Indexing drill bit for oil and gas exploitation

Abstract

The invention provides a transposition drill bit for oil and gas exploitation, and relates to the technical field of oil and gas exploitation. The transposition drill bit for oil and gas exploitation comprises an alloy base body, a fixed fluted disc is arranged on the upper portion of the alloy base body, a cutter wing is arranged in the middle of the fixed fluted disc, a plurality of cutting teeth are fixedly connected to the peripheral wall of the cutter wing, a rotating shaft is fixedly connected to the middle of the cutter wing, and the rotating shaft is rotationally connected with the fixed fluted disc. The blades are provided with limiting mechanisms connected with the fixed fluted disc. The fixed fluted disc is rotationally connected with the cutter wings through the rotating shafts, and the limiting mechanisms are arranged between the fixed fluted disc and the cutter wings, so that after the cutting teeth are abraded, the intact cutting teeth and the abraded cutting teeth can be subjected to transposition through transposition of the cutter wings, the effect of recycling the drill bit is achieved, the loss of the drill bit is reduced, the frequency of replacing the drill bit is reduced, and the service life of the drill bit is prolonged. And the use cost of the drill bit is further reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploitation, in particular to a rotary drill bit used for oil and gas exploitation. Background Art

[0002] Before oil and gas extraction, underground exploration is first carried out on the location where drilling is required. PDC (Polycrystalline Diamond Compact) drill bits have high hardness, wear resistance, and self-sharpening polycrystalline diamond composite pieces to shear and crush rocks. They have high mechanical drilling speed, long service life, and low drilling cost in soft to medium-hard formations, so they are widely used in drilling projects. Existing PDC drill bits are all fixed cutting tooth drill bits. The polycrystalline diamond composite pieces as cutting elements are arranged according to a certain pattern and consolidated on the drill bit body, forming the cutting structure of the PDC drill bit for crushing rocks.

[0003] Although PDC drill bits have a series of excellent properties such as high hardness and wear resistance, they will still wear out after long-term use. At this time, the drill bit needs to be replaced. When using a PDC drill bit to drill below the surface, high-temperature hard formations may be encountered sometimes. Conventional PDC drill bits have poor high-temperature resistance. Therefore, when drilling high-temperature hard formations, PDC drill bits are prone to thermal damage and reduced hardness and wear resistance. In addition, due to the alternation of high temperature and cooling, the diamond and alloy matrix are easily separated. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a rotary drill bit for oil and gas production, which solves the problem of poor high temperature resistance of the drill bit, improves the wear resistance of the drill bit and reduces the replacement frequency.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: a rotary drill bit for oil and gas extraction, comprising an alloy substrate, a fixed toothed disc is arranged on the upper part of the alloy substrate, a blade wing is arranged in the middle part of the fixed toothed disc, a plurality of cutting teeth are fixedly connected to the peripheral wall of the blade wing, a rotating shaft is fixedly connected to the middle part of the blade wing, the rotating shaft is rotatably connected to the fixed toothed disc, the blade wing is provided with a limiting mechanism connected to the fixed toothed disc, and a water spray hole and a reflux hole are arranged through the fixed toothed disc.

[0006] Preferably, the cutting teeth are composed of a composite of PDC and TSP, and the surface of the cutting teeth is prepared by ultra-high-speed flame spraying technology to form a dense tungsten carbide coating.

[0007] Preferably, the blade wing and the cutting tooth are connected by brazing technology.

[0008] Preferably, the alloy substrate, the fixed toothed disc, and the blade are all made of superhard alloy, and the alloy substrate and the fixed toothed disc are integrally formed.

[0009] Preferably, the limiting mechanism includes a limiting hole, a threaded hole, and a fixing bolt. The limiting hole passes through and is arranged on the blade wing. The threaded hole is arranged on a fixed toothed disk and corresponds to the limiting hole. The threaded end of the fixing bolt passes through the limiting hole and is threadedly connected to the inside of the threaded hole.

