A drilling tool with high tension and convergence success rate and capable of replacing drill bits without lifting the drill

Abstract

The present invention relates to the technical field of drill tools for changing drill bits without lifting the drill bit, and specifically discloses a drill tool for changing drill bits without lifting the drill bit with a high success rate of tension and convergence, wherein the suspension joint is connected to the drill bit frame; the upper outer tube is connected to the positioning end tube; the outer cylindrical surface of the suspension joint and the inner cylindrical surface of the upper outer tube form an annular gap; the lower end surface of the suspension joint contacts the upper end surface of the positioning end tube, forming both a plane-sealed end face sealing mechanism and a surface-suspended suspension mechanism; the arrow-shaped spline pair composed of the outer arrow-shaped spline of the drill bit frame and the inner arrow-shaped spline of the positioning end tube constitutes an aiming mechanism. The present invention changes point suspension to surface suspension, increases the suspension area and makes the suspension more secure; the aiming mechanism is more flexible and reliable; and the overall success rate of tension and convergence is increased to more than 90%.

Description

Technical Field

[0001] The invention relates to the technical field of drilling machinery, in particular to a drilling tool with high tension and convergence success rate and the ability to replace a drill bit without lifting the drill. Background Art

[0002] Among the existing drill tools that can be replaced without lifting the drill bit, the most mature technology is the expansion and tensioning type drill tool that can be replaced without lifting the drill bit. The expansion and tensioning type drill tool that can be replaced without lifting the drill bit adopts the main drill bit and the auxiliary drill bit for secondary rock crushing, and is usually used in conjunction with the rope drill rod, rope winch and rope salvage device for core drilling.

[0003] The existing hole expansion and convergence type drill tool without lifting the drill bit includes a main drill tool as a salvage part and an auxiliary drill tool as a non-salvage part. The auxiliary drill tool only includes a positioning end tube, an upper outer tube and a sealing ring. The main drill bit, auxiliary drill bit, hanging joint, drill bit rack and other parts are the main drill tool. Among them, the main drill bit is slightly smaller than the inner diameter of the rope drill pipe and drills a pilot hole; the auxiliary drill bit is usually composed of 3 to 6 petals and has a convergence function. After convergence, it is equivalent to the diameter of the main drill bit and can be raised and lowered inside the rope drill pipe. After opening, it can realize hole expansion drilling and drill a hole 4mm to 10mm larger than the outer diameter of the rope drill pipe.

[0004] The success rate of the auxiliary drill bit reaching the predetermined position at the bottom of the well and opening to the designed size is the opening success rate of the drill bit without lifting the drill bit to change the drill bit; when the rope salvage device salvages the main drill bit, the success rate of the auxiliary drill bit being able to converge to the designed size and the main drill bit being successfully salvaged to the surface is the convergence success rate. The opening success rate and the convergence success rate, together, are the opening and convergence success rate. In each coring round, only the main drill bit is salvaged to the surface by the rope salvage device, and the work of coring, replacing the drill bit, and checking the drill bit is completed. The auxiliary drill bit is connected to the drill pipe and does not need to be lifted to the surface. Only when the drill bit fails to open or converge, will the large drill be lifted to lift the auxiliary drill bit to the surface.

[0005] Taking the positioning tensioning type drill tool for changing drill bits without lifting the drill bit disclosed in the Chinese utility model with the announcement number CN85200563U and the drill tool for changing drill bits without lifting the drill bit disclosed in the Chinese invention patent with the announcement number CN103603625B as examples, the drill tools for changing drill bits without lifting the drill bit disclosed in the two have an aiming positioning device and a suspension device. The aiming positioning device is an arrow-shaped spline pair composed of an arrow-shaped external spline of the drill bit frame and an arrow-shaped internal spline of the positioning end tube for initial aiming positioning and guidance. The arrow-shaped spline pair can make the rectangular window hole of the drill bit frame and the trapezoidal torque groove at the lower end of the positioning end tube basically consistent in orientation with the help of gravity and the spiral guiding effect of the arrow head part, and then use the trapezoidal meshing pair composed of the trapezoidal end of the auxiliary drill bit and the trapezoidal torque groove of the positioning end tube to perform micro-aiming correction and transmit torque. At the same time, the upper end of the drill bit rack is connected to a hanging joint, which is a round tube with a boss on the lower part of the outer circle. The lower plane of the boss close to the external thread is the hanging surface, which can be hung on the arrow part of the arrow-shaped internal spline of the positioning end tube to form a point-suspended hanging mechanism.

[0006] The maximum well depth of the above-mentioned drilling tool for replacing the drill bit without lifting the drill bit is currently 2,200 meters, and its success rate of tension and convergence is only about 80%. Summary of the invention

[0007] The present invention is based on the prior art and provides a drill tool with a high tensioning and convergence success rate for changing drill bits without lifting the drill bit. The suspension mechanism, aiming mechanism and sealing structure of the liquid flow auxiliary channel are optimized and designed, which greatly improves the tensioning and convergence success rate of the drill tool for changing drill bits without lifting the drill bit.

[0008] The present invention is realized through the following technical scheme: a drill tool with high tension and convergence success rate and capable of replacing a drill bit without lifting the drill, which is installed on a drill pipe joint for use.

