Anti-balling PDC (Polycrystalline Diamond Compact) drill bit and anti-balling method

Abstract

The invention discloses an anti-balling PDC drill bit and an anti-balling method, and the anti-balling PDC drill bit comprises a drill bit body which is provided with a water hole and a chip groove; one end of the flow guide wire is connected with the drill bit body, the other end of the flow guide wire extends into the water hole along the chip groove, and the flow guide wire is formed by bending a rigid material. According to the PDC drill bit, the flow guide wire is arranged on the drill bit, and one end of the flow guide wire extends into the water hole through the chip groove, so that rock debris is prevented from being accumulated in the water hole, meanwhile, the flow guide effect can be achieved, flushing of drilling fluid to the rock debris is increased, the overflowing area of the chip groove is increased, and therefore the problem of balling of the PDC drill bit is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil drilling, and particularly relates to an anti-caking PDC bit and an anti-caking method. Background Art

[0002] With the continuous development of oil resource exploration technology, deep and ultra-deep oil and gas resources have been continuously discovered, and the requirements for the efficiency and safety of drilling technology have also been increasing, and the requirements for the performance and service life of bits have also increased accordingly. In oil drilling, PDC bits (polycrystalline diamond compact bits) have the advantages of high life and good performance, so they are also the most widely used. At present, the drilling footage of PDC bits accounts for about 80% of the total global drilling footage, and can effectively cope with drilling operations under various geological conditions such as soft formations, hard formations, and alternating soft and hard formations.

[0003] Drilling fluid is the circulating liquid used in oil drilling, which plays a role in balancing formation pressure and cooling the bit tool, etc. It can be divided into oil-based drilling fluid and water-based drilling fluid, etc. Water-based drilling fluid has a higher cost performance, so it is widely used. When the PDC bit is working, it rotates continuously, and mainly relies on the composite sheets on the cutter wings to form shear stress on the formation to break rock and drill; the water holes between the cutter wings connect the inside of the drill string with the annulus between the drill string and the wellbore, so that the drilling fluid circulates in the passage, playing a role in balancing formation pressure, cooling, carrying cuttings, and cleaning the wellbore. During the drilling process, it is crucial to keep the liquid circulation path in the drill string, water holes, chip discharge grooves, and annulus unobstructed, which can not only maintain the balance of formation pressure, avoid well leakage or overflow, but also clean the bottom of the well in time, ensure that the cutting teeth of the bit are in continuous contact with the unbroken rock formation, and continuously generate drilling footage.

[0004] However, about 60-80% of the formations drilled in domestic oil drilling are shale formations. Under the condition of water-based drilling fluid, due to the high content of clay minerals in the formation, the muddy formation and cuttings are prone to hydration swelling, and are extremely easy to block the bit water holes and gradually adhere to the chip discharge grooves, cutter wings and gauge surfaces of the PDC bit, resulting in the bit caking phenomenon, so that the functional structures such as cutter wings, chip discharge grooves, and water holes in the PDC bit are covered and it is difficult to play the role of cutting the formation, which greatly affects the rock-breaking efficiency and mechanical drilling speed of the PDC bit, and in severe cases, it leads to no drilling footage. In addition, due to the tight fit between the caked bit and the wellbore, the "pulling piston" effect is likely to occur during the tripping process, cutting off the drilling fluid circulation path, generating swabbing pressure in the wellbore, causing formation fluids to enter the wellbore, and then triggering serious drilling accidents such as well kick and even blowout. At present, the main anti-caking measures for PDC bits include optimizing the flow channel structure and material design of PDC bits, improving the hydraulic parameter design of PDC bits, adjusting the performance parameters of drilling fluid, and improving the utilization rate of solids control equipment.

[0005] ① By optimizing the structural design of the PDC bit's blade, nozzle, or chip removal groove, the hydraulic conditions of the PDC bit are improved. However, the R & D cost is high, and it is not very applicable to existing bits. For example: In the Chinese patent CN202011394515.6, a bit with anti-sludging function, a front blade is designed at the top, and second blades are designed on both sides of the side blades to crush rock debris multiple times and continuously discharge it. The principle is to design blades for cutting in the sludging-prone areas. In the Chinese patent CN201810445639.9, a PDC bit with anti-sludging function optimizes the blade position to increase the chip removal groove volume, thereby reducing the accumulation of hydrated mudstone in the chip removal groove. In the Chinese patent CN201110066903.6, a downhole tool with anti-sludging characteristics and its formation and repair methods uses a special map-shaped material to wrap around the sludging-prone chip removal groove and other parts, thereby reducing the components accumulated by rock cutting on this special material.

