CN109424319B

CN109424319B - Vertical drilling tool

Info

Publication number: CN109424319B
Application number: CN201710761870.4A
Authority: CN
Inventors: 孙峰; 胡群爱; 孙明光; 宗艳波; 钱德儒; 陶兴华; 臧艳彬; 王甲昌; 王光磊
Original assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Current assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Priority date: 2017-08-30
Filing date: 2017-08-30
Publication date: 2021-01-05
Anticipated expiration: 2037-08-30
Also published as: CN109424319A

Abstract

The invention relates to a vertical drilling tool, comprising: the drilling fluid overflowing device comprises a mandrel with a hollow tubular structure, wherein a drilling fluid overflowing channel is arranged in the center of the mandrel; the outer cylinder is sleeved on the mandrel and can independently rotate, and the outer cylinder is rotatably supported on the mandrel through a bearing assembly; a biasing member disposed between the outer barrel and the mandrel, the biasing member configured to automatically rotate upon tilting of the drilling tool to open a high-side flow passage and close a low-side flow passage of the drilling tool to dispense an overflow drilling fluid to the high-side flow passage; and the pushing device is arranged at the lower part of the outer cylinder, and pushes against the well wall along the high-side direction under the action of the drilling fluid from the high-side flow passage so as to correct the inclination state of the drilling tool.

Description

Vertical drilling tool

Technical Field

The invention relates to the field of downhole tools for oil and gas well engineering, in particular to a vertical drilling tool.

Background

With the continuous deepening of the exploration and development work of oil and gas fields, the drilled stratum structure is more and more complex, particularly the problem of 'preventing from being inclined and getting fast' of a high and steep structure is the difficult point and the key point in the drilling technology, and therefore the requirement on a vertical drilling tool is higher and higher.

The traditional full-hole drilling tool combination and pendulum drilling tool combination use the lateral force of the drilling tool as the theoretical basis of well deviation control, and have great limitation. The developed anti-inclination technologies such as eccentric drilling tools, off-axis drilling tools, flexible drilling tools, reverse pendulum drilling tools, guide drilling tools and the like enhance the revolution effect of a drill string, weaken the inclination increasing effect of a drill bit inclination angle, effectively control the lateral force of the drilling tools, better control well inclination and improve the mechanical drilling speed, but the inherent mechanical properties of the drilling tool combination determine that the drilling tool combination still has insufficient function of resisting the formation inclination force. Therefore, well deviation control effectiveness for highly steep formations and strongly deviated formations remains difficult to sufficiently ensure.

In order to solve the problem of 'anti-deviation and rapid drilling', people need to research an automatic closed-loop vertical drilling tool which can automatically adjust well deviation and keep a well vertical without manual intervention regardless of underground strata so as to drill a vertical well with a very straight and smooth track. For this reason, the automatic vertical drilling technology is increasingly used in drilling engineering.

The automatic vertical drilling technology is a drilling technology which can prevent inclination in real time, actively correct inclination and improve the drilling speed. The automatic vertical drilling tool based on the automatic vertical drilling technology is provided with an underground closed-loop control system, and can realize underground active inclination prevention and correction, so that the well wall is kept vertical, the mechanical drilling speed can be effectively improved, the drilling cost is reduced, and the tool is particularly suitable for vertical drilling of high and steep stratum and deep wells.

Automatic vertical drilling tools in the prior art can be divided into two types according to different modes of pushing against a well wall, wherein one type adopts a static pushing manner. The static pushing type automatic vertical drilling tool has the characteristic of organic-electric liquid integration, and structurally adopts a static pushing outer cylinder, and a driving main shaft capable of being provided with a screw rod is arranged in the middle. Although the static push-type automatic vertical drilling tool can release the bit pressure and improve the drilling efficiency, and has accurate measurement and control, stable pushing force and small dynamic error, more electronic components and complex hydraulic structure can not bear severe environments such as high temperature and strong vibration, and the application range is limited.

The other type is a dynamic modulation type automatic vertical drilling tool. The double-motor torque balance system is absolutely static relative to the ground, so that the accurate measurement of engineering parameters such as well deviation direction and the like is realized. However, the dynamic modulation type automatic vertical drilling tool still has a plurality of problems, such as complex wing rib stress, impact load bearing, abrasion, block falling and the like; the measurement and control platform is arranged on the middle shaft, is easily influenced by the vibration impact of the drill bit, and has the problems of difficult dynamic precision control and the like; the dynamic modulation type automatic vertical drilling tool has more electronic components, cannot bear high temperature, is difficult to control dynamic precision, is easily influenced by the vibration impact of the drill bit, influences the service life of the drill bit, and limits the application range of the drill bit.

