CN114427350A - Drill bit for breaking rock - Google Patents
Drill bit for breaking rock Download PDFInfo
- Publication number
- CN114427350A CN114427350A CN202011007175.7A CN202011007175A CN114427350A CN 114427350 A CN114427350 A CN 114427350A CN 202011007175 A CN202011007175 A CN 202011007175A CN 114427350 A CN114427350 A CN 114427350A
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- China
- Prior art keywords
- drilling
- sleeve
- drill bit
- teeth
- rock
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- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/42—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
- E21B10/43—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits characterised by the arrangement of teeth or other cutting elements
Abstract
The invention relates to a drill bit for breaking rock, comprising: a drilling sleeve extending axially, the drilling sleeve configured with a plurality of sleeve drilling teeth for breaking rock, the drilling sleeve configured with a hollow space for receiving a rock string; and a plurality of inboard crushing teeth axially spaced from an end face of the working end of the drilling sleeve, the plurality of inboard crushing teeth being located within the hollow space of the drilling sleeve; wherein, during drilling, the formation opposite the hollow space of the drilling sleeve is not fractured by the sleeve drilling teeth of the drilling sleeve such that the rock pillar is receivable within the hollow space, the rock pillar and the drilling sleeve cooperating to define a lateral position of the drill bit, the plurality of inner fracturing teeth fracture the rock pillar when the rock pillar extends to the plurality of inner fracturing teeth. Vibration damping can be effectively achieved by such a drill.
Description
Technical Field
The invention relates to the technical field of petroleum drilling, in particular to a drill bit for breaking rock.
Background
The drill bit is the primary tool for breaking rock. The quality of the drill bit, the drill bit's lithology (e.g., hardness), and other drilling process conditions are adapted to directly affect drilling speed, drilling quality, drilling costs, and the like. For example, if the formation hardness is too great relative to the drill bit, very significant lateral and axial vibrations may be induced, resulting in severe tripping phenomena. There are many problems with current drilling operations and the development of drill bits is still in progress.
Existing drill bits often have a plurality of jaws surrounding a body, with a respective crushing tooth provided on each jaw for crushing formation rock contacted thereby. However, for very hard formations, these prior art bits generate very large vibrations.
CN107762417A discloses a vibration-proof damage-proof PDC drill bit with a protection function of drilling equipment. The drill is vibration-proof by providing movable members such as a piston and a return spring. However, these moving parts are easily damaged during use and have poor reliability.
CN109538128A discloses a vibration-proof PDC drill bit. The drill bit improves the working stability of the drill bit by enabling each cutting tooth to have a unique placing angle, so that the vibration reduction function of the drill bit is improved. However, this arrangement has very limited adaptability to downhole complications and does not continue to provide effective damping in practice.
There is therefore a need for a drill bit for breaking rock that is capable of effective vibration damping.
Disclosure of Invention
In view of the above problems, the present invention proposes a drill bit for breaking rock. Vibration damping can be effectively achieved by such a drill.
According to the invention, a drill bit for breaking rock is proposed, comprising: a drilling sleeve extending axially, the drilling sleeve configured with a plurality of sleeve drilling teeth for breaking rock, the drilling sleeve configured with a hollow space for receiving a rock string; and a plurality of inboard crushing teeth axially spaced from an end face of the working end of the drilling sleeve, the plurality of inboard crushing teeth being located within the hollow space of the drilling sleeve; wherein, during drilling, the formation opposite the hollow space of the drilling sleeve is not fractured by the sleeve drilling teeth of the drilling sleeve such that the rock pillar is receivable within the hollow space, the rock pillar and the drilling sleeve cooperating to define a lateral position of the drill bit, the plurality of inner fracturing teeth fracture the rock pillar when the rock pillar extends to the plurality of inner fracturing teeth.
During the drilling process of the drill bit, the drilling sleeve firstly drills the stratum, so that a section of rock pillar can be kept in the hollow space. By cooperation of the rock string with the drilling sleeve, the lateral position of the drill bit can be defined, whereby lateral vibrations of the drill bit are attenuated or even avoided. The efficiency and speed of drilling can be effectively improved by avoiding transverse vibration. Meanwhile, the structural stability of the drill bit is improved, and the service life of the drill bit is prolonged. This can effectively reduce the cost of drilling.
In one embodiment, the drill bit further comprises an axially extending bit body having an orifice configured on a face of a working end thereof for distributing drilling fluid, the drilling sleeve extending axially from the working end of the bit body, the orifice communicating to the hollow space, wherein a plurality of radially extending grooves are configured at the working end of the drilling sleeve through which drilling fluid injected into the hollow space by the orifice can flow to an annulus external to the drill bit.