[0006] ② Adjust the performance parameters of the drilling fluid to improve the inhibition of the drilling fluid. However, the preparation and maintenance technical requirements are high. For example: In the Chinese patent CN202210857744.X, an environmentally friendly and degradable lubricant for drilling and its preparation method discloses a lubricant with significant lubrication effect, low foaming rate, and low freezing point at a high temperature of 160 - 200 °C, which can meet the needs of bit anti-sludging. However, the anti-sludging effect of the bit is closely related to the coating ability of this material on the bit surface. In the Chinese patent CN201110130011.8, a drilling fluid for active mud shale drilling discloses a drilling fluid with inhibition and lubrication close to that of oil-based drilling fluid, but the cost is high and the formula is complex.

[0007] ③ Change the material on the bit surface, and pre-apply anti-sludging coatings, coatings, materials, etc. on the bit. However, the treatment processes of such measures are complex and the cost is high. For example: In the Chinese patent CN202210455501.3, a preparation method of a laser-textured nickel-phosphorus alloy anti-sludging composite coating requires first pre-treating the substrate surface, then scanning and processing micro-textures, cleaning and chemical plating pre-treatment, and finally preparing the coating. The process is complex and the reliability is insufficient. In the Chinese patent CN201711197734.3, a preparation method of an anti-sludging and wear-resistant modified layer on the bit steel body surface can prepare an anti-sludging and wear-resistant modified layer on the surface of alloy steel, but the corresponding cost is high and the promotion value is not great.

[0008] ④Install a mechanical device on the drill bit to flush or sweep away the mud, and use a mechanical structure to isolate the drill bit from the formation. This method has a complex structure, does not treat the water eye, and cannot prevent mud packing from the source. For example, in the Chinese published patent CN202022017528.3, a new type of anti-mud-packing PDC drill bit uses the cooperation of a driving mechanism and a rotating mechanism to automatically rotate multiple sweeping plates to sweep away the mud in the drill bit flow channel, avoiding the occurrence of mud packing. However, the mechanical structure of the device is complex and the reliability is insufficient. In the Chinese published patent CN202022791974.X, an anti-mud-packing device for an oil and gas operation drill bit can isolate the drill bit body from the rock mud during the downhole operation, completely avoiding the occurrence of mud packing during the downhole operation, but the piston pulling effect is inevitable.

[0009] In summary, among the existing similar measures ①, ③, and ④ for optimizing the drill bit, although measures ① and ③ prevent mud packing by optimizing the drill bit structure, the cost is high and the limiting conditions are many; measure ④ cannot prevent mud packing and can only remove mud packing through mechanical devices operating downhole. The research and development cost of avoiding drill bit mud packing by optimizing the drill bit water eye, blade, and tooth profile is high, and it is not very applicable to existing drill bits and drilling fluid systems; the method of improving parameters and equipment utilization rate can basically maintain the characteristic performance of the drill bit. However, the effect on plugging the water eye is not obvious, and the methods for reducing the risk of water eye blockage and increasing the flow capacity of the chip removal groove have not been realized.

[0010] Therefore, there is an urgent need for a practical and low-cost method for preventing mud packing of PDC drill bits, so as to efficiently solve the problem of mud packing of existing PDC drill bits, reduce the risk of re-occurring mud packing, and maintain the stability of PDC drill bits. Summary of the Invention

[0011] The purpose of the present invention is to provide an anti-mud-packing PDC drill bit and an anti-mud-packing method for the current problem of preventing mud packing of PDC drill bits, which can minimize the influence of mud packing caused by hydration swelling of PDC drill bits in shale formations without changing the basic characteristic parameters of PDC drill bits and reduce economic losses.