At present, most of the automatic vertical drilling tools commonly used at home and abroad adopt an electromechanical-hydraulic integrated automatic vertical drilling system. Most of the automatic vertical well drilling tools have a large number of electronic elements, are complex in structure, cannot bear high temperature, are easily influenced by external environments such as vibration impact and the like, and are poor in reliability, so that the dynamic control precision of the automatic vertical well drilling tools is reduced, and the service life and the working efficiency of the automatic vertical well drilling tools are influenced. In addition, the later maintenance cost of the vertical drilling tool based on the electromechanical-hydraulic integrated system is high, and the cost performance is low.

Disclosure of Invention

In view of at least some of the above technical problems, the present invention is directed to a vertical drilling tool, which can overcome the problems of intolerance to high temperature and strong vibration and shock of an electromechanical-hydraulic integrated automatic vertical drilling system, so that the vertical drilling tool can be used in high temperature, soft-hard interaction or extremely hard formation.

To this end, according to the present invention, there is provided a vertical drilling tool comprising: the drilling fluid overflowing device comprises a mandrel with a hollow tubular structure, wherein a drilling fluid overflowing channel is arranged in the center of the mandrel; the outer cylinder is sleeved on the mandrel and can independently rotate, and the outer cylinder is rotatably supported on the mandrel; a biasing member disposed between the outer barrel and the mandrel, the biasing member being automatically rotatable upon tilting of the drilling tool to open a high-side flow passage and close a low-side flow passage of the drilling tool to dispense an overflow drilling fluid to the high-side flow passage; and the pushing device is arranged at the lower part of the outer cylinder, and pushes against the well wall along the high-side direction under the action of the drilling fluid from the high-side flow passage so as to correct the inclination state of the drilling tool.

In a preferred embodiment, the biasing member is provided as a cylindrical member which is open over a part of the outer wall area with an elongate flow space.

In a preferred embodiment, the biasing member is arranged to be isolated from the spindle but connected at both ends to the outer barrel by bearings.

In a preferred embodiment, an overflow means is provided between the mandrel and the biasing member, the overflow means comprising a filter element.

In a preferred embodiment, the pushing device comprises an opening mechanism for selectively opening one of the high-side flow passage and the low-side flow passage and simultaneously closing the other of the high-side flow passage and the low-side flow passage, and a pushing mechanism capable of pushing against the well wall in the high-side direction under the action of the drilling fluid.

In a preferred embodiment, the opening mechanism comprises a first annular valve attached to the lower end of the biasing member and a second annular valve attached to the lower inner wall of the outer barrel, the first and second annular valves being configured as discs abutting each other.

In a preferred embodiment, the disk surface of the first annular valve is provided with an arc-shaped through hole extending along the circumferential direction, the second annular valve is uniformly provided with a plurality of flow passage holes along the circumferential direction, and the first annular valve can rotate along with the weight piece, so that the arc-shaped through hole is aligned with the flow passage holes of the second annular valve located in the high-side or low-side area, and the high-side flow passage or the low-side flow passage is opened.

In a preferred embodiment, the side wall of the first annular valve provided with the arc-shaped through hole is circumferentially aligned with the side wall of the biasing member opened with the elongated flow passage space.

In a preferred embodiment, said pushing means comprise a cylinder jacket mounted downstream of said opening mechanism, inside which a radially movable member is arranged.

In a preferred embodiment, the movable member comprises a thrust rib disposed within the casing, and a piston capable of applying a radial force to the thrust rib, wherein the piston is capable of pushing the thrust rib against the borehole wall under the action of drilling fluid.

Drawings

The invention will now be described with reference to the accompanying drawings.

FIG. 1 shows the configuration of a vertical drilling tool according to the present invention.

FIG. 2 illustrates the configuration of a biasing member in the vertical drilling tool of FIG. 1.

FIG. 3 shows the configuration of the backup device in the vertical well tool of FIG. 1.

FIG. 4 shows a schematic diagram of the operation of the vertical drilling tool according to the present invention.

In the present application, the drawings are all schematic and are used only for illustrating the principles of the invention and are not drawn to scale.

Detailed Description

The invention is described below with reference to the accompanying drawings.