In one embodiment, the flutes comprise precession surfaces oriented toward a direction of rotation of the drill bit, and the plurality of sleeve drilling teeth comprise first sleeve drilling teeth projecting from the precession surfaces of the flutes.
In one embodiment, the cutting portion of the first sleeve drilling tooth extends axially at least partially beyond the end face of the working end of the drilling sleeve.
In one embodiment, an axially extending flow channel is formed on the inner side of the drilling sleeve, which flow channel communicates with the groove and through which drilling fluid entering the hollow space from the orifice can flow to the groove.
In one embodiment, the inner end of the groove has a smaller cross-section than the outer end, so that the groove has a radial shape.
In one embodiment, the plurality of box boring teeth includes a second box boring tooth projecting from an end face of the working end of the boring box.
In one embodiment, the end surface of the working end of the drilling sleeve is axially spaced from the inner breaker teeth by a distance sufficient to allow frictional forces between the rock pillar within the hollow space and the inner side of the drilling sleeve to avoid axial and torsional vibration of the drill bit.
In one embodiment, the drill bit further comprises: an axially extending bit body; and a plurality of inner crushing ridges circumferentially spaced apart from each other on an end surface of the working end of the bit body, the plurality of inner crushing teeth being provided on each inner crushing ridge.
In one embodiment, the drill bit further comprises: an axially extending bit body; and a plurality of outer crushing ridges circumferentially spaced apart from each other on the outer peripheral surfaces of the bit body and the drilling sleeve, each outer crushing ridge extending in an axial direction, a plurality of outer crushing teeth being provided on each outer crushing ridge.
The drill bit of the invention provides an idea of breaking the stratum in stages, namely: the method comprises the steps of firstly destroying a part of annular stratum rock to form a rock pillar, and then crushing the rock pillar. In the present invention, the engagement of the rock string with the drilling sleeve serves at least to attenuate lateral vibrations and in some cases even axial and/or torsional vibrations. By weakening the vibration, the occurrence of the phenomenon of jumping can be avoided, the drilling efficiency is effectively improved, and the drilling cost is reduced. The drill bit with the structure has strong adaptability, and can be generally suitable for a large number of stratum conditions without high customization. In addition, the drill bit has no movable part, has strong structural stability, is not easy to damage and has high reliability.
Drawings
The invention is described in more detail below with reference to the accompanying drawings. Wherein:
fig. 1 shows a schematic view of a drill bit for breaking rock according to an embodiment of the invention;
FIG. 2 shows a schematic side view of the drill bit of FIG. 1;
fig. 3 shows a schematic top view of the drill bit of fig. 1.
In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.
Detailed Description
The invention will be further explained with reference to the drawings.
Fig. 1 to 3 schematically show an embodiment of a drill bit 100 for breaking rock according to the invention.
The drill bit 100 includes a bit body 120 that is generally cylindrical. The connecting end of the bit body 120 is provided with a connecting threaded section (pin) 110 for connection with the rest of the drilling tool. A drilling sleeve 130 is attached to the working end of the bit body 120. The drilling sleeve 130 has a generally cylindrical shape and extends axially away from the working end of the bit body 120.
As shown in FIG. 1, the outer side of the drilling sleeve 130 may be aligned with the outer surface of the bit body 120. A cylindrical hollow space is formed inside the drilling sleeve 130. An orifice (e.g., a nozzle) 121 is provided on an end surface of the working end of the bit body 120, and the orifice 121 is located in the hollow space to communicate with the hollow space. During operation of the drill bit 100, drilling fluid (e.g., water) may be injected into the hollow space through the orifices 121. The effects of the drilling fluid include: (1) cooling the portion being drilled; (2) providing lubrication to the portion of the drill bit in contact with the rock; and (3) carry away the broken rock fragments from the hollow space and the location of the formation being drilled.
It should be understood that the orifice may have other arrangements as long as it communicates with the hollow space to enable injection of drilling fluid into the hollow space.
To facilitate the flow of drilling fluid from within the hollow space, to the annulus between the drill bit and the formation, and thus to the surface, a plurality of grooves 131 may be formed at the working end of the drill sleeve 130. These grooves 131 may extend radially through the side wall of the drilling sleeve 130 to provide communication between the hollow space and the annulus. For example, as shown in fig. 1 and 3, an end (inner end) of the groove 131 close to the hollow space has a smaller cross section, and an end (outer end) of the groove 131 far from the hollow space has a larger cross section, so that the groove has a radial shape. With this configuration, fluid carrying debris can flow quickly out of the drilling sleeve 130, thereby avoiding the retention and accumulation of debris.
