CN111411897B

CN111411897B - Punching PDC drill bit

Info

Publication number: CN111411897B
Application number: CN202010463890.5A
Authority: CN
Inventors: 张春亮; 包泽军; 杨明; 杨迎新; 雷艳虹; 段玉涛; 代洋
Original assignee: Chengdu Weiyi Petroleum Technology Co ltd; Southwest Petroleum University
Current assignee: Chengdu Weiyi Petroleum Technology Co ltd; Southwest Petroleum University
Priority date: 2020-05-28
Filing date: 2020-05-28
Publication date: 2023-07-14
Anticipated expiration: 2040-05-28
Also published as: CN111411897A

Abstract

A punching PDC drill bit comprises a drill bit body and a blade, wherein the blade is fixedly connected with the drill bit body or integrally formed, cutting teeth are arranged on the blade, a gauge protection section is further arranged on the blade, a supporting body is extended from the gauge protection section, an impact unit is arranged on the supporting body, and the impact unit 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 gauge section of the blade in the radial direction is L, the range of the L/L is more than or equal to-d/4 and less than or equal to d/4, and d is the diameter of the cutting tooth; the impact device consists of an impact rod and at least one impact tooth. According to the invention, an impactor tool is not required to be arranged when the impact rock breaking is realized, so that the drilling cost is saved, the invasion capacity of the cutting teeth is improved, and the rock breaking efficiency is improved.

Description

Punching PDC drill bit

Technical Field

The invention relates to the technical fields of petroleum and natural 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, impact, or the like. PDC (Polycrystalline Diamond Compact polycrystalline diamond compact) bits are an important category in the prior art of bits and are increasingly being used in petroleum drilling, geology, and even construction engineering. The PDC drill bit is used for rock breaking in a mode of mainly cutting through cutting teeth arranged on the drill bit, can obtain ideal drilling speed in soft to medium hard stratum, and is widely applied to oil and gas drilling.

With the depletion of shallow hydrocarbon resources, the focus of hydrocarbon exploration development is gradually turned to deep, deep sea, unconventional hydrocarbon (including shale gas). In general, rock materials of deep formations are hard, strong in abrasiveness, and poor in drillability. PDC bits, which drill in these formations, often fail to achieve high rates of penetration, one of the most important of which is limited by the penetration capacity of the cutter. In particular, as the depth of the formation increases, the complexity of the formation increases, such as hard-plastic formations, hard-brittle formations, hard-soft formations, gravel-containing formations, etc., the cutting teeth do not effectively penetrate the formation, drilling efficiency is low, and rapid wear of the cutting teeth is easily caused. After excessive wear of the cutting teeth, the workload of adjacent teeth is increased, further interlocking failure of the cutting teeth occurs, and once the cutting teeth in a larger area fail, the cutting capability of the drill bit is basically lost.

In order to solve the problems of poor bit invasion capability, low rock breaking efficiency, short service life and the like in difficult-to-drill stratum, workers in various scientific research institutions and bit manufacturers try to use impactor tools (such as axial impactors and torsional impactors) together with the bit. By the method, the drill bit generates small impact in the drilling process, so that the sudden stress applied to the cutting teeth in the process of acting with rock is achieved, the rock stress at the bottom of the well is greatly released, and the penetration capacity of the cutting teeth is improved. However, the impact of the impactor acts directly on the entire bit. In general, cutting teeth mounted on a drill bit are polycrystalline diamond compacts, the impact resistance of the cutting teeth is relatively weak, and when the impact load of an impactor acts on the drill bit, the cutting teeth on the drill bit and rock are impacted to easily cause collapse and other failures of part of the cutting teeth. In this case, a composite impact-scraping drill bit (202659151U) is proposed by southwest petroleum university, which directly acts the impact generated by the impactor on the impact cutting structure, but not on the whole drill bit, thereby improving the intrusion capability of the cutting teeth and prolonging the service life of the drill bit. However, the above impact rock breaking techniques are all combinations of an impactor tool and a rock breaking bit, and the increase of impact equipment increases the drilling cost.

Disclosure of Invention

The invention aims to provide a punching PDC drill bit, wherein an impact unit is arranged on the PDC drill bit, impact crushing or pre-damaging of a stratum can be realized without independently arranging an impactor tool, the rock breaking efficiency is improved, and the cost is saved.