[0009] The drill tool for changing drill bits without lifting the drill bit includes a main drill tool and an auxiliary drill tool. The main drill tool includes a suspension joint and a drill bit rack. The auxiliary drill tool includes a positioning end tube and an upper outer tube. When in use, the upper outer tube of the drill tool for changing drill bits without lifting the drill bit is installed on a drill pipe joint.

[0010] The suspension joint is connected to the drill bit frame.

[0011] The upper outer tube is connected to the positioning end tube.

[0012] The outer cylindrical surface of the suspension joint and the inner cylindrical surface of the upper outer tube form an annular gap; the lower end surface of the suspension joint contacts the upper end surface of the positioning end tube, forming both a plane-sealed end surface sealing mechanism and a surface-suspended suspension mechanism; that is, the surface where the suspension joint and the positioning end tube contact each other is both a sealing surface and a suspension surface.

[0013] The drill bit rack is provided with an outer arrow-shaped spline, the positioning end tube is provided with an inner arrow-shaped spline, and the arrow-shaped spline pair composed of the outer arrow-shaped spline and the inner arrow-shaped spline constitutes an aiming mechanism.

[0014] In the present invention, the outer cylindrical surface of the suspension joint and the inner cylindrical surface of the upper outer tube form an annular gap, and the annular gap is a section of the liquid flow auxiliary channel. The suspension joint and the positioning end tube constitute both an end face sealing mechanism and a suspension mechanism. The outer arrow-shaped spline of the drill bit holder and the inner arrow-shaped spline of the positioning end tube constitute an aiming mechanism.

[0015] Compared with the prior art, the present invention changes the structures of the suspension joint, the drill bit holder, the positioning end tube, and the upper outer tube: first, the original sealing ring structure is omitted; second, the aiming part of the original aiming mechanism and the hanging part of the suspension mechanism are designed separately; third, the hanging part of the suspension mechanism is changed to a surface contact structure, thereby optimizing the point suspension to the surface suspension; fourth, the suspension joint and the positioning end tube are designed to be in a structure of mutual plane contact, thereby forming a plane-sealed end face sealing mechanism. Moreover, the suspension surface of the suspension mechanism is in the same position as the sealing surface of the end face sealing mechanism.

[0016] Furthermore, in order to better implement the present technical solution, a drain hole is also provided on the suspension joint.

[0017] Furthermore, in order to better implement the present technical solution, a strip-shaped powder discharge channel is added to the outer cylindrical surface of the positioning end tube.

[0018] Furthermore, in order to better implement the present technical solution, the number of petals of the auxiliary drill bit is 4 or 5; when the maximum outer diameter of the auxiliary drill bit when it is opened is 95mm~98mm, the number of petals of the auxiliary drill bit is 4; when the maximum outer diameter of the auxiliary drill bit when it is opened is 122~125mm, the number of petals of the auxiliary drill bit is 5.

[0019] Furthermore, in order to better implement the present technical solution, based on the inner diameter d of the drill pipe joint, the unit is mm; the outer diameter of the suspension joint is (d-1.7) mm; the inner diameter of the upper outer tube is (d-1.3) mm to (d-1.4) mm.

[0020] Furthermore, in order to better implement the technical solution, the outer diameter of the suspension surface is (d-1.7) mm; the inner diameter of the suspension surface is (d-2.4) mm.

[0021] Furthermore, in order to better implement the present technical solution, the major diameter of the outer arrow spline is (d-2.4) mm; the minor diameter of the outer arrow spline is (d-5) mm; the major diameter of the inner arrow spline is (d-2.4) mm; the minor diameter of the inner arrow spline is (d-5) mm; the fillet radius R of the arrow portion of the outer arrow spline and the inner arrow spline are both 0.4 mm~0.8 mm.

[0022] Furthermore, in order to better implement the technical solution, the main drilling tool also includes a main drill bit; the outer diameter of the main drill bit is (d-6) mm.

[0023] Furthermore, in order to better implement the technical solution, the main drilling tool also includes a signal valve; the number of external grooves of the signal valve is 5 or 6.

[0024] Furthermore, in order to better implement the technical solution, the main drilling tool also includes a stopper; the wall thickness of the stopper is 1.5 mm to 1.75 mm.

[0025] Compared with the prior art, the present invention has the following advantages and beneficial effects.

[0026] (1) The present invention provides a drill bit replacement drill with a high tensioning and convergence success rate. The suspension mechanism, aiming mechanism, sealing structure of the fluid secondary channel, key dimensions of some parts, etc. are optimized to increase the tensioning and convergence success rate of the drill bit replacement drill without lifting the drill to about 95%.

[0027] (2) The present invention provides a drill bit replacement tool with a high tension and convergence success rate without lifting the drill, wherein the tip of the arrow head is sharper, that is, the fillet radius of the arrow head is smaller, and the aiming mechanism is more flexible and reliable.

[0028] (3) The present invention provides a drill bit replacement tool with a high tensioning and convergence success rate without lifting the drill. The annular gap is enlarged, making it easier for the suspension joint to enter the upper outer tube, thereby improving the tensioning and convergence success rate. While increasing the annular gap, an end face sealing structure is added, so that the main drill bit will not burn due to flow distribution problems.

[0029] (4) The present invention provides a high tension and convergence success rate drill tool that does not require the drill bit to be replaced. More powder discharge channels are added, which can greatly increase the cross-sectional area of ​​the powder discharge channels and have little effect on the strength of the positioning end tube.