When the drilling tool is in a tilted state, there is a tilted bottom circle with a highest point. In this application, the direction from the center of the inclined bottom hole circle to the highest point is defined as the high side direction, and the direction relatively rotated by 180 degrees is defined as the low side direction.

FIG. 1 shows the configuration of a vertical drilling tool 150 according to the present invention. As shown in FIG. 1, the vertical drilling tool 150 includes a mandrel 50 having a hollow tubular structure. The interior of the mandrel 50 is provided with a flow passage 55 for the majority of the drilling fluid to flow through. The upper end of the mandrel 50 is provided with a conical joint part 51, and the conical joint part 51 is connected with the upper joint nipple 10. And a step-shaped lower joint short section 52 is arranged outside the lower end of the mandrel 50, a conical cavity 53 is arranged inside the lower joint short section 52, and the conical cavity 53 is communicated with a flow passage 55 of the mandrel 50.

According to the present invention, the upper end of the mandrel 50 is connected to a conventional drilling tool or a screw motor through the upper joint sub 10, thereby transmitting weight-on-bit torque and providing power. The lower sub 52 at the lower end of the mandrel 50 is connected directly to the bit of the vertical drilling tool 150 for withstanding weight on bit, torque and bottom hole vibratory impacts.

An outer cylinder 20 capable of rotating independently is sleeved on the upper part of the mandrel 50. The outer barrel 20 may be rotatably supported on the mandrel 50, such as by a bearing assembly 40, thereby isolating the mandrel 50 from the outer barrel 20 so that the outer barrel 20 can remain relatively stationary or slowly rotate downhole. The outer cylinder 20 occupies more than half of the entire vertical drilling tool 150, and serves as a housing for the vertical drilling tool 150, and the outer cylinder 20 plays a certain role in guiding the vertical drilling tool 150 during the drilling process.

In addition, a biasing member 30 is provided between the outer barrel 20 and the mandrel 50. Bearings 44 are disposed between both ends of the weight bias member 30 and the inner wall of the outer cylinder 20, and the weight bias member 30 is isolated from the spindle 50. Thereby isolating the impact of vibration and impact caused by the drill bit and other drilling tools during the rock breaking process and ensuring the control precision of the vertical drilling tool 150.

As shown in fig. 2, the weight 30 has a cylindrical structure. A long and narrow flow passage space is formed in a part of the outer wall region of the weight 30, and is, for example, a long and narrow flow passage through hole 31. Thus, with respect to the center line of the weight member 30, one side thereof is a complete outer wall and the other side is an outer wall having the elongated flow passage through hole 31, so that both sides are asymmetrical, so that the weight member 30 has an eccentric action. Thus, the biasing member 30 will automatically rotate under gravity when the drilling tool is tilted, with the side without through-holes being in the lower region due to the heavier weight and the side with through-holes being in the higher region due to the lighter weight. This opens the high side flow path and closes the low side flow path of the drilling tool, thereby distributing the excess flow drilling fluid to the high side flow path.

In the embodiment shown in fig. 2, the biasing member 30 is provided with a shoulder portion 32 at both ends, and a bearing assembly 44 is mounted on the shoulder portion 32. Biasing member 30 is made of a material that is overweight so that biasing member 30 has a more pronounced eccentric effect, thereby enabling a quick response to inclination of vertical drilling tool 150 and improving the accuracy of deviation correction.

At the lower end of the outer barrel 20 there is provided a thrust means 140 which provides a lateral force along the high side of the drilling tool. The thrust device 140 is urged against the borehole wall in the high-side direction by the drilling fluid from the high-side flow path to correct the inclination of the vertical drilling tool 150.

As shown in fig. 3, the pushing device 140 includes an opening mechanism 144 installed at a lower portion of the outer tub 20 for selectively opening one of the high-side flow passage and the low-side flow passage while closing the other of the high-side flow passage and the low-side flow passage. In particular, the opening mechanism 144 can automatically open the high side flow path and close the low side flow path when the drilling tool 150 is deflected. Wherein the opening mechanism 144 includes a first annular valve 60 attached to the lower end of the biasing member 30 and a second annular valve 70 attached to the inner wall of the lower end of the outer cartridge 20, the first and second annular valves being configured as disks attached to each other. The first annular valve 60 has a disk shape, and a through hole through which the spindle 50 passes is formed in the center of the disk surface of the first annular valve 60. A cavity 61 is formed in the middle of the first annular valve 60, and the cavity 61 is connected to the flow passage 55 of the mandrel 50 through a flow passage not shown, so that the drilling fluid can be received from the flow passage 55 of the mandrel 50. An arc-shaped through hole (not shown) extending in the circumferential direction of the first annular valve 60 is provided on the end surface of the first annular valve 60 that abuts against the second annular valve 70, and communicates with the chamber 61. In one embodiment, not shown, the first annular valve 60 may be provided in a fan-shaped configuration.