The invention is realized in the following way:

the die-cut 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 gauge protection sections are arranged on the blades; the rolling body can rotate around the axis of the rolling body, and the distance L between the outer contour of the rolling body and the gauge section in the radial direction is in the range of-d/4 to be less than or equal to L to be less than or equal to d/4, wherein d is the diameter of the cutting tooth; the impact device consists of an impact rod and at least one impact tooth; the rotation of the rolling bodies can realize the impact of the impact device along the impact direction through the transmission device.

In the above structure, the rolling element of the impact unit contacts with the rock to generate a rotational moment to rotate during the rock breaking process. The rolling elements are typically cone structures, roller structures, rollers. The rotation of the rolling bodies realizes that the impact device impacts the broken rock or pre-damaged rock along the preset impact direction through the transmission device, and the cutting teeth on the blades have low energy consumption and high efficiency when breaking the weakened stratum. On the one hand, the impact unit can well assist the cutting teeth on the drill bit to break rock, prolong the service life of the cutting teeth, and further prolong the sustainable high-efficiency 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 are not required to be independently arranged, so that the drilling cost is saved. Finally, the rolling bodies are arranged on the gauge section of the drill bit, so that contact supporting points of the drill bit and a well wall are increased, vibration energy of the drill bit in the drilling process is obviously reduced, and meanwhile, working torque of the drill bit in the drilling process can be obviously reduced by the rolling bodies.

The distance L of the rolling body outer contour from the gauge section is described with reference to fig. 7. In the bottom hole coverage map, an outer envelope line of the rolling body is an outer contour line, and the nearest distance between the outer contour line and the gauge section is L.

The direction of impact refers to the direction of movement of the impact teeth in the bottom hole coverage map, typically contained within the coverage (BS) of the cutting teeth on the blades, as shown in fig. 7. Obviously, the impact direction is not set at will, but should be set for the core purpose of breaking or damaging the rock.

The bottom hole coverage tooth distribution diagram refers to that in any axial plane passing through the central line of the drill bit, the cutting profile of the cutting tooth rotates around the central line of the drill bit and forms an intersection line with the axial plane, the intersection line is the cutting profile line, and the cutting profile lines of all the cutting teeth are collected together to form the bottom hole coverage tooth distribution diagram, as shown in fig. 7. The bottom hole coverage tooth distribution diagram directly reflects important parameters such as the positioning radius, the positioning height and the like of the cutting tooth. Similarly, the coverage of the single blade is formed in a similar manner, and will not be described again.

The impact teeth can be cone teeth, wedge teeth, spoon teeth, spherical teeth and the like, and the materials of the impact teeth comprise artificial polycrystalline diamond, natural diamond, hard alloy, ceramics, cubic boron nitride and the like. The connection mode of the impact teeth and the impact rod can be a threaded connection mode, an interference fit mode, a welding mode, an integrated forming mode or the like.

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

As a preferred embodiment of the invention, the transmission is a gear mechanism. The realization and transmission principle of the gear mechanism are described by referring to fig. 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 bodies drive the transmission shafts and the transmission gears at the bottom ends of the transmission shafts to rotate, the driven gears are meshed with the transmission gears and rotate, the convex bodies on the driven gears and the impact rod in the impact device form a cam pair, and impact teeth impact towards the impact direction. The gear transmission is stable and easy to realize.

As a preferable mode of the invention, the rolling bodies comprise roller cones, rollers and rollers.

As a preferable scheme of the invention, the impact rod is provided with an elastic element, and the elastic element can be a spring, a disc spring, rubber and the like and is used for realizing rebound of the impact rod after impact. 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 successfully complete the next impact. The impact rod is provided with the elastic element, so that the impact rod is easy to realize, and has a simple and reliable structure.

As a preferred embodiment of the present invention, the impact teeth are provided in front of or behind the cutting teeth. It is apparent to those skilled in the art that the impact teeth are co-orbital with 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 self rotation of the drill bit without being provided with an impactor tool, thereby saving cost. The impact unit is arranged at the gauge of the drill bit, the rolling body on the impact unit is contacted with the well wall, contact supporting points with the well wall are increased, vibration in the drilling process is reduced, and meanwhile working torque in the drilling process of the drill bit can be reduced;

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

3. when the transmission device in the impact unit adopts a cam mechanism or a gear transmission mechanism, the impact unit has the advantages of 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 needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some examples of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of a die cut PDC drill bit provided in accordance with a first embodiment of the present invention.