[0030] (5) The present invention provides a high tension and convergence success rate drill bit replacement without lifting the drill, which is equipped with a drainage hole to increase the speed of the main drilling tool, further reduce the auxiliary time, and improve the utilization rate of the pure drilling time.

[0031] (6) The present invention provides a high tension and convergence success rate drill bit replacement drill bit without lifting the drill, the number of petals of the auxiliary drill bit is preferably 4 or 5 petals, at this time the auxiliary drill bit has a better cooling effect and the drill bit rotation is more stable.

[0032] (7) The present invention provides a high tension and convergence success rate drill bit replacement drill tool that does not require the drill bit to be lifted. The key dimensions of the suspension joint, upper outer tube and other parts are optimized to meet the water flow requirements while ensuring the strength of the drill tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the cross-sectional structure of the upper part of the drilling tool of the present invention in the open state.

[0034] Figure 2 It is a schematic diagram of the cross-sectional structure of the lower half of the drilling tool of the present invention in an open state.

[0035] Figure 3 It is a schematic diagram of the cross-sectional structure of the upper part of the drilling tool in the convergent state according to the present invention.

[0036] Figure 4 for Figure 3 Schematic diagram of the structure of the AA section.

[0037] Figure 5 Schematic diagram of the suspension surface in the suspension mechanism.

[0038] Figure 6 It is a structural schematic diagram of the arrow part of the optimized arrow-shaped spline.

[0039] Figure 7 Schematic diagram of the local structure of the front liquid flow secondary channel for optimization.

[0040] Figure 8 Schematic diagram of the local structure of the optimized liquid flow secondary channel.

[0041] Fig. 9 It is a schematic diagram of the radial section of the positioning end tube corresponding to the enlarged powder discharge channel.

[0042] Fig.10 for Fig. 9 Schematic diagram of the structure of the BB section.

[0043] Fig.11 It is a schematic diagram of the cross-sectional structure of the rectangular window of the drill bit holder of the 5-petal auxiliary drill bit.

[0044] Fig.12 A schematic diagram of the structure of a suspension joint with an additional drain hole.

[0045] Among them, 1. main drilling tool; 2. auxiliary drilling tool; 3. original powder discharge channel; 4. strip powder discharge channel; 5. alarm valve; 6. drainage rod; 7. tension and convergence shaft; 8. drain hole; 9. hanging joint; 10. drill bit rack; 11. auxiliary drill bit; 12. limiter; 13. annular gap; 14. upper outer tube; 15. positioning end tube; 16. hanging surface; 17. sealing surface; 18. arrow-shaped spline pair; 19. main drill bit; 20. sealing ring; 100. drill pipe joint. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0047] Note: All "drilling tools" in the present invention refer to "drilling tools for replacing drill bits without lifting the drill bit", and "drilling tools" include "main drilling tools 1" and "auxiliary drilling tools 2".

[0048] Embodiment 1:

[0049] Prior art 1: A positioning tension-retracting drill tool for changing drill bits without lifting the drill bit disclosed in Chinese utility model CN85200563U, Prior art 2: A casing coring drill tool disclosed in Chinese invention patent with announcement number CN103603625B, wherein the aiming mechanism and suspension mechanism of the drill tool are both based on an arrow-shaped spline pair 18. On the one hand, when the main drill tool 1 enters the auxiliary drill tool 2, the outer arrow-shaped spline of the drill bit holder 10 and the inner arrow-shaped spline of the positioning end tube 15 are automatically aimed, so that the auxiliary drill bit 11 is aligned with the rectangular window of the drill bit holder 10; on the other hand, when suspended, the suspension joint 9 is suspended on the arrow portion of the arrow-shaped spline inside the positioning end tube 15, presenting a point suspension structure.

[0050] The drill tool for changing drill bits without lifting the drill bit provided in this embodiment and the drill tool for changing drill bits without lifting the drill bit in the prior art both include a main drill tool 1 and an auxiliary drill tool 2. The main drill tool 1 is roped to the surface for coring, inspection, and drill bit replacement in each coring round; the auxiliary drill tool 2 is connected to the drill rod joint 100 at the bottom of the rope drill rod and can only be lifted to the ground when the large drill is lifted. The main drill tool 1 has two working states, namely, the drilling working state after opening and the convergence state. The conversion of the two working states is achieved by turning on the pump to push the tensioning and convergence shaft assembly downward and pulling the rope salvage device upward to drive the tensioning and convergence shaft assembly upward. Among them, the auxiliary drill tool 2 includes a positioning end tube 15, an upper outer tube 14, and an upper reamer; the main drill tool 1 includes other components except the three components covered by the auxiliary drill tool 2.

[0051] The drill tool provided in this embodiment is a drill tool with a high tensioning and convergence success rate that does not require lifting the drill bit to change the drill bit, after optimizing the structure of the drill tool in the prior art, which greatly improves its tensioning and convergence success rate. When used for operations at a well depth of 2,200 meters, its tensioning and convergence success rate can reach 97%; for operations at a well depth of more than 2,200 meters, its tensioning and convergence success rate can also be guaranteed to be above 90%.