[0010] Preferably, the alloy matrix and the surface of the fixed gear disc are subjected to nickel-phosphorus wear-resistant thickening treatment and electroplating treatment to form a strong chemical bond.

[0011] Preferably, the water spray hole is located in the middle of the fixed toothed disc, and a plurality of the reflux holes are arranged and distributed around the edge of the fixed toothed disc.

[0012] The present invention provides a rotary drill bit for oil and gas production, which has the following beneficial effects:

[0013] 1. The present invention is connected to the fixed toothed disc and the blade by a rotating shaft, and a limit mechanism is provided between the fixed toothed disc and the blade, so that after the cutting teeth are worn, the intact cutting teeth can be replaced with the worn cutting teeth by rotating the blade, so as to achieve the effect of reusing the drill bit, reduce the loss of the drill bit, reduce the frequency of replacing the drill bit, and further reduce the use cost of the drill bit. Moreover, by providing the water spray hole and the reflux hole, the drill bit can be cooled in time to ensure that the drill bit can operate within a suitable temperature range.

[0014] 2. The present invention uses a composite of PDC and TSP to form cutting teeth and uses ultra-high-speed flame spraying technology to prepare a dense tungsten carbide coating on the surface of the cutting teeth, so that the high-temperature resistance of the cutting teeth is greatly improved, which not only avoids the problem of thermal damage to the drill bit when drilling high-temperature hard formations, but also further improves the hardness and wear resistance of the drill bit.

[0015] 3. The present invention adopts brazing technology to connect the blade wing and the cutting tooth, so that the cutting tooth and the blade wing have better impact resistance and improve the upper load limit of the delamination and peeling of the cutting tooth and the blade wing.

[0016] 4. The surfaces of the alloy substrate and the fixed toothed disc are treated by nickel-phosphorus wear-resistant thickening and electroplating to form strong chemical bonds on their surfaces, making their surfaces smoother. This not only improves the wear resistance of the alloy substrate and the fixed toothed disc, but also helps prevent surface mud packing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A perspective view of the present invention;

[0018] Figure 2 It is a front view of the present invention;

[0019] Figure 3 A top view of the present invention;

[0020] Figure 4 A side view of a blade of the present invention;

[0021] Figure 5 is a cross-sectional view of a blade of the present invention;

[0022] Figure 6 for Figure 2 Enlarged view of point A in the middle.

[0023] Among them, 1. alloy matrix; 2. fixed toothed disc; 3. blade; 4. cutting teeth; 5. water spray hole; 6. reflux hole; 7. limit hole; 8. fixing bolt; 9. rotating shaft; 10. threaded hole. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0025] Example:

[0026] like Figure 1-6 As shown, an embodiment of the present invention provides a rotary drill bit for oil and gas production (hereinafter referred to as "the drill bit"), including an alloy substrate 1, a fixed toothed disc 2 is provided on the upper part of the alloy substrate 1, a blade wing 3 is provided in the middle part of the fixed toothed disc 2, and a plurality of cutting teeth 4 are fixedly connected to the peripheral wall of the blade wing 3. The blade wing 3 is disc-shaped, and the plurality of cutting teeth 4 are distributed around the circumference of the blade wing 3. A rotating shaft 9 is fixedly connected to the middle part of the blade wing 3, and the rotating shaft 9 is rotatably connected to the fixed toothed disc 2. The blade wing 3 is provided with a limiting mechanism connected to the fixed toothed disc 2, a water spray hole 5 is passed through the middle part of the fixed toothed disc 2, a plurality of reflux holes 6 are passed through the surrounding of the fixed toothed disc 2, and a reflux hole 6 is provided between two adjacent blade wings 3.

[0027] The fixed toothed disc 2 and the blade wing 3 are rotatably connected via a rotating shaft 9, and a limiting mechanism is provided between the fixed toothed disc 2 and the blade wing 3, so that when the cutting teeth 4 are worn, the intact cutting teeth 4 can be replaced with the worn cutting teeth 4 by rotating the blade wing 3, thereby achieving the effect of reusing the drill bit, reducing the wear of the drill bit, reducing the frequency of replacing the drill bit, and further reducing the use cost of the drill bit.