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

FIG. 3 is a schematic view of the structure of an impact unit on a die cut PDC bit provided in accordance with a first embodiment of the present invention.

FIG. 4 is a schematic illustration of the structure of an impact unit on a die-cut PDC bit provided in accordance with a first embodiment of the present invention in which the drive shaft has the same diameter as the cam body.

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

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

Fig. 7 is a schematic view of the impact range of the impact teeth and the distance L between the rolling elements and the gauge section in the impact unit according to the first embodiment of the present invention.

Fig. 8 is a schematic structural view of the impact teeth in the impact unit according to the first embodiment of the present invention.

Fig. 9 is a schematic structural view of an impact unit according to a second embodiment of the present invention, wherein the transmission structure is a gear mechanism.

FIG. 10 is a schematic view of a die cut PDC bit provided in accordance with a third embodiment of the present invention in which support seats are provided on blades.

Fig. 11 is a schematic view of the design of the impingement teeth and cutting teeth in-orbit in a third embodiment of the present invention.

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

Icon: 1-PDC drill bit; 2-a bit body; 3-blades; 31-cutting teeth; 32-impingement holes; 4-gauge section; 40-gauge wire; 5-a support; 51-a support matrix; 52-a support complex; 53-a drive hole; a 6-impingement unit; 61-rolling elements; 62-transmission device; 63-an impact device; 610-rolling the outer profile; 611-rollers; 621-a transmission shaft; 622-convex body; 623-a cam body; 631-impact teeth; 632-impact bar; 7-a supporting seat; 8-an elastic element; 81-springs; 82-disc spring element; 91-a transmission gear; 92-driven gear.

Detailed Description

For the purpose of making 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 clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention. Thus, the following detailed description of the embodiments of the invention, as 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, based on the embodiments of the invention, which are apparent to those of ordinary skill in the art without inventive faculty, are intended to be within the scope of the invention.

First embodiment:

referring to fig. 1-8, a die cut PDC bit 1 is provided in accordance with an embodiment of the present invention.

The utility model provides a die-cut PDC drill bit 1, includes bit body 2, wing 3, and the fixed continuous or integrated into one piece of wing 3 and bit body 2 is provided with cutting tooth 31 on the wing 3, is provided with gauge section 4 on the wing 3, extends from wing section 4 department has supporter 5, is provided with impact unit 6 on the supporter 5.

Referring to fig. 3 to 5, the impact unit 6 is composed of a rolling body 61, a transmission 62 and an impact device 63; the rolling element 61 can rotate around the axis of the rolling element 61, and in the bottom hole coverage diagram (refer to fig. 7), the distance between the outer contour 610 of the rolling element 61 and the gauge section 4 (gauge line 40) in the radial direction is L, the range is-d/4-L-d/4, and d is the diameter of the cutting teeth; the impact device 63 consists of an impact rod 632 and at least one impact tooth 631; the rotation of the rolling bodies 61 enables the impact device 63 to impact in the impact direction by means of the transmission device 62. To facilitate the mounting of the impact unit 6, the support body 5 is provided as a separate body (partly a base body 51 and partly a mating body 52), see fig. 5.

In the embodiment of the invention, the rolling bodies 61 of the impact unit 6 are of a roller cone structure, and the roller cones are contacted with rock to generate a rotational moment to rotate in the rock breaking process. The rolling elements 61 may also be rollers (see fig. 6) or rollers 611 (see fig. 10).