[0052] This embodiment only describes the optimized structure of the drilling tool, and the structures not specifically described are the same as the prior art. For example: the auxiliary drilling tool 2 includes a positioning end tube 15, an upper outer tube 14, and an upper reamer, but since the present invention mainly optimizes the structure of the positioning end tube 15 and the upper outer tube 14, only the positioning end tube 15 and the upper outer tube 14 are described. Another example: the main drilling tool 1 includes other parts in addition to the three parts covered by the auxiliary drilling tool 2, but since the present invention mainly optimizes the structure of the suspension joint 9, the drill bit frame 10, the main drill bit 19, and the stopper 12, other parts are not described in detail.

[0053] like Figure 1-Figure 4 As shown, in this embodiment, the suspension joint 9 is connected to the drill bit frame 10, the upper outer tube 14 is connected to the positioning end tube 15, the outer cylindrical surface of the suspension joint 9 and the inner cylindrical surface of the upper outer tube 14 form an annular gap 13, and the lower end surface of the suspension joint 9 contacts the upper end surface of the positioning end tube 15 to form a suspension surface 16, and the suspension surface 16 is also a sealing surface 17; the suspension joint 9 and the positioning end tube 15 form a surface suspension suspension mechanism, and also a plane sealing end surface sealing mechanism. The drill bit frame 10 is provided with an outer arrow-shaped spline, and the positioning end tube 15 is provided with an inner arrow-shaped spline, and the arrow-shaped spline pair 18 composed of the outer arrow-shaped spline and the inner arrow-shaped spline constitutes an aiming mechanism.

[0054] First, the suspension mechanism and the aiming mechanism are set separately, and the point suspension structure is changed to a surface suspension structure.

[0055] In the prior art, since the suspension mechanism needs to withstand the impact force when the main drilling tool 1 is dropped and the force when the core is pulled out, the arrowhead of the inner arrow-shaped spline and the four points where the suspension joint contacts it are prone to burrs, resulting in failure of convergence and positioning. Therefore, in this embodiment, the suspension mechanism is set separately from the aiming mechanism, and the point suspension structure is changed to a surface suspension structure.

[0056] like Figure 5 As shown, the suspension in prior art 1 and prior art 2 is 2mm×2mm with four sharp points; in this embodiment, the suspension joint 9 and the positioning end tube 15 constitute a surface suspension suspension mechanism. Since the suspension mechanism is separately provided from the spline aiming mechanism, the four arrowheads of the arrow-shaped spline pair 18 no longer bear the impact force when the drilling tool is dropped and the force of pulling out the core, so it can be designed to be sharper.

[0057] Second, the surface-suspended suspension mechanism is also a plane-sealed end-face sealing mechanism. Due to the addition of the end-face seal, the annular gap 13 can be designed to be larger.

[0058] The drills without drill bit replacement in prior art 1 and prior art 2 have two liquid flow channels, namely, the main liquid flow channel and the secondary liquid flow channel. The main liquid flow channel: the drain hole of the drainage rod 6 → the central hole of the tension and convergence shaft 7 → the main drill bit 19. The secondary liquid flow channel: the annular gap 13 between the suspension joint 9 and the sealing ring 20 → the secondary drill bit 11. The flow rate of the main liquid flow channel must account for more than 90% of the total flow rate, otherwise it will cause the main drill bit 19 to burn the drill, which requires that the annular gap 13 of the secondary liquid flow channel should not be too large, but the smaller annular gap 13 makes it difficult to get into position, that is, it is difficult for the suspension joint to enter the sealing ring.

[0059] like Figure 7 As shown, in the prior art, a sealing ring 20 is arranged between the upper outer tube 14 and the suspension joint 9, and an annular gap 13 is formed between the sealing ring 20 and the suspension joint 9. When suspended, the outer cylindrical surface of the suspension joint 9 and the inner cylindrical surface of the sealing ring 20 form a liquid flow secondary channel.

[0060] like Figure 8 As shown, the present embodiment directly omits the sealing ring 20, and optimizes the structure of the suspension joint 9, the drill bit frame 10, the upper outer tube 14, and the positioning end tube 15. After optimization, the sealing ring 20 is directly omitted, which can improve the success rate of tensioning and convergence, and also improve the life of the drilling tool. Originally, the sealing ring 20 has a thin wall and is easy to deform. The size of the annular gap 13 is originally very small, and it becomes even smaller after deformation, which seriously affects the opening of the main drilling tool 1 and reduces the success rate of tensioning and convergence; after omitting the sealing ring 20, the structure of the upper outer tube 14 is changed, which is equivalent to merging the sealing ring 20 into the upper outer tube 14. Since the upper outer tube 14 has a thick wall and will not deform, the success rate of tensioning and convergence is improved. The sealing ring 20 has a thin wall, is easy to deform, and has a short life. It is a consumable part of the drilling tool. By omitting the sealing ring 20, a consumable part is removed, thereby improving the life of the drilling tool.

