阅读说明：本技术 一种冲切pdc钻头 (Punching PDC drill bit ) 是由 张春亮 包泽军 杨明 杨迎新 雷艳虹 段玉涛 代洋 于 2020-05-28 设计创作，主要内容包括：一种冲切PDC钻头,包括钻头本体、刀翼,刀翼与钻头本体固定相连或一体成型,刀翼上设置有切削齿,刀翼上还设置有保径段,自保径段处延伸有支承体,支承体上设置有冲击单元,冲击单元由滚动体、传动装置和冲击装置构成；所述滚动体能绕自身轴线转动,且所述滚动体的外轮廓在径向方向上与刀翼保径段的距离为L,其范围为-d/4≤L≤d/4,d为切削齿直径；冲击装置由冲击杆和至少一个冲击齿组成。本发明在实现冲击破岩时无需配备冲击器工具,节约钻井成本的同时,改善切削齿侵入能力,提高破岩效率。(A punching PDC drill bit comprises a drill bit body and blades, wherein the blades are fixedly connected with the drill bit body or integrally formed, cutting teeth are arranged on the blades, a diameter protection section is further arranged on the blades, a supporting body extends from the diameter protection section, an impact unit is arranged on the supporting body and consists of a rolling body, a transmission device and an impact device, the rolling body can rotate around the axis of the rolling body, the distance between the outer contour of the rolling body and the diameter protection section of the blades in the radial direction is L, the range of d/4 is-L-d/4, and d is the diameter of the cutting teeth, and the impact device consists of an impact rod and at least one impact tooth.)

1. A punching PDC drill bit comprises a drill bit body and blades, wherein the blades are fixedly connected with the drill bit body or integrally formed, cutting teeth are arranged on the blades, and a gauge protection section is further arranged on the blades.

2. A die cut PDC bit according to claim 1 wherein the transmission is a cam mechanism.

3. A die cut PDC bit according to claim 1, wherein the transmission is a gear mechanism.

4. The PDC cutter of claim 1, wherein the rolling elements comprise cones, rollers.

5. A PDC cutter according to claim 1 wherein the impact rod is provided with a resilient element; the elastic element comprises a spring, a disc spring and rubber; the elastic element is used for realizing the rebound of the impact device after the impact is finished.

6. A PDC cutter according to claim 1 wherein the impact teeth are disposed forwardly or rearwardly of the cutter teeth.

7. A die-cut PDC bit according to claim 1 wherein the blades are provided with a bearing support, the percussive assembly being connected to the drive assembly via the bearing support.

8. The PDC cutter of claim 1, wherein the percussive teeth comprise tapered teeth, wedge teeth, spoon teeth, ball teeth; the material of the impact tooth comprises artificial polycrystalline diamond, natural diamond, hard alloy, ceramic and cubic boron nitride.

Technical Field

The invention relates to the technical fields of oil and gas drilling engineering, mining engineering, geological drilling, tunnel engineering and the like, in particular to a punching PDC drill bit.

Background

A drill bit is a tool that directly contacts rock during drilling and breaks the rock by cutting, impacting, etc. PDC (Polycrystalline Diamond Compact) bits, which are an important type of existing bit technologies, are increasingly used in oil drilling, geological and even construction. The PDC drill bit mainly cuts rock through cutting teeth arranged on the drill bit, can obtain ideal drilling rate in soft to medium hard strata, and is widely applied to oil and gas drilling.

With the development of shallow oil and gas resources being almost exhausted, the emphasis of oil and gas exploration and development gradually shifts to deep-layer, deep-sea and unconventional oil and gas (including shale gas). Typically, the rock material of deep formations is hard, abrasive and poorly drillable. PDC bits, drilling in these formations, often fail to achieve high rates of penetration, one of the most important reasons being limited by the cutting tooth's penetration capability. Particularly, as the depth of the stratum increases, the complexity of the stratum is higher and higher, such as a hard-plastic stratum, a hard-brittle stratum, a soft-hard interlayer, a gravel-containing stratum and the like, the cutting teeth cannot effectively bite into the stratum, the drilling efficiency is low, and the rapid abrasion of the cutting teeth is easily caused. Excessive wear of the cutting teeth increases the workload of adjacent teeth, and consequently, cascading failure of the cutting teeth occurs, and once the cutting teeth fail in a larger area, the cutting ability of the drill bit is substantially lost.