[0028] The cutting tooth 4 is composed of a composite of PDC and TSP (Thermally Stable Polycrystalline Diamond), and a dense tungsten carbide coating is prepared on the surface of the cutting tooth 4 by using ultra-high-speed flame spraying technology.

[0029] PDC is manufactured by sintering diamond powder onto a matrix under high temperature and high pressure. As the temperature decreases, the residual compressive stress of the diamond layer and the tensile stress of the matrix change. This residual stress increases as the temperature decreases. When the temperature rises, the diamond layer generates high tensile stress. Under the action of this tensile stress, the PDC teeth may experience tooth collapse and delamination; the cutting teeth made of PDC mainly rely on the diamond layer to crush hard rocks. Catalytic metals used for catalysis often remain in the diamond layer. The thermal expansion coefficients of these metal materials and diamond materials are very different. In the process of drilling into high-temperature hard formations, due to the obvious enhancement of the elastic-plastic properties of the rock, conventional PDC teeth often show reciprocating motion on the rock surface when rotating and cutting underground. Most of the energy is converted from crushing the formation to generating heat. The original high temperature of the environment underground and the heat generated by cutting friction form a superposition effect, which leads to a sharp increase in the thermal stress of the diamond layer, resulting in the destruction of the connecting bonds between the diamond crystals, causing the diamond particles to fall off along the edge and finally causing the PDC cutting teeth 4 to collapse.

[0030] The PDC and TSP composite is a composite of PDC and TSP materials to manufacture the drill bit. The TSP drill bit has a higher cost but has high temperature resistance and still has good drilling effect in high hardness and high wear resistance formations, effectively avoiding the problem of abnormal wear caused by rapid increase in reciprocating friction temperature of conventional drill bits under high temperature and hard formation conditions. Therefore, the drill bit can integrate the advantages of the two materials to effectively improve the overall performance and meet various drilling requirements.

[0031] The ultra-high-speed flame spraying technology is used to prepare a dense tungsten carbide coating for the cutting tooth 4. The fewer the pores and inclusions in the coating, the higher the density; the finer the hard particles in the coating and the more uniform the distribution, the higher the microhardness of the coating and the higher the resistance to drilling fluid erosion.

[0032] By using PDC and TSP composite to make the cutting teeth 4 and using ultra-high speed flame spraying technology to prepare a dense tungsten carbide coating on the surface of the cutting teeth 4, the high temperature resistance of the cutting teeth 4 is greatly improved, which not only avoids the problem of thermal damage to the drill bit when drilling high-temperature hard formations, but also further improves the hardness and wear resistance of the drill bit.

[0033] The blade wing 3 and the cutting tooth 4 are connected by brazing technology.

[0034] The shedding of the polycrystalline diamond layer is also a very serious problem. When drilling into high-temperature hard formations, the bonding between the diamond layer and the cemented carbide substrate is destroyed due to thermal shock, resulting in wear and tear. The delamination of the diamond layer and the cemented carbide substrate is often attributed to the mismatch between the thermal expansion of the polycrystalline diamond layer and the cemented carbide substrate at high temperatures. As the drilling process progresses, the friction between the diamond layer of the cutting tooth 4 and the rock interface generates huge thermal stress, and thermal cracks appear on the cutting tooth 4. As the temperature rises, high tensile stress will be generated on the diamond table. At the same time, the cooling effect of the drilling fluid will cause different contractions between the diamond layer and the cemented carbide substrate, accelerating the expansion of the cracks.

[0035] The brazing connection method enables the diamond layer to have a better impact-resistant connection with the alloy substrate 1, and increases the upper load limit of the delamination and peeling of the diamond layer and the substrate.

[0036] The alloy substrate 1, the fixed toothed disc 2 and the blade wing 3 are all made of superhard alloy, and the alloy substrate 1 and the fixed toothed disc 2 are integrally formed.