[0061] On the one hand, the outer cylindrical surface of the suspension joint 9 forms an annular gap 13 with the inner cylindrical surface of the upper outer tube 14, and on the other hand, the lower end surface of the suspension joint 9 contacts the upper end surface of the positioning end tube 15 to form a sealing surface 17. This plane-sealed end face sealing mechanism allows the size of the annular gap 13 to be increased, which is conducive to improving the success rate of opening in place. At the same time, because of the end face sealing, the flow rate of the liquid flow secondary channel will not increase. Taking the Φ95mm drill bit replacement drill tool as an example, the original annular gap 13 is 0.08mm~0.125mm. After being optimized to the end face sealing structure, the annular gap 13 in this embodiment can be adjusted to 0.15mm~0.20mm. At this time, the suspension joint 9 is easier to enter the upper outer tube 14, thereby improving the success rate of opening and convergence. Due to the addition of the end face sealing mechanism, the increase of the annular gap 13 will not cause too much flushing liquid to flow away from the liquid flow secondary channel and cause insufficient flow in the liquid flow main channel, and naturally there will be no drilling burn accident caused by flow distribution problems. Furthermore, in order to make the structure more compact, the suspension surface 16 of the suspension mechanism is aligned with the sealing surface 17 of the end face sealing mechanism. Figure 8 As shown, the suspension surface 16 is the sealing surface 17 .

[0062] The present embodiment provides a drill tool with a high tensioning and convergence success rate for changing drill bits without lifting the drill bit. The optimized design of the suspension mechanism, aiming mechanism, and end face sealing structure greatly improves the tensioning and convergence success rate of the drill tool for changing drill bits without lifting the drill bit.

[0063] Embodiment 2:

[0064] This embodiment is further optimized based on the above embodiment. Figure 3 , Fig.12 As shown, a drain hole 8 is also provided on the suspension joint 9.

[0065] Generally speaking, there is water in the drill pipe in the hole. When the main drill 1 is put into operation, the gap between the outer diameter of the main drill 1 and the inner diameter of the drill pipe is very small, usually 1mm~2mm. The water in the drill pipe needs to be continuously discharged upward through this gap, so that the main drill 1 can continue to move downward, similar to the movement of a piston. Therefore, the main drill 1 in the prior art 1 and the prior art 2 has a slow descent speed, and generally it takes about 15 minutes to reach a hole depth of 800m. If a water unloading hole is added to the hanging joint 9 of the main drill 1, the water flow area will be increased by 47%, and it will only take about 10 minutes to lower the main drill 1 to a hole depth of 800m.

[0066] Therefore, by adding the drainage hole 8 to the suspension joint 9, the delivery speed of the main drilling tool 1 can be increased, the auxiliary time can be further reduced, and the utilization rate of the pure drilling time can be improved.

[0067] The other parts of this embodiment are the same as those of the above embodiment, so they will not be described in detail.

[0068] Embodiment 3:

[0069] This embodiment is further optimized on the basis of the above embodiment, in that a strip-shaped powder discharge channel 4 is added to the outer cylindrical surface of the positioning end tube 15 .

[0070] In this embodiment, the drill bit replacement is not mentioned. The drill tool adopts the main drill bit 19 and the auxiliary drill bit 11 for two-stage rock crushing, just like the prior art 1 and the prior art 2. The total rock crushing area is large, so there is a lot of rock powder. In addition, the cross-section mutation at the positioning end tube 15 easily causes rock powder accumulation, resulting in repeated crushing, which seriously affects the drilling efficiency and greatly reduces the life of the auxiliary drill bit 11. Therefore, in this embodiment, by adding a strip-shaped powder discharge channel 4 to the outer cylindrical surface of the auxiliary drill bit 11, the powder discharge channel of the auxiliary drill bit 11 is enlarged, repeated crushing is reduced, and the life of the auxiliary drill bit 11 and the mechanical drilling speed can be increased. Fig. 9 , Fig.10 As shown, compared with the original powder discharge channel 3, the strip-shaped powder discharge channel 4 is added in this embodiment, thereby adding more powder discharge channels, which can greatly increase the cross-sectional area of ​​the powder discharge channel and has little effect on the strength of the positioning end tube 15.

[0071] The other parts of this embodiment are the same as those of the above embodiment, so they will not be described in detail.

[0072] Embodiment 4:

[0073] This embodiment is further optimized based on the above embodiment, and the number of outer grooves of the warning valve 5 is 5 or 6.

[0074] The signaling valve 5 and the suspension joint 9 together constitute a signaling mechanism, which utilizes the different matching positions of the signaling valve 5 and the inner cavity of the suspension joint 9 to open or close the main liquid flow channel, causing pump pressure changes to reflect the state of the drill tool in the hole. In the convergence state, the main liquid flow channel of the drill tool is closed. After the pump is turned on, the pressure rises to the signaling pressure, pushing the signaling valve 5, the drainage rod 6 and the tensioning and convergence shaft 7 downward at the same time, driving the auxiliary drill bit 11 to open; after the auxiliary drill bit 11 is opened in place, the main liquid flow channel of the drill tool is opened, and the pump pressure immediately drops to normal pressure. This working principle is a prior art and will not be repeated here. Based on this working principle, this embodiment optimizes the number of external grooves of the signaling valve 5 to 5 or 6. The water trough is wider, and the debris in the mud is not easy to clog the water trough, thereby reducing the number of pump jams.

[0075] The number of outer grooves of the signal valve 5 was originally 9, and the width of the water groove was 9mm. During use, debris in the mud, such as cotton yarn, iron filings, butter, etc., can easily clog the water groove, causing the pump pressure to rise sharply, resulting in the pump being blocked and unable to drill. The main drilling tool can only be salvaged to the surface for inspection and cleaning.

