of the piston cylinder 23 and communicates with the second diversion channel 102. The second connection end 52 is located on the upper side of the piston cylinder 23, and the third connection end 53 is located at the upper part of the piston cylinder 23. Both the second connection end 52 and the third connection end 53 communicate with the first diversion channel 101. When the lower part of the floating piston 24 is pressurized, the pressure pushes the floating piston 24 to move. By using the second connection end 52 and the third connection end 53, it is convenient to discharge the medium above the floating piston 24 from the piston cylinder 23. When the floating piston 24 moves to the position of the second connection end 52, the third connection end 53 can continue to discharge the medium, so that the floating piston 24 can move to the upper part of the second connection end 52.

[0046] When the bit is clogged with mud, resulting in a sharp increase in the drilling fluid pressure at the head of the bit, the drilling fluid can enter the second diversion channel 102. The drilling fluid in the diversion cavity 12 enters the piston cylinder 23 from the first connection end 51. Under the action of the drilling fluid pressure, the floating piston 24 in the piston cylinder 23 is pushed upward. When the floating piston 24 moves to the upper part of the piston cylinder 23, the second connection end 52 is exposed below the floating piston 24. At this time, the drilling fluid between the first connection end 51 and the second connection end 52 in the piston cylinder 23 can penetrate. The drilling fluid enters the side hole 21 from the first diversion channel 101. As the floating piston 24 moves, the piston rod 26 is pulled to move, driving the support ring 22 to move towards the head of the bit. The discharge screw 46 on the support ring 22 is inserted into the gap between the cutter wings 2. When the discharge screw 46 rotates, it can push the mud between the cutter wings 2 to flow towards the tail of the bit, which is beneficial to cleaning the soil between the cutter wings 2.

[0047] When the clogging of the side of the bit is relieved, more drilling fluid in the diversion cavity 12 is ejected from the spray holes 14 at the head of the bit, and the pressure in the diversion cavity 12 decreases. As a result, the acting pressure of the drilling fluid on the floating piston 24 in the piston cylinder 23 decreases. At this time, under the action of the compression spring 27, the support ring 22 is pushed downward, and then the piston rod 26 and the floating piston 24 are pulled downward. The floating piston 24 is pulled towards the upper part of the piston cylinder 23, and the medium below the floating piston 24 will be pressed into the diversion cavity 12 from the first connection end 51 and the second diversion channel 102. As the support ring 22 moves downward, the discharge screw 46 is driven to move downward, and the discharge screw 46 is withdrawn from the gap between the cutter wings 2. When the bit is not clogged with mud and the surrounding drilling fluid has good fluidity, the discharge screw 46 is withdrawn from the gap position between the cutter wings 2 to reduce the resistance of the drilling fluid flowing between the cutter wings 2. When the bit is clogged with mud, the discharge screw 46 can be pushed into the gap between the cutter wings 2, and the rotation of the discharge screw 46 is used to push the mud between the cutter wings 2 to flow.

[0048] A first baffle 61 is fixedly installed on the support ring 22, and a second baffle 62 is fixed on the upper side of the annular groove 25. The first baffle 61 is slidably inserted into the second baffle 62. The pressure relief hole 34 is located in the chamber formed among the first baffle 61, the second baffle 62 and the drill body 1. The drilling fluid discharged from the pressure relief hole 34 directly acts on the first baffle 61 and the second baffle 62, avoiding directly impacting the side wall of the well hole. Blocked by the first baffle 61 and the second baffle 62, the drilling fluid ejected from the pressure relief hole 34 flows through the support ring 22 towards the tail of the drill bit;

[0049] The second diversion channel 102 is perpendicular to the axis of the diversion chamber 12, and an acute angle is formed between the axis of the spray hole 14 and the axis of the diversion chamber 12. When the drilling fluid flowing in the diversion chamber 12 passes through the spray hole 14 relative to the second diversion channel 102, the resistance is relatively small. Thus, when the liquid flow channel outside the drill bit is unobstructed, more of the drilling fluid flowing in the diversion chamber 12 will flow into the spray hole 14.