In order to solve the problems of poor drill bit invasion capacity, low rock breaking efficiency, short service life and the like in difficult-to-drill stratum, workers of scientific research units and drill bit production enterprises try to use impacter tools (such as axial impacters and torsional impacters) together with drill bits. By the method, the drill bit generates small impact in the drilling process so as to realize the sudden stress application of the cutting teeth in the action process with the rock, the rock stress at the bottom of the well is greatly released, and the cutting teeth biting capacity is improved. However, the impact generated by the impactor acts directly on the entire drill bit. Generally, the cutting teeth mounted on the drill bit are polycrystalline diamond compacts, the impact resistance of the cutting teeth is relatively weak, and when impact load of an impactor is applied to the drill bit, the impact between the cutting teeth on the drill bit and rocks is easy to cause failure such as breaking-off of part of the cutting teeth. Under the circumstances, the southwest oil university proposes an impact-skiving composite drill bit (202659151U) which increases the working life of the drill bit while increasing the cutting tooth penetration capability by applying the impact generated by the impactor directly to the impact cutting structure rather than directly to the entire drill bit. However, the above impact rock breaking techniques are all the combination of the impactor tool and the rock breaking drill bit, and the increase of impact equipment raises the drilling cost.

Disclosure of Invention

The invention aims to provide a punching PDC drill bit, wherein the PDC drill bit is provided with an impact unit, so that the impact crushing or the pre-damage of a stratum can be realized without independently preparing an impactor tool, the rock crushing efficiency is improved, and the cost is saved.

The invention is realized by the following steps:

a punching PDC drill bit comprises a drill bit body and blades, wherein the blades are fixedly connected with the drill bit body or integrally formed, cutting teeth are arranged on the blades, and a diameter protection section is arranged on each blade.

In the structure, the rolling bodies of the impact unit are contacted with rocks in the rock breaking process to generate rotation torque to rotate. The rolling elements are typically cone structures, roller structures, rollers. The autorotation of the rolling body realizes that the impact device impacts broken rocks or pre-damages the rocks along the preset impact direction through the transmission device, and the cutting teeth on the blades have low energy consumption and high efficiency when crushing the weakened strata. On the one hand, the impact unit can well assist the cutting teeth on the drill bit to break rocks, prolong the service life of the cutting teeth, and further prolong the sustainable and efficient drilling capability of the drill bit. On the other hand, the impact formed by the impact unit only depends on the revolution of the drill bit, and tools such as an impactor and the like do not need to be arranged independently, so that the drilling cost is saved. And finally, the rolling body is arranged at the diameter-protecting section of the drill bit, so that contact supporting points of the drill bit and the well wall are increased, the vibration of the drill bit in the drilling process can be obviously reduced, and meanwhile, the working torque of the drill bit in the drilling process can be obviously reduced by the rolling body.

The distance L between the outer contour of the rolling element and the gauge section is explained by combining fig. 7, in a bottom-hole overlay diagram, the outer envelope line of the rolling element is the outer contour line, and the closest distance between the outer contour line and the gauge section is L.

The direction of impact refers to the direction of motion of the impact tooth in the bottom hole overlay, typically contained within the coverage area (BS) of the cutting tooth on the blade, as shown in fig. 7. Obviously, the direction of impact is not set at will, but should be set with the core purpose of breaking or damaging the rock.

The bottom hole covering tooth distribution diagram refers to that in any axial plane passing through the central line of the drill bit, the cutting profiles of the cutting teeth rotate around the central line of the drill bit and form an intersection line with the axial plane, the intersection line is a cutting profile line, and the cutting profile lines of all the cutting teeth are gathered together to form the bottom hole covering tooth distribution diagram, which is shown in fig. 7. The bottom hole covering tooth distribution diagram directly reflects the important parameters of the positioning radius, the positioning height and the like of the cutting tooth. Similarly, the forming principle of the coverage map of a single blade is similar, and the description is omitted.