[0076] The number of outer grooves of the alarm valve 5 is changed to 6, and the width of the water groove is 12mm; the number of outer grooves of the alarm valve 5 is changed to 5, and the width of the water groove is 13mm; in this way, the phenomenon of debris in the mud clogging the water groove has been greatly improved, thereby reducing the number of times the main drilling tool must be salvaged by the pump, and improving the utilization rate of pure drilling time and the monthly efficiency.

[0077] The other parts of this embodiment are the same as those of the above embodiment, so they will not be described in detail.

[0078] Embodiment 5:

[0079] This embodiment is further optimized on the basis of the above embodiment. The number of petals of the auxiliary drill bit 11 is 4 or 5. When the maximum outer diameter of the auxiliary drill bit 11 is 95mm~98mm when it is opened, the number of petals of the auxiliary drill bit 11 is 4. When the maximum outer diameter of the auxiliary drill bit 11 is 122mm~125mm when it is opened, the number of petals of the auxiliary drill bit 11 is 5. Fig.11 As shown, the number of petals of the auxiliary drill bit 11 is preferably 5. At this time, the cooling effect of the auxiliary drill bit 11 is better and the rotation of the drilling tool is more stable.

[0080] In order to ensure strength, the one-petal auxiliary drill bit 11 can only be designed as a whole, that is, no water tank can be opened inside the auxiliary drill bit 11. Strength and cooling performance requirements: The width of the one-petal auxiliary drill bit 11 should be 20mm~23mm. When the maximum outer diameter of the auxiliary drill bit 11 is 95mm~98mm when it is opened, the number of petals of the auxiliary drill bit 11 is 4 petals, and the width of the auxiliary drill bit 11 is 21mm; when the maximum outer diameter of the auxiliary drill bit 11 is 122mm~125mm when it is opened, if the number of petals of the auxiliary drill bit 11 is still 4 petals, the width of the auxiliary drill bit 11 is 28mm, because the auxiliary drill bit 11 is too wide and no water tank can be opened inside, the middle part of the auxiliary drill bit 11 cannot be fully cooled; if the number of petals of the auxiliary drill bit 11 is designed to be 5 petals, the width of the auxiliary drill bit 11 is 21mm, and the middle part of the auxiliary drill bit 11 can be fully cooled; in addition, 5 petals are more stable than 4 petals, and the drilling tool rotates more smoothly.

[0081] The other parts of this embodiment are the same as those of the above embodiment, so they will not be described in detail.

[0082] Embodiment 6:

[0083] This embodiment is further optimized based on the above embodiment. Figure 1 As shown, based on the inner diameter d of the drill pipe joint 100, the unit is mm, and the dimensions of some key components of the drilling tool are optimized.

[0084] 1. A specific embodiment based on the inner diameter d of the drill pipe joint 100 is to optimize the sizes of the suspension joint 9 and the upper outer tube 14. After optimization, the outer diameter of the suspension joint 9 is (d~1.7) mm; the inner diameter of the upper outer tube 14 is (d~1.3) mm to (d~1.4) mm.

[0085] Note: The outer diameter of the suspension joint 9 is Dxw; the inner diameter of the upper outer tube 14 is Dshn; Figure 8 shown.

[0086] On one hand, the outer diameter of the suspension joint 9 is the maximum outer diameter of the main drilling tool 1 , and the gap S1 between the outer diameter of the suspension joint 9 and the inner diameter of the drill pipe joint 100 determines the descending speed of the main drilling tool 1 when it is dropped.

[0087] If the gap S1 is too large, the strength of the main drill 1 will be reduced and the rock crushing area will be increased. Specific analysis: The outer diameter of the suspension joint 9 becomes smaller, resulting in a corresponding decrease in the outer diameter of the main drill bit 19, increasing the tension and convergence value of the auxiliary drill bit 11, where the tension and convergence value of the auxiliary drill bit 11 = (open diameter - converged diameter) = (open diameter - outer diameter of the main drill bit 19). The increase in the tension and convergence value of the auxiliary drill bit 11 will reduce the strength of the tension and convergence shaft 7 and the auxiliary drill bit 11. The reduction in the outer diameter of the main drill bit 19 will increase the rock crushing area of ​​the auxiliary drill bit 11, reduce the drilling speed, and at the same time reduce the diameter of the core obtained.

[0088] If the gap S1 is too small, it will not only affect the descending speed of the main drilling tool 1, but also may cause the main drilling tool 1 to be stuck in the drill pipe joint 100, so that the main drilling tool 1 cannot reach the predetermined position and the drilling tool cannot be opened normally, thereby reducing the success rate of opening the drilling tool.

[0089] After research, it is found that the gap S1 must be ≧0.85mm, so S1=0.85mm. At this time, the outer diameter of the suspension joint 9 = d-2×0.85=d-1.7.

[0090] On the other hand, the difference between the outer diameter of the suspension joint 9 and the inner diameter of the upper outer tube 14 corresponds to the size of the annular gap 13 in the liquid flow auxiliary channel.

[0091] Due to the optimized design of the drilling tool structure, the sealing structure of the liquid flow secondary channel is optimized to an end face sealing structure, so the annular gap 13 can be designed to be larger than the prior art, making it easier for the suspension joint 9 to enter the upper outer tube 14, thereby improving the success rate of tension and convergence; while increasing the annular gap 13, an end face sealing structure is added, so the main drill bit 19 will not burn due to flow distribution problems. According to research, when the gap of the liquid flow secondary channel is increased from the original 0.08-0.125mm to 0.15-0.20mm, the suspension joint 9 is easier to enter the upper outer tube 14, and the flow distribution requirements of the liquid flow main channel and the liquid flow secondary channel can be guaranteed.