[0012] The present invention is realized through the following technical solutions:

[0013] In the first aspect, the present invention provides an anti-mud-packing PDC drill bit, including:

[0014] A drill bit body having a water eye and a chip removal groove;

[0015] A guiding wire, one end of which is connected to the drill bit body, and the other end extends into the water eye along the chip removal groove. The guiding wire is bent from a rigid material.

[0016] In the above solution, by providing a diversion wire on the drill bit, since one end of the diversion wire extends into the water eye through the chip removal groove, it prevents rock chips from accumulating in the water eye, and at the same time can play a role in diversion, which helps to increase the scouring of the drilling fluid on the rock chips and increase the flow area of the chip removal groove, thereby effectively improving the problem of mud packing of the PDC bit.

[0017] In some embodiments, the anti-mud-packing PDC bit further includes a fixing wire, the fixing wire is disposed around in a groove on the bit body, and one end of the diversion wire is connected to the fixing wire.

[0018] In some embodiments, the diversion wire includes a closed end and an unclosed end, the closed end is sleeved on the fixing wire, and the unclosed end extends into the water eye.

[0019] In some embodiments, the diversion wire is in a J shape, the end of the diversion wire far from the hook forms the closed end, and the end close to the hook forms the unclosed end.

[0020] In some embodiments, the diversion wire is in a double-fold J shape, the diversion wire is bent into a required shape by folding, the closed end is formed at the folding part of the diversion wire, and the end far from the folding part forms the unclosed end.

[0021] In some embodiments, the number of the diversion wires is the same as the number of the water eyes, and each diversion wire extends into the corresponding water eye through the corresponding chip removal groove.

[0022] In some embodiments, the diversion wire is radially lower than the radial dimension of the cutter wing on the bit body, so that it is located in the middle of the chip removal groove in the radial direction.

[0023] In some embodiments, the material strength of the diversion wire is at least higher than the adhesion force of the downhole muddy attachment to the bit.

[0024] In some embodiments, the diversion wire is a metal wire.

[0025] In a second aspect, the present invention provides a method for preventing mud packing of a PDC bit. By providing a diversion wire on the bit body, the diversion wire is bent from a rigid material, and one end of the diversion wire is connected to the bit body, and the other end extends into the water eye along the chip removal groove. During the drilling process, one end of the diversion wire is in the water eye to play a role in diversion to prevent rock chips from accumulating in the water eye.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0027] On the basis of maintaining the existing PDC bit shape and drilling fluid performance, the present invention reduces the possibility of water eye blockage by arranging a diversion wire on the bit. Since one end of the diversion wire extends into the water eye through the chip removal groove, the flow capacity of the chip removal groove is increased at the same time, effectively improving the problem of mud packing of the PDC bit. Since the diversion wire extends to the water eye through the chip removal groove, the requirements for the material and strength of the diversion wire are not harsh, and it has a wide applicability and can be efficiently applied to the actual oil field site. Any material that can meet the structure and requirements proposed by this method can be used, and the raw material source is wide, and it can adapt to various well site conditions. At the same time, the performance is stable and controllable, the ability to wash the cuttings at the bottom of the well can be improved, and the mud packing of the bit caused by the difficult discharge of cuttings due to the compaction effect can be avoided. The present invention can maintain the rock-breaking efficiency and mechanical drilling speed of the PDC bit, improve the life of the cutting teeth, reduce the drilling risk as much as possible, increase the mechanical drilling speed, shorten the well construction period, and reduce the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts. In the drawings:

[0029] Figure 1 is a side view schematic diagram of the anti-mud-packing PDC bit in the present invention;

[0030] Figure 2 is a top view schematic diagram of the anti-mud-packing PDC bit in the present invention;

[0031] Figure 3 is a combined schematic diagram of the diversion wire and the fixing wire in the present invention.

[0032] Reference numerals in the drawings and the corresponding component names:

[0033] 1 - diversion wire, 2 - unclosed end, 3 - water eye, 4 - closed end, 5 - bit body, 6 - fixing wire. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the purpose, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below with reference to the embodiments and the drawings. The illustrative embodiments of the present invention and their descriptions are only used to explain the present invention and are not used to limit the present invention.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used herein are for the purpose of describing specific embodiments only and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0036] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features.