The impact teeth can be conical teeth, wedge-shaped teeth, spoon-shaped teeth, spherical teeth and the like, and the materials of the impact teeth comprise artificial polycrystalline diamond, natural diamond, hard alloy, ceramic, cubic boron nitride and the like. The connection mode of the impact teeth and the impact rod can be threaded connection, interference fit, welding, integral forming or the like.

In a preferred embodiment of the present invention, the transmission is a cam mechanism. The implementation and transmission principle of the cam mechanism will be described with reference to fig. 3, and the cam mechanism includes a transmission shaft, a cam body at the shaft end, and a convex body on the cam body. The rolling body is fixedly connected with the transmission shaft or integrally formed, and the convex body on the shaft end cam body and the impact rod in the impact device form a cam pair in the rotation process of the transmission shaft, so that the rotation of the rolling body can realize the impact of the impact device along the preset direction through the cam mechanism. The cam has simple structure, safety, reliability and easy implementation.

In a preferred embodiment of the present invention, the transmission is a gear mechanism. The realization and transmission principle of the gear mechanism are explained by combining with the attached figure 9, the gear mechanism comprises a transmission shaft, a transmission gear, a driven gear and a convex body on the driven gear, the transmission shaft is fixedly connected with or integrally formed with the rolling body, and the transmission gear is fixedly connected with or integrally formed with the transmission shaft. When the impact device works, the rolling body drives the transmission shaft and the transmission gear at the bottom end of the transmission shaft to rotate, the driven gear is meshed with the transmission gear and rotates, and the convex body on the driven gear and the impact rod in the impact device form a cam pair to realize impact of the impact teeth towards the impact direction. The gear transmission is stable and easy to realize.

In a preferred embodiment of the present invention, the rolling elements include cones, rollers, and rollers.

As a preferred embodiment of the present invention, the impact bar is provided with an elastic element, which may be a spring, a disc spring, rubber, or the like, and the elastic element is used to realize the rebound of the impact bar after the impact is completed. For the impact unit, after the impact rod completes one impact, the impact rod needs to return in time, and if not, the impact rod cannot complete the next impact smoothly. The elastic element arranged on the impact rod is easy to realize, and the structure is simple and reliable.

As a preferable aspect of the present invention, the impact teeth are provided in front of or behind the cutting teeth. It is apparent that those skilled in the art will readily appreciate that the impact teeth are of the same orbital design as the cutting teeth.

As a preferable scheme of the invention, the blade is provided with a supporting seat, and the impact device is connected with the transmission device through the supporting seat.

The invention at least comprises the following beneficial effects:

1. the impact unit realizes impact under the condition of relying on the rotation of the drill bit without being provided with an impactor tool, so that the cost is saved. The impact unit is arranged at the gauge protection position of the drill bit, and the rolling bodies on the impact unit are in contact with the well wall, so that contact supporting points with the well wall are increased, vibration in the drilling process is reduced, and meanwhile, the working torque in the drilling process of the drill bit can be reduced;

2. the impact action of the impact unit can impact and crush or pre-damage the rock, the energy consumption of the cutting teeth of the drill bit is low when the weakened stratum is crushed, and the probability of tooth breakage failure of the cutting teeth is reduced while the rock crushing efficiency is improved;

3. when the transmission device in the impact unit adopts a cam mechanism or a gear transmission mechanism, the impact unit has simple structure, safety, reliability and easy implementation.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic diagram of a first embodiment of a die-cut PDC bit according to the present invention.

Fig. 2 is a top view of fig. 1.

Fig. 3 is a schematic structural diagram of an impact unit on a die-cut PDC bit according to a first embodiment of the present invention.

Fig. 4 is a schematic structural view of a punching unit on a punching PDC bit according to a first embodiment of the present invention, in which a drive shaft and a cam body have the same diameter.

Fig. 5 is a partial cross-sectional view of fig. 2.