[0037] By adopting super-hard alloy one-piece molding, the mechanical strength and wear resistance of the drill bit are greatly improved.

[0038] The limiting mechanism includes a limiting hole 7, a threaded hole 10, and a fixing bolt 8. The limiting hole 7 passes through and is arranged around the middle of the blade wing 3, the threaded hole 10 is arranged around the middle of the fixed toothed disc 2, and the threaded end of the fixing bolt 8 passes through the limiting hole 7 and is threadedly connected with the inside of the threaded hole 10.

[0039] The surfaces of the alloy substrate 1 and the fixed toothed disc 2 are treated with nickel-phosphorus wear-resistant thickening and electroplating to form a chemical bond.

[0040] The rough surface of the drill bit matrix increases the adhesion of the drill bit, especially after the drilling fluid is stationary, the electrostatic force of the drill bit makes the clay adhere to the surface of the drill bit, thereby forming mud bags on the surface of the drill bit. The drill bit is treated with anti-mud bag coating technology, that is, the drill bit is treated with nickel-phosphorus wear-resistant thickening and electroplating to form strong chemical bonds to avoid the above-mentioned problems, making the surface of the drill bit smoother, which is beneficial to prevent mud bags on the drill bit. The smoother surface further reduces the friction, thereby further improving the wear resistance of the drill bit.

[0041] The blade 3 transfer method comprises the following steps:

[0042] When the cutting tooth 4 is damaged, remove the fixing bolt 8, rotate the blade wing 3 90° or 180° so that the intact cutting tooth 4 is located outside the alloy matrix 1, and then install and tighten the fixing bolt 8 to limit and fix the blade wing 3 and the alloy matrix 1, thereby completing the rotation of the blade wing 3.

[0043] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A rotary drill bit for oil and gas production, comprising an alloy substrate (1), characterized in that: A fixed toothed disc (2) is arranged on the upper part of the alloy matrix (1), a blade wing (3) is arranged in the middle part of the fixed toothed disc (2), a plurality of cutting teeth (4) are fixedly connected to the peripheral wall of the blade wing (3), a rotating shaft (9) is fixedly connected to the middle part of the blade wing (3), the rotating shaft (9) is rotatably connected to the fixed toothed disc (2), the blade wing (3) is provided with a limiting mechanism connected to the fixed toothed disc (2), and a water spray hole (5) and a reflux hole (6) are arranged through the fixed toothed disc (2).

2. A rotary drill bit for oil and gas production according to claim 1, characterized in that: The cutting teeth (4) are formed by compounding PDC and TSP, and the surface of the cutting teeth (4) is prepared by ultra-high-speed flame spraying technology to form a dense tungsten carbide coating.

3. The indexable drill bit for oil and gas production according to claim 1, characterized in that: The blade wing (3) and the cutting tooth (4) are connected by brazing.

4. The indexable drill bit for oil and gas production according to claim 1, characterized in that: The alloy matrix (1), the fixed toothed disc (2), and the blade (3) are all made of superhard alloy, and the alloy matrix (1) and the fixed toothed disc (2) are integrally formed.

5. The indexable drill bit for oil and gas production according to claim 1, characterized in that: The limiting mechanism comprises a limiting hole (7), a threaded hole (10), and a fixing bolt (8); the limiting hole (7) passes through and is arranged on the blade wing (3); the threaded hole (10) is arranged on the fixed toothed disc (2) and corresponds to the limiting hole (7); the threaded end of the fixing bolt (8) passes through the limiting hole (7) and is threadedly connected to the inside of the threaded hole (10).

6. A rotary drill bit for oil and gas production according to claim 1, characterized in that: The surfaces of the alloy matrix (1) and the fixed toothed disc (2) are subjected to nickel-phosphorus wear-resistant thickening treatment and electroplating treatment to form a chemical bond.

7. A rotary drill bit for oil and gas production according to claim 1, characterized in that: The water spray hole (5) is located in the middle of the fixed toothed disc (2), and a plurality of return holes (6) are provided and distributed around the edge of the fixed toothed disc (2).

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