[0037] Reference to "embodiment" herein means that a particular feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0038] In the description of the embodiments of this application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can mean: A exists, both A and B exist, and B exists. In addition, the character " / " herein generally indicates that the associated objects before and after are in an "or" relationship.

[0039] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only illustrative and should not constitute any limitation to this application.

[0040] In the description of the embodiments of this application, the term "plurality" means two or more (including two). Similarly, "multiple groups" means two or more groups (including two groups), and "multiple pieces" means two or more pieces (including two pieces), unless otherwise specifically defined.

[0041] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of the present application.

[0042] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "coupling", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0043] Embodiment 1

[0044] Please refer to Figures 1 - 3 , a mud - resistant PDC bit provided in the embodiments of the present application includes a bit body 5 and a diversion wire 1. The bit body 5 has water holes 3 and chip - removal grooves; one end of the diversion wire 1 is connected to the bit body 5, and the other end extends into the water holes 3 along the chip - removal grooves. The diversion wire 1 is bent from a rigid material.

[0045] By arranging the diversion wire 1 on the bit, since one end of the diversion wire 1 extends into the water holes 3 through the chip - removal grooves, it prevents rock chips from accumulating in the water holes 3, reduces the risk of blockage of the water holes 3, and at the same time can play a role in guiding the flow, which helps to increase the scouring of the drilling fluid on the rock chips, increases the flow - through area of the chip - removal grooves, and ensures the stability and flow - through capacity of the circulation channel of the drilling fluid at the bit, thereby effectively improving the problem of mud - packing of the PDC bit.

[0046] The purpose of setting the nozzles on a PDC bit is not only to form a fluid passage, but also to wash the bottom hole and clean the wellbore. The bit balling problem is caused by insufficient washing of the bottom hole, and the direct cause is the blockage of the nozzles. Nozzle blockage will lead to insufficient jet energy, unable to carry cuttings, resulting in a vortex-like backflow at the bottom of the bit, changing the properties of the cuttings, and thus forming a hydration effect in the shale formation, adhering to the nozzles, and then adhering to the chip discharge groove and other areas along the fluid passage, further blocking the flow of drilling fluid and forming a balled bit. The principle of nozzle blockage is that due to the interfacial tension of the liquid-solid interface in the annular space, shale continuously accumulates at the nozzle outlet. The principle of setting the guiding wire is to break the interfacial tension of the original liquid-solid interface in the annular space, form an outward conical guiding space in the center of the annulus, break the chip accumulation surface, and thus internally disintegrate the chip accumulation blocking the nozzles.

[0047] When the PDC bit is lowered into the well in an environment prone to bit balling such as shale, special-shaped guiding wires 1 are distributed and installed at the nozzles 3 and the corresponding chip discharge grooves. Once the cuttings accumulate at the bottom of the bit, they are cut by the guiding wires along with the lowering action. The drilling fluid at the nozzles 3 flushes the bottom hole under the guiding action of the guiding wires 1 to achieve the effect of eliminating the bit balling effect caused by the hydration swelling of the shale formation.

[0048] It should be noted that the bit can be any type of PDC bit. The bit body 5 is evenly distributed with a plurality of cutter wings along the circumferential direction. Each cutter wing has a plurality of cutting teeth. Chip discharge grooves are formed between adjacent cutter wings. The nozzles 3 are usually arranged at the front end of the bit body 5, which is similar to the existing PDC bits and will not be elaborated here.

[0049] During the drilling process, the bit body 5 is connected to the upper drill string. The drilling fluid flushes the bottom hole through the bit nozzles to achieve the function of cleaning the cuttings at the bottom hole, ensuring that the PDC bit continuously cuts the new formation to obtain the required penetration rate and footage, and avoiding downhole complications. By installing special-shaped guiding wires on the PDC bit, the anti-bit balling performance of the bit itself can be improved.

