1. An eccentric drill bit, characterized in that the eccentric drill bit comprises a drilling part and a connecting part which are connected with each other;

the drilling part comprises a plurality of blades which are arranged at equal angles, cutting pieces are arranged on the blades, a chip groove is formed between every two adjacent blades, and spray holes are formed in the chip groove; the blade comprises a reinforced blade;

a water channel is formed in the connecting part and is communicated with the spray holes; the axis of the drilling part and the axis of the connecting part deviate by a preset distance, and the deviation direction is the direction of the reinforcing blade.

2. The eccentric drill bit of claim 1, wherein the cutters on the reinforcing blades are harder and/or more numerous than the cutters on the other blades.

3. The eccentric drill bit of claim 1, wherein the reinforcing blades have a circumferential dimension greater than the other blades.

4. The eccentric drill bit of claim 1, wherein the blades comprise a cutting portion and a gauge portion, the cutters comprising cutting teeth and cemented carbide elements;

the cutting part is positioned at the top end of the eccentric drill bit, the surface of the cutting part is an arc-shaped surface, the cutting teeth are arranged on the arc-shaped surface, and the cutting teeth on the same blade are arranged in rows and face the same direction;

the gauge protection part and the cutting part are connected into a whole and are close to the root of the eccentric drill bit, the hard alloy element is arranged on the gauge protection part, and the surfaces of the hard alloy elements arranged on the gauge protection parts of the blades belong to the same cylindrical surface.

5. The eccentric drill bit according to claim 1, wherein a water diversion member is arranged in the water channel, the water diversion member is rotatably connected with the connecting part, water diversion holes are formed in the water diversion member, the number of the water diversion holes is smaller than that of the spray holes, and the water diversion holes can be over against the spray holes in the rotation process of the water diversion member.

6. The eccentric drill bit according to claim 5, wherein the water diversion member is a parabolic rotation body and is hollow inside, a spiral ridge is arranged in the water diversion member, and the wall surface of the water diversion member is provided with the water diversion hole.

7. The eccentric drill bit according to claim 6, wherein the inlet end of the water diversion member is provided with an annular end surface, the connecting part is internally provided with a boss matched with the annular end surface, and the matching surfaces of the annular end surface and the boss are both provided with a one-way friction structure; when the eccentric drill bit rotates for cutting, the connecting part drives the water diversion part to rotate in a single direction through the one-way friction structure.

8. The eccentric drill bit of claim 7, wherein the one-way friction structure acts in the same direction as the force generated by the helical rib.

9. The eccentric drill bit of claim 7, wherein the one-way friction structures are annularly arranged tooth structures, the tooth structures being right triangular teeth.

10. A drilling apparatus, characterized in that the drilling apparatus comprises:

the eccentric drill bit according to any of claims 1 to 9; and

and the driving module is in transmission connection with the eccentric drill bit and is used for driving the eccentric drill bit to rotate so as to realize drilling.

Background

The PDC (Polycrystalline Diamond Compact bit) is a commonly used rock breaking tool in the current petroleum, natural gas and gas exploitation drilling engineering, has the advantages of high mechanical drilling speed, long service life, reliable underground safety and the like, and is widely applied to drilling construction.

Along with the increasing of the layers to be produced, the lithological drillability level of the deep well stratum is increased, and the requirements on the technical performance of the PDC diamond bit are higher and higher. Because the directional sidetracking uses the conventional PDC drill bit, the contact friction between the drill bit and the well wall is large, the abrasion resistance is large during drilling, and the drill jamming phenomenon is easy to occur when the drill bit meets a sand bridge and a reducing stratum. Drilling construction stuck drill is a major underground accident, the procedure for processing the stuck drill accident is complicated, the well is filled and the well is reopened under the condition that the stuck drill cannot be processed, and a large amount of manpower, material resources and time are wasted.

It can be seen that the prior art does not provide an effective solution to the sticking problem of PDC diamond bits and needs to be improved.

Disclosure of Invention

The embodiment of the invention aims to provide an eccentric drill bit and aims to solve the problem that the conventional PDC diamond drill bit is easy to block.

The embodiment of the invention is realized by an eccentric drill bit, which comprises a drilling part and a connecting part which are connected with each other;

the drilling part comprises a plurality of blades which are arranged at equal angles, cutting pieces are arranged on the blades, a chip groove is formed between every two adjacent blades, and spray holes are formed in the chip groove; the blade comprises a reinforced blade;

a water channel is formed in the connecting part and is communicated with the spray holes; the axis of the drilling part and the axis of the connecting part deviate by a preset distance, and the deviation direction is the direction of the reinforcing blade.

