阅读说明：本技术 一种高效抽吸引流式反循环pdc钻头 (High-efficient suction drainage type reverse circulation PDC drill bit ) 是由 邓嵘 黄安龙 张家彧 刘建平 刘瑜 何清 江炫君 陈科 于 2020-06-23 设计创作，主要内容包括：本发明涉及一种高效抽吸引流式反循环PDC钻头,它主要包括：接头、钻头体、切削刀翼。所述切削刀翼的冠部均设有PDC切削齿、背面均设有耐磨保径齿并固定安装在钻头体上,所述钻头体与接头的中心轴线上均设有同轴的中心通道,其中钻头体内的中心通道分三段呈阶梯状且直径从下到上递减,所述钻头体内设有扩压槽且与中心通道间有两条倾斜的引流通道,其引流通道与中心通道交汇处上侧壁面分别设有圆弧段,所述接头内远离中心轴线处设有入流通道并与扩压槽相连且在同一轴线上。本发明的一种高效抽吸引流式反循环PDC钻头,可以作为反循环钻井时使用,对泥浆和岩屑的吸入能力强,清理岩屑的能力强,钻进效率高。(The invention relates to a high-efficiency suction drainage type reverse circulation PDC drill bit, which mainly comprises: a joint, a bit body, and a cutting blade. The crown of cutting blade all is equipped with PDC cutting tooth, the back all is equipped with wear-resisting gauge protection tooth and fixed mounting on the drill bit body, all be equipped with coaxial central channel on the central axis of drill bit body and joint, wherein the central channel in the drill bit body divides the three-section to be echelonment and diameter from the bottom up degressive, be equipped with in the drill bit body and have two drainage passageways of slope with central channel within a definite time, its drainage passageway is equipped with the circular arc section respectively with central channel junction upside wall, keep away from central axis department in the joint and be equipped with the inflow passageway and link to each other and on same axis with the diffusion groove. The efficient suction drainage type reverse circulation PDC drill bit can be used for reverse circulation drilling, and is high in suction capacity of mud and rock debris, strong in rock debris cleaning capacity and high in drilling efficiency.)

1. A high-efficiency suction drainage type reverse circulation PDC drill bit mainly comprises a joint 1, a flow inlet channel 2, a central channel upper section 3, a central channel middle section 4, an upper drainage channel 5, a bit body 6, a pressure expansion groove 7, a lower drainage channel 8, a central channel lower section 9, PDC cutting teeth 10, wear-resistant gauge protection teeth 11, blades 12 and a central channel 13; the method is characterized in that: the crown parts of the 12-blades are provided with 10-PDC cutting teeth, the back surfaces of the 12-blades are provided with 11-wear-resistant gauge teeth, the 10-PDC cutting teeth and the back surfaces of the 12-blades are fixedly arranged on a 6-bit body, and the 6-bit body is connected with a 1-joint.

2. The high-efficiency suction drainage type reverse circulation PDC drill bit of claim 1, wherein: coaxial 13-central channels are arranged on the central axes of the 6-bit body and the 1-joint, a 7-diffusion groove is arranged in the 6-bit body, and an inclined 5-upper drainage channel and an inclined 8-lower drainage channel are respectively arranged between the 7-diffusion groove and the upper section of the 3-central channel and the middle section of the 4-central channel.

3. The high-efficiency suction drainage type reverse circulation PDC drill bit of claim 1, wherein: and a 2-inflow channel is arranged in the 1-joint and far away from the central axis, is connected with the 7-diffusion groove and is on the same axis.

4. The high-efficiency suction drainage type reverse circulation PDC drill bit of claim 2, wherein: the central channel in the 6-drill bit body is divided into three sections, namely a 3-central channel upper section, a 4-central channel middle section and a 9-central channel lower section, which are in a step shape, and the diameters of the three sections are gradually reduced from bottom to top, wherein the 3-central channel upper section is the same as the diameter of the 13-central channel in the 1-joint.

5. The high-efficiency suction drainage type reverse circulation PDC drill bit of claim 2, wherein: the upper side wall surface of the intersection of the upper section of the 5-upper drainage channel and the upper section of the 3-central channel is provided with an arc section, and the upper side wall surface of the intersection of the middle section of the 8-lower drainage channel and the 4-central channel is provided with an arc section.

6. The high-efficiency suction drainage type reverse circulation PDC drill bit of claim 2, wherein: and a circle of circular arc section is arranged at the junction of the lower section of the 9-central channel in the 6-bit body and the end face of the 6-bit body.

Technical Field

The invention relates to the fields of petroleum and natural gas drilling engineering and geological drilling, in particular to a high-efficiency suction drainage type reverse circulation PDC drill bit.