[0050] According to some embodiments of the present application, the anti-bit balling PDC bit further includes a fixing wire 6. The fixing wire 6 is wound and arranged in a groove on the bit body 5. One end of the guiding wire 1 is connected to the fixing wire 6 to prevent the guiding wire 1 from detaching from the bit body 5. It should be noted that the fixing wire 6 can be fixed in the groove of the bit body 5 or not fixed. Preferably, the fixing wire 6 is not fixed, so that the fixing wire 6 can move slightly along the axial and circumferential directions of the bit body 5 in the groove. Similarly, the connection method between the guiding wire 1 and the fixing wire 6 can be fixed or not fixed, that is, the end of the guiding wire 1 slides along the fixing wire 6. Preferably, the guiding wire 1 is not fixed, so that the end of the guiding wire 1 can slide slightly along the fixing wire 6, that is, the guiding wire 1 is connected to the bit body 5 in a semi-fixed manner.

[0051] The fixing wire 6 is an annular shape that is consistent with the circumferential shape of the drill bit body 5. The fixing wire 6 can be adjusted according to the shapes of different drill bit bodies 5. The key to using this semi-fixed mode lies in ensuring that the wire is always close to the drill bit but not fixed. With the rotation and up-and-down movement of the drill bit, relative circumferential and axial movements are generated correspondingly, thereby generating relative frictional force to further scrape the possible mud-like adhesions and eliminate the influence of drill bit mud packing.

[0052] According to some embodiments of the present application, the diversion wire 1 includes a closed end 4 and an open end 2. The closed end 4 is sleeved on the fixing wire 6, and the open end 2 extends into the water eye 3. The open end 2 of the diversion wire 1 extends into the water eye 3 from the outer periphery, preventing cuttings from accumulating in the water eye 3, and at the same time can play a role in diversion, increasing the flushing of the drilling fluid on the blade to avoid the occurrence of mud packing. The closed end 4 of the diversion wire 1 is sleeved on the fixing wire 6, thereby realizing the connection of one end of the diversion wire 1 to the drill bit body 5 to prevent the diversion wire 1 from falling off.

[0053] According to some embodiments of the present application, the diversion wire 1 is in a J shape. One end of the diversion wire 1 away from the hook forms the closed end 4, and one end close to the hook forms the open end 2. The closed end 4 of the diversion wire 1 can be formed into a circular ring shape, which is convenient for sleeving the closed end 4 on the fixing wire 6 and connecting one end of the diversion wire 1 to the drill bit body 5. During the actual process of lowering the drill, the downward force of the drill bit can further deform the hook, and then promote the open end 2 of the diversion wire 1 to break the cutting accumulation surface at the outlet of the water eye 3, thereby dredging the water eye channel and ensuring the continuous flushing of the cuttings.

[0054] According to some embodiments of the present application, the diversion wire 1 is in a double-folded J shape. The diversion wire 1 is bent into the required shape after being folded in half, and the closed end 4 is formed at the folded part of the diversion wire 1, and one end away from the folded part forms the open end 2. The diversion wire 1 with the above structure forms a U-shaped structure at the folded part. When the diversion wire 1 is connected to the fixing wire 6, the fixing wire 6 is placed in the above U-shaped structure. After the closed end 4 of the diversion wire 1 is connected in series by the annular fixing wire 6, it is semi-fixed on the drill bit body 5. After adopting the diversion wire in the double-folded J shape, two separated sub-diversion wires are formed at its open end. In this way, the two sub-diversion wires extend into the same water eye, which can further reduce the risk of water eye blockage.

[0055] According to some embodiments of the present application, the number of the diversion wires 1 is the same as the number of the water eyes 3, and each diversion wire 1 extends into the corresponding water eye 3 through the corresponding chip removal groove. The number of diversion wires 1 arranged in each chip removal groove may be one or two, specifically determined according to the number of water eyes 3 corresponding to the chip removal groove.

[0056] According to some embodiments of the present application, the guide wire 1 is radially lower than the radial dimension of the blade on the drill body 5, so that it is located in the middle of the chip groove in the radial direction. That is, the guide wire 1 is at a certain height from the bottom wall of the chip groove. The middle part of the guide wire 1 is placed in the middle of the chip groove to increase the flow area of ​​the chip groove and destroy the rock chip accumulation surface on the chip groove. During the rotation and drilling of the drill bit, the "egg beater" mode is simulated to scrape off the mud-like attachments adhering to the surface of the drill body.