[0092] 2. Another specific embodiment based on the inner diameter d of the drill pipe joint 100 is to optimize the relevant dimensions of the hanging surface 16. After optimization: the outer diameter of the hanging surface 16 is (d-1.7) mm; the inner diameter of the hanging surface 16 is (d-2.4) mm.

[0093] The outer diameter of the suspension surface 16 is consistent with the outer diameter of the suspension joint 9, both of which are (d-1.7) mm. After research, it is found that the radial dimension of the suspension surface 16 must be ≧0.35 mm, and 0.35 mm is taken. At this time, the inner diameter of the suspension surface 16 is (d-2.4) mm.

[0094] If the value of the suspension surface 16 in the radial direction is larger than 0.35 mm, just like the aforementioned gap S1 is too large, which will reduce the strength of the main drilling tool 1 and increase the rock crushing area, it will also reduce the strength of the main drilling tool 1 and increase the rock crushing area.

[0095] 3. Another specific embodiment based on the inner diameter d of the drill pipe joint 100 is to optimize the relevant dimensions of the arrow-shaped spline pair 18. After optimization: the major diameter of the outer arrow-shaped spline is (d-2.4) mm; the minor diameter of the outer arrow-shaped spline is (d-5) mm; the major diameter of the inner arrow-shaped spline is (d-2.4) mm; the minor diameter of the inner arrow-shaped spline is (d-5) mm.

[0096] The major diameter of the arrow spline pair 18 is consistent with the inner diameter of the hanging surface 16, both of which are (d-2.4) mm. The major diameter and minor diameter of the outer arrow spline and the inner arrow spline of the arrow spline pair 18 are corresponding. The major diameter of the outer arrow spline is consistent with the major diameter of the inner arrow spline, and the minor diameter of the outer arrow spline is consistent with the minor diameter of the inner arrow spline, that is, the major diameter of the arrow spline pair 18 is (d-2.4) mm, the minor diameter of the arrow spline pair 18 is (d-5) mm, and the spline key height of the arrow spline pair 18 is 1.3 mm. At this time, the aiming can be guaranteed and the occupied radial dimension is reduced as much as possible. If the spline key height of the arrow spline pair 18 continues to increase, that is, the minor diameter of the arrow spline pair 18 is reduced, the aiming performance is better, but just like the aforementioned gap S1 is too large, it will reduce the strength of the main drilling tool 1 and increase the rock crushing area.

[0097] Furthermore, the fillet radius R of the arrowhead portion of the outer arrow-shaped spline and the inner arrow-shaped spline is 0.4 mm to 0.8 mm; Figure 6 As shown, the optimal value is R=0.5mm.

[0098] Due to the optimized design of the drilling tool structure, the original point suspension is changed to the current surface suspension, and the suspension surface 16 is enlarged to make the suspension more secure; at the same time, the suspension mechanism is separated from the aiming mechanism, and the arrowhead of the arrow-shaped spline no longer bears the impact force when the drilling tool is released and the force of pulling out the core, so it will not have burrs. Therefore, the tip of the arrowhead can be sharper, that is, the fillet radius of the arrowhead can be smaller, making the aiming of the aiming mechanism more flexible and reliable.

[0099] 4. Another specific embodiment based on the inner diameter d of the drill rod joint 100 is to optimize the relevant dimensions of the main drill bit 19. After the optimization, the outer diameter of the main drill bit 19 is (d-6) mm.

[0100] If the outer diameter of the main drill bit 19 is smaller, it is easier for the main drill bit 19 to pass through the inner arrow spline; however, the rock crushing area of ​​the auxiliary drill bit 11 will increase, and more importantly, the tension and convergence value of the auxiliary drill bit 11 will increase. The increase in the tension and convergence value of the auxiliary drill bit 11 will reduce the strength of the tension and convergence shaft 7 and the auxiliary drill bit 11. Therefore, the outer diameter of the main drill bit 19 cannot be too small. According to research, in order for the main drill bit 19 to pass smoothly through the inner arrow spline, the minor diameter of the inner arrow spline is more than 1mm larger than the outer diameter of the main drill bit 19; the minor diameter of the inner arrow spline is (d-5)mm, so the maximum outer diameter of the main drill bit 19 is (d-6)mm.

[0101] This embodiment optimizes the design of key dimensions such as the annular gap 13, the hanging surface 16, the arrow-shaped spline pair 18, and the main drill bit 19, which can not only meet the functional requirements of each mechanism, improve the success rate of the main drill bit's tension and convergence, reasonably distribute the flow to avoid drill burning, reduce the auxiliary time and improve the efficiency, make the aiming more flexible and reliable, but also ensure the strength of the drill bit.

[0102] The other parts of this embodiment are the same as those of the above embodiment, so they will not be described in detail.

[0103] Embodiment 7:

[0104] This embodiment is further optimized on the basis of embodiment 6. The wall thickness of the stopper 12 is 1.5 mm to 1.75 mm, which improves the success rate of opening in place and the life of the parts.