Background

The existing drilling mode mainly comprises a forward circulation drilling mode and a reverse circulation drilling mode, wherein a drill rod is required to be used in the drilling process, one end of the drill rod is connected with a drill bit, in the forward circulation drilling process, mud is pumped into an inner cavity of the drill rod from a mud pool by a mud pump, is conveyed to the drill bit from the inner cavity of the drill rod, is continuously conveyed into the drilling well through a water hole of the drill bit, and is discharged from an annular space between a well wall and the drill rod, and meanwhile, rock debris generated in the drilling process is discharged to the ground along with the mud; the circulation mode of the mud for reverse circulation drilling is just the reverse, the mud is conveyed from an annular space between a drill rod and a well wall by a mud pump, and then compressed air or the mud pump is used for sucking the mud and rock debris into an inner cavity of the drill rod through a water hole of a drill bit and then pumping the mud and the rock debris out of the inner cavity of the drill rod to the ground.

The drill bit for the forward circulation drilling has very strict requirements on the relative positions of the water holes and the blades, and the general design is that each blade corresponds to one water hole, so that the limited diameter of the water holes of the drill bit for the forward circulation drilling on the limited end face of the drill bit is smaller, the suction capacity for mud and rock debris is poorer, and the capacity for cleaning the rock debris is poorer.

Research shows that no drill bit specially used for reverse circulation drilling is available during reverse circulation drilling, only the drill bit for forward circulation drilling can be used for drilling during reverse circulation drilling, however, in the reverse circulation drilling process, mud and rock debris generated in the drilling process are sucked into a drill rod through a water hole in the drill bit, the water hole is easily blocked by the mud and the rock debris in the reverse circulation drilling due to the fact that the diameter of the water hole in the drill bit is small, and the suction capacity of the drill rod on the mud and the rock debris is poor, so that part of the mud and the rock debris can be accumulated around the water hole, and the drilling efficiency is affected. Therefore, the efficient suction drainage type reverse circulation PDC drill bit is designed, and the problems can be effectively solved.

Disclosure of Invention

In order to avoid the problems, the invention provides a high-efficiency suction drainage type reverse circulation PDC drill bit which comprises: the flow direction of liquid can be changed, a large negative pressure area can be formed in the liquid, a strong suction effect can be generated on external liquid, mud and rock debris can be effectively sucked into the drill rod, the capability of clearing the rock debris is enhanced, and the drilling efficiency is improved.

In order to solve the technical problem, the technical scheme adopted by the invention is as follows: a high-efficiency suction drainage type reverse circulation PDC drill bit comprises a joint, a drill bit body and cutting blades. The cutting blade is characterized in that PDC cutting teeth are arranged on the crown portion of each cutting blade, wear-resistant gauge protection teeth are arranged on the back face of each cutting blade, the cutting blades are fixedly mounted on the bit body, coaxial central channels are arranged on central axes of the bit body and the joint, the central channels in the bit body are divided into three sections and are stepped, the diameters of the central channels are gradually reduced from bottom to top, the diameter of the uppermost section of the central channels is the same as that of the central channels in the joint, two inclined drainage channels are arranged between the diffusion grooves and the central channels, arc sections are respectively arranged on the side wall surfaces of the intersection of the drainage channels and the central channels, a circle of arc sections are arranged at the intersection of the central channels of the lowermost section in the bit body and the end face of the bit body, and inflow channels are arranged in the joint far.

The further technical scheme is that a section of upward concave arc chamfer is arranged at the bottom of the pressure expansion groove in the drill bit body.

The further technical scheme is that the number of the cutting blades is six, and 6 cutting blades are uniformly distributed on the periphery of the crown of the bit body.

The further technical scheme is that the inflow channel has two embodiments. The first method comprises the following steps: distributed around the central axis for one turn. And the second method comprises the following steps: 6 inflow channels.

The technical scheme is that the diffuser groove has two implementation modes which respectively correspond to the implementation modes of the inflow channel. The first method comprises the following steps: distributed around the central axis for one turn. And the second method comprises the following steps: 6 diffusion grooves.

The further technical scheme is that the upper drainage channel has two implementation modes, which are respectively corresponding to the implementation modes of the inflow channel and the pressure expansion groove. The first method comprises the following steps: distributed around the central axis for one turn. And the second method comprises the following steps: 6 upper drainage channels.

The further technical scheme is that the lower drainage channel has two implementation modes which respectively correspond to the implementation modes of the inflow channel, the pressure expansion groove and the upper drainage channel. The first method comprises the following steps: distributed around the central axis for one turn.

And the second method comprises the following steps: 6 lower drainage channels.

The invention has the following advantages:

the high-efficiency suction drainage type reverse circulation PDC drill bit can be used for reverse circulation drilling, and is high in suction capacity of mud and rock debris, strong in rock debris cleaning capacity and high in drilling efficiency.