[0057] According to some embodiments of the present application, the material strength of the guide wire 1 is at least higher than the adhesion of the mud attachments in the well to the drill bit. This method has no special requirements for the material of the guide wire. Any material that can adapt to the temperature and pressure requirements in the well and has a certain strength can be used. The strength must be higher than the adhesion of the mud attachments in the well to the drill bit. When scraping off the mud attachments adhering to the surface of the drill bit body, the guide wire is not prone to permanent deformation.

[0058] According to some embodiments of the present application, both the guide wire 1 and the fixing wire 6 can be metal wires.

[0059] The speed of penetration is faster and shorter than that of the conventional PDC drill bit, which has the advantage of being a good sticking point and being easy to break.It has the advantage of being a good drill bit with a good foundation and being easy to drill.PDC drills are a good choice for drill bit owners.The higher the penetration rate, the smaller the drill bit will be, and the faster it will be used.

[0060] Example 2

[0061] A method for preventing mud balling of a PDC drill bit is provided in an embodiment of the present application, wherein a guide wire 1 as described in Example 1 is arranged on a drill bit body 5, wherein the guide wire 1 is formed by bending a rigid material, and one end of the guide wire 1 is connected to the drill bit body 5, and the other end extends into the water eye 3 along a chip groove. During the drilling process, one end of the guide wire 1 is in the water eye 3 to play a guiding role to prevent rock cuttings from accumulating in the water eye 3.

[0062] The key to this method lies in using a diversion wire to destroy the debris attachment surface in the water eye, increasing the flow area in the chip removal groove, and the cooperation with the drill bit is a semi-fixed type. During the use process, there is relative movement between the diversion wire and the drill bit body, so as to achieve the "egg beater" and scraping effects and prevent the drill bit from being mud-packed. This method can, on the basis of not changing the original drill bit design, use the diversion wire as a carrier to provide a new solution for preventing mud-packing of PDC drill bits, effectively maintaining the drilling efficiency of PDC drill bits, avoiding downhole complications, shortening the operation cycle, and reducing construction risks and costs.

[0063] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A mud-proof PDC bit, characterized in that, Comprising: A drill bit body having a water eye and a chip discharge groove; A guiding wire, one end of which is connected to the drill bit body, and the other end extends into the water eye along the chip discharge groove, and the guiding wire is bent from a rigid material.

2. The anti-mud-packing PDC bit according to claim 1, wherein It further includes a fixing wire, the fixing wire is disposed around a groove on the drill bit body, and one end of the guiding wire is connected to the fixing wire.

3. The anti-mud-packing PDC bit according to claim 2, wherein The guiding wire includes a closed end and an open end, the closed end is sleeved on the fixing wire, and the open end extends into the water eye.

4. The anti-mud-packing PDC bit according to claim 3, characterized in that, The guiding wire is in a J shape, the end of the guiding wire far from the hook forms the closed end, and the end close to the hook forms the open end.

5. The anti-mud-packing PDC bit according to claim 4, wherein The guiding wire is in a double-folded J shape, the guiding wire is bent into a required shape after being folded in half, the closed end is formed at the folded part of the guiding wire, and the end far from the folded part forms the open end.

6. The anti-mud-packing PDC bit according to any one of claims 1-5, characterized in that The number of the guiding wires is the same as the number of the water eyes, and each guiding wire extends into the corresponding water eye through the corresponding chip discharge groove.

7. The anti-mud-packing PDC bit according to claim 6, characterized in that, The guiding wire is radially lower than the radial dimension of the cutter blade on the drill bit body, so that it is located in the middle of the chip discharge groove in the radial direction.

8. The anti-mud-packing PDC bit according to any one of claims 1-5, characterized in that, The material strength of the guiding wire is at least higher than the adhesion force of the downhole muddy attachments to the drill bit.

9. The anti-mud-packing PDC bit according to claim 8, wherein The guiding wire is a metal wire.

10. A method for preventing mud packing of a PDC bit, characterized in that, By arranging a guiding wire on the drill bit body, the guiding wire is bent from a rigid material, and one end of the guiding wire is connected to the drill bit body, and the other end extends into the water eye along the chip discharge groove. During the drilling process, one end of the guiding wire is in the water eye to play a guiding role to prevent rock chips from accumulating in the water eye.

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