During actual drilling of the vertical drilling tool 150, when the well deviation exceeds the standard, the first annular valve 60 is rotated to a position such that the curved through-hole is at the high side of the borehole in order to allow the biasing member 30 to rotate automatically. To this end, it is preferable that the side wall of the first annular valve 60 provided with the arc-shaped through hole is substantially aligned in the circumferential direction with the side wall of the biasing member 30 opened with the elongated through-flow hole 31.

According to the invention, a flow-passing device 130 is arranged on the pipe wall of the mandrel 50 where the first annular valve 60 is installed, and the flow-passing device 130 is communicated with the flow-passing channel 55 of the mandrel 50 and the cavity 61 of the first annular valve 60. The flow-through device 130 comprises a filter 133 for filtering the drilling fluid to prevent filter residue or sand in the drilling fluid from clogging the drilling fluid flow passage holes.

Similarly, the second annular valve 70 has a disk-like configuration, and a central through hole through which the spindle 50 passes is opened in a disk surface of the second annular valve 70. Meanwhile, a plurality of flow passage holes 71 are uniformly provided in the disk surface of the second annular valve 70 in the circumferential direction. Since the first annular valve 60 is able to rotate with the biasing member 30 such that the arcuate through bore is aligned with the flow passage bore 71 of the second annular valve 70 in the high or low side region, the high or low side flow passage is opened to dispense the excess flow drilling fluid.

In addition, the pushing device 140 further comprises a pushing mechanism 141 mounted at the lower end of the outer cylinder 20 and capable of applying a pushing force to the well wall in the high-edge direction under the action of the drilling fluid. The pushing mechanism 141 pushes against the borehole wall in the high-side direction under the action of the drilling fluid from the high-side flow passage, obtains a reaction force from the borehole wall, and corrects the inclination state of the vertical drilling tool 150 under the action of the reaction force.

As shown in fig. 3, the pushing mechanism 141 includes a pushing body 100 having a hollow rectangular parallelepiped structure. The pushing body 100 comprises a pair of pushing wing ribs 101 which are opposite in the radial direction, and the outer edge profile surface of the pushing wing ribs 101 is formed into a cylindrical surface or a spherical surface, so that the contact area of the pushing wing ribs 101 and the well wall can be increased, and the pushing effect is enhanced. The thrust rib 101 is provided with a through hole 102 including a step portion. The head of the piston is formed as a stepped shaft and is fitted in the through hole of the thrust rib. In order to reduce the surface abrasion of the thrust rib 101, a wear-resistant material such as cemented carbide or polycrystalline diamond compact can be sprayed on the cylindrical surface of the thrust rib 101.

In this embodiment, the thrust body 100 further comprises a pair of diametrically opposed ribs. Diametrically opposed thrust ribs 101 are interconnected by ribs to form an interlocking structure. That is, when the rib at one end is extended or retracted, the corresponding rib at the other end, which is radially symmetrical, is retracted or extended in a linked manner. Therefore, the accurate control of the pushing force in the direction when the pushing wing rib 101 pushes against the well wall is ensured, and meanwhile, the pushing wing rib 101 on one side is ensured to be in a withdrawing state when the pushing wing rib 101 on the other side extends out, so that the complex conditions under the well such as scraping or being clamped on the well wall are avoided.

As shown in fig. 3, the pushing device 140 includes a rectangular cylinder sleeve 80 mounted inside the pushing body 100 and sleeved on the mandrel 50 of the vertical drilling tool 150. Grooves 81 are formed in a first pair of diametrically opposite side walls of the cylinder sleeve 80, and the grooves 81 communicate with the inner cavity of the mandrel 50 through flow passages. A through hole 102 including a step is provided in the thrust rib 101. The grooves 81 on the first pair of side walls of the cylinder liner 80 define, in combination with the through holes 102 in the respective thrust ribs 101 of the thrust body 100, a pair of piston chambers. A cylindrical piston 110 is installed in each piston cavity, and a head of the piston 110 is formed as a stepped shaft and is correspondingly installed in the through hole 102 pushing against the rib 101. The piston 110 is capable of radial movement under the action of drilling fluid from the mandrel 50 of the vertical drilling tool 150, thereby radially pushing out the thrust ribs 101 to push against the borehole wall. A guide rail (not shown) is provided on the wall surface of the rib that contacts the second side wall of the cylinder liner 80. In this way, the rib is able to slide on the second pair of side walls relative to the cylinder liner 80 and cause the pair of thrust ribs 101 to move in the same direction.