In one embodiment, a plurality of flow channels (not shown) may be provided on the inside of the well sleeve 130. Each flow channel extends in the axial direction and communicates with a corresponding groove 131. Thereby facilitating the evacuation of the drilling fluid carrier rock debris out of the hollow space.
Additionally, a plurality of trepanning teeth, preferably a plurality of trepanning teeth, are provided at the working end of the drilling sleeve 130. For example, the plurality of trephine teeth may comprise a plurality of first trephine teeth 132. As shown in fig. 1, the first sleeve drilling teeth 132 are provided on and project relative to the precession plane of the flutes 131, thereby enabling cutting of the formation rock as the drill bit is rotated. The precession plane here refers to the side of the groove 131 oriented towards the direction of rotation R (see fig. 3).
In a preferred embodiment, the cutting portion of the first sleeve drilling tooth 132 extends at least partially axially beyond the end face 133 of the working end of the drilling sleeve 130. This facilitates the crushing of the formation rock by the first sleeve drilling tooth 132.
Alternatively or additionally, the plurality of box boring teeth may also include a second plurality of box boring teeth (not shown) that protrude relative to the end face 133 of the working end of the boring box 130. The plurality of second sleeve drilling teeth are spaced apart from one another. The formation rock is also effectively crushed by the second sleeve drilling tooth.
It will be appreciated that where second sleeve drilling teeth are provided, drilling fluid and rock debris may be displaced through the gaps between the spaced apart second sleeve drilling teeth. Thus, the grooves 131 and the first sleeve drilling teeth 132 may be omitted.
Additionally, the drill bit 100 may also include a plurality of inner crushing ridges 150 disposed on the face of the working end of the bit body 120. These inboard crush ridges 150 are circumferentially spaced from one another and are generally radially disposed. A plurality of inner crushing teeth 151 are provided on each inner crushing ridge 150. These inner crushing teeth 151 are provided on the precession end (i.e., the end oriented toward the direction of rotation R) of the inner crushing ridge 150. The inner crushing teeth 151 are used to crush the rock in the hollow space.
The inboard crushing teeth 151 and the inboard crushing ridge 150 may also be provided with other forms or configurations as desired.
In addition, the drill bit 100 may also include a plurality of outer crushing ridges 140 disposed on the outer side of the bit body 120. Each outer crushing ridge 140 extends in the axial direction. A plurality of outer crushing ridges 140 are arranged spaced apart from each other in the circumferential direction. As shown in FIG. 3, each outer breaker ridge 140 may also extend to the outer side of the drilling sleeve 130 and to near the working end surface of the drilling sleeve 130. A plurality of outer crushing teeth are provided on each outer crushing ridge 140. The outer crushing teeth include a plurality of first outer crushing teeth 141. These first outer crushing teeth 141 are provided on the precession ends of the outer crushing ridges 140. The outer crushing teeth may also include a plurality of second outer crushing teeth 142. These second outer crushing teeth 142 are provided on the outer side face of each outer crushing ridge 140. The formation outside the drilling sleeve 130 may be drilled by the first and second outer breaker teeth 141, 142 on the outer breaker ridge 140 to ensure that the wellbore is of sufficient and proper size. At the same time, the outer breaker ridges 140 may be provided to prevent the bit body 120 from directly engaging the formation with the outer side of the drilling sleeve 130. This is advantageous in reducing the drag of the drill bit during operation. In addition, adjacent outer crushing ridges 140 may form channels for debris-laden fluid to flow to the surface.
The outer crushing teeth and outer crushing ridges 140 may also be provided with other forms or configurations as desired.
During operation of the drill bit 100 of the present invention, the working end of the drilling sleeve 130 (or the trepanning teeth) first contact the formation. As the drill bit 100 rotates, the drilling sleeve 130 drills the formation annularly. Thus, the formation opposite the hollow space of the drilling sleeve 130 is not fractured by the drilling sleeve 130, but rather extends into the hollow space as the drill bit 100 is drilled to form a section of a rock pillar. The lateral position of the drilling sleeve 130, and thus the entire drill bit 100, may be limited by the engagement of the rock string with the drilling sleeve 130, thereby facilitating the reduction of lateral vibration of the drill bit 100.
The length of the rock string is limited by the distance h between the end surface 133 of the working end of the drilling sleeve 130 and the inner crushing tooth 151. When the top end of the rock pillar extends to the inner crushing teeth 151, the inner crushing teeth 151 crush the top end of the rock pillar as the drill bit 100 rotates.
Thereby, a staged formation rock breaking process is formed. Vibration damping can be effectively achieved by this process while ensuring that the drill bit 100 can effectively break up formation rock.