[0050] Embodiment 4

[0051] A method for using a PDC drill bit for preventing mud packing in oil drilling is as follows: Install the drill bit on the drill pipe on the drilling platform, connect the liquid inlet 13 on the drill bit to the drilling fluid conveying pipeline, and perform drilling operations.

[0052] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A PDC drill bit for anti-mud balling oil drilling, characterized in that: include: A drill body and a blade, wherein at least two blades are provided, the blades are mounted on the drill head, and PDC teeth are mounted on the blades; A flow guide cavity is provided inside the drill body, a spray hole connected to the flow guide cavity is provided at the head of the drill body, and a liquid inlet connected to the flow guide cavity is provided at the lower part of the drill body; A side hole is provided on the side wall of the drill body between the blades, a piston cylinder is provided inside the drill body, the side portion of the upper end of the piston cylinder is connected to the side hole through a first flow guide channel, the lower end of the piston cylinder is connected to the flow guide cavity through a second flow guide channel, a floating piston is provided inside the piston cylinder, and when the floating piston is displaced to the upper part of the piston cylinder, the connection between the first flow guide channel and the piston cylinder is located at the lower part of the floating piston; The drill body side is provided with an annular groove, the blade is located at the upper part of the annular groove, a support ring is slidably installed in the annular groove, a piston rod is connected between the support ring and the floating piston, and an extrusion spring is provided between the support ring and the upper end side of the annular groove.

2. The anti-mud balling PDC drill bit for oil drilling according to claim 1, characterized in that: The side hole is arranged at an angle of 60 degrees to the axis of the drill body, and the angle is arranged toward the rear end of the drill body.

3. The anti-mud balling PDC drill bit for oil drilling according to claim 1, characterized in that: The drill body is provided with a driving cavity, the inner wall of the driving cavity is provided with a spiral liquid guide groove, the driving cavity is communicated with the guide cavity through a pressure relief channel, the tail of the drill body is provided with a pressure relief hole, and the pressure relief hole is communicated with the driving cavity.

4. The anti-mud balling PDC drill bit for oil drilling according to claim 3, characterized in that: A driving shaft is rotatably installed in the driving cavity, a turbine is installed on the driving shaft, the driving shaft extends outward to the outside of the drill body, a driving gear is installed at the end, a transmission shaft is rotatably installed on the upper side of the ring groove along the axial direction, one end of the transmission shaft is connected to the driving gear through a gear, a transmission gear is rotatably installed on the support ring, the transmission shaft passes through the transmission gear through a keyway, a driven ring is rotatably installed on the support ring, the transmission gear meshes with the driven ring, a discharge screw is rotatably installed on the support ring, and the discharge screw is connected to the driven ring through a gear.

5. The anti-balling PDC drill bit for oil drilling according to claim 1, characterized in that: A first baffle is fixedly mounted on the support ring, a second baffle is fixed on the upper end side of the ring groove, and the first baffle is slidably inserted into the second baffle.

6. The anti-mud balling PDC drill bit for oil drilling according to claim 1, characterized in that: The piston cylinder is provided with a first connecting end, a second connecting end, and a third connecting end. The first connecting end is located at the lower part of the piston cylinder and is connected to the second flow guide channel. The second connecting end is located on the side of the upper part of the piston cylinder. The third connecting end is located at the upper part of the piston cylinder. The second connecting end and the third connecting end are both connected to the first flow guide channel.

7. The anti-balling PDC drill bit for oil drilling according to claim 6, characterized in that: The second flow guide channel is perpendicular to the axis of the flow guide cavity.

8. A method for using a PDC drill bit for oil well drilling with an anti-mud balling function, using the PDC drill bit for oil well drilling with an anti-mud balling function as claimed in any one of claims 1 to 7, characterized in that: The process includes the following steps: installing the drill bit on the drill rod on the drilling platform, connecting the fluid inlet on the drill bit to the drilling fluid delivery pipeline, and performing the drilling operation.

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