In the present embodiment, the head end surface of the piston 110 forms a spherical crown surface on which the nozzle 90 is mounted. The cylindrical piston 110 is provided with a central through hole 112 communicating with the recess 81 of the cylinder casing 80, and the outlet of the nozzle 90 communicates with the central through hole 112 of the piston 110. In addition, the rear portion of the cylindrical piston 110 is fitted in the recess 81 of the cylinder casing 80, and a groove (not shown) is provided on the wall surface of the recess 81, and a packing or wiper ring is provided in the groove to ensure sealing performance between the cylinder casing 80 and the piston 110.

According to the invention, in order to increase the pushing effect of the pushing device 140, at least two pushing mechanisms 141 are arranged on the mandrel 50 at a distance from one another in the axial direction, and the at least two pushing mechanisms 141 are arranged offset from one another by an angle in the circumferential direction. Preferably, as shown in fig. 1, two pushing mechanisms 141 are arranged on the mandrel 50 at an axial distance from each other, which are offset from each other by 90 degrees in the circumferential direction. Thus, a total of four thrust ribs 101 spaced 90 degrees apart from each other in the circumferential direction can apply a thrust force against the borehole wall.

As shown in fig. 3, a stepped first joint portion 84 is provided outside the upper end of the cylinder liner 80. The first joint portion 84 of the cylinder casing 80 is connected to the lower portion of the outer cylinder 20, and the end surface of the first joint portion 84 abuts against the disk surface of the second annular valve, so that the second annular valve 70 is in close contact with the first annular valve 60. Meanwhile, a stepped second joint section 85 matching the stepped lower joint nipple 52 of the mandrel 50 is provided inside the lower end of the cylinder liner 80. The bearing assembly 40 is arranged between the second joint part 85 of the cylinder sleeve 80 and the lower joint sub of the mandrel 50, so that the pushing device 140 can be kept relatively static or slowly rotated underground, and the pushing effect and the control precision of the pushing device 140 are guaranteed.

The principles of operation and the flow of use of the vertical drilling tool 150 according to the present invention are briefly described below. In the actual drilling process, the lower end of the vertical drilling tool 150 is directly connected with a drill bit, the upper end is connected with a conventional drilling tool and a screw, the adjustment of drilling engineering parameters such as high drilling pressure, high rotating speed and the like is realized through the mandrel 50, and the outer barrel 20 sleeved on the mandrel 50 is not influenced by the mandrel and is basically in a static or slow rotating state. As shown in fig. 4, during drilling, most of the drilling fluid 170 flows to the drill bit through the flow passage 55 in the middle of the mandrel 50 and enters the annulus, and only a small part of the drilling fluid 171, after being subjected to grinding and filtering treatment, enters the inside of the outer cylinder 20 through the flow hole 130 between the mandrel 50 and the outer cylinder 20 and is used as high-pressure working fluid to drive the pushing mechanism 141 and cool and lubricate the bearing assembly 40. Under the action of the water pressure difference of the drill bit, the small-displacement drilling fluid 171 is used for driving the pushing mechanism 141 to interact with the high side of the well hole, so that effective static pushing of the vertical drilling tool 150 is realized.

As shown in fig. 4, when the well deviation exceeds the standard, the weight 30 located in the outer cylinder 20 is rotated by gravity, and at the same time, the first annular valve 60 attached to the lower end of the outer cylinder 20 is rotated to a position perpendicular to the lower side of the well drilling tool 150 and is maintained within a certain dynamic stability accuracy range. At this time, the port opening of the opening mechanism 144 located in the high side direction of the second annular valve 70 is opened, and the small-displacement drilling fluid 171 filtered by the flow passage device 130 on the mandrel 50 flows into the high-pressure flow passage at the high side position of the outer cylinder 20 and enters the corresponding piston cavity, so that the push piston 110 slides in the radial direction, and the push rib 101 is driven to extend outwards, thereby statically pushing against the well wall, applying a static pushing force 160 to the high side position of the well bore, and under the action of the reaction force of the well bore, the vertical drilling tool 150 deflects towards the low side direction of the well bore, so as to realize the inclination correction in the drilling process. When the vertical drilling tool 150 enters the vertical state from the inclined state, the eccentric action of gravity is not applied to the eccentric piece 30 in the outer cylinder 20, and the fixed position does not exist between the first annular valve 60 and the second annular valve 70 to judge the high and low sides, so that the random rotation state is realized, and the extension of the thrust rib 101 is random uncertain and has no deviation rectifying effect.