With continued reference to fig. 3-5, the transmission 62 is a cam mechanism that includes a transmission shaft 621, a cam body 623 at the end of the shaft, and a protrusion 622 on the cam body 623. The rolling body 61 is fixedly connected with the transmission shaft 621 or integrally formed, the transmission shaft 621 is arranged in the transmission hole 53 of the supporting body 5, the convex body 622 on the shaft end cam body 623 and the impact rod 632 in the impact device 63 form a cam pair during rotation, and the impact rod 632 is arranged in the 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 the preset direction through the cam mechanism. The connection between the cam body 623 and the drive shaft 621 includes an excessively hard fit, a threaded connection, welding, integral molding, etc. The cam has simple structure, safety and reliability and is easy to implement. Referring to fig. 4, the driving shaft 21 and the cam body 623 have the same outer diameter. For the impact unit, after the impact teeth 631 complete an impact, a return stroke is required, and if the impact teeth cannot successfully complete the next impact (stroke), in order to achieve this purpose, the impact rod 632 in the embodiment of the present invention is provided with an elastic element 8, where the elastic element 8 may be a spring 81 (see fig. 4), a disc spring 82 (see fig. 9), rubber, etc., and the elastic element 8 is used to achieve rebound after the impact device 63 completes the impact. The elastic element 8 provided on the impact rod 632 in this embodiment is easy to implement and has a simple and reliable structure.

The impact teeth 631 may be cone teeth (see fig. 1-5, 9, and 10), wedge teeth (see fig. 8), spoon teeth, ball teeth, etc., and the impact teeth 631 may be made of artificial polycrystalline diamond, natural diamond, cemented carbide, ceramics, cubic boron nitride, etc. The connection mode of the impact teeth 631 and the impact rod 632 can be a threaded connection mode, an interference fit mode, a welding mode, an integral forming mode or the like, and in this example, the integral forming mode is adopted.

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

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

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

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 die-cut PDC bit, and the PDC bit 1 has substantially the same structure as the PDC bit 1 of the first embodiment, and differs in 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 protrusion 622 on the driven gear 92, wherein the transmission shaft 621 is fixedly connected or integrally formed with the rolling body 61, and the transmission gear 91 is fixedly connected or integrally formed with the transmission shaft 621. In 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.

Third embodiment:

the embodiment of the present invention provides a die-cut PDC bit, and the PDC bit 1 has substantially the same structure as the PDC bit 1 of the first embodiment, and differs in that: referring to fig. 10 to 12, a support seat 7 is provided on the blade 3. The impact rod 632 is connected to the transmission 62 through the support 7. It is easily conceivable that the support seat 7 may be provided in front of or behind the blade 3. When provided in front, the impingement teeth 631 are located in front of the cutting teeth 31 on the blade 3. Of the arrangements in which the impact teeth 631 are disposed in front of the cutting teeth 31, there is a preferred arrangement in which the impact teeth 631 are co-orbital with the cutting teeth 31, see fig. 11 and 12. When the impact teeth 631 and the cutting teeth 31 are designed in the same track, two of the impact teeth 631 and the cutting teeth 31 have the same positioning radius R in the bottom hole coverage diagram, the impact teeth 631 impact the rock first, the rock forms pre-damage, microcracks are generated inside the rock, and the energy consumption for breaking the damaged stratum by the cutting teeth 31 rotating along the track is greatly reduced.

Claims

1. The die-cut 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 gauge protection sections are further arranged on the blades; the rolling body can rotate around the axis of the rolling body, the rolling body is contacted with rock to generate a rotation moment in the rock breaking process, the self-rotation energy rotates around the axis of the rolling body, and the range of the distance L between the outer contour of the rolling body and the gauge protection section in the radial direction is as follows: d/4.ltoreq.L.ltoreq.d/4, where d is the cutting tooth diameter; the impact device consists of an impact rod and at least one impact tooth; the rotation of the rolling bodies can realize the impact of the impact device along the impact direction through the transmission device.

2. The die cut PDC bit of claim 1 wherein the transmission is a cam mechanism.

3. The die cut PDC bit of claim 1 wherein the transmission is a gear mechanism.

4. The die cut PDC bit of claim 1 wherein the rolling bodies are roller cones, rollers or rollers.

5. The die cut PDC bit of claim 1 wherein the impact rod is provided with resilient elements thereon; the elastic element is a spring, a disc spring or rubber; the elastic element is used for realizing rebound after the impact device finishes impact.

6. The die cut PDC bit of claim 1 wherein the impact teeth are disposed either forward or aft of the cutting teeth.

7. The die-cut PDC bit of claim 1 wherein the blades are provided with support seats through which the impact device is coupled to the transmission.

8. The die cut PDC bit of claim 1 wherein the impact teeth are cone teeth, wedge teeth, scoop teeth or ball teeth; the impact teeth are made of artificial polycrystalline diamond, natural diamond, hard alloy, ceramic or cubic boron nitride.