It is a further object of embodiments of the present invention to provide a drilling apparatus comprising:

an eccentric drill bit according to an embodiment of the present invention; and

and the driving module is in transmission connection with the eccentric drill bit and is used for driving the eccentric drill bit to rotate so as to realize drilling.

Embodiments of the present invention provide an eccentric drill bit that includes a drilling portion for drilling an opening and a connecting portion for connecting to a drive element to drive rotation of the eccentric drill bit. The drilling part comprises a plurality of equal-angle blades, cutting pieces are arranged on the blades, and cutting is realized by the cutting pieces; a chip removal groove is formed between every two adjacent blades and used for removing chips in the drilling process; the chip removal device is characterized in that spray holes are formed in the chip removal device, and water or cooling liquid is sprayed out through the spray holes, so that chip removal and cooling of the blades are facilitated; the blade comprises a reinforced blade, and the drilling part and the connecting part deviate by a preset distance, so that the drilled hole diameter is slightly larger than the maximum diameter of a drill bit, and the problem of drill sticking is effectively prevented.

Drawings

FIG. 1 is a general block diagram of an eccentric drill bit according to an embodiment of the present invention;

FIG. 2 is a bottom view of an eccentric drill bit provided in accordance with an embodiment of the present invention;

FIG. 3 is a top view of an eccentric drill bit provided by an embodiment of the present invention;

FIG. 4 is a partial cross-sectional view of an eccentric bit provided in accordance with an embodiment of the present invention;

FIG. 5 is a bottom view of a water diversion member provided in accordance with an embodiment of the present invention;

fig. 6 is a schematic view of a one-way friction structure according to an embodiment of the present invention.

In the drawings: 1. a drilling section; 2. a blade; 3. cutting teeth; 4. a cemented carbide component; 5. spraying a hole; 6. a connecting portion; 7. a water diversion member; 8. a water channel; 9. a spiral edge; 10. water distribution holes; 11. a top hole; 12. an annular end face; 13. a one-way friction structure; 14. and (4) a boss.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Specific implementations of the present invention are described in detail below with reference to specific embodiments.

As shown in fig. 1, a structure diagram of an eccentric drill bit according to an embodiment of the present invention includes a drilling portion 1 and a connecting portion 6 connected to each other;

the drilling part 1 comprises a plurality of blades 2 which are arranged at equal angles, cutting pieces are arranged on the blades 2, a chip groove is formed between every two adjacent blades 2, and a spray hole 5 is formed in the chip groove; the blade 2 comprises a reinforced blade 2;

a water channel 8 is formed in the connecting part 6, and the water channel 8 is communicated with the spray holes 5; the axis of the drilling part 1 and the axis of the connecting part 6 are offset by a preset distance, and the offset direction is the direction of the reinforcing blade 2.

In the embodiment of the invention, a plurality of blades 2 are arranged at equal angles, and the number of the blades 2 is preferably 3-7. A spiral chip groove is formed between two adjacent blades 2, and materials or soil cut off during cutting are discharged along the chip groove. The chip groove is internally provided with the spray hole 5, and in the drilling process, the drill bit core part can be filled with water to ensure that the water is sprayed out from the spray hole 5, so that the chip can be removed conveniently on one hand, and the cooling of the blade 2 is facilitated on the other hand.

In the embodiment of the present invention, the blades 2 include at least one reinforced blade 2, and the reinforced blade 2 has a strength higher than that of the conventional blade 2, and the number of the cutters is increased, the cutters having higher hardness are used, the size of the blade 2 is increased, and the like. In the embodiment of the present invention, the axis of the drilling part 1 is offset from the axis of the connecting part 6 by a distance, for example, 0.5mm to 2mm, and the offset direction is the direction in which the reinforcing blades 2 are located, and by this device, the hole diameter drilled by the drilling part 1 is slightly larger than the maximum diameter of the drill bit, thereby preventing the problem of drill sticking. Further, the number of the reinforcing bits may not be unique, such as 2, 3, etc. However, it should be noted that when the number of the reinforced drill bits is not unique, several reinforced drill bits should be disposed adjacently, and the offset direction of the axis of the drilling portion 1 with respect to the axis of the connecting portion 6 is the central direction of several reinforced drill bits.