[0105] The wall thickness of the original limiter 12 is 1mm, and there are the following problems: first, the strength is weak and the length is short; second, the rigidity is insufficient and it is difficult to bear the weight of the tensioning and convergence shaft assembly and the impact during the drilling process. As a result, during the release of the main drill bit 1, the tensioning and convergence shaft assembly moves downward, and the auxiliary drill bit 11 is partially opened and stuck in the middle of the drill pipe. At this time, the release fails, and the main drill bit can only be salvaged by a rope salvage device to get rid of the jam and re-release.

[0106] The wall thickness of the stopper 12 is optimized to 1.5mm~1.75mm, which firstly improves the service life of the parts and secondly basically avoids the phenomenon of the auxiliary drill bit 11 partially opening during the placement of the main drilling tool 1, thereby improving the success rate of opening in place. However, the wall thickness of the stopper 12 cannot be too thick, firstly due to space limitations, and secondly, if the wall thickness is too thick, the clamping force of the stopper 12 on the tensioning and convergence shaft 7 is too large, and the rope salvage device may not be able to pull or even break the wire rope when salvaging the main drilling tool, resulting in salvage failure.

[0107] The present embodiment provides a drill tool with a high tensioning and convergence success rate for changing the drill bit without lifting the drill bit. The optimized design of the suspension mechanism, aiming mechanism, end face sealing structure, key dimensions of some parts, etc., can increase the tensioning and convergence success rate of the drill tool for changing the drill bit without lifting the drill bit from the current 80% to about 95%.

[0108] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A drill tool for changing drill bits without lifting the drill bit and having a high tension and convergence success rate, comprising a main drill tool (1) and an auxiliary drill tool (2); the main drill tool (1) comprises a suspension joint (9), a drill bit frame (10), a main drill bit (19), an auxiliary drill bit (11), a signal valve (5) and a stopper (12); the auxiliary drill tool (2) comprises a positioning end tube (15) and an upper outer tube (14); when in use, the upper outer tube (14) of the drill tool for changing drill bits without lifting the drill bit is installed on a drill pipe joint (100); the characteristics are: The suspension joint (9) is connected to the drill bit rack (10); The upper outer tube (14) is connected to the positioning end tube (15); The outer cylindrical surface of the suspension joint (9) and the inner cylindrical surface of the upper outer tube (14) form an annular gap (13); the lower end surface of the suspension joint (9) contacts the upper end surface of the positioning end tube (15), forming both a plane-sealed end surface sealing mechanism and a surface-suspended suspension mechanism; that is, the surface where the suspension joint (9) and the positioning end tube (15) contact each other is both a sealing surface (17) and a suspension surface (16); The drill bit holder (10) is provided with an outer arrow-shaped spline, the positioning end tube (15) is provided with an inner arrow-shaped spline, and the arrow-shaped spline pair (18) composed of the outer arrow-shaped spline and the inner arrow-shaped spline constitutes an aiming mechanism; The signal valve (5) is arranged in the suspension joint (9), and the limiter (12) is arranged in the main drill bit (19) to limit the tension and contraction state.

2. The high tension and convergence success rate drilling tool according to claim 1, characterized in that: The suspension joint (9) is also provided with a drain hole (8).

3. The high tension and convergence success rate drilling tool according to claim 1, characterized in that: The outer cylindrical surface of the positioning end tube (15) is additionally provided with a strip-shaped powder discharge channel (4).

4. The high tension and convergence success rate drilling tool according to claim 1, characterized in that: The number of petals of the auxiliary drill bit (11) is 4 or 5; when the maximum outer diameter of the auxiliary drill bit (11) is 95 mm to 98 mm when it is opened, the number of petals of the auxiliary drill bit (11) is 4; when the maximum outer diameter of the auxiliary drill bit (11) is 122 to 125 mm when it is opened, the number of petals of the auxiliary drill bit (11) is 5.

5. A high tension and convergence success rate drilling tool without drill bit replacement according to any one of claims 1 to 4, characterized in that: Based on the inner diameter d of the drill pipe joint (100), the unit is mm; The outer diameter of the suspension joint (9) is (d-1.7) mm; The inner diameter of the upper outer tube (14) is (d-1.3) mm to (d-1.4) mm.

6. The high tension and convergence success rate drilling tool according to claim 5, characterized in that: The outer diameter of the suspension surface (16) is (d-1.7) mm; The inner diameter of the suspension surface (16) is (d-2.4) mm.

7. The high tension and convergence success rate drilling tool according to claim 5, characterized in that: The major diameter of the outer arrow-shaped spline is (d-2.4) mm; The minor diameter of the outer arrow-shaped spline is (d-5) mm; The major diameter of the inner arrow-shaped spline is (d-2.4) mm; The minor diameter of the inner arrow-shaped spline is (d-5) mm; The fillet radius R of the arrowhead portion of the outer arrow-shaped spline and the inner arrow-shaped spline is 0.4 mm to 0.8 mm.

8. The high tension and convergence success rate drilling tool according to claim 5, characterized in that: The outer diameter of the main drill bit (19) is (d-6) mm.

9. A high tension and convergence success rate drilling tool without lifting the drill bit and replacing the drill bit according to any one of claims 1 to 4, characterized in that: The number of outer grooves of the signal valve (5) is 5 or 6.

10. A drilling tool with high tension and convergence success rate and capable of replacing the drill bit without lifting the drill according to any one of claims 1 to 4, characterized in that: The wall thickness of the stopper (12) is 1.5 mm to 1.75 mm.

Images