Fig. 6 is a schematic structural diagram of a roller as a rolling body in an impact unit according to a first embodiment of the present invention.

Fig. 7 is a schematic diagram of the impact range of the impact tooth and the distance L between the rolling element and the gauge in the impact unit according to the first embodiment of the present invention.

Fig. 8 is a schematic structural view of an impact unit in which impact teeth are wedge-shaped teeth according to a first embodiment of the present invention.

Fig. 9 is a schematic structural diagram of an impact unit provided in a second embodiment of the present invention, wherein the transmission structure is a gear mechanism.

Fig. 10 is a schematic diagram of a third embodiment of a PDC piercing bit according to the present invention, wherein the blades have supporting seats.

FIG. 11 is a schematic structural view of a third embodiment of the present invention in which the impact teeth and cutting teeth have the same orbital design.

Fig. 12 is a schematic illustration of the principle of breaking rock with the same orbital design of the impact and cutting teeth of fig. 11.

Icon: 1-PDC drill bits; 2-a drill bit body; 3-a blade; 31-a cutting tooth; 32-impingement holes; 4-diameter-keeping section; 40-maintaining the diameter line; 5-a support; 51-a support matrix; 52-a support conjugate; 53-drive hole; 6-an impact unit; 61-rolling bodies; 62-a transmission; 63-an impact device; 610-outer contour of rolling body; 611-rollers; 621-a transmission shaft; 622-convex body; 623-a cam body; 631-impact teeth; 632-impact bar; 7-a support seat; 8-a resilient element; 81-spring; 82-disc spring element; 91-a transmission gear; 92-driven gear.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

The first embodiment:

referring to fig. 1-8, an embodiment of the present invention provides a PDC bit 1 for blanking.

The utility model provides a die-cut PDC drill bit 1, includes drill bit body 2, wing 3, and wing 3 and drill bit body 2 are fixed continuous or integrated into one piece, are provided with cutting teeth 31 on the wing 3, are provided with on the wing 3 and protect footpath section 4, extend from wing section 4 department has support 5, are provided with impact unit 6 on the support 5.

Referring to fig. 3-5, the impact unit 6 is composed of a rolling body 61, a transmission device 62 and an impact device 63, the rolling body 61 can rotate around its axis, in a shaft bottom overlay (see fig. 7), the outer contour 610 of the rolling body 61 is spaced from the gauge section 4 (gauge line 40) in the radial direction by L in the range of-d/4 ≤ L ≤ d/4, d is the diameter of the cutting teeth, the impact device 63 is composed of an impact rod 632 and at least one impact tooth 631, the rolling body 61 can impact the impact device 63 in the impact direction through the transmission device 62, the support body 5 is provided in a split type (a part is a base body 51 and a part is a matching body 52) for facilitating the installation of the impact unit 6, and referring to fig. 5.

In the embodiment of the invention, the rolling body 61 of the impact unit 6 is of a cone structure, and the cone contacts with rock to generate a rotation torque and rotate in the rock breaking process. The rolling elements 61 may also be rollers (see fig. 6) or rollers 611 (see fig. 10).

Referring to fig. 3-5, the driving device 62 is a cam mechanism, and the cam mechanism includes a driving shaft 621, a cam body 623 at the shaft end, and a convex body 622 on the cam body 623. The rolling body 61 is fixedly connected with or integrally formed with a transmission shaft 621, the transmission shaft 621 is arranged in a transmission hole 53 of the support body 5, a convex body 622 on the shaft end cam body 623 and an impact rod 632 in the impact device 63 form a cam pair during rotation, and the impact rod 632 is arranged in an impact hole 32 of the blade, so that the rotation of the rolling body 61 can realize the impact of the impact device 63 along a preset direction through a cam mechanism. The connection between the cam body 623 and the transmission shaft 621 includes over-hard fitting, screwing, welding, integral molding, etc. The cam has simple structure, safety, reliability and easy implementation. Referring to fig. 4, the transmission shaft 21 and the cam body 623 have the same outer diameter. For the impact unit, after the impact teeth 631 complete one impact, the impact teeth need to return, and if the impact teeth cannot complete the next impact (stroke) smoothly, in order to achieve the purpose, the impact rod 632 in the embodiment of the present invention is provided with the elastic element 8, the elastic element 8 may be a spring 81 (see fig. 4), a disc spring 82 (see fig. 9), rubber, or the like, and the elastic element 8 is used for realizing the rebound after the impact device 63 completes the impact. The elastic element 8 provided on the striking rod 632 in this embodiment is easy to implement and has a simple and reliable structure.