Additionally, the distance h may be long enough to effectively reduce axial and torsional vibrations of the drill bit 100 through frictional forces between the inner side of the drilling sleeve 130 and the outer side of the rock string. For obtaining inclined wells or horizontal wells or other situations requiring changing the drilling direction, the distance h needs to be relatively limited to ensure that the drilling direction can be flexibly changed.
The drill bit 100 of the present invention is particularly well suited for drilling hard formations. Even in this case, large vibration (especially lateral vibration) is not generated, thereby improving the efficiency and speed of drilling and the safety of drilling.
In this context, if not otherwise expressly limited or contradicted, the terms "axial," "radial," and "circumferential" are used in the description with respect to the entire drill bit or with respect to the bit body 120 and the drilling sleeve 130 as the primary components.
While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
Claims (10)
1. A drill bit for breaking rock comprising:
a drilling sleeve extending axially, the drilling sleeve configured with a plurality of sleeve drilling teeth for breaking rock, the drilling sleeve configured with a hollow space for receiving a rock string; and
a plurality of inner crushing teeth axially spaced from an end face of the working end of the drilling sleeve, the plurality of inner crushing teeth being located within the hollow space of the drilling sleeve;
wherein, during drilling, the formation opposite the hollow space of the drilling sleeve is not fractured by the sleeve drilling teeth of the drilling sleeve such that the rock pillar is receivable within the hollow space, the rock pillar and the drilling sleeve cooperating to define a lateral position of the drill bit, the plurality of inner fracturing teeth fracture the rock pillar when the rock pillar extends to the plurality of inner fracturing teeth.
2. A drill bit for breaking rock according to claim 1, further comprising an axially extending bit body, an orifice configured on an end face of the working end of the bit body for distributing drilling fluid, the drilling sleeve extending axially out from the working end of the bit body, the orifice communicating to the hollow space,
wherein a plurality of radially penetrating channels are configured at the working end of the drilling sleeve through which drilling fluid injected into the hollow space by the orifice can flow to an annulus outside the drill bit.
3. The drill bit for breaking rock of claim 2, wherein the flute includes a precession face oriented toward a direction of rotation of the drill bit, the plurality of sleeve drilling teeth including a first sleeve drilling tooth projecting from the precession face of the flute.
4. A drill bit for breaking rock according to claim 3, wherein the cutting portion of the first sleeve drilling tooth extends axially at least partially beyond the end face of the working end of the drilling sleeve.
5. A drill bit for breaking up rock according to any one of claims 2 to 4, characterized in that axially extending flow channels communicating with the grooves are formed on the inner side of the drilling sleeve, through which flow channels drilling fluid entering the hollow space from the orifice can flow towards the grooves.
6. A drill bit for breaking rock according to any one of claims 2 to 4, wherein the inner end of the flutes has a smaller cross-section than the outer end, such that the flutes have a radial shape.
7. A drill bit for breaking rock according to any one of claims 1 to 6, wherein the plurality of sleeve drilling teeth comprises a second sleeve drilling tooth projecting from an end face of the working end of the drilling sleeve.
8. A drill bit for breaking rock according to any one of claims 1 to 7, characterized in that the distance in the axial direction between the end surface of the working end of the drilling sleeve and the inner breaking teeth is sufficient to enable the friction between the rock pillar in the hollow space and the inner side of the drilling sleeve to avoid axial and torsional vibration of the drill bit.
9. A drill bit for breaking rock according to any one of claims 1 to 8, further comprising:
an axially extending bit body; and
a plurality of inner crushing ridges circumferentially spaced apart from each other on an end face of the working end of the bit body, the plurality of inner crushing teeth being provided on each inner crushing ridge.
10. A drill bit for breaking rock according to any one of claims 1 to 9, further comprising:
an axially extending bit body; and
a plurality of outer crushing ridges circumferentially spaced apart from one another on the outer peripheral surfaces of the bit body and the drilling sleeve, each outer crushing ridge extending in an axial direction, a plurality of outer crushing teeth being provided on each outer crushing ridge.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011007175.7A CN114427350A (en) | 2020-09-23 | 2020-09-23 | Drill bit for breaking rock |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011007175.7A CN114427350A (en) | 2020-09-23 | 2020-09-23 | Drill bit for breaking rock |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114427350A true CN114427350A (en) | 2022-05-03 |
Family
ID=81309635
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011007175.7A Pending CN114427350A (en) | 2020-09-23 | 2020-09-23 | Drill bit for breaking rock |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114427350A (en) |
-
2020
- 2020-09-23 CN CN202011007175.7A patent/CN114427350A/en active Pending
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