The eccentric drill bit provided by the embodiment of the invention comprises a drilling part 1 and a connecting part 6, wherein the drilling part 1 is used for drilling a hole, and the connecting part 6 is used for being connected with a transmission element to drive the eccentric drill bit to rotate. The drilling part 1 comprises a plurality of equal-angle blades 2, cutting pieces are arranged on the blades 2, and cutting is realized by the cutting pieces; a chip removal groove is formed between every two adjacent blades 2 and used for removing chips in the drilling process; the chip discharging device is characterized in that the chip discharging device is also internally provided with a jet hole 5, and water or cooling liquid is sprayed out through the jet hole 5, so that chip discharging and the cooling of the blade 2 are facilitated; the blade 2 comprises a reinforced blade 2, and the drilling part 1 and the connecting part 6 are deviated by a preset distance, so that the drilled hole diameter is slightly larger than the maximum diameter of a drill bit, and the problem of drill jamming is effectively prevented.

In one embodiment of the invention, the cutters on the reinforced blade 2 are harder and/or more numerous than the cutters on the other blades 2.

In embodiments of the present invention, the strength of the reinforcing blade 2 is preferably increased by increasing the number of cutters on the reinforcing blade 2, which facilitates interchangeability of cutters on drill bits.

In one embodiment of the invention, the reinforcing blade 2 has a larger circumferential dimension than the other blades 2.

In the embodiment of the invention, the circumferential dimension of the reinforced blade 2 refers to the thickness of the reinforced blade 2, and the thickness of the reinforced blade 2 is thicker than that of other blades 2, so that the durability of the reinforced blade 2 can be improved; optionally, the width of the reinforcing blade 2 is 1.1 to 1.5 times that of the other blades 2.

In one embodiment of the invention, the blade 2 comprises a cutting portion and a gauge portion, the cutter comprising a cutting tooth 3 and a cemented carbide element 4;

the cutting part is positioned at the top end of the eccentric drill bit, the surface of the cutting part is an arc-shaped surface, the cutting teeth 3 are arranged on the arc-shaped surface, and the cutting teeth 3 on the same blade 2 are arranged in rows and face the same direction;

the gauge portion and the cutting portion are connected into a whole and are close to the root of the eccentric drill bit, the hard alloy element 4 is arranged on the gauge portion, and the surfaces of the hard alloy elements 4, which are arranged on the gauge portion of the blades 2, belong to the same cylindrical surface.

In the embodiment of the invention, the maximum diameter of the cutting part is not smaller than that of the diameter-protecting part, and the diameter-protecting part is used for ensuring that the diameter of the drilled hole meets the requirement. The cutting part is located the top of eccentric drill bit, and its surface sets up to the arcwall face, and the arc extends to the top and the side of drill bit, is provided with cutting tooth 3 on the arcwall face, and cutting tooth 3 is preferred to be the PDC compound piece, and the PDC compound piece adopts welding material BAg50CdZnCu, welds in the cutting part tooth hole through brazing process. In the embodiment of the invention, the cutting teeth 3 are positioned at the same side of the cutting part, and the cutting teeth 3 on different blades 2 face the same rotary cutting direction; furthermore, at least two blades 2 extend and meet at the top end of the eccentric drill to form a rotational symmetric structure, and the extended part is also provided with cutting teeth 3.

In the embodiment of the invention, the gauge part is a cylindrical surface, the cemented carbide elements 4 are arranged on the cylindrical surface of the gauge part, and the number of the cemented carbide elements 4 on the gauge part of the reinforced blade 2 is more than that of the other blades 2.

In the embodiment of the present invention, it is understood that the blades 2 are composed of cutting portions and gauge portions, the flutes between the blades 2 divide the drill into a plurality of blades 2, the nozzle holes 5 in the flutes preferably face the cutting teeth 3 on the cutting portions, and a plurality of the nozzle holes may be provided depending on the shape of the cutting portions.

In an embodiment of the present invention, a water diversion member 7 is disposed in the water channel 8, the water diversion member 7 is rotatably connected to the connection portion 6, water diversion holes 10 are disposed on the water diversion member 7, the number of the water diversion holes 10 is smaller than the number of the spray holes 5, and the water diversion holes 10 can face the spray holes 5 in a rotation process of the water diversion member 7.

In the embodiment of the invention, the water diversion piece 7 is arranged in the water channel 8, the spray holes 5 in the chip groove are intermittently communicated by utilizing the rotation of the water diversion piece 7, so that water is sequentially sprayed out from the spray holes 5, the water pressure of the sprayed water can be improved, and when the water diversion piece 7 rotates to ensure that the water diversion holes 10 are not aligned with the spray holes 5, chips can be prevented from entering the water channel 8 by utilizing the water diversion piece 7 to cause the blockage of the water channel 8.

In an embodiment of the present invention, the water diversion member 7 is a parabolic rotation body, the interior of the water diversion member is hollow, a spiral ridge 9 is arranged in the water diversion member 7, and the wall surface of the water diversion member 7 is provided with the water diversion hole 10.

In the embodiment of the invention, water with pressure enters the water diversion piece 7, the water diversion piece 7 is driven to rotate when the water flows along the spiral edge 9, and then the water is sprayed out from the water diversion holes 10 formed in the wall surface of the water diversion piece 7. The water diversion piece 7 is arranged to be a parabolic revolving body, on one hand, water can be sprayed out after being gathered by utilizing an inner cavity of the parabolic revolving body, on the other hand, the friction between the water diversion piece 7 and the interior of the water channel 8 is reduced by utilizing the characteristic that the outer wall of the parabolic revolving body is smooth, and the water diversion piece 7 is enabled to rotate easily. In the embodiment of the invention, optionally, the water diversion piece 7 may further be provided with a top hole 11 for water outlet, and the top hole 11 is larger and is constantly communicated with a water outlet hole at the top of the cutting piece, and is used for maintaining water flow in the water diversion piece 7 and preventing blockage.

In one embodiment of the present invention, the inlet end of the water diversion member 7 is provided with an annular end face 12, the connecting portion 6 is provided with a boss 14 therein, the boss 14 is engaged with the annular end face 12, and the engaging faces of the annular end face 12 and the boss 14 are both provided with a one-way friction structure 13; when the eccentric drill bit rotates for cutting, the connecting part 6 drives the water diversion piece 7 to rotate in a single direction through the one-way friction structure 13.

In the embodiment of the invention, the eccentric drill bit has a certain rotating speed when working, the water diversion piece 7 needs to rotate relative to the eccentric drill bit when the water diversion piece is to play a role, the one-way friction structure 13 is arranged to enable the connecting part 6 to drive the water diversion piece 7 to rotate in one way, and the rotating speed of the water diversion piece 7 is not less than that of the eccentric drill bit.

In one embodiment of the present invention, the one-way friction structure 13 acts in the same direction as the acting force generated by the spiral rib 9.

In the embodiment of the invention, the eccentric drill bit has a certain steering direction during working, and the eccentric drill bit can drive the water diversion piece 7 to rotate in the same direction through the one-way friction structure 13; the spiral edge 9 enables the water diversion piece 7 to be forced to rotate under the action of water flow, the rotating direction is the same as the rotating direction of the eccentric drill bit, so that under the action of water pressure, the rotating speed of the water diversion piece 7 is usually larger than that of the drill bit, and a speed difference exists between the rotating speed and the drill bit, so that the water diversion holes 10 in the water diversion piece 7 can be periodically opposite to the spray holes 5, and intermittent water spraying is realized.

In one embodiment of the present invention, the one-way friction structure 13 is a tooth-shaped structure arranged annularly, and the tooth-shaped structure is a right-angled triangle tooth.

In the embodiment of the invention, preferably, the length of one cathetus of the right-angled triangle is 1.5-2 times that of the other cathetus, so that the matched surface is larger, and the boss 14 is not easy to separate from the annular end surface 12.

An embodiment of the present invention also provides a drilling apparatus including:

an eccentric drill bit according to an embodiment of the present invention; and

and the driving module is in transmission connection with the eccentric drill bit and is used for driving the eccentric drill bit to rotate so as to realize drilling.

For a detailed explanation of the drill bit in the embodiments of the present invention, please refer to any one or a combination of one or more of the foregoing embodiments, which will not be described in detail herein.

In the embodiment of the invention, the driving module comprises a power part and a transmission part, wherein the power part can be a motor and the like, the transmission part is usually a transmission shaft, the transmission shaft adopts a hollow structure, and the middle part of the transmission shaft is communicated with the water channel 8 of the eccentric drill bit through water.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.