The impact teeth 631 may be tapered teeth (see fig. 1-5, 9, 10), wedge-shaped teeth (see fig. 8), spoon-shaped teeth, ball-shaped teeth, etc., and the impact teeth 631 may be made of artificial polycrystalline diamond, natural diamond, cemented carbide, ceramic, cubic boron nitride, etc. The connection between the striking teeth 631 and the striking rod 632 may be a threaded connection, an interference fit, a welding connection, or an integral molding, in this example, an integral molding.

The PDC drill bit provided by the embodiment of the invention has the beneficial effects that:

1. the impact unit 6 realizes impact under the condition of relying on the rotation of the drill bit without being provided with an impactor tool, and the cost is saved. The impact unit 6 is arranged at the gauge 4 of the drill bit, and the rolling bodies 61 on the impact unit are contacted with the well wall, so that contact supporting points of the drill bit and the well bottom are increased, vibration of the drill bit in the drilling process is weakened, and working torque of the drill bit in the drilling process can be reduced;

2. the impact action of the impact unit 6 can impact and break rock or pre-damage rock, the energy consumption of the cutting teeth 31 on the drill bit is low when the weakened stratum is broken, and the probability of tooth breaking failure of the cutting teeth 31 is reduced while the rock breaking efficiency is improved;

3. the transmission device 62 in the impact unit 6 is a cam mechanism, and has the advantages of simple and easy structure, safety, reliability and easy implementation.

Second embodiment:

the embodiment of the present invention provides a punching PDC drill bit, and the structure of this PDC drill bit 1 is substantially the same as that of the PDC drill bit 1 in the first embodiment, except that: referring to fig. 9, in the present embodiment, the transmission device is a gear mechanism, and includes a transmission shaft 621, a transmission gear 91, a driven gear 92, and a convex body 622 on the driven gear 92, wherein the transmission shaft 621 is fixedly connected to or integrally formed with the rolling body 61, and the transmission gear 91 is fixedly connected to or integrally formed with the transmission shaft 621. During operation, the rolling body 61 drives the transmission shaft 621 and the transmission gear 91 at the bottom end of the transmission shaft 621 to rotate, the driven gear 92 is meshed with the transmission gear 91 and rotates, the convex body 622 on the driven gear 92 and the impact rod 632 in the impact device 63 form a cam pair, and impact of the impact teeth 631 towards the impact direction is realized. The gear transmission is stable and easy to realize.

The third embodiment:

the embodiment of the present invention provides a punching PDC drill bit, and the structure of this PDC drill bit 1 is substantially the same as that of the PDC drill bit 1 in the first embodiment, except that: referring to fig. 10-12, a support base 7 is disposed on the blade 3. The impact rod 632 is connected with the transmission device 62 through the support seat 7. It is easily conceivable that the support 7 can be arranged in front of or behind the blade 3. When positioned in front, the impact teeth 631 are located in front of the cutting teeth 31 on the blades 3. In the case of the impact tooth 631 arranged in front of the cutting tooth 31, a more advantageous embodiment is to design the impact tooth 631 with the cutting tooth 31 in the same orbit, see fig. 11 and 12. When the impact teeth 631 and the cutting teeth 31 are designed in the same orbit, the two have the same positioning radius R in a bottom hole coverage map, the impact teeth 631 firstly complete impact on the rock, the rock is pre-damaged, micro cracks are generated inside the rock, and the energy consumption for crushing the damaged stratum by the cutting teeth 31 following the rotation of the orbit is greatly reduced.