Drawings

FIG. 1 is a schematic longitudinal sectional view of the present invention;

shown in the figure: 1-joint, 2-inflow channel, 3-central channel upper section, 4-central channel middle section, 5-upper drainage channel, 6-bit body, 7-diffusion groove, 8-lower drainage channel, 9-central channel lower section, 10-PDC cutting tooth, 11 wear-resistant gauge tooth, 12-blade, 1201-first blade, 1202-second blade and 13-central channel.

FIG. 2 is a schematic bottom view of the present invention;

FIG. 3 is a transverse cross-sectional view in direction A of the present invention;

shown in the figure: there are two embodiments for the direction a. The first method comprises the following steps: distributed around the central axis for one turn. And the second method comprises the following steps: 6 inflow channels.

FIG. 4 is a transverse cross-sectional view in the direction B of the present invention;

shown in the figure: two embodiments of the direction B correspond to the two embodiments of the direction a. The first method comprises the following steps: distributed around the central axis for one turn. And the second method comprises the following steps: 6 diffusion grooves and 6 upper drainage channels.

Fig. 5 is a transverse cross-sectional view in the direction C of the present invention.

Shown in the figure: there are two embodiments of the C direction corresponding to the two embodiments of the A, B direction.

The first method comprises the following steps: distributed around the central axis for one turn. And the second method comprises the following steps: 6 diffusion grooves and 6 lower drainage channels.

Detailed Description

The present invention will be further described with reference to the following examples and the accompanying drawings.

As shown in figure 1, the high-efficiency suction drainage type reverse circulation PDC drill bit comprises a 1-joint, a 2-inflow channel, a 3-central channel upper section, a 4-central channel middle section, a 5-upper drainage channel, a 6-drill bit body, a 7-diffusion groove, an 8-lower drainage channel, a 9-central channel lower section, 10-PDC cutting teeth, 11 wear-resistant gauge protection teeth, 12-blades and a 13-central channel, wherein the crown of each 12-blade is provided with the 10-PDC cutting teeth, the back of each 12-blade is provided with the 11-wear-resistant gauge protection teeth and is fixedly arranged on the 6-drill bit body, the central axes of the 6-drill bit body and the 1-joint are respectively provided with a coaxial 13-central channel, wherein the central channel in the 6-drill bit body is divided into the 3-central channel upper section, Three sections of a 4-central channel middle section and a 9-central channel lower section are in a step shape, the diameters of the three sections are gradually reduced from bottom to top, wherein the diameter of the 3-central channel upper section is the same as that of the 13-central channel in the 1-joint, a 7-diffusion groove is arranged in the 6-bit body, an inclined 5-upper drainage channel and an inclined 8-lower drainage channel are respectively arranged between the 5-central channel upper section and the 4-central channel middle section, the upper side wall surface of the intersection of the 5-upper drainage channel and the 3-central channel upper section is provided with an arc section, the upper side wall surface of the intersection of the 8-lower drainage channel and the 4-central channel middle section is provided with an arc section, the intersection of the 9-central channel lower section and the 6-bit body in the 6-bit body is provided with a circle arc section, and, a2-inflow channel is arranged in the 1-joint and far away from the central axis, is connected with the 7-diffusion groove and is on the same axis, and the bottom of the 7-diffusion groove in the 6 drill bit body is provided with a section of upward concave arc chamfer.

As shown in FIG. 2, the number of the 12-blades is six, and 3 blades 1201-first blades and 3 blades 1202-second blades are distributed on the periphery of the crown of the 6-bit body in an intersecting manner.

As shown in fig. 3, there are two embodiments for the direction a. The first method comprises the following steps: 2-the inflow channels are distributed around the central axis in one turn. And the second method comprises the following steps: 6 2-inflow channels.

As shown in fig. 4, two embodiments in the B direction correspond to the two embodiments in the a direction. The first method comprises the following steps: 7-the diffusion groove and 5-the upper drainage channel are distributed for a circle around the central axis. And the second method comprises the following steps: 6 7-diffusion grooves and 6 5-upper drainage channels.

As shown in fig. 5, two embodiments in the C direction correspond to the two embodiments in the A, B direction. The first method comprises the following steps: 7-the diffusion groove and 8-the lower drainage channel are distributed for a circle around the central axis. And the second method comprises the following steps: 6 7-diffusion grooves and 6 8-lower drainage channels.

In a second embodiment corresponding to the A, B, C orientation, shown in FIGS. 3-5, the 2-inflow channel, the 7-diffuser slot, the 5-up-flow channel, and the 8-down-flow channel are all in the radial plane between the 12-blade and the blade.

Although the present invention has been described with reference to the above embodiments, it should be understood that the present invention is not limited to the above embodiments, and those skilled in the art can make various changes and modifications without departing from the scope of the present invention.