The vertical drilling tool 150 provided by the invention is completely composed of mechanical parts, has no electronic components and hydraulic structures, is not limited by a high-temperature environment, and has a wide application range. Wherein the mandrel 50 has flowed through most of the drilling fluid, transferred weight on bit torque, provided high rotational speed, experienced major vibrational shock, reduced adverse effects on the outer barrel 20. Meanwhile, the eccentric weight 30 is installed on the inner wall of the outer cylinder 20 through the bearing 44 and isolated from the mandrel 50, so that the influence of vibration impact generated by rock breaking of the drill bit is avoided, and the vertical drilling tool 150 can quickly and accurately respond to well deviation change. In addition, the pushing mechanism 141 is arranged at the lower part of the outer cylinder 20, so that the stress condition and the abrasion condition of the pushing mechanism are greatly improved, and the stability and the reliability of the pushing mechanism 141 are improved.

Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and do not limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing examples, or that equivalents may be substituted for elements thereof. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A vertical drilling tool, comprising:

the drilling fluid overflowing device comprises a mandrel with a hollow tubular structure, wherein a drilling fluid overflowing channel is arranged in the center of the mandrel;

the outer cylinder is sleeved on the mandrel and can independently rotate, and the outer cylinder is rotatably supported on the mandrel;

a biasing member disposed between the outer barrel and the mandrel, the biasing member configured to automatically rotate upon tilting of the drilling tool to open a high-side flow passage and close a low-side flow passage of the drilling tool to dispense an overflow drilling fluid to the high-side flow passage;

and a pushing device arranged at the lower part of the outer cylinder, wherein the pushing device pushes against a well wall along the high-side direction under the action of drilling fluid from the high-side flow passage to correct the inclination state of the drilling tool, the pushing device comprises a cylinder sleeve and a pushing mechanism, the cylinder sleeve is rectangular, the pushing mechanism comprises a pushing body which is arranged in the cylinder sleeve and has a hollow cuboid structure, a pair of ribs which are opposite in the radial direction, and a piston, the pushing body comprises a pair of pushing wing ribs which are opposite in the radial direction, the outer edge profile surfaces of the pushing wing ribs are formed into cylindrical surfaces or spherical surfaces, the piston can apply radial force to the pushing wing ribs under the action of the drilling fluid to push the pushing wing ribs out along the high-side direction to push against the well wall, the pushing wing ribs which are opposite in the radial direction are mutually connected through the ribs to form an interlocking structure, and the head end surface of the piston forms, the spherical crown surface is provided with a nozzle which is communicated with the inner cavity of the mandrel, an overflowing device is arranged between the mandrel and the eccentric member, and the overflowing device comprises a filtering piece for filtering drilling fluid.

2. The vertical drilling tool of claim 1, wherein the biasing member is provided as a cylindrical member having an elongate flow space open to a portion of an outer wall area.

3. The vertical drilling tool of claim 1 or 2, wherein the biasing member is arranged to be isolated from the mandrel but connected at both ends to the outer barrel by bearings.

4. The vertical drilling tool of claim 1, wherein the pushing device comprises an opening mechanism for selectively opening one of the high-side flow passage and the low-side flow passage while closing the other of the high-side flow passage and the low-side flow passage.

5. The vertical well tool of claim 4, wherein the opening mechanism comprises a first annular valve secured to a lower end of the biasing member and a second annular valve secured to a lower inner wall of the outer barrel, the first and second annular valves being configured as abutting discs.

6. The vertical drilling tool of claim 5, wherein the first annular valve has a disk surface with a circumferentially extending arcuate through bore and the second annular valve has a plurality of flow passage bores uniformly circumferentially disposed thereon, the first annular valve being rotatable with the biasing member such that the arcuate through bore is aligned with the flow passage bores of the second annular valve in the high or low side region to open the high side flow passage or the low side flow passage.

7. The vertical drilling tool of claim 6, wherein the sidewall of the first annular valve having the arcuate through-hole is circumferentially aligned with the sidewall of the biasing member having the